# Port of https://github.com/akkartik/crenshaw/blob/master/tutor2.1.pas
# which corresponds to the section "single digits" in https://compilers.iecc.com/crenshaw/tutor2.txt
# except that we support hex numbers of multiple digits.
#
# To run:
#   $ ./bootstrap translate init.linux [01]*.subx apps/crenshaw2-1b.subx -o apps/crenshaw2-1b
#   $ echo '1a'  |./bootstrap run apps/crenshaw2-1b
# Expected output:
#   # syscall(exit, 1a)
#   bb/copy-to-ebx  3/imm32
#   b8/copy-to-eax  1/imm32/exit
#   cd/syscall  0x80/imm8
#
# To run the generated output:
#   $ echo '1a'  |./bootstrap run apps/crenshaw2-1b > z1.subx
#   $ ./bootstrap translate init.linux z1.subx -o z1
#   $ ./bootstrap run z1
#   $ echo $?
#   26  # 0x1a in decimal
#
# Stdin must contain just a single hex digit. Other input will print an error:
#   $ echo 'xyz'  |./bootstrap run apps/crenshaw2-1b
#   Error: integer expected
#
# Names in this file sometimes follow Crenshaw's original rather than my usual
# naming conventions.

== 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, call 'compile' if not
    # . prologue
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp

    # initialize heap
    # . 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

    # - if argc > 1 and argv[1] == "test", then return run_tests()
    # if (argc <= 1) goto run-main
    81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0/disp8         1/imm32           # compare *ebp
    7e/jump-if-<=  $run-main/disp8
    # if (!kernel-string-equal?(argv[1], "test")) goto run-main
    # . 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 run-main
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $run-main/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  $main:end/disp8
$run-main:
    # - otherwise read a program from stdin and emit its translation to stdout
    # . compile(Stdin, 1/stdout, 2/stderr, 0)
    # . . push args
    68/push  0/imm32/exit-descriptor
    68/push  2/imm32/stderr
    68/push  1/imm32/stdout
    68/push  Stdin/imm32
    # . . call
    e8/call  compile/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # syscall(exit, 0)
    bb/copy-to-ebx  0/imm32
$main:end:
    e8/call  syscall_exit/disp32

# the main entry point
compile:  # in: (addr buffered-file), out: fd or (addr stream byte), err: fd or (addr stream byte), ed: (addr exit-descriptor)
    # . 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
    # prime the pump
    # . Look = get-char(in)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8      .                    # push *(ebp+8)
    # . . call
    e8/call  get-char/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # var num/ecx: (stream byte 7)
    # Numbers can be 32 bits or 8 hex bytes long. One of them will be in 'Look', so we need space for 7 bytes.
    # Sizing the stream just right buys us overflow-handling for free inside 'get-num'.
    # Add 12 bytes for 'read', 'write' and 'size' fields, for a total of 19 bytes, or 0x13 in hex.
    # The stack pointer is no longer aligned, so dump_stack() can be misleading past this point.
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0x13/imm32       <style>pre { line-height: 125%; }
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.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
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.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */</style><div class="highlight"><pre><span></span>[colours]
bkgnd=default
titlebar=blue
titlebar.text=bold_white
titlebar.brackets=bold_cyan
titlebar.unencrypted=bold_red
titlebar.encrypted=bold_white
titlebar.untrusted=bold_yellow
titlebar.trusted=bold_white
titlebar.online=bold_white
titlebar.offline=bold_white
titlebar.away=bold_white
titlebar.chat=bold_white
titlebar.dnd=bold_white
titlebar.xa=bold_white
statusbar=blue
statusbar.text=bold_white
statusbar.time=bold_white
statusbar.brackets=bold_cyan
statusbar.active=bold_cyan
statusbar.new=bold_white
main.text=bold_white
main.text.me=bold_white
main.text.them=bold_white
main.splash=bold_cyan
main.help.header=bold_white
main.time=bold_white
input.text=bold_white
subscribed=bold_green
unsubscribed=bold_red
otr.started.trusted=bold_green
otr.started.untrusted=bold_yellow
otr.ended=bold_red
otr.trusted=bold_green
otr.untrusted=bold_yellow
online=bold_green
away=bold_cyan
chat=bold_green
dnd=bold_red
xa=bold_cyan
offline=bold_red
incoming=bold_yellow
mention=bold_yellow
trigger=bold_yellow
typing=bold_yellow
gone=bold_yellow
error=bold_red
roominfo=bold_yellow
roommention=bold_yellow
roommention.term=bold_yellow
roomtrigger=bold_yellow
roomtrigger.term=bold_yellow
me=bold_yellow
them=bold_green
roster.header=bold_yellow
roster.chat=bold_green
roster.online=bold_green
roster.away=bold_cyan
roster.xa=bold_cyan
roster.dnd=bold_red
roster.offline=bold_red
roster.chat.active=bold_green
roster.online.active=bold_green
roster.away.active=bold_cyan
roster.xa.active=bold_cyan
roster.dnd.active=bold_red
roster.offline.active=bold_red
roster.chat.unread=bold_green
roster.online.unread=bold_green
roster.away.unread=bold_cyan
roster.xa.unread=bold_cyan
roster.dnd.unread=bold_red
roster.offline.unread=bold_red
roster.room=bold_green
roster.room.unread=bold_green
roster.room.mention=bold_green
roster.room.trigger=bold_green
occupants.header=bold_yellow
receipt.sent=bold_red
</pre></div>
</code></pre></td></tr></table>
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        .           6/r32/esi   8/disp8         .                 # copy *(ebp+8) to esi
    # edi = out
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           7/r32/edi   0xc/disp8       .                 # copy *(ebp+12) to edi
    # ecx = out->write
    8b/copy                         0/mod/indirect  7/rm32/edi    .           .             .           1/r32/ecx   .               .                 # copy *edi to ecx
    # edx = out->size
    8b/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           2/r32/edx   8/disp8         .                 # copy *(edi+8) to edx
$get-num:loop:
    # if (out->write >= out->size) error
    39/compare                      3/mod/direct    2/rm32/edx    .           .             .           1/r32/ecx   .               .                 # compare edx with ecx
    7d/jump-if-<  $get-num:loop-stage2/disp8
    # . error(ed, err, msg)  # TODO: show full number
    # . . push args
    68/push  "get-num: too many digits in number"/imm32
    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    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
    # . . call
    e8/call  error/disp32  # never returns
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
$get-num:loop-stage2:
    # out->data[out->write] = LSB(Look)
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    7/base/edi  1/index/ecx   .           3/r32/ebx   0xc/disp8       .                 # copy edi+ecx+12 to ebx
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Look/disp32     .                 # copy *Look to eax
    88/copy-byte                    0/mod/indirect  3/rm32/ebx    .           .             .           0/r32/AL    .               .                 # copy byte at AL to *ebx
    # ++out->write
    41/increment-ecx
    # Look = get-char(in)
    # . . push args
    56/push-esi
    # . . call
    e8/call  get-char/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # if (is-digit?(Look)) loop
    # . eax = is-digit?(Look)
    # . . push args
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Look/disp32     .                 # push *Look
    # . . call
    e8/call  is-digit?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax != false) loop
    3d/compare-eax-and  0/imm32/false
    0f 85/jump-if-!=  $get-num:loop/disp32
$get-num:loop-end:
    # persist necessary variables from registers
    89/copy                         0/mod/indirect  7/rm32/edi    .           .             .           1/r32/ecx   .               .                 # copy ecx to *edi
$get-num: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-get-num-reads-single-digit:
    # - check that get-num returns first character if it's a digit
    # This test uses exit-descriptors. Use ebp for setting up local variables.
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # clear all streams
    # . clear-stream(_test-stream)
    # . . push args
    68/push  _test-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-buffered-file->buffer)
    # . . push args
    68/push  $_test-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-error-stream)
    # . . push args
    68/push  _test-error-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 'in'
    # . write(_test-stream, "3")
    # . . push args
    68/push  "3"/imm32
    68/push  _test-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # initialize exit-descriptor 'ed' for the call to 'get-num' below
    # . var ed/eax: exit-descriptor
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # subtract from esp
    89/copy                         3/mod/direct    0/rm32/eax    .           .             .           4/r32/esp   .               .                 # copy esp to eax
    # . tailor-exit-descriptor(ed, 16)
    # . . push args
    68/push  0x10/imm32/nbytes-of-args-for-get-num
    50/push-eax/ed
    # . . call
    e8/call  tailor-exit-descriptor/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # prime the pump
    # . get-char(_test-buffered-file)
    # . . push args
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-char/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # get-num(in, out, err, ed)
    # . . push args
    50/push-eax/ed
    68/push  _test-error-stream/imm32
    68/push  _test-output-stream/imm32
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-num/disp32
    # registers except esp may be clobbered at this point
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # check-ints-equal(*_test-output-stream->data, '3', msg)
    # . . push args
    68/push  "F - test-get-num-reads-single-digit"/imm32
    68/push  0x33/imm32
    b8/copy-to-eax  _test-output-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           0xc/disp8       .                 # push *(eax+12)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    5d/pop-to-ebp
    c3/return

test-get-num-aborts-on-non-digit-in-Look:
    # - check that get-num returns first character if it's a digit
    # This test uses exit-descriptors. Use ebp for setting up local variables.
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # clear all streams
    # . clear-stream(_test-stream)
    # . . push args
    68/push  _test-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-buffered-file->buffer)
    # . . push args
    68/push  $_test-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-error-stream)
    # . . push args
    68/push  _test-error-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 'in'
    # . write(_test-stream, "3")
    # . . push args
    68/push  "3"/imm32
    68/push  _test-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # initialize exit-descriptor 'ed' for the call to 'get-num' below
    # . var ed/eax: exit-descriptor
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # subtract from esp
    89/copy                         3/mod/direct    0/rm32/eax    .           .             .           4/r32/esp   .               .                 # copy esp to eax
    # . tailor-exit-descriptor(ed, 16)
    # . . push args
    68/push  0x10/imm32/nbytes-of-args-for-get-num
    50/push-eax/ed
    # . . call
    e8/call  tailor-exit-descriptor/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # *don't* prime the pump
    # get-num(in, out, err, ed)
    # . . push args
    50/push-eax/ed
    68/push  _test-error-stream/imm32
    68/push  _test-output-stream/imm32
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-num/disp32
    # registers except esp may be clobbered at this point
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # check that get-num tried to call exit(1)
    # . check-ints-equal(ed->value, 2, msg)  # i.e. stop was called with value 1
    # . . push args
    68/push  "F - test-get-num-aborts-on-non-digit-in-Look"/imm32
    68/push  2/imm32
    # . . push ed->value
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           4/disp8         .                 # push *(eax+4)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    5d/pop-to-ebp
    c3/return

test-get-num-reads-multiple-digits:
    # - check that get-num returns all initial digits until it encounters a non-digit
    # This test uses exit-descriptors. Use ebp for setting up local variables.
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # clear all streams
    # . clear-stream(_test-stream)
    # . . push args
    68/push  _test-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-buffered-file->buffer)
    # . . push args
    68/push  $_test-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-error-stream)
    # . . push args
    68/push  _test-error-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 'in'
    # . write(_test-stream, "3456 x")
    # . . push args
    68/push  "3456"/imm32
    68/push  _test-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # initialize exit-descriptor 'ed' for the call to 'get-num' below
    # . var ed/eax: exit-descriptor
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # subtract from esp
    89/copy                         3/mod/direct    0/rm32/eax    .           .             .           4/r32/esp   .               .                 # copy esp to eax
    # . tailor-exit-descriptor(ed, 16)
    # . . push args
    68/push  0x10/imm32/nbytes-of-args-for-get-num
    50/push-eax/ed
    # . . call
    e8/call  tailor-exit-descriptor/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # prime the pump
    # . get-char(_test-buffered-file)
    # . . push args
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-char/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # get-num(in, out, err, ed)
    # . . push args
    50/push-eax/ed
    68/push  _test-error-stream/imm32
    68/push  _test-output-stream/imm32
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-num/disp32
    # registers except esp may be clobbered at this point
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # check-ints-equal(*_test-output-stream->data, '3456', msg)
    # . . push args
    68/push  "F - test-get-num-reads-multiple-digits"/imm32
    68/push  0x36353433/imm32
    b8/copy-to-eax  _test-output-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           0xc/disp8       .                 # push *(eax+12)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    5d/pop-to-ebp
    c3/return

test-get-num-reads-multiple-digits-followed-by-nondigit:
    # - check that get-num returns all initial digits until it encounters a non-digit
    # This test uses exit-descriptors. Use ebp for setting up local variables.
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # clear all streams
    # . clear-stream(_test-stream)
    # . . push args
    68/push  _test-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-buffered-file->buffer)
    # . . push args
    68/push  $_test-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-error-stream)
    # . . push args
    68/push  _test-error-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 'in'
    # . write(_test-stream, "3456 x")
    # . . push args
    68/push  "3456 x"/imm32
    68/push  _test-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # initialize exit-descriptor 'ed' for the call to 'get-num' below
    # . var ed/eax: exit-descriptor
    81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # subtract from esp
    89/copy                         3/mod/direct    0/rm32/eax    .           .             .           4/r32/esp   .               .                 # copy esp to eax
    # . tailor-exit-descriptor(ed, 16)
    # . . push args
    68/push  0x10/imm32/nbytes-of-args-for-get-num
    50/push-eax/ed
    # . . call
    e8/call  tailor-exit-descriptor/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # prime the pump
    # . get-char(_test-buffered-file)
    # . . push args
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-char/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # get-num(in, out, err, ed)
    # . . push args
    50/push-eax/ed
    68/push  _test-error-stream/imm32
    68/push  _test-output-stream/imm32
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  get-num/disp32
    # registers except esp may be clobbered at this point
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # check-ints-equal(*_test-output-stream->data, '3456', msg)
    # . . push args
    68/push  "F - test-get-num-reads-multiple-digits-followed-by-nondigit"/imm32
    68/push  0x36353433/imm32
    b8/copy-to-eax  _test-output-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           0xc/disp8       .                 # push *(eax+12)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # . reclaim locals
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    5d/pop-to-ebp
    c3/return

## helpers

# write(f, "Error: "+s+" expected\n") then stop(ed, 1)
expected:  # ed: (addr exit-descriptor), f: fd or (addr stream byte), s: (addr array byte)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # write(f, "Error: ")
    # . . push args
    68/push  "Error: "/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(f, s)
    # . . 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)
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # write(f, " expected\n")
    # . . push args
    68/push  " expected\n"/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # stop(ed, 1)
    # . . push args
    68/push  1/imm32
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  stop/disp32
    # should never get past this point
$expected:dead-end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# read a byte from 'f', and save it in 'Look'
get-char:  # f: (addr buffered-file)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    # eax = read-byte-buffered(f)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  read-byte-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # save eax to Look
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Look/disp32     .                 # copy eax to *Look
$get-char:end:
    # . restore registers
    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

is-digit?:  # c: int -> eax: boolean
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # eax = false
    b8/copy-to-eax  0/imm32
    # if (c < '0') return false
    81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         0x30/imm32        # compare *(ebp+8)
    7c/jump-if-<  $is-digit?:end/disp8
    # if (c > '9') return false
    81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         0x39/imm32        # compare *(ebp+8)
    7f/jump-if->  $is-digit?:end/disp8
    # otherwise return true
    b8/copy-to-eax  1/imm32
$is-digit?:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

== data

Look:  # (char with some extra padding)
    0/imm32

# . . vim:nowrap:textwidth=0