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<title>Mu - 312copy.subx</title>
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<a href='https://github.com/akkartik/mu/blob/main/312copy.subx'>https://github.com/akkartik/mu/blob/main/312copy.subx</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span>== code
<span id="L2" class="LineNr"> 2 </span>
<span id="L3" class="LineNr"> 3 </span><span class="subxFunction">copy-array-object</span>:  <span class="subxComment"># src: (addr array T), dest-ah: (addr handle array T)</span>
<span id="L4" class="LineNr"> 4 </span>    <span class="subxS1Comment"># . prologue</span>
<span id="L5" class="LineNr"> 5 </span>    55/push-ebp
<span id="L6" class="LineNr"> 6 </span>    89/&lt;- %ebp 4/r32/esp
<span id="L7" class="LineNr"> 7 </span>    <span class="subxComment">#</span>
<span id="L8" class="LineNr"> 8 </span>    (<a href='120allocate.subx.html#L669'>copy-array</a> <span class="SpecialChar"><a href='120allocate.subx.html#L27'>Heap</a></span> *(ebp+8) *(ebp+0xc))
<span id="L9" class="LineNr"> 9 </span><span class="Constant">$copy-array-object:end</span>:
<span id="L10" class="LineNr">10 </span>    <span class="subxS1Comment"># . epilogue</span>
<span id="L11" class="LineNr">11 </span>    89/&lt;- %esp 5/r32/ebp
<span id="L12" class="LineNr">12 </span>    5d/pop-to-ebp
<span id="L13" class="LineNr">13 </span>    c3/return
</pre>
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4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693
# Assign addresses (co-ordinates) to instructions (landmarks) in a program
# (landscape).
# Use the addresses assigned to:
#   a) replace labels
#   b) add an ELF header and segment headers with addresses and offsets correctly filled in
#
# To build:
#   $ bootstrap/bootstrap translate [01]*.subx subx-params.subx survey_elf.subx  -o survey_elf
#
# The expected input is a stream of bytes with '==' segment headers, comments
# and some interspersed labels.
#   $ cat x
#   == code 0x1
#   l1:
#   aa bb l1/imm8
#   cc dd l2/disp32
#   l2:
#   ee foo/imm32
#   == data 0x10
#   foo:
#     00
#
# The output is the stream of bytes without segment headers or label definitions,
# and with label references replaced with numeric values/displacements.
#
#   $ cat x  |bootstrap/bootstrap run survey_elf
#   ...ELF header bytes...
#   # ELF header above will specify that code segment begins at this offset
#   aa bb nn  # some computed address
#   cc dd nn nn nn nn  # some computed displacement
#   ee nn nn nn nn  # some computed address
#   # ELF header above will specify that data segment begins at this offset
#   00
#
# The ELF format has some persnickety constraints on the starting addresses of
# segments, so input headers are treated as guidelines and adjusted in the
# output.

== code
#   instruction                     effective address                                                   register    displacement    immediate
# . op          subop               mod             rm32          base        index         scale       r32
# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes

Entry:  # run tests if necessary, convert stdin if not
    # . prologue
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp

    # Heap = new-segment(Heap-size)
    # . . push args
    68/push  Heap/imm32
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Heap-size/disp32                  # push *Heap-size
    # . . call
    e8/call  new-segment/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # initialize-trace-stream(Trace-size)
    # . . push args
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-size/disp32                 # push *Heap-size
    # . . call
    e8/call  initialize-trace-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp

    # - if argc > 1 and argv[1] == "test", then return run_tests()
    # if (argc <= 1) goto interactive
    81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0/disp8         1/imm32           # compare *ebp
    7e/jump-if-<=  $subx-survey-main:interactive/disp8
    # if (!kernel-string-equal?(argv[1], "test")) goto interactive
    # . eax = kernel-string-equal?(argv[1], "test")
    # . . push args
    68/push  "test"/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  kernel-string-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) goto interactive
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $subx-survey-main:interactive/disp8
    # run-tests()
    e8/call  run-tests/disp32
    # syscall(exit, *Num-test-failures)
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/ebx   Num-test-failures/disp32          # copy *Num-test-failures to ebx
    eb/jump  $subx-survey-main:end/disp8
$subx-survey-main:interactive:
    # - otherwise convert stdin
    # subx-survey(Stdin, Stdout)
    # . . push args
    68/push  Stdout/imm32
    68/push  Stdin/imm32
    # . . call
    e8/call  subx-survey/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # syscall(exit, 0)
    bb/copy-to-ebx  0/imm32
$subx-survey-main:end:
    e8/call  syscall_exit/disp32

# data structures:
#   segment-info: {address, file-offset, size}                                  (12 bytes)
#   segments: (addr stream {(handle array byte), segment-info})                 (20 bytes per row)
#   label-info: {segment-name: (handle array byte), segment-offset, address}    (16 bytes)
#   labels: (addr stream {(handle array byte), label-info})                     (24 bytes per row)
# these are all inefficient, using sequential scans for lookups

subx-survey:  # infile: (addr buffered-file), out: (addr buffered-file)
    # pseudocode
    #   var in: (stream byte Input-size)
    #   slurp(infile, in)
    #   var segments: (stream {segment-name, segment-info})
    #   var labels: (stream {label-name, label-info} Max-labels)
    #   compute-offsets(in, segments, labels)
    #   compute-addresses(segments, labels)
    #   rewind-stream(in)
    #   emit-output(in, out, segments, labels)
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    51/push-ecx
    52/push-edx
    56/push-esi
    # var segments/ecx: (stream {string, segment-info} 200)   # 10 rows * 20 bytes/row
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc8/imm32        # subtract from esp
    68/push  0xc8/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # var labels/edx: (stream label-info Max-labels)
    # . data
    2b/subtract                     0/mod/indirect  5/rm32/.disp32            .             .           4/r32/esp   Max-labels/disp32                 # subtract *Max-labels from esp
    # . size
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Max-labels/disp32                 # push *Max-labels
    # . read
    68/push  0/imm32/read
    # . write
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # var in/esi: (stream byte Input-size)
    # . data
    2b/subtract                     0/mod/indirect  5/rm32/.disp32            .             .           4/r32/esp   Input-size/disp32                 # subtract *Input-size from esp
    # . size
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Input-size/disp32                 # push *Input-size
    # . read
    68/push  0/imm32/read
    # . write
    68/push  0/imm32/write
    89/copy                         3/mod/direct    6/rm32/esi    .           .             .           4/r32/esp   .               .                 # copy esp to esi
    # slurp(infile, in)
    # . . push args
    56/push-esi
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  slurp/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # compute-offsets(in, segments, labels)
    # . . push args
    52/push-edx
    51/push-ecx
    56/push-esi
    # . . call
    e8/call  compute-offsets/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # compute-addresses(segments, labels)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  compute-addresses/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # rewind-stream(in)
    # . . push args
    56/push-esi
    # . . call
    e8/call  rewind-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # emit-output(in, out, segments, labels)
    # . . push args
    52/push-edx
    51/push-ecx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    56/push-esi
    # . . call
    e8/call  emit-output/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # flush(out)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$subx-survey:end:
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xec/imm32        # add to esp
    03/add                          0/mod/indirect  5/rm32/.disp32            .             .           4/r32/esp   Max-labels/disp32                 # add *Max-labels to esp
    03/add                          0/mod/indirect  5/rm32/.disp32            .             .           4/r32/esp   Input-size/disp32                 # add *Input-size to esp
    # . restore registers
    5e/pop-to-esi
    5a/pop-to-edx
    59/pop-to-ecx
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-subx-survey-computes-addresses:
    # input:
    #   == code 0x1
    #   Entry:
    #   ab x/imm32
    #   == data 0x1000
    #   x:
    #     01
    #
    # trace contains (in any order):
    #   label x is at address 0x1079
    #   segment code starts at address 0x74
    #   segment code has size 5
    #   segment data starts at address 0x1079
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream($_test-input-buffered-file->buffer)
    # . . push args
    68/push  $_test-input-buffered-file->buffer/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream($_test-output-buffered-file->buffer)
    # . . push args
    68/push  $_test-output-buffered-file->buffer/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "== code 0x1\n")
    # . . push args
    68/push  "== code 0x1\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "Entry:\n")
    # . . push args
    68/push  "Entry:\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "ab x/imm32\n")
    # . . push args
    68/push  "ab x/imm32\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "== data 0x1000\n")
    # . . push args
    68/push  "== data 0x1000\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "x:\n")
    # . . push args
    68/push  "x:\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "01\n")
    # . . push args
    68/push  "01\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # subx-survey(_test-input-buffered-file, _test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    68/push  _test-input-buffered-file/imm32
    # . . call
    e8/call  subx-survey/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # check trace
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # . check-trace-contains("label 'x' is at address 0x00001079.", msg)
    # . . push args
    68/push  "F - test-subx-survey-computes-addresses/0"/imm32
    68/push  "label 'x' is at address 0x00001079."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'code' starts at address 0x00000074.", msg)
    # . . push args
    68/push  "F - test-subx-survey-computes-addresses/1"/imm32
    68/push  "segment 'code' starts at address 0x00000074."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'code' has size 0x00000005.", msg)
    # . . push args
    68/push  "F - test-subx-survey-computes-addresses/2"/imm32
    68/push  "segment 'code' has size 0x00000005."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'data' starts at address 0x00001079.", msg)
    # . . push args
    68/push  "F - test-subx-survey-computes-addresses/3"/imm32
    68/push  "segment 'data' starts at address 0x00001079."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# global scratch space for compute-offsets
== data

compute-offsets:file-offset:  # int
  0/imm32
compute-offsets:segment-offset:  # int
  0/imm32
compute-offsets:segment-tmp:  # slice
  0/imm32/start
  0/imm32/end

== code

# write segments->file-offset,
#       segments->size,
#       labels->segment-name, and
#       labels->segment-offset
compute-offsets:  # in: (addr stream byte), segments: (addr stream {(handle array byte), segment-info}), labels: (addr stream {(handle array byte), label-info})
    # skeleton:
    #   for lines in 'in'
    #     for words in line
    #       switch word
    #         case 1
    #         case 2
    #         ...
    #         default
    #
    # pseudocode:
    #   var curr-segment-name: (handle array byte)
    #   var file-offset = 0
    #   var segment-offset = 0
    #   var line: (stream byte 512)
    #   var sinfo: (addr segment-info)
    #   var linfo: (addr label-info)
    #   while true                                  # line loop
    #     clear-stream(line)
    #     read-line(in, line)
    #     if (line->write == 0) break               # end of file
    #     while true                                # word loop
    #       word-slice = next-word(line)
    #       if slice-empty?(word-slice)             # end of line
    #         break
    #       else if slice-starts-with?(word-slice, "#")  # comment
    #         break                                 # end of line
    #       else if slice-equal?(word-slice, "==")
    #         if *curr-segment-name != 0
    #           sinfo = get-or-insert-handle(segments, curr-segment-name)
    #           sinfo->size = file-offset - sinfo->file-offset
    #           trace("segment '", curr-segment-name, "' has size ", sinfo->size)
    #         segment-tmp = next-word(line)
    #         if slice-empty?(segment-tmp)
    #           abort
    #         curr-segment-name = slice-to-string(segment-tmp)
    #         segment-tmp = next-word(line)
    #         if slice-empty?(segment-tmp)
    #           abort
    #         sinfo = get-or-insert-handle(segments, curr-segment-name)
    #         sinfo->starting-address = parse-hex-int-from-slice(segment-tmp)
    #         sinfo->file-offset = file-offset
    #         trace("segment '", curr-segment-name, "' is at file offset ", sinfo->file-offset)
    #         segment-offset = 0
    #         break  (next line)
    #       else if label?(word-slice)
    #         strip trailing ':' from word-slice
    #         linfo: (addr label-info) = get-or-insert-slice(labels, word-slice)
    #         linfo->segment-name = curr-segment-name
    #         trace("label '", word-slice, "' is in segment '", curr-segment-name, "'.")
    #         linfo->segment-offset = segment-offset
    #         trace("label '", word-slice, "' is at segment offset ", segment-offset, ".")
    #         # labels occupy no space, so no need to increment offsets
    #       else
    #         width = compute-width-of-slice(word-slice)
    #         segment-offset += width
    #         file-offset += width
    #   sinfo = get-or-insert-handle(segments, curr-segment-name)
    #   sinfo->size = file-offset - sinfo->file-offset
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # var curr-segment-name/esi: (handle array byte)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    6/rm32/esi    .           .             .           4/r32/esp   .               .                 # copy esp to esi
    # file-offset = 0
    c7          0/subop/copy        0/mod/indirect  5/rm32/.disp32            .             .           .           compute-offsets:file-offset/disp32  0/imm32  # copy to *compute-offsets:file-offset
    # segment-offset = 0
    c7          0/subop/copy        0/mod/indirect  5/rm32/.disp32            .             .           .           compute-offsets:segment-offset/disp32  0/imm32  # copy to *compute-offsets:segment-offset
    # var line/ecx: (stream byte 512)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0x200/imm32       # subtract from esp
    68/push  0x200/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # var word-slice/edx: (addr slice)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
$compute-offsets:line-loop:
    # clear-stream(line)
    # . . push args
    51/push-ecx
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # read-line(in, line)
    # . . push args
    51/push-ecx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  read-line/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # if (line->write == 0) break
    8b/copy                         0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/eax   .               .                 # copy *ecx to eax
    3d/compare-eax-and  0/imm32
    0f 84/jump-if-=  $compute-offsets:break-line-loop/disp32
#?     # dump line {{{
#?     # . write(2/stderr, "LL: ")
#?     # . . push args
#?     68/push  "LL: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # write-stream(2/stderr, line)
#?     # . . push args
#?     51/push-ecx
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . rewind-stream(line)
#?     # . . push args
#?     51/push-ecx
#?     # . . call
#?     e8/call  rewind-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # }}}
$compute-offsets:word-loop:
    # next-word(line, word-slice)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
$compute-offsets:case-empty:
    # if slice-empty?(word-slice) break
    # . eax = slice-empty?(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != false) break
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $compute-offsets:line-loop/disp32
$compute-offsets:case-comment:
    # if slice-starts-with?(word-slice, "#") continue
    # . . push args
    68/push  "#"/imm32
    52/push-edx
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax != false) break
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $compute-offsets:line-loop/disp32
$compute-offsets:case-segment-header:
    # if (!slice-equal?(word-slice, "==")) goto next case
    # . eax = slice-equal?(word-slice, "==")
    # . . push args
    68/push  "=="/imm32
    52/push-edx
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) goto next case
    3d/compare-eax-and  0/imm32/false
    0f 84/jump-if-=  $compute-offsets:case-label/disp32
    # if (*curr-segment-name == 0) goto construct-next-segment
    81          7/subop/compare     0/mod/indirect  6/rm32/esi    .           .             .           .           .               0/imm32           # compare *esi
    74/jump-if-=  $compute-offsets:construct-next-segment/disp8
    # sinfo/edi = get-or-insert-handle(segments, curr-segment-name, row-size=16)
    # . eax = get-or-insert-handle(segments, curr-segment-name, row-size=16)
    # . . push args
    68/push  0x14/imm32/row-size
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  get-or-insert-handle/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . edi = eax
    89/copy                         3/mod/direct    7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to edi
    # sinfo->size = file-offset - sinfo->file-offset
    # . save ecx
    51/push-ecx
    # . ebx = *file-offset
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/ebx   compute-offsets:file-offset/disp32  # copy *file-offset to ebx
    # . ecx = sinfo->file-offset
    8b/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           1/r32/ecx   4/disp8         .                 # copy *(edi+4) to ecx
    # . ebx -= ecx
    29/subtract                     3/mod/direct    3/rm32/ebx    .           .             .           1/r32/ecx   .               .                 # subtract ecx from ebx
    # . sinfo->size = ebx
    89/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           3/r32/ebx   8/disp8         .                 # copy ebx to *(edi+8)
    # . restore ecx
    59/pop-to-ecx
    # trace-sssns("segment '", curr-segment-name, "' has size ", sinfo->size, ".")
    # . eax = lookup(curr-segment-name)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . trace-sssns("segment '", eax, "' has size ", sinfo->size, ".")
    # . . push args
    68/push  "."/imm32
    53/push-ebx
    68/push  "' has size "/imm32
    50/push-eax
    68/push  "segment '"/imm32
    # . . call
    e8/call  trace-sssns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
$compute-offsets:construct-next-segment:
    # next-word(line, segment-tmp)
    # . . push args
    68/push  compute-offsets:segment-tmp/imm32
    51/push-ecx
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # if slice-empty?(segment-tmp) abort
    # . eax = slice-empty?(segment-tmp)
    # . . push args
    68/push  compute-offsets:segment-tmp/imm32
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != false) abort
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $compute-offsets:abort/disp32
$compute-offsets:update-curr-segment-name:
    # slice-to-string(Heap, segment-tmp, curr-segment-name)
    # . . push args
    56/push-esi
    68/push  compute-offsets:segment-tmp/imm32
    68/push  Heap/imm32
    # . . call
    e8/call  slice-to-string/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # next-word(line, segment-tmp)
    # . . push args
    68/push  compute-offsets:segment-tmp/imm32
    51/push-ecx
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # if slice-empty?(segment-tmp) abort
    # . eax = slice-empty?(segment-tmp)
    # . . push args
    68/push  compute-offsets:segment-tmp/imm32
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != false) abort
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $compute-offsets:abort/disp32
    # sinfo/edi = get-or-insert-handle(segments, curr-segment-name, row-size=16)
    # . eax = get-or-insert-handle(segments, curr-segment-name, row-size=16)
    # . . push args
    68/push  0x14/imm32/row-size
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  get-or-insert-handle/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . edi = eax
    89/copy                         3/mod/direct    7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to edi
    # sinfo->address = parse-hex-int-from-slice(segment-tmp)
    # . eax = parse-hex-int-from-slice(segment-tmp)
    # . . push args
    68/push  compute-offsets:segment-tmp/imm32
    # . . call
    e8/call  parse-hex-int-from-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . sinfo->address = eax
    89/copy                         0/mod/indirect  7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to *edi
    # sinfo->file-offset = *file-offset
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   compute-offsets:file-offset/disp32  # copy *file-offset to eax
    89/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           0/r32/eax   4/disp8         .                 # copy eax to *(edi+4)
    # trace-sssns("segment '", curr-segment-name, "' is at file offset ", sinfo->file-offset, "")
    # . eax = lookup(curr-segment-name)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . trace-sssns("segment '", eax, "' is at file offset ", file-offset, ".")
    # . . push args
    68/push  "."/imm32
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           compute-offsets:file-offset/disp32  # push *file-offset
    68/push  "' is at file offset "/imm32
    50/push-eax
    68/push  "segment '"/imm32
    # . . call
    e8/call  trace-sssns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
    # segment-offset = 0
    c7          0/subop/copy        0/mod/indirect  5/rm32/.disp32            .             .           .     compute-offsets:segment-offset/disp32  0/imm32  # copy to *segment-offset
    # break
    e9/jump $compute-offsets:line-loop/disp32
$compute-offsets:case-label:
    # if (!label?(word-slice)) goto next case
    # . eax = label?(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call  label?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax == false) goto next case
    3d/compare-eax-and  0/imm32/false
    0f 84/jump-if-=  $compute-offsets:case-default/disp32
    # strip trailing ':' from word-slice
    ff          1/subop/decrement   1/mod/*+disp8   2/rm32/edx    .           .             .           .           4/disp8         .                 # decrement *(edx+4)
    # linfo/edi = get-or-insert-slice(labels, word-slice, row-size=24)
    # . eax = get-or-insert-slice(labels, word-slice, row-size=24)
    # . . push args
    68/push  Heap/imm32
    68/push  0x18/imm32/row-size
    52/push-edx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    # . . call
    e8/call  get-or-insert-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . edi = eax
    89/copy                         3/mod/direct    7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to edi
$compute-offsets:save-label-offset:
    # linfo->segment-name = curr-segment-name
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           0/r32/eax   .               .                 # copy *esi to eax
    89/copy                         0/mod/indirect  7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to *edi
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   4/disp8         .                 # copy *(esi+4) to eax
    89/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           0/r32/eax   4/disp8         .                 # copy eax to *(edi+4)
    # trace-slsss("label '" word-slice "' is in segment '" current-segment-name "'.")
    # . eax = lookup(curr-segment-name)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . trace-slsss("label '" word-slice "' is in segment '" eax "'.")
    # . . push args
    68/push  "'."/imm32
    50/push-eax
    68/push  "' is in segment '"/imm32
    52/push-edx
    68/push  "label '"/imm32
    # . . call
    e8/call  trace-slsss/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
    # linfo->segment-offset = segment-offset
    # . ebx = segment-offset
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/ebx   compute-offsets:segment-offset/disp32  # copy *segment-offset to ebx
    # . linfo->segment-offset = ebx
    89/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           3/r32/ebx   8/disp8         .                 # copy ebx to *(edi+8)
    # trace-slsns("label '" word-slice "' is at segment offset " *segment-offset/eax ".")
    # . . push args
    68/push  "."/imm32
    53/push-ebx
    68/push  "' is at segment offset "/imm32
    52/push-edx
    68/push  "label '"/imm32
    # . . call
    e8/call  trace-slsns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
    # continue
    e9/jump  $compute-offsets:word-loop/disp32
$compute-offsets:case-default:
    # width/eax = compute-width-of-slice(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call compute-width-of-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # segment-offset += width
    01/add                          0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   compute-offsets:segment-offset/disp32  # add eax to *segment-offset
    # file-offset += width
    01/add                          0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   compute-offsets:file-offset/disp32  # add eax to *file-offset
#?     # dump segment-offset {{{
#?     # . write(2/stderr, "segment-offset: ")
#?     # . . push args
#?     68/push  "segment-offset: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . clear-stream($Stderr->buffer)
#?     # . . push args
#?     68/push  $Stderr->buffer/imm32
#?     # . . call
#?     e8/call  clear-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write-int32-hex-buffered(Stderr, segment-offset)
#?     # . . push args
#?     52/push-edx
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           compute-offsets:segment-offset/disp32  # push *segment-offset
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-int32-hex-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, "\n")
#?     # . . push args
#?     68/push  Newline/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    e9/jump $compute-offsets:word-loop/disp32
$compute-offsets:break-line-loop:
    # sinfo/edi = get-or-insert-handle(segments, curr-segment-name, row-size=16)
    # . eax = get-or-insert-handle(segments, curr-segment-name, row-size=16)
    # . . push args
    68/push  0x14/imm32/row-size
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  get-or-insert-handle/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . edi = eax
    89/copy                         3/mod/direct    7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to edi
    # sinfo->size = file-offset - sinfo->file-offset
    # . save ecx
    51/push-ecx
    # . ebx = *file-offset
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/ebx   compute-offsets:file-offset/disp32  # copy *file-offset to ebx
    # . ecx = sinfo->file-offset
    8b/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           1/r32/ecx   4/disp8         .                 # copy *(edi+4) to ecx
    # . ebx -= ecx
    29/subtract                     3/mod/direct    3/rm32/ebx    .           .             .           1/r32/ecx   .               .                 # subtract ecx from ebx
    # . sinfo->size = ebx
    89/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           3/r32/ebx   8/disp8         .                 # copy ebx to *(edi+8)
    # . restore ecx
    59/pop-to-ecx
    # trace-sssns("segment '", curr-segment-name, "' has size ", sinfo->size, ".")
    # . eax = lookup(curr-segment-name)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . trace-sssns("segment '", eax, "' has size ", ebx, ".")
    # . . push args
    68/push  "."/imm32
    53/push-ebx
    68/push  "' has size "/imm32
    50/push-eax
    68/push  "segment '"/imm32
    # . . call
    e8/call  trace-sssns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
$compute-offsets:end:
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x21c/imm32       # add to esp
    # . restore registers
    5f/pop-to-edi
    5e/pop-to-esi
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

$compute-offsets:abort:
    # . _write(2/stderr, error)
    # . . push args
    68/push  "'==' must be followed by segment name and optionally an address\n"/imm32
    68/push  2/imm32/stderr
    # . . call
    e8/call  _write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . syscall(exit, 1)
    bb/copy-to-ebx  1/imm32
    e8/call  syscall_exit/disp32
    # never gets here

test-compute-offsets:
    # input:
    #   == code 0x1
    #   ab x/imm32  # skip comment
    #   == data 0x1000
    #   00
    #   x:
    #     34
    #
    # trace contains (in any order):
    #   segment 'code' is at file offset 0x0.
    #   segment 'code' has size 0x5.
    #   segment 'data' is at file offset 0x5.
    #   segment 'data' has size 0x2.
    #   label 'x' is in segment 'data'.
    #   label 'x' is at segment offset 0x1.
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # var segments/ecx: (stream byte 2*20)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0x28/imm32        # subtract from esp
    68/push  0x28/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # var labels/edx: (stream byte 2*24)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0x30/imm32        # subtract from esp
    68/push  0x30/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # initialize input
    # . write(_test-input-stream, "== code 0x1\n")
    # . . push args
    68/push  "== code 0x1\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "ab x/imm32  # skip comment\n")
    # . . push args
    68/push  "ab x/imm32  # skip comment\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "== data 0x1000\n")
    # . . push args
    68/push  "== data 0x1000\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "00\n")
    # . . push args
    68/push  "00\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "x:\n")
    # . . push args
    68/push  "x:\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "34\n")
    # . . push args
    68/push  "34\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # compute-offsets(_test-input-stream, segments, labels)
    # . . push args
    52/push-edx
    51/push-ecx
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  compute-offsets/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32        # add to esp
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # check trace
    # . check-trace-contains("segment 'code' is at file offset 0x00000000.", msg)
    # . . push args
    68/push  "F - test-compute-offsets/0"/imm32
    68/push  "segment 'code' is at file offset 0x00000000."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'code' has size 0x00000005", msg)
    # . . push args
    68/push  "F - test-compute-offsets/1"/imm32
    68/push  "segment 'code' has size 0x00000005."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'data' is at file offset 0x00000005.", msg)
    # . . push args
    68/push  "F - test-compute-offsets/2"/imm32
    68/push  "segment 'data' is at file offset 0x00000005."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'data' has size 0x00000002.", msg)
    # . . push args
    68/push  "F - test-compute-offsets/3"/imm32
    68/push  "segment 'data' has size 0x00000002."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("label 'x' is in segment 'data'.", msg)
    # . . push args
    68/push  "F - test-compute-offsets/4"/imm32
    68/push  "label 'x' is in segment 'data'."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("label 'x' is at segment offset 0x00000001.", msg)
    # . . push args
    68/push  "F - test-compute-offsets/5"/imm32
    68/push  "label 'x' is at segment offset 0x00000001."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-ints-equal(labels->write, 0x18, msg)
    # . . push args
    68/push  "F - test-compute-offsets-maintains-labels-write-index"/imm32
    68/push  0x18/imm32/1-entry
    ff          6/subop/push        0/mod/indirect  2/rm32/edx    .           .             .           .           .               .                 # push *edx
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# write segments->file-offset,
#       segments->address, and
#       labels->address
compute-addresses:  # segments: (addr stream {(handle array byte), segment-info}), labels: (addr stream {(handle array byte), label-info})
    # pseudocode:
    #   var srow: (addr segment-row) = segments->data
    #   var max: (addr byte) = &segments->data[segments->write]
    #   var num-segments: int = segments->write / 20
    #   var starting-offset: int = 0x34 + (num-segments * 0x20)
    #   while true
    #     if (srow >= max) break
    #     srow->file-offset += starting-offset
    #     srow->address &= 0xfffff000  # clear last 12 bits for p_align
    #     srow->address += (srow->file-offset & 0x00000fff)
    #     trace-sssns("segment " srow->key " starts at address " srow->address)
    #     srow += 20  # row-size
    #   var lrow: (addr label-row) = labels->data
    #   max = &labels->data[labels->write]
    #   while true
    #     if (lrow >= max) break
    #     var seg-name: (addr array byte) = lookup(lrow->segment-name)
    #     var label-seg: (addr segment-info) = get(segments, seg-name)
    #     lrow->address = label-seg->address + lrow->segment-offset
    #     trace-sssns("label " lrow->key " is at address " lrow->address)
    #     lrow += 24  # row-size
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # esi = segments
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   8/disp8         .                 # copy *(ebp+8) to esi
    # var num-segments/edi: int = segments->write / 20 (row-size)
    # . eax = segments->write
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           0/r32/eax   .               .                 # copy *esi to eax
    # . edx = 0
    ba/copy-to-edx  0/imm32
    # . ecx = 20 (row-size)
    b9/copy-to-ecx  0x14/imm32/row-size
    # . eax /= ecx (clobbering edx)
    f7          7/subop/divide      3/mod/direct    1/rm32/ecx    .           .             .           .           .               .                 # divide eax by ecx
    # . edi = eax
    89/copy                         3/mod/direct    7/rm32/edi    .           .             .           0/r32/eax   .               .                 # copy eax to edi
    # var starting-offset/edi: int = 0x34 + (num-segments * 0x20)  # make room for ELF headers
    c1/shift    4/subop/left        3/mod/direct    7/rm32/edi    .           .             .           .           .               5/imm8            # shift edi left by 5 bits
    81          0/subop/add         3/mod/direct    7/rm32/edi    .           .             .           .           .               0x34/imm32        # add to edi
    # var max/ecx: (addr byte) = &segments->data[segments->write]
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           1/r32/ecx   .               .                 # copy *esi to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/esi  1/index/ecx   .           1/r32/ecx   0xc/disp8       .                 # copy esi+ecx+12 to ecx
    # var srow/esi: (addr segment-row) = segments->data
    8d/copy-address                 1/mod/*+disp8   6/rm32/esi    .           .             .           6/r32/esi   0xc/disp8       .                 # copy esi+12 to esi
$compute-addresses:segment-loop:
    # if (srow >= max) break
    39/compare                      3/mod/direct    6/rm32/esi    .           .             .           1/r32/ecx   .               .                 # compare esi with ecx
    73/jump-if-addr>=  $compute-addresses:segment-break/disp8
    # srow->file-offset += starting-offset
    01/add                          1/mod/*+disp8   6/rm32/esi    .           .             .           7/r32/edi   0xc/disp8       .                 # add edi to *(esi+12)
    # clear last 12 bits of srow->address for p_align=0x1000
    # . edx = srow->address
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           2/r32/edx   8/disp8         .                 # copy *(esi+8) to edx
    # . edx &= 0xfffff000
    81          4/subop/and         3/mod/direct    2/rm32/edx    .           .             .           .           .               0xfffff000/imm32  # bitwise and of edx
    # update last 12 bits from srow->file-offset
    # . ebx = srow->file-offset
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           3/r32/ebx   0xc/disp8       .                 # copy *(esi+12) to ebx
    # . ebx &= 0xfff
    81          4/subop/and         3/mod/direct    3/rm32/ebx    .           .             .           .           .               0x00000fff/imm32  # bitwise and of ebx
    # . srow->address = edx | ebx
    09/or                           3/mod/direct    2/rm32/edx    .           .             .           3/r32/ebx   .               .                 # edx = bitwise OR with ebx
    89/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           2/r32/edx   8/disp8         .                 # copy edx to *(esi+8)
    # trace-sssns("segment " srow " starts at address " srow->address ".")
    # . eax = lookup(*srow)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . trace-sssns("segment " eax " starts at address " srow->address ".")
    # . . push args
    68/push  "."/imm32
    52/push-edx
    68/push  "' starts at address "/imm32
    50/push-eax
    68/push  "segment '"/imm32
    # . . call
    e8/call  trace-sssns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
    # srow += 20  # size of row
    81          0/subop/add         3/mod/direct    6/rm32/esi    .           .             .           .           .               0x14/imm32        # add to esi
    eb/jump  $compute-addresses:segment-loop/disp8
$compute-addresses:segment-break:
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # esi = labels
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   0xc/disp8       .                 # copy *(ebp+12) to esi
    # var max/ecx: (addr byte) = &labels->data[labels->write]
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           1/r32/ecx   .               .                 # copy *esi to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/esi  1/index/ecx   .           1/r32/ecx   0xc/disp8       .                 # copy esi+ecx+12 to ecx
    # var lrow/esi: (addr label-row) = labels->data
    8d/copy-address                 1/mod/*+disp8   6/rm32/esi    .           .             .           6/r32/esi   0xc/disp8       .                 # copy esi+12 to esi
$compute-addresses:label-loop:
    # if (lrow >= max) break
    39/compare                      3/mod/direct    6/rm32/esi    .           .             .           1/r32/ecx   .               .                 # compare esi with ecx
    0f 83/jump-if-addr>=  $compute-addresses:end/disp32
#?     # dump lrow->key {{{
#?     # . write(2/stderr, "label: ")
#?     # . . push args
#?     68/push  "label: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, lrow->key)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # var seg-name/edx: (addr array byte) = lookup(lrow->segment-name)
    # . eax = lookup(lrow->segment-name)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           0xc/disp8       .                 # push *(esi+12)
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           8/disp8         .                 # push *(esi+8)
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . edx = eax
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           0/r32/eax   .               .                 # copy eax to edx
#?     # dump seg-name {{{
#?     # . write(2/stderr, "compute-addresses: seg-name: ")
#?     # . . push args
#?     68/push  "seg-name: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, seg-name)
#?     # . . push args
#?     52/push-edx
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # var label-seg/edx: (addr segment-info) = get(segments, seg-name, row-size=20, "segment table")
    # . eax = get(segments, seg-name, row-size=20)
    # . . push args
    68/push  "segment table"/imm32
    68/push  0x14/imm32/row-size
    52/push-edx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  get/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . edx = eax
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           0/r32/eax   .               .                 # copy eax to edx
    # ebx = label-seg->address
    8b/copy                         0/mod/indirect  2/rm32/edx    .           .             .           3/r32/ebx   .               .                 # copy *edx to ebx
    # ebx += lrow->segment-offset
    03/add                          1/mod/*+disp8   6/rm32/esi    .           .             .           3/r32/ebx   0x10/disp8      .                 # add *(esi+16) to ebx
    # lrow->address = ebx
    89/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           3/r32/ebx   0x14/disp8      .                 # copy ebx to *(esi+20)
    # trace-sssns("label " lrow->key " is at address " lrow->address ".")
    # . eax = lookup(lrow->key)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . trace-sssns("label " eax " is at address " lrow->address ".")
    # . . push args
    68/push  "."/imm32
    53/push-ebx
    68/push  "' is at address "/imm32
    50/push-eax
    68/push  "label '"/imm32
    # . . call
    e8/call  trace-sssns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
    # lrow += 24  # size of row
    81          0/subop/add         3/mod/direct    6/rm32/esi    .           .             .           .           .               0x18/imm32        # add to esi
    e9/jump  $compute-addresses:label-loop/disp32
$compute-addresses:end:
    # . restore registers
    5f/pop-to-edi
    5e/pop-to-esi
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-compute-addresses:
    # input:
    #   segments:
    #     - 'a': {0x1000, 0, 5}
    #     - 'b': {0x2018, 5, 1}
    #     - 'c': {0x5444, 6, 12}
    #   labels:
    #     - 'l1': {'a', 3, 0}
    #     - 'l2': {'b', 0, 0}
    #
    # trace contains in any order (comments in parens):
    #   segment 'a' starts at address 0x00001094.  (0x34 + 0x20 for each segment)
    #   segment 'b' starts at address 0x00002099.  (0x018 discarded)
    #   segment 'c' starts at address 0x0000509a.  (0x444 discarded)
    #   label 'l1' is at address 0x00001097.       (0x1094 + segment-offset 3)
    #   label 'l2' is at address 0x00002099.       (0x2099 + segment-offset 0)
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . var segments/ecx: (stream byte 10*20)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc8/imm32        # subtract from esp
    68/push  0xc8/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # . var labels/edx: (stream byte 8*24)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc0/imm32        # subtract from esp
    68/push  0xc0/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # . var h/ebx: (handle array byte)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # . h = copy-array(Heap, "a")
    # . . push args
    53/push-ebx
    68/push  "a"/imm32
    68/push  Heap/imm32
    # . . call
    e8/call  copy-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . stream-add5(segments, "a", 0x1000, 0, 5)
    # . . push args
    68/push  5/imm32/segment-size
    68/push  0/imm32/file-offset
    68/push  0x1000/imm32/start-address
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    51/push-ecx
    # . . call
    e8/call  stream-add5/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x18/imm32        # add to esp
    # . h = copy-array(Heap, "b")
    # . . push args
    53/push-ebx
    68/push  "b"/imm32
    68/push  Heap/imm32
    # . . call
    e8/call  copy-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . stream-add5(segments, "b", 0x2018, 5, 1)
    # . . push args
    68/push  1/imm32/segment-size
    68/push  5/imm32/file-offset
    68/push  0x2018/imm32/start-address
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    51/push-ecx
    # . . call
    e8/call  stream-add5/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x18/imm32        # add to esp
    # . h = copy-array(Heap, "c")
    # . . push args
    53/push-ebx
    68/push  "c"/imm32
    68/push  Heap/imm32
    # . . call
    e8/call  copy-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . stream-add5(segments, "c", 0x5444, 6, 12)
    68/push  0xc/imm32/segment-size
    68/push  6/imm32/file-offset
    68/push  0x5444/imm32/start-address
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    51/push-ecx
    # . . call
    e8/call  stream-add5/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x18/imm32        # add to esp
    # . stream-add6(labels, "l1", "a", 3, 0)
    # . . push args
    68/push  0/imm32/label-address
    68/push  3/imm32/segment-offset
    # . . push "a"
    53/push-ebx
    68/push  "a"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push "l1"
    53/push-ebx
    68/push  "l1"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push labels
    52/push-edx
    # . . call
    e8/call  stream-add6/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x1c/imm32        # add to esp
    # . stream-add6(labels, "l2", "b", 0, 0)
    # . . push args
    68/push  0/imm32/label-address
    68/push  0/imm32/segment-offset
    # . . push "b"
    53/push-ebx
    68/push  "b"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push "l2"
    53/push-ebx
    68/push  "l2"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push labels
    52/push-edx
    # . . call
    e8/call  stream-add6/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x1c/imm32        # add to esp
    # component under test
    # . compute-addresses(segments, labels)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  compute-addresses/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # checks
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # . check-trace-contains("segment 'a' starts at address 0x00001094.", msg)
    # . . push args
    68/push  "F - test-compute-addresses/0"/imm32
    68/push  "segment 'a' starts at address 0x00001094."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'b' starts at address 0x00002099.", msg)
    # . . push args
    68/push  "F - test-compute-addresses/1"/imm32
    68/push  "segment 'b' starts at address 0x00002099."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'c' starts at address 0x0000509a.", msg)
    # . . push args
    68/push  "F - test-compute-addresses/2"/imm32
    68/push  "segment 'c' starts at address 0x0000509a."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("label 'l1' is at address 0x00001097.", msg)
    # . . push args
    68/push  "F - test-compute-addresses/3"/imm32
    68/push  "label 'l1' is at address 0x00001097."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("label 'l2' is at address 0x00002099.", msg)
    # . . push args
    68/push  "F - test-compute-addresses/4"/imm32
    68/push  "label 'l2' is at address 0x00002099."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-ints-equal(labels->write, 0x30, msg)
    # . . push args
    68/push  "F - test-compute-addresses/maintains-labels-write-index"/imm32
    68/push  0x30/imm32/2-entries
    ff          6/subop/push        0/mod/indirect  2/rm32/edx    .           .             .           .           .               .                 # push *edx
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-compute-addresses-large-segments:
    # input:
    #   segments:
    #     - 'a': {0x1000, 0, 0x5604}
    #     - 'b': {0x2018, 0x5604, 1}
    #   labels:
    #     - 'l1': {'a', 3, 0}
    #
    # trace contains in any order (comments in parens):
    #   segment 'a' starts at address 0x00001074.  (0x34 + 0x20 for each segment)
    #   segment 'b' starts at address 0x00002678.  (0x018 discarded; last 3 nibbles from 0x1074 + 0x5604)
    #   label 'l1' is at address 0x00001077.       (0x1074 + segment-offset 3)
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . var segments/ecx: (stream byte 10*20)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc8/imm32        # subtract from esp
    68/push  0xc8/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # . var labels/edx: (stream byte 8*24)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc0/imm32        # subtract from esp
    68/push  0xc0/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # . var h/ebx: (handle array byte)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # . h = copy-array(Heap, "a")
    # . . push args
    53/push-ebx
    68/push  "a"/imm32
    68/push  Heap/imm32
    # . . call
    e8/call  copy-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . stream-add5(segments, "a", 0x1000, 0, 0x5604)
    68/push  0x5604/imm32/segment-size
    68/push  0/imm32/file-offset
    68/push  0x1000/imm32/start-address
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    51/push-ecx
    # . . call
    e8/call  stream-add5/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x18/imm32        # add to esp
    # . h = copy-array(Heap, "b")
    # . . push args
    53/push-ebx
    68/push  "b"/imm32
    68/push  Heap/imm32
    # . . call
    e8/call  copy-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . stream-add5(segments, "b", 0x2018, 0x5604, 1)
    68/push  1/imm32/segment-size
    68/push  0x5604/imm32/file-offset
    68/push  0x2018/imm32/start-address
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    51/push-ecx
    # . . call
    e8/call  stream-add5/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x18/imm32        # add to esp
    # . stream-add6(labels, "l1", "a", 3, 0)
    68/push  0/imm32/label-address
    68/push  3/imm32/segment-offset
    # . . push "a"
    53/push-ebx
    68/push  "a"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push "l1"
    53/push-ebx
    68/push  "l1"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push labels
    52/push-edx
    # . . call
    e8/call  stream-add6/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x1c/imm32        # add to esp
    # component under test
    # . compute-addresses(segments, labels)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  compute-addresses/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # checks
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # . check-trace-contains("segment 'a' starts at address 0x00001074.", msg)
    # . . push args
    68/push  "F - test-compute-addresses-large-segments/0"/imm32
    68/push  "segment 'a' starts at address 0x00001074."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("segment 'b' starts at address 0x00002678.", msg)
    # . . push args
    68/push  "F - test-compute-addresses-large-segments/1"/imm32
    68/push  "segment 'b' starts at address 0x00002678."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-trace-contains("label 'l1' is at address 0x00001077.", msg)
    # . . push args
    68/push  "F - test-compute-addresses-large-segments/3"/imm32
    68/push  "label 'l1' is at address 0x00001077."/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

emit-output:  # in: (addr stream byte), out: (addr buffered-file), segments: (addr stream {(handle array byte), segment-info}), labels: (addr stream {(handle array byte), label-info})
    # pseudocode:
    #   emit-headers(out, segments, labels)
    #   emit-segments(in, out, labels)
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
#?     # write(2/stderr, "emit-headers\n") {{{
#?     # . . push args
#?     68/push  "emit-headers\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # emit-headers(out, segments, labels)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8       .                # push *(ebp+20)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8       .                # push *(ebp+16)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8        .                # push *(ebp+12)
    # . . call
    e8/call  emit-headers/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
#?     # write(2/stderr, "emit-segments\n") {{{
#?     # . . push args
#?     68/push  "emit-segments\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # emit-segments(in, out, labels)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  emit-segments/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
$emit-output:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# global scratch space for emit-segments
== data

emit-segments:datum:  # slice
  0/imm32/start
  0/imm32/end

== code

emit-segments:  # in: (addr stream byte), out: (addr buffered-file), labels: (addr stream {(handle array byte), label-info})
    # pseudocode:
    #   var offset-of-next-instruction = 0
    #   var line: (stream byte 512)
    #   line-loop:
    #   while true
    #     clear-stream(line)
    #     read-line(in, line)
    #     if (line->write == 0) break               # end of file
    #     offset-of-next-instruction += num-bytes(line)
    #     var far-jump-or-call? = far-jump-or-call?(line)
    #     rewind-stream(line)
    #     while true
    #       var word-slice = next-word(line)
    #       if slice-empty?(word-slice)             # end of line
    #         break
    #       if slice-starts-with?(word-slice, "#")  # comment
    #         break
    #       if label?(word-slice)                # no need for label declarations anymore
    #         goto line-loop                        # don't insert empty lines
    #       if slice-equal?(word-slice, "==")       # no need for segment header lines
    #         goto line-loop                        # don't insert empty lines
    #       if length(word-slice) == 2
    #         write-slice-buffered(out, word-slice)
    #         write-buffered(out, " ")
    #         continue
    #       var datum: (addr slice) = next-token-from-slice(word-slice->start, word-slice->end, "/")
    #       var info: (addr label-info) = get-slice(labels, datum)
    #       if has-metadata?(word-slice, "imm8")
    #         abort
    #       else if has-metadata?(word-slice, "imm32")
    #         emit(out, info->address, 4)
    #       else if has-metadata?(word-slice, "disp8")
    #         value = info->offset - offset-of-next-instruction
    #         emit(out, value, 1)
    #       else if has-metadata?(word-slice, "disp32")
    #         if far-jump-or-call?
    #           value = info->offset - offset-of-next-instruction
    #         else
    #           value = info->address
    #         emit(out, value, 4)
    #       else
    #         abort
    #     write-buffered(out, "\n")
    #
    # registers:
    #   line: ecx
    #   word-slice: edx
    #   offset-of-next-instruction: ebx
    #   far-jump-or-call?: edi
    #   info: esi (inner loop only)
    #   temporaries: eax, esi (outer loop)
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # var line/ecx: (stream byte 512)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0x200/imm32       # subtract from esp
    68/push  0x200/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # var word-slice/edx: slice
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # offset-of-next-instruction/ebx = 0
    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
$emit-segments:line-loop:
    # clear-stream(line)
    # . . push args
    51/push-ecx
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # read-line(in, line)
    # . . push args
    51/push-ecx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  read-line/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # dump line {{{
#?     # . write(2/stderr, "LL: ")
#?     # . . push args
#?     68/push  "LL: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # write-stream(2/stderr, line)
#?     # . . push args
#?     51/push-ecx
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . rewind-stream(line)
#?     # . . push args
#?     51/push-ecx
#?     # . . call
#?     e8/call  rewind-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # }}}
$emit-segments:check-for-end-of-input:
    # if (line->write == 0) break
    81          7/subop/compare     0/mod/indirect  1/rm32/ecx    .           .             .           .           .               0/imm32           # compare *ecx
    0f 84/jump-if-=  $emit-segments:end/disp32
    # offset-of-next-instruction += num-bytes(line)
    # . eax = num-bytes(line)
    # . . push args
    51/push-ecx
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . ebx += eax
    01/add                          3/mod/direct    3/rm32/ebx    .           .             .           0/r32/eax   .               .                 # add eax to ebx
    # var far-jump-or-call?/edi: boolean = far-jump-or-call?(line)
    # . . push args
    51/push-ecx
    # . . call
    e8/call  far-jump-or-call?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # rewind-stream(line)
    # . . push args
    51/push-ecx
    # . . call
    e8/call  rewind-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$emit-segments:word-loop:
    # next-word(line, word-slice)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # dump word-slice {{{
#?     # . write(2/stderr, "w: ")
#?     # . . push args
#?     68/push  "w: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-slice-buffered(Stderr, word-slice)
#?     # . . push args
#?     52/push-edx
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-slice-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
$emit-segments:check-for-end-of-line:
    # if (slice-empty?(word-slice)) break
    # . eax = slice-empty?(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != 0) break
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $emit-segments:next-line/disp32
$emit-segments:check-for-comment:
    # if (slice-starts-with?(word-slice, "#")) break
    # . start/esi = word-slice->start
    8b/copy                         0/mod/indirect  2/rm32/edx    .           .             .           6/r32/esi   .               .                 # copy *edx to esi
    # . c/eax = *start
    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
    8a/copy-byte                    0/mod/indirect  6/rm32/esi    .           .             .           0/r32/AL    .               .                 # copy byte at *esi to AL
    # . if (eax == '#') break
    3d/compare-eax-and  0x23/imm32/hash
    0f 84/jump-if-=  $emit-segments:next-line/disp32
$emit-segments:check-for-label:
    # if label?(word-slice) break
    # . eax = label?(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call  label?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != false) break
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $emit-segments:line-loop/disp32
$emit-segments:check-for-segment-header:
    # if (slice-equal?(word-slice, "==")) break
    # . eax = slice-equal?(word-slice, "==")
    # . . push args
    68/push  "=="/imm32
    52/push-edx
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax != false) break
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $emit-segments:line-loop/disp32
$emit-segments:2-character:
    # if (size(word-slice) != 2) goto next check
    # . eax = size(word-slice)
    8b/copy                         1/mod/*+disp8   2/rm32/edx    .           .             .           0/r32/eax   4/disp8         .                 # copy *(edx+4) to eax
    2b/subtract                     0/mod/indirect  2/rm32/edx    .           .             .           0/r32/eax   .               .                 # subtract *edx from eax
    # . if (eax != 2) goto next check
    3d/compare-eax-and  2/imm32
    75/jump-if-!=  $emit-segments:check-metadata/disp8
    # write-slice-buffered(out, word-slice)
    # . . push args
    52/push-edx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  write-slice-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-buffered(out, " ")
    # . . push args
    68/push  Space/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # continue
    e9/jump  $emit-segments:word-loop/disp32
$emit-segments:check-metadata:
    # - if we get here, 'word-slice' must be a label to be looked up
    # datum = next-token-from-slice(word-slice->start, word-slice->end, "/")
    # . . push args
    68/push  emit-segments:datum/imm32
    68/push  0x2f/imm32/slash
    ff          6/subop/push        1/mod/*+disp8   2/rm32/edx    .           .             .           .           4/disp8         .                 # push *(edx+4)
    ff          6/subop/push        0/mod/indirect  2/rm32/edx    .           .             .           .           .               .                 # push *edx
    # . . call
    e8/call  next-token-from-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
#?     # dump datum {{{
#?     # . write(2/stderr, "datum: ")
#?     # . . push args
#?     68/push  "datum: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-slice-buffered(Stderr, datum)
#?     # . . push args
#?     68/push  emit-segments:datum/imm32
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-slice-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # info/esi = get-slice(labels, datum, row-size=24, "label table")
    # . eax = get-slice(labels, datum, row-size=24, "label table")
    # . . push args
    68/push  "label table"/imm32
    68/push  0x18/imm32/row-size
    68/push  emit-segments:datum/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    # . . call
    e8/call  get-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . esi = eax
    89/copy                         3/mod/direct    6/rm32/esi    .           .             .           0/r32/eax   .               .                 # copy eax to esi
$emit-segments:check-imm8:
    # if (has-metadata?(word-slice, "imm8")) abort
    # . eax = has-metadata?(edx, "imm8")
    # . . push args
    68/push  "imm8"/imm32
    52/push-edx
    # . . call
    e8/call  has-metadata?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax != false) abort
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $emit-segments:imm8-abort/disp32
$emit-segments:check-imm32:
    # if (!has-metadata?(word-slice, "imm32")) goto next check
    # . eax = has-metadata?(edx, "imm32")
    # . . push args
    68/push  "imm32"/imm32
    52/push-edx
    # . . call
    e8/call  has-metadata?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) goto next check
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $emit-segments:check-disp8/disp8
#?     # dump info->address {{{
#?     # . write(2/stderr, "info->address: ")
#?     # . . push args
#?     68/push  "info->address: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-int32-hex-buffered(Stderr, info->address)
#?     # . . push args
#?     ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           0xc/disp8       .                 # push *(esi+12)
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-int32-hex-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
$emit-segments:emit-imm32:
    # emit-hex(out, info->address, 4)
    # . . push args
    68/push  4/imm32
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           0xc/disp8       .                 # push *(esi+12)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  emit-hex/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # continue
    e9/jump  $emit-segments:word-loop/disp32
$emit-segments:check-disp8:
    # if (!has-metadata?(word-slice, "disp8")) goto next check
    # . eax = has-metadata?(edx, "disp8")
    # . . push args
    68/push  "disp8"/imm32
    52/push-edx
    # . . call
    e8/call  has-metadata?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) goto next check
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $emit-segments:check-disp32/disp8
$emit-segments:emit-disp8:
    # emit-hex(out, info->offset - offset-of-next-instruction, 1)
    # . . push args
    68/push  1/imm32
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   8/disp8         .                 # copy *(esi+8) to eax
    29/subtract                     3/mod/direct    0/rm32/eax    .           .             .           3/r32/ebx   .               .                 # subtract ebx from eax
    50/push-eax
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  emit-hex/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # continue
    e9/jump  $emit-segments:word-loop/disp32
$emit-segments:check-disp32:
    # if (!has-metadata?(word-slice, "disp32")) abort
    # . eax = has-metadata?(edx, "disp32")
    # . . push args
    68/push  "disp32"/imm32
    52/push-edx
    # . . call
    e8/call  has-metadata?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) abort
    3d/compare-eax-and  0/imm32/false
    0f 84/jump-if-=  $emit-segments:abort/disp32
$emit-segments:emit-disp32:
    # var value/eax = info->address
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   0xc/disp8       .                 # copy *(esi+12) to eax
    # if (far-jump-or-call?) value = info->offset - offset-of-next-instruction
    81          7/subop/compare     3/mod/direct    7/rm32/edi    .           .             .           .           .               0/imm32/false     # compare edi
    74/jump-if-=  $emit-segments:really-emit-disp32/disp8
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   8/disp8         .                 # copy *(esi+8) to eax
    29/subtract                     3/mod/direct    0/rm32/eax    .           .             .           3/r32/ebx   .               .                 # subtract ebx from eax
$emit-segments:really-emit-disp32:
    # emit-hex(out, value, 4)
    # . . push args
    68/push  4/imm32
    50/push-eax
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  emit-hex/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # continue
    e9/jump  $emit-segments:word-loop/disp32
$emit-segments:next-line:
    # write-buffered(out, "\n")
    # . . push args
    68/push  Newline/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # loop
    e9/jump  $emit-segments:line-loop/disp32
$emit-segments:end:
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x214/imm32       # add to esp
    # . restore registers
    5f/pop-to-edi
    5e/pop-to-esi
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

$emit-segments:imm8-abort:
    # . _write(2/stderr, error)
    # . . push args
    68/push  "emit-segments: cannot refer to code labels with /imm8"/imm32
    68/push  2/imm32/stderr
    # . . call
    e8/call  _write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . syscall(exit, 1)
    bb/copy-to-ebx  1/imm32
    e8/call  syscall_exit/disp32
    # never gets here

$emit-segments:abort:
    # print(stderr, "missing metadata in " word-slice)
    # . _write(2/stderr, "missing metadata in word ")
    # . . push args
    68/push  "emit-segments: missing metadata in "/imm32
    68/push  2/imm32/stderr
    # . . call
    e8/call  _write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write-slice-buffered(Stderr, word-slice)
    # . . push args
    52/push-edx
    68/push  Stderr/imm32
    # . . call
    e8/call  write-slice-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . flush(Stderr)
    # . . push args
    68/push  Stderr/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . syscall(exit, 1)
    bb/copy-to-ebx  1/imm32
    e8/call  syscall_exit/disp32
    # never gets here

test-emit-segments-non-far-control-flow:
    # labels turn into absolute addresses if opcodes are not far jumps or calls
    #
    # input:
    #   in:
    #     == code 0x1000
    #     ab cd ef gh
    #     ij x/disp32
    #     == data 0x2000
    #     00
    #     x:
    #       34
    #   labels:
    #     - 'x': {'data', 1, 0x207a}
    #
    # output:
    #   ab cd ef gh
    #   ij 7a 20 00 00
    #   00
    #   34
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream($_test-output-buffered-file->buffer)
    # . . push args
    68/push  $_test-output-buffered-file->buffer/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . var labels/edx: (stream byte 8*24)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc0/imm32        # subtract from esp
    68/push  0xc0/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # . var h/ebx: (handle array byte)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # initialize input
    # . write(_test-input-stream, "== code 0x1000\n")
    # . . push args
    68/push  "== code 0x1000\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "ab cd ef gh\n")
    # . . push args
    68/push  "ab cd ef gh\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "ij x/disp32\n")
    # . . push args
    68/push  "ij x/disp32\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "== data 0x2000\n")
    # . . push args
    68/push  "== data 0x2000\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "00\n")
    # . . push args
    68/push  "00\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "x:\n")
    # . . push args
    68/push  "x:\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "34\n")
    # . . push args
    68/push  "34\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . stream-add6(labels, "x", "data", 1, 0x207a)
    68/push  0x207a/imm32/label-address
    68/push  1/imm32/segment-offset
    # . . push "data"
    53/push-ebx
    68/push  "data"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push "l1"
    53/push-ebx
    68/push  "x"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push labels
    52/push-edx
    # . . call
    e8/call  stream-add6/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x1c/imm32        # add to esp
    # component under test
    # . emit-segments(_test-input-stream, _test-output-buffered-file, labels)
    # . . push args
    52/push-edx
    68/push  _test-output-buffered-file/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  emit-segments/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # checks
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # dump output {{{
#?     # . write(2/stderr, "result: ^")
#?     # . . push args
#?     68/push  "result: ^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . rewind-stream(_test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     # . . call
#?     e8/call  rewind-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # }}}
    # . check-next-stream-line-equal(_test-output-stream, "ab cd ef gh ", msg)
    # . . push args
    68/push  "F - test-emit-segments-global-variable/0"/imm32
    68/push  "ab cd ef gh "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "ij 7a 20 00 00 ", msg)
    # . . push args
    68/push  "F - test-emit-segments-global-variable/1"/imm32
    68/push  "ij 7a 20 00 00 "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "00 ", msg)
    # . . push args
    68/push  "F - test-emit-segments-global-variable/2"/imm32
    68/push  "00 "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "34 ", msg)
    # . . push args
    68/push  "F - test-emit-segments-global-variable/3"/imm32
    68/push  "34 "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-emit-segments-code-label:
    # labels turn into PC-relative addresses if opcodes are far jumps or calls
    #
    # input:
    #   in:
    #     == code 0x1000
    #     ab cd
    #     l1:
    #       ef gh
    #       e8 l1/disp32
    #   labels:
    #     - 'l1': {'code', 2, 0x1056}
    #
    # output:
    #   ab cd
    #   ef gh
    #   e8 f9 ff ff ff  # -7
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream($_test-output-buffered-file->buffer)
    # . . push args
    68/push  $_test-output-buffered-file->buffer/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . var labels/edx: (stream byte 8*24)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc0/imm32        # subtract from esp
    68/push  0xc0/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # . var h/ebx: (handle array byte)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # initialize input
    # . write(_test-input-stream, "== code 0x1000\n")
    # . . push args
    68/push  "== code 0x1000\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "ab cd\n")
    # . . push args
    68/push  "ab cd\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "l1:\n")
    # . . push args
    68/push  "l1:\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "  ef gh\n")
    # . . push args
    68/push  "  ef gh\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "  e8 l1/disp32\n")
    # . . push args
    68/push  "  e8 l1/disp32\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . stream-add6(labels, "l1", "code", 2, 0x1056)
    68/push  0x1056/imm32/label-address
    68/push  2/imm32/segment-offset
    # . . push "data"
    53/push-ebx
    68/push  "code"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push "l1"
    53/push-ebx
    68/push  "l1"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push labels
    52/push-edx
    # . . call
    e8/call  stream-add6/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x1c/imm32        # add to esp
    # component under test
    # . emit-segments(_test-input-stream, _test-output-buffered-file, labels)
    # . . push args
    52/push-edx
    68/push  _test-output-buffered-file/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  emit-segments/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # checks
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # dump output {{{
#?     # . write(2/stderr, "result: ^")
#?     # . . push args
#?     68/push  "result: ^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . rewind-stream(_test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     # . . call
#?     e8/call  rewind-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # }}}
    # . check-next-stream-line-equal(_test-output-stream, "ab cd ", msg)
    # . . push args
    68/push  "F - test-emit-segments-code-label/0"/imm32
    68/push  "ab cd "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "ef gh ", msg)
    # . . push args
    68/push  "F - test-emit-segments-code-label/1"/imm32
    68/push  "ef gh "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "e8 f9 ff ff ff ", msg)
    # . . push args
    68/push  "F - test-emit-segments-code-label/2"/imm32
    68/push  "e8 f9 ff ff ff "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-emit-segments-code-label-absolute:
    # labels can also convert to absolute addresses
    #
    # input:
    #   in:
    #     == code 0x1000
    #     ab cd
    #     l1:
    #       ef gh
    #       ij l1/imm32
    #   labels:
    #     - 'l1': {'code', 2, 0x1056}
    #
    # output:
    #   ab cd
    #   ef gh
    #   ij 56 10 00 00
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream($_test-output-buffered-file->buffer)
    # . . push args
    68/push  $_test-output-buffered-file->buffer/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . var labels/edx: (stream byte 8*24)
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc0/imm32        # subtract from esp
    68/push  0xc0/imm32/size
    68/push  0/imm32/read
    68/push  0/imm32/write
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # . var h/ebx: (handle array byte)
    68/push  0/imm32
    68/push  0/imm32
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # initialize input
    # . write(_test-input-stream, "== code 0x1000\n")
    # . . push args
    68/push  "== code 0x1000\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "ab cd\n")
    # . . push args
    68/push  "ab cd\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "l1:\n")
    # . . push args
    68/push  "l1:\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "  ef gh\n")
    # . . push args
    68/push  "  ef gh\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(_test-input-stream, "  ij l1/imm32\n")
    # . . push args
    68/push  "  ij l1/imm32\n"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . stream-add6(labels, "l1", "code", 2, 0x1056)
    68/push  0x1056/imm32/label-address
    68/push  2/imm32/segment-offset
    # . . push "data"
    53/push-ebx
    68/push  "code"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push "l1"
    53/push-ebx
    68/push  "l1"/imm32
    68/push  Heap/imm32
    e8/call  copy-array/disp32
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    ff          6/subop/push        1/mod/*+disp8   3/rm32/ebx    .           .             .           .           4/disp8         .                 # push *(ebx+4)
    ff          6/subop/push        0/mod/indirect  3/rm32/ebx    .           .             .           .           .               .                 # push *ebx
    # . . push labels
    52/push-edx
    # . . call
    e8/call  stream-add6/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x1c/imm32        # add to esp
    # component under test
    # . emit-segments(_test-input-stream, _test-output-buffered-file, labels)
    # . . push args
    52/push-edx
    68/push  _test-output-buffered-file/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  emit-segments/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # checks
    # . flush(_test-output-buffered-file)
    # . . push args
    68/push  _test-output-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # dump output {{{
#?     # . write(2/stderr, "result: ^")
#?     # . . push args
#?     68/push  "result: ^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, _test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . rewind-stream(_test-output-stream)
#?     # . . push args
#?     68/push  _test-output-stream/imm32
#?     # . . call
#?     e8/call  rewind-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # }}}
    # . check-next-stream-line-equal(_test-output-stream, "ab cd ", msg)
    # . . push args
    68/push  "F - test-emit-segments-code-label-absolute/0"/imm32
    68/push  "ab cd "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "ef gh ", msg)
    # . . push args
    68/push  "F - test-emit-segments-code-label-absolute/1"/imm32
    68/push  "ef gh "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . check-next-stream-line-equal(_test-output-stream, "ij f9 ff ff ff ", msg)
    # . . push args
    68/push  "F - test-emit-segments-code-label-absolute/2"/imm32
    68/push  "ij 56 10 00 00 "/imm32
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  check-next-stream-line-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# reads line to make some checks
# don't assume the read state of line after calling this function
far-jump-or-call?:  # line: (addr stream byte) -> result/edi: boolean
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    # ecx = line
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
    # var word-slice/edx: slice
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # var datum-slice/ebx: slice
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # result = false
    bf/copy-to-edi  0/imm32/false
$far-jump-or-call?:check-first-word:
    # next-word(line, word-slice)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # if (slice-empty?(word-slice)) return false
    # . eax = slice-empty?(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != 0) return
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $far-jump-or-call?:end/disp32
    # datum = next-token-from-slice(word-slice->start, word-slice->end, "/")
    # . . push args
    53/push-ebx
    68/push  0x2f/imm32/slash
    ff          6/subop/push        1/mod/*+disp8   2/rm32/edx    .           .             .           .           4/disp8         .                 # push *(edx+4)
    ff          6/subop/push        0/mod/indirect  2/rm32/edx    .           .             .           .           .               .                 # push *edx
    # . . call
    e8/call  next-token-from-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # if (datum-slice == "e8") return true
    # . eax = slice-equal?(datum-slice, "e8")
    # . . push args
    68/push  "e8"/imm32
    53/push-ebx
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax != false) return true
    3d/compare-eax-and  0/imm32/false
    75/jump-if-!=  $far-jump-or-call?:return-true/disp8
    # if (datum-slice == "e9") return true
    # . eax = slice-equal?(datum-slice, "e9")
    # . . push args
    68/push  "e9"/imm32
    53/push-ebx
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax != false) return true
    3d/compare-eax-and  0/imm32/false
    75/jump-if-!=  $far-jump-or-call?:return-true/disp8
    # if (datum-slice != "0f") return false
    # . eax = slice-equal?(datum-slice, "0f")
    # . . push args
    68/push  "0f"/imm32
    53/push-ebx
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) return
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $far-jump-or-call?:end/disp8
$far-jump-or-call?:check-second-word:
    # next-word(line, word-slice)
    # . . push args
    52/push-edx
    51/push-ecx
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # if (slice-empty?(word-slice)) return false
    # . eax = slice-empty?(word-slice)
    # . . push args
    52/push-edx
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != 0) return
    3d/compare-eax-and  0/imm32/false
    75/jump-if-!=  $far-jump-or-call?:end/disp8
    # if datum of word-slice does not start with "8", return false
    # . start/eax = word-slice->start
    8b/copy                         0/mod/indirect  2/rm32/edx    .           .             .           0/r32/eax   .               .                 # copy *edx to eax
    # . c/eax = *start
    8a/copy-byte                    0/mod/indirect  0/rm32/eax    .           .             .           0/r32/AL    .               .                 # copy byte at *eax to AL
    25/and-eax-with  0xff/imm32
    # . if (eax != '8') return
    3d/compare-eax-and  0x38/imm32/8
    75/jump-if-!=  $far-jump-or-call?:end/disp8
    # otherwise return true
$far-jump-or-call?:return-true:
    bf/copy-to-edi  1/imm32/true
$far-jump-or-call?:end:
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . restore registers
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

emit-headers:  # out: (addr buffered-file), segments: (addr stream {(handle array byte), segment-info}), labels: (addr stream {(handle array byte), label-info})
    # pseudocode:
    #   emit-elf-header(out, segments, labels)
    #   var curr-segment-row: (addr handle array byte) = segments->data
    #   max = &segments->data[segments->write]
    #   while true
    #     if (curr-segment >= max) break
    #     emit-elf-program-header-entry(out, curr-segment-row)
    #     curr-segment-row += 20                        # size of a row
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    # emit-elf-header(out, segments, labels)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  emit-elf-header/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # eax = segments
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           0/r32/eax   0xc/disp8       .                 # copy *(ebp+12) to eax
    # ecx = segments->write
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy *eax to ecx
    # curr-segment/eax = segments->data
    8d/copy-address                 1/mod/*+disp8   0/rm32/eax    .           .             .           0/r32/eax   0xc/disp8       .                 # copy eax+12 to eax
    # max/ecx = &segments->data[segments->write]
    01/add                          3/mod/direct    1/rm32/ecx    .           .             .           0/r32/eax   .               .                 # add eax to ecx
$emit-headers:loop:
    # if (curr-segment >= max) break
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # compare eax with ecx
    0f 83/jump-if-addr>=  $emit-headers:end/disp32
#?     # dump curr-segment->name {{{
#?     # . write(2/stderr, "about to emit ph entry: segment->name: ")
#?     # . . push args
#?     68/push  "about to emit ph entry: segment->name: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . clear-stream($Stderr->buffer)
#?     # . . push args
#?     68/push  $Stderr->buffer/imm32
#?     # . . call
#?     e8/call  clear-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write-int32-hex-buffered(Stderr, &curr-segment)
#?     # . . push args
#?     50/push-eax
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-int32-hex-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, " -> ")
#?     # . . push args
#?     68/push  " -> "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-int32-hex-buffered(Stderr, curr-segment->name)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  0/rm32/eax    .           .             .           .           .               .                 # push *eax
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-int32-hex-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, "\n")
#?     # . . push args
#?     68/push  Newline/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
#?     # write(2/stderr, "emit-segment-header\n") {{{
#?     # . . push args
#?     68/push  "emit-segment-header\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # emit-elf-program-header-entry(out, curr-segment)
    # . . push args
    50/push-eax
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  emit-elf-program-header-entry/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # curr-segment += 20                        # size of a row
    05/add-to-eax  0x14/imm32
    e9/jump  $emit-headers:loop/disp32
$emit-headers:end:
    # . restore registers
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

emit-elf-header:  # out: (addr buffered-file), segments: (addr stream {(handle array byte), segment-info}), labels: (addr stream {(handle array byte), label-info})
    # pseudocode
    #   *$Elf_e_entry = get(labels, "Entry")->address
    #   *$Elf_e_phnum = segments->write / 20         # size of a row
    #   emit-hex-array(out, Elf_header)
    #   write-buffered(out, "\n")
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx  # just because we need to call idiv
    # *$Elf_e_entry = get(labels, "Entry")->address
    # . eax = labels
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           0/r32/eax   0x10/disp8      .                 # copy *(ebp+16) to eax
    # . label-info/eax = get(labels, "Entry", row-size=24, "label table")
    # . . push args
    68/push  "label table"/imm32
    68/push  0x18/imm32/row-size
    68/push  "Entry"/imm32
    50/push-eax
    # . . call
    e8/call  get/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # . eax = label-info->address
    8b/copy                         1/mod/*+disp8   0/rm32/eax    .           .             .           0/r32/eax   0xc/disp8       .                 # copy *(eax+12) to eax
    # . *$Elf_e_entry = eax
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_e_entry/disp32               # copy eax to *$Elf_e_entry
    # *$Elf_e_phnum = segments->write / 20
    # . eax = segments
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           0/r32/eax   0xc/disp8       .                 # copy *(ebp+12) to eax
    # . len/eax = segments->write
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           0/r32/eax   .               .                 # copy *eax to eax
    # . eax = len / 20  (clobbering ecx and edx)
    b9/copy-to-ecx  0x14/imm32
    31/xor                          3/mod/direct    2/rm32/edx    .           .             .           2/r32/edx   .               .                 # clear edx
    f7          7/subop/idiv        3/mod/direct    1/rm32/ecx    .           .             .           .           .               .                 # divide edx:eax by ecx, storing quotient in eax and remainder in edx
    # . *$Elf_e_phnum = eax
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_e_phnum/disp32               # copy eax to *$Elf_e_phnum
    # emit-hex-array(out, Elf_header)
    # . . push args
    68/push  Elf_header/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  emit-hex-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-buffered(out, "\n")
    # . . push args
    68/push  Newline/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
$emit-elf-header:end:
    # . restore registers
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# segment-info: {address, file-offset, size}                                  (12 bytes)
# segments: (addr stream {(handle array byte), segment-info})                 (20 bytes per row)
emit-elf-program-header-entry:  # out: (addr buffered-file), curr-segment: (addr {(handle array byte), segment-info})
    # pseudocode:
    #   *$Elf_p_offset = curr-segment->file-offset
    #   *$Elf_p_vaddr = curr-segment->address
    #   *$Elf_p_paddr = curr-segment->address
    #   *$Elf_p_filesz = curr-segment->size
    #   *$Elf_p_memsz = curr-segment->size
    #   if curr-segment->name == "code"
    #     *$Elf_p_flags = 5  # r-x
    #   else
    #     *$Elf_p_flags = 6  # rw-
    #   emit-hex-array(out, Elf_program_header_entry)
    #   write-buffered(out, "\n")
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    56/push-esi
    # esi = curr-segment
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   0xc/disp8       .                 # copy *(ebp+12) to esi
    # *$Elf_p_offset = curr-segment->file-offset
    # . eax = curr-segment->file-offset
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   0xc/disp8       .                 # copy *(esi+12) to eax
    # . *$Elf_p_offset = eax
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_p_offset/disp32              # copy eax to *$Elf_p_offset
    # *$Elf_p_vaddr = curr-segment->address
    # . eax = curr-segment->address
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   8/disp8         .                 # copy *(esi+8) to eax
    # . *$Elf_p_vaddr = eax
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_p_vaddr/disp32               # copy eax to *$Elf_p_vaddr
    # *$Elf_p_paddr = curr-segment->address
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_p_paddr/disp32               # copy eax to *$Elf_p_paddr
    # *$Elf_p_filesz = curr-segment->size
    # . eax = curr-segment->size
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   0x10/disp8       .                # copy *(esi+16) to eax
    # . *$Elf_p_filesz = eax
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_p_filesz/disp32              # copy eax to *$Elf_p_filesz
    # *$Elf_p_memsz = curr-segment->size
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   $Elf_p_memsz/disp32               # copy eax to *$Elf_p_memsz
    # if (!string-equal?(name, "code") goto next check
    # . var name/eax: (addr array byte) = lookup(curr-segment->name)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
    ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
    # . . call
    e8/call  lookup/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . eax = string-equal?(name, "code")
    # . . push args
    68/push  "code"/imm32
    50/push-eax
    # . . call
    e8/call  string-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax == false) goto next check
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $emit-elf-program-header-entry:data/disp8
    # *$Elf_p_flags = r-x
    c7          0/subop/copy        0/mod/indirect  5/rm32/.disp32            .             .           .           $Elf_p_flags/disp32  5/imm32      # copy to *$Elf_p_flags
    eb/jump  $emit-elf-program-header-entry:really-emit/disp8
$emit-elf-program-header-entry:data:
    # otherwise *$Elf_p_flags = rw-
    c7          0/subop/copy        0/mod/indirect  5/rm32/.disp32            .             .           .           $Elf_p_flags/disp32  6/imm32      # copy to *$Elf_p_flags
$emit-elf-program-header-entry:really-emit:
    # emit-hex-array(out, Elf_program_header_entry)
    # . . push args
    68/push  Elf_program_header_entry/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  emit-hex-array/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-buffered(out, "\n")
    # . . push args
    68/push  Newline/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  write-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
$emit-elf-program-header-entry:end:
    # . restore registers
    5e/pop-to-esi
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# - some helpers for tests

stream-add5:  # in: (addr stream byte), key: handle, val1: addr, val2: addr, val3: addr
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    56/push-esi
    # esi = in
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   8/disp8         .                 # copy *(ebp+8) to esi
    # curr/eax = &in->data[in->write]
    # . eax = in->write
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           0/r32/eax   .               .                 # copy *esi to eax
    # . eax = esi+eax+12
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/esi  0/index/eax   .           0/r32/eax   0xc/disp8       .                 # copy esi+eax+12 to eax
    # max/edx = &in->data[in->size]
    # . edx = in->size
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           2/r32/edx   8/disp8         .                 # copy *(esi+8) to edx
    # . edx = esi+edx+12
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/esi  2/index/edx   .           2/r32/edx   0xc/disp8       .                 # copy esi+edx+12 to edx
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add5:abort/disp8
    # *curr = key->alloc-id
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0xc/disp8       .                 # copy *(ebp+12) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add5:abort/disp8
    # *curr = key->payload
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x10/disp8      .                 # copy *(ebp+16) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add5:abort/disp8
    # *curr = val1
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x14/disp8      .                 # copy *(ebp+20) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add5:abort/disp8
    # *curr = val2
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x18/disp8      .                 # copy *(ebp+24) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add5:abort/disp8
    # *curr = val3
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x1c/disp8      .                 # copy *(ebp+28) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # in->write += 20
    81          0/subop/add         0/mod/indirect  6/rm32/esi    .           .             .           .           .               0x14/imm32        # add to *esi
$stream-add5:end:
    # . restore registers
    5e/pop-to-esi
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

$stream-add5:abort:
    # . _write(2/stderr, error)
    # . . push args
    68/push  "overflow in stream-add5\n"/imm32
    68/push  2/imm32/stderr
    # . . call
    e8/call  _write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . syscall(exit, 1)
    bb/copy-to-ebx  1/imm32
    e8/call  syscall_exit/disp32
    # never gets here

stream-add6:  # in: (addr stream byte), key: handle, val1: addr, val2: addr, val3: addr, val4: addr
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    56/push-esi
    # esi = in
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   8/disp8         .                 # copy *(ebp+8) to esi
    # curr/eax = &in->data[in->write]
    # . eax = in->write
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           0/r32/eax   .               .                 # copy *esi to eax
    # . eax = esi+eax+12
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/esi  0/index/eax   .           0/r32/eax   0xc/disp8       .                 # copy esi+eax+12 to eax
    # max/edx = &in->data[in->size]
    # . edx = in->size
    8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           2/r32/edx   8/disp8         .                 # copy *(esi+8) to edx
    # . edx = esi+edx+12
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/esi  2/index/edx   .           2/r32/edx   0xc/disp8       .                 # copy esi+edx+12 to edx
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add6:abort/disp8
    # *curr = key->alloc-id
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0xc/disp8       .                 # copy *(ebp+12) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add6:abort/disp8
    # *curr = key->payload
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x10/disp8      .                 # copy *(ebp+16) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add6:abort/disp8
    # *curr = val1
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x14/disp8      .                 # copy *(ebp+20) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add6:abort/disp8
    # *curr = val2
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x18/disp8      .                 # copy *(ebp+24) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add6:abort/disp8
$aa-write-segment-offset:
    # *curr = val3
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x1c/disp8      .                 # copy *(ebp+28) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # curr += 4
    05/add-to-eax  4/imm32
    # if (curr >= max) abort
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # compare eax with edx
    73/jump-if-addr>=  $stream-add6:abort/disp8
    # *curr = val4
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   0x20/disp8      .                 # copy *(ebp+32) to ecx
    89/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy ecx to *eax
    # in->write += 24
    81          0/subop/add         0/mod/indirect  6/rm32/esi    .           .             .           .           .               0x18/imm32        # add to *esi
$stream-add6:end:
    # . restore registers
    5e/pop-to-esi
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

$stream-add6:abort:
    # . _write(2/stderr, error)
    # . . push args
    68/push  "overflow in stream-add6\n"/imm32
    68/push  2/imm32/stderr
    # . . call
    e8/call  _write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . syscall(exit, 1)
    bb/copy-to-ebx  1/imm32
    e8/call  syscall_exit/disp32
    # never gets here

# some variants of 'trace' that take multiple arguments in different combinations of types:
#   n: int
#   c: character [4-bytes, will eventually be UTF-8]
#   s: (addr array byte)
#   l: (addr slice)
# one gotcha: 's5' must not be empty

trace-sssns:  # s1: (addr array byte), s2: (addr array byte), s3: (addr array byte), n4: int, s5: (addr array byte)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # write(*Trace-stream, s1)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(*Trace-stream, s2)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(*Trace-stream, s3)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-int32-hex(*Trace-stream, n4)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write-int32-hex/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # trace(s5)  # implicitly adds a newline and finalizes the trace line
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x18/disp8      .                 # push *(ebp+24)
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$trace-sssns:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-trace-sssns:
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . *Trace-stream->write = 0
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy *Trace-stream to eax
    c7          0/subop/copy        0/mod/direct    0/rm32/eax    .           .             .           .           .               0/imm32           # clear *eax
    # trace-sssns("A" "b" "c " 3 " e")
    # . . push args
    68/push  " e"/imm32
    68/push  3/imm32
    68/push  "c "/imm32
    68/push  "b"/imm32
    68/push  "A"/imm32
    # . . call
    e8/call  trace-sssns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # check-trace-contains("Abc 0x00000003 e")
    # . . push args
    68/push  "F - test-trace-sssns"/imm32
    68/push  "Abc 0x00000003 e"/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

trace-slsls:  # s1: (addr array byte), l2: (addr slice), s3: (addr array byte), l4: (addr slice), s5: (addr array byte)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # write(*Trace-stream, s1)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-slice(*Trace-stream, l2)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(*Trace-stream, s3)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-slice(*Trace-stream, l4)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # trace(s5)  # implicitly adds a newline and finalizes the trace line
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x18/disp8      .                 # push *(ebp+24)
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$trace-slsls:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-trace-slsls:
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . *Trace-stream->write = 0
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy *Trace-stream to eax
    c7          0/subop/copy        0/mod/direct    0/rm32/eax    .           .             .           .           .               0/imm32           # clear *eax
    # (eax..ecx) = "b"
    b8/copy-to-eax  "b"/imm32
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy *eax to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/eax  1/index/ecx   .           1/r32/ecx   4/disp8         .                 # copy eax+ecx+4 to ecx
    05/add-to-eax  4/imm32
    # var b/ebx: slice = {eax, ecx}
    51/push-ecx
    50/push-eax
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # (eax..ecx) = "d"
    b8/copy-to-eax  "d"/imm32
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy *eax to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/eax  1/index/ecx   .           1/r32/ecx   4/disp8         .                 # copy eax+ecx+4 to ecx
    05/add-to-eax  4/imm32
    # var d/edx: slice = {eax, ecx}
    51/push-ecx
    50/push-eax
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           4/r32/esp   .               .                 # copy esp to edx
    # trace-slsls("A" b "c" d "e")
    # . . push args
    68/push  "e"/imm32
    52/push-edx
    68/push  "c"/imm32
    53/push-ebx
    68/push  "A"/imm32
    # . . call
    e8/call  trace-slsls/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # check-trace-contains("Abcde")
    # . . push args
    68/push  "F - test-trace-slsls"/imm32
    68/push  "Abcde"/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

trace-slsns:  # s1: (addr array byte), l2: (addr slice), s3: (addr array byte), n4: int, s5: (addr array byte)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # write(*Trace-stream, s1)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-slice(*Trace-stream, l2)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(*Trace-stream, s3)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-int32-hex(*Trace-stream, n4)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write-int32-hex/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # trace(s5)  # implicitly adds a newline and finalizes the trace line
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x18/disp8      .                 # push *(ebp+24)
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$trace-slsns:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-trace-slsns:
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . *Trace-stream->write = 0
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy *Trace-stream to eax
    c7          0/subop/copy        0/mod/direct    0/rm32/eax    .           .             .           .           .               0/imm32           # clear *eax
    # (eax..ecx) = "b"
    b8/copy-to-eax  "b"/imm32
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy *eax to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/eax  1/index/ecx   .           1/r32/ecx   4/disp8         .                 # copy eax+ecx+4 to ecx
    05/add-to-eax  4/imm32
    # var b/ebx: slice = {eax, ecx}
    51/push-ecx
    50/push-eax
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # trace-slsls("A" b "c " 3 " e")
    # . . push args
    68/push  " e"/imm32
    68/push  3/imm32
    68/push  "c "/imm32
    53/push-ebx
    68/push  "A"/imm32
    # . . call
    e8/call  trace-slsns/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # check-trace-contains("Abc 0x00000003 e")
    # . . push args
    68/push  "F - test-trace-slsls"/imm32
    68/push  "Abc 0x00000003 e"/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

trace-slsss:  # s1: (addr array byte), l2: (addr slice), s3: (addr array byte), s4: (addr array byte), s5: (addr array byte)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # write(*Trace-stream, s1)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write-slice(*Trace-stream, l2)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(*Trace-stream, s3)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(*Trace-stream, s4)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # trace(s5)  # implicitly adds a newline and finalizes the trace line
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x18/disp8      .                 # push *(ebp+24)
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$trace-slsss:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-trace-slsss:
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . *Trace-stream->write = 0
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy *Trace-stream to eax
    c7          0/subop/copy        0/mod/direct    0/rm32/eax    .           .             .           .           .               0/imm32           # clear *eax
    # (eax..ecx) = "b"
    b8/copy-to-eax  "b"/imm32
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy *eax to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/eax  1/index/ecx   .           1/r32/ecx   4/disp8         .                 # copy eax+ecx+4 to ecx
    05/add-to-eax  4/imm32
    # var b/ebx: slice = {eax, ecx}
    51/push-ecx
    50/push-eax
    89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           4/r32/esp   .               .                 # copy esp to ebx
    # trace-slsss("A" b "c" "d" "e")
    # . . push args
    68/push  "e"/imm32
    68/push  "d"/imm32
    68/push  "c"/imm32
    53/push-ebx
    68/push  "A"/imm32
    # . . call
    e8/call  trace-slsss/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x14/imm32        # add to esp
#?     # dump *Trace-stream {{{
#?     # . write(2/stderr, "^")
#?     # . . push args
#?     68/push  "^"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write-stream(2/stderr, *Trace-stream)
#?     # . . push args
#?     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # check-trace-contains("Abcde")
    # . . push args
    68/push  "F - test-trace-slsss"/imm32
    68/push  "Abcde"/imm32
    # . . call
    e8/call  check-trace-contains/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

num-bytes:  # line: (addr stream byte) -> eax: int
    # pseudocode:
    #   result = 0
    #   while true
    #     var word-slice = next-word(line)
    #     if slice-empty?(word-slice)             # end of line
    #       break
    #     if slice-starts-with?(word-slice, "#")  # comment
    #       break
    #     if label?(word-slice)                # no need for label declarations anymore
    #       break
    #     if slice-equal?(word-slice, "==")
    #       break                                 # no need for segment header lines
    #     result += compute-width(word-slice)
    #   return result
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    51/push-ecx
    52/push-edx
    53/push-ebx
    # var result/eax = 0
    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
    # var word-slice/ecx: slice
    68/push  0/imm32/end
    68/push  0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
#?     # dump line {{{
#?     # . write(2/stderr, "LL: ")
#?     # . . push args
#?     68/push  "LL: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # write-stream(2/stderr, line)
#?     # . . push args
#?     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
    # . rewind-stream(line)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  rewind-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$num-bytes:loop:
    # next-word(line, word-slice)
    # . . push args
    51/push-ecx
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  next-word/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # dump word-slice {{{
#?     # . write(2/stderr, "AA: ")
#?     # . . push args
#?     68/push  "AA: "/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . clear-stream($Stderr->buffer)
#?     # . . push args
#?     68/push  $Stderr->buffer/imm32
#?     # . . call
#?     e8/call  clear-stream/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write-slice-buffered(Stderr, word-slice)
#?     # . . push args
#?     51/push-ecx
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  write-slice-buffered/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # . flush(Stderr)
#?     # . . push args
#?     68/push  Stderr/imm32
#?     # . . call
#?     e8/call  flush/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
#?     # . write(2/stderr, "$\n")
#?     # . . push args
#?     68/push  "$\n"/imm32
#?     68/push  2/imm32/stderr
#?     # . . call
#?     e8/call  write/disp32
#?     # . . discard args
#?     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
#?     # }}}
$num-bytes:check0:
    # if (slice-empty?(word-slice)) break
    # . save result
    50/push-eax
    # . eax = slice-empty?(word-slice)
    # . . push args
    51/push-ecx
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != false) break
    3d/compare-eax-and  0/imm32/false
    # . restore result now that ZF is set
    58/pop-to-eax
    75/jump-if-!=  $num-bytes:end/disp8
$num-bytes:check-for-comment:
    # if (slice-starts-with?(word-slice, "#")) break
    # . start/edx = word-slice->start
    8b/copy                         0/mod/indirect  1/rm32/ecx    .           .             .           2/r32/edx   .               .                 # copy *ecx to edx
    # . c/ebx = *start
    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
    8a/copy-byte                    0/mod/indirect  2/rm32/edx    .           .             .           3/r32/BL    .               .                 # copy byte at *edx to BL
    # . if (ebx == '#') break
    81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0x23/imm32/hash   # compare ebx
    74/jump-if-=  $num-bytes:end/disp8
$num-bytes:check-for-label:
    # if (slice-ends-with?(word-slice, ":")) break
    # . end/edx = word-slice->end
    8b/copy                         1/mod/*+disp8   1/rm32/ecx    .           .             .           2/r32/edx   4/disp8         .                 # copy *(ecx+4) to edx
    # . c/ebx = *(end-1)
    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
    8a/copy-byte                    1/mod/*+disp8   2/rm32/edx    .           .             .           3/r32/BL    -1/disp8        .                 # copy byte at *ecx to BL
    # . if (ebx == ':') break
    81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0x3a/imm32/colon  # compare ebx
    74/jump-if-=  $num-bytes:end/disp8
$num-bytes:check-for-segment-header:
    # if (slice-equal?(word-slice, "==")) break
    # . push result
    50/push-eax
    # . eax = slice-equal?(word-slice, "==")
    # . . push args
    68/push  "=="/imm32
    51/push-ecx
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . if (eax != false) break
    3d/compare-eax-and  0/imm32/false
    # . restore result now that ZF is set
    58/pop-to-eax
    75/jump-if-!=  $num-bytes:end/disp8
$num-bytes:loop-body:
    # result += compute-width-of-slice(word-slice)
    # . copy result to edx
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           0/r32/eax   .               .                 # copy eax to edx
    # . eax = compute-width-of-slice(word-slice)
    # . . push args
    51/push-ecx
    # . . call
    e8/call compute-width-of-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . eax += result
    01/add                          3/mod/direct    0/rm32/eax    .           .             .           2/r32/edx   .               .                 # add edx to eax
    e9/jump  $num-bytes:loop/disp32
$num-bytes:end:
    # . rewind-stream(line)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  rewind-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . restore registers
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-handles-empty-string:
    # if a line starts with '#', return 0
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # no contents in input
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-num-bytes-handles-empty-string"/imm32
    68/push  0/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-ignores-comments:
    # if a line starts with '#', return 0
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "# abcd")
    # . . push args
    68/push  "# abcd"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-num-bytes-ignores-comments"/imm32
    68/push  0/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-ignores-labels:
    # if the first word ends with ':', return 0
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "ab: # cd")
    # . . push args
    68/push  "ab: # cd"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-num-bytes-ignores-labels"/imm32
    68/push  0/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-ignores-segment-headers:
    # if the first word is '==', return 0
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "== ab cd")
    # . . push args
    68/push  "== ab cd"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-num-bytes-ignores-segment-headers"/imm32
    68/push  0/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-counts-words-by-default:
    # without metadata, count words
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "ab cd ef")
    # . . push args
    68/push  "ab cd ef"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 3, msg)
    # . . push args
    68/push  "F - test-num-bytes-counts-words-by-default"/imm32
    68/push  3/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-ignores-trailing-comment:
    # trailing comments appropriately ignored
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "ab cd # ef")
    # . . push args
    68/push  "ab cd # ef"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 2, msg)
    # . . push args
    68/push  "F - test-num-bytes-ignores-trailing-comment"/imm32
    68/push  2/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-num-bytes-handles-imm32:
    # if a word has the /imm32 metadata, count it as 4 bytes
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # setup
    # . clear-stream(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . clear-stream(_test-output-stream)
    # . . push args
    68/push  _test-output-stream/imm32
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # initialize input
    # . write(_test-input-stream, "ab cd/imm32 ef")
    # . . push args
    68/push  "ab cd/imm32 ef"/imm32
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # eax = num-bytes(_test-input-stream)
    # . . push args
    68/push  _test-input-stream/imm32
    # . . call
    e8/call  num-bytes/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 6, msg)
    # . . push args
    68/push  "F - test-num-bytes-handles-imm32"/imm32
    68/push  6/imm32/true
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

== data

# This block of bytes gets copied to the start of the output ELF file, with
# some fields (the ones with labels capitalized) filled in.
# http://www.sco.com/developers/gabi/latest/ch4.eheader.html
Elf_header:
  # - size
  0x34/imm32
  # - data
$e_ident:
  7f 45/E 4c/L 46/F
  01/32-bit  01/little-endian  01/file-version  00/no-os-extensions
  00 00 00 00 00 00 00 00  # 8 bytes of padding
$e_type:
  02 00
$e_machine:
  03 00
$e_version:
  1/imm32
$Elf_e_entry:
  0x09000000/imm32  # approximate default; must be updated
$e_phoff:
  0x34/imm32  # offset for the 'program header table' containing segment headers
$e_shoff:
  0/imm32  # no sections
$e_flags:
  0/imm32  # unused
$e_ehsize:
  0x34 00
$e_phentsize:
  0x20 00
$Elf_e_phnum:
  00 00  # number of segments; must be updated
$e_shentsize:
  00 00  # no sections
$e_shnum:
  00 00
$e_shstrndx:
  00 00

# This block of bytes gets copied after the Elf_header once for each segment.
# Some fields need filling in each time.
# https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-83432/index.html
Elf_program_header_entry:
  # - size
  0x20/imm32
  # - data
$p_type:
  1/imm32/PT_LOAD
$Elf_p_offset:
  0/imm32  # byte offset in the file at which a segment begins; must be updated
$Elf_p_vaddr:
  0/imm32  # starting address to store the segment at before running the program
$Elf_p_paddr:
  0/imm32  # should have same value as $Elf_p_vaddr
$Elf_p_filesz:
  0/imm32
$Elf_p_memsz:
  0/imm32  # should have same value as $Elf_p_filesz
$Elf_p_flags:
  6/imm32/rw-  # read/write/execute permissions for the segment; must be updated for the code segment
$p_align:
  # we hold this constant; changing it will require adjusting the way we
  # compute the starting address for each segment
  0x1000/imm32

# . . vim:nowrap:textwidth=0