summary refs log tree commit diff stats
path: root/doc
Commit message (Collapse)AuthorAgeFilesLines
* Fixed suggested cd-after-exit-script for zshhut2010-04-131-1/+1
|
* added doc/print_keys.pyhut2010-04-081-0/+14
|
* corrected documentationhut2010-04-061-1/+1
|
* Improved tabshut2010-04-061-0/+3
|
* updated keybindings and documentationhut2010-04-061-1/+21
|
* ranger.1: updatehut2010-04-011-4/+7
|
* ranger.1: updatedhut2010-04-011-1/+1
|
* added a man pagehut2010-04-011-0/+187
|
* rebuilt pydochut2010-03-3118-65/+188
|
* removed doc/pick.sh, pointless to have it therehut2010-03-311-25/+0
|
* removed UML stuff, it's uselesshut2010-03-3115-2337/+0
|
* removed the cd-after-exit hackhut2010-03-291-161/+0
| | | | | | | | | Fear not. You still get the same functionality by using a function like: ranger() { $(which ranger) $@ && cd "$(grep \^\' ~/.ranger/bookmarks | cut -b3-)" }
* updated TODO and pydochut2010-03-2120-52/+85
|
* doc/colorschemes: ugh, its no logical but bitwise OR!hut2010-03-171-1/+1
|
* incremented verison number v1.0.4hut2010-03-121-2/+2
|
* standardized formatting of headings in doc/hut2010-03-122-13/+31
|
* added doc/uml.txthut2010-03-121-0/+5
|
* updated pydochut2010-03-1217-161/+33
|
* updated pydochut2010-03-1270-3946/+816
|
* added two new colorschemes using 88 colorshut2010-03-121-0/+23
|
* added documentation on how colorschemes workhut2010-03-121-0/+91
|
* added symlink: doc/help => ranger/helphut2010-02-281-0/+1
|
* incremented version number and updated pydoc html files v1.0.3hut2010-02-1675-1972/+1415
|
* doc/cd-after-exit: updatedhut2010-02-141-21/+15
|
* doc/pick.sh: corrected commit orderhut2010-02-091-1/+1
|
* doc: what breaks cd-after-exit support in zshhut2010-02-091-0/+2
|
* pick.sh: added -m to checkout commadshut2010-02-051-3/+3
|
* pick.sh: added variables for easier customizationhut2010-02-041-7/+8
|
* added doc/pick.shhut2010-02-041-0/+24
|
* updated dochut2010-01-211-4/+20
|
* 1.0.2! v1.0.2hut2010-01-1430-84/+116
|
* updated pydoc documentationhut2010-01-1361-846/+795
|
* todo: added more info on bug #31hut2010-01-091-0/+5
|
* random cleanups and fixeshut2010-01-071-5/+6
|
* new minor version v1.0.1hut2010-01-022-4/+4
|
* updated pydoc documentationhut2010-01-0248-788/+3167
|
* notify: merged into statusbar, allow to view the log in the pagerhut2010-01-013-35/+2
|
* cleanupshut2009-12-311-1/+5
|
* rename filelist(container) to browsercolumn/browserviewhut2009-12-313-38/+76
|
* updated uml projecthut2009-12-305-73/+215
|
* shorten comment in ranger.pyhut2009-12-261-0/+4
|
* moved /uml to /doc/umlhut2009-12-2514-0/+2180
|
* Explained cd-after-exit featurehut2009-12-251-0/+132
|
* moved pydoc pages to doc/pydochut2009-12-2565-0/+0
|
* updated pydoc pageshut2009-12-2565-0/+10505
'>712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750
# 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/bootstrap translate [01]*.subx crenshaw2-1b.subx -o crenshaw2-1b
#   $ echo '1a'  |bootstrap/bootstrap run 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/bootstrap run crenshaw2-1b > z1.subx
#   $ bootstrap/bootstrap translate z1.subx -o z1
#   $ bootstrap/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/bootstrap run 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        # subtract from esp
    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
    # initialize the stream
    # . num->size = 7
    c7          0/subop/copy        1/mod/*+disp8   1/rm32/ecx    .           .             .           .           8/disp8         7/imm32           # copy to *(ecx+8)
    # . clear-stream(num)
    # . . 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 a digit from 'in' into 'num'
    # . get-num(in, num, err, ed)
    # . . 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)
    51/push-ecx/num
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8      .                    # push *(ebp+8)
    # . . call
    e8/call  get-num/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
    # render 'num' into the following template on 'out':
    #   bb/copy-to-ebx  _num_
    #   b8/copy-to-eax  1/imm32/exit
    #   cd/syscall  0x80/imm8
    #
    # . write(out, "bb/copy-to-ebx  ")
    # . . push args
    68/push  "bb/copy-to-ebx  "/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-stream(out, num)
    # . . push args
    51/push-ecx/num
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . call
    e8/call  write-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(out, Newline)
    # . . 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/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . write(out, "b8/copy-to-eax  1/imm32/exit\n")
    # . . push args
    68/push  "b8/copy-to-eax  1/imm32/exit\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
    # . write(out, "cd/syscall  0x80/imm8\n")
    # . . push args
    68/push  "cd/syscall  0x80/imm8\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
$compile: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

# Read a sequence of digits into 'out'. Abort if there are none, or if there is
# no space in 'out'.
# Input comes from the global variable 'Look' (first byte) and the argument
# 'in' (rest). We leave the next byte from 'in' into 'Look' on exit.
get-num:  # in: (addr buffered-file), out: (addr stream byte), err: fd or (addr stream byte), ed: (addr exit-descriptor)
    # pseudocode:
    #   if (!digit?(Look)) expected(ed, err, "integer")
    #   do
    #     if out->write >= out->size
    #       write(err, "Error: too many digits in number\n")
    #       stop(ed, 1)
    #     out->data[out->write] = LSB(Look)
    #     ++out->write
    #     Look = get-char(in)
    #   while digit?(Look)
    # This is complicated because I don't want to hard-code the error strategy in
    # a general helper like write-byte-buffered. Maybe I should just create a
    # local helper.
    #
    # within the loop we'll try to keep things in registers:
    #   in: esi
    #   out: edi
    #   out->write: ecx (cached copy; need to keep in sync)
    #   out->size: edx
    #   temporaries: eax, ebx
    # We can't allocate Look to a register because it gets written implicitly in
    # get-char in each iteration of the loop. (Thereby demonstrating that it's
    # not the right interface for us. But we'll keep it just to follow Crenshaw.)
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # - if (digit?(Look)) expected(ed, err, "integer")
    # . eax = digit?(Look)
    # . . push args
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Look/disp32     .                 # push *Look
    # . . call
    e8/call  digit?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . if (eax == false)
    3d/compare-eax-and  0/imm32/false
    75/jump-if-!=  $get-num:main/disp8
    # . expected(ed, err, "integer")
    # . . push args
    68/push  "integer"/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  expected/disp32  # never returns
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
$get-num:main:
    # - otherwise read a digit
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # read necessary variables to registers
    # esi = in
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           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 (digit?(Look)) loop
    # . eax = digit?(Look)
    # . . push args
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Look/disp32     .                 # push *Look
    # . . call
    e8/call  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

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-<  $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->  $digit?:end/disp8
    # otherwise return true
    b8/copy-to-eax  1/imm32
$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