1 # Port of https://github.com/akkartik/crenshaw/blob/master/tutor2.1.pas
  2 # which corresponds to the section "single digits" in https://compilers.iecc.com/crenshaw/tutor2.txt
  3 # except that we support hex numbers of multiple digits.
  4 #
  5 # To run:
  6 #   $ ./subx translate init.linux 0*.subx apps/crenshaw2-1b.subx -o apps/crenshaw2-1b
  7 #   $ echo '1a'  |./subx run apps/crenshaw2-1b
  8 # Expected output:
  9 #   # syscall(exit, 1a)
 10 #   bb/copy-to-ebx  3/imm32
 11 #   b8/copy-to-eax  1/imm32/exit
 12 #   cd/syscall  0x80/imm8
 13 #
 14 # To run the generated output:
 15 #   $ echo '1a'  |./subx run apps/crenshaw2-1b > z1.subx
 16 #   $ ./subx translate init.linux z1.subx -o z1
 17 #   $ ./subx run z1
 18 #   $ echo $?
 19 #   26  # 0x1a in decimal
 20 #
 21 # Stdin must contain just a single hex digit. Other input will print an error:
 22 #   $ echo 'xyz'  |./subx run apps/crenshaw2-1b
 23 #   Error: integer expected
 24 #
 25 # Names in this file sometimes follow Crenshaw's original rather than my usual
 26 # naming conventions.
 27 
 28 == code
 29 #   instruction                     effective address                                                   register    displacement    immediate
 30 # . op          subop               mod             rm32          base        index         scale       r32
 31 # . 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
 32 
 33 Entry:  # run tests if necessary, call 'compile' if not
 34     # . prologue
 35     89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
 36 
 37     # initialize heap
 38     # . Heap = new-segment(Heap-size)
 39     # . . push args
 40     68/push  Heap/imm32
 41     ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Heap-size/disp32                  # push *Heap-size
 42     # . . call
 43     e8/call  new-segment/disp32
 44     # . . discard args
 45     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
 46 
 47     # - if argc > 1 and argv[1] == "test", then return run_tests()
 48     # if (argc <= 1) goto run-main
 49     81          7/subop/compare     1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0/disp8         1/imm32           # compare *ebp
 50     7e/jump-if-lesser-or-equal  $run-main/disp8
 51     # if (!kernel-string-equal?(argv[1], "test")) goto run-main
 52     # . eax = kernel-string-equal?(argv[1], "test")
 53     # . . push args
 54     68/push  "test"/imm32
 55     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
 56     # . . call
 57     e8/call  kernel-string-equal?/disp32
 58     # . . discard args
 59     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
 60     # . if (eax == false) goto run-main
 61     3d/compare-eax-and  0/imm32/false
 62     74/jump-if-equal  $run-main/disp8
 63     # run-tests()
 64     e8/call  run-tests/disp32
 65     # syscall(exit, *Num-test-failures)
 66     8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/ebx   Num-test-failures/disp32          # copy *Num-test-failures to ebx
 67     eb/jump  $main:end/disp8
 68 $run-main:
 69     # - otherwise read a program from stdin and emit its translation to stdout
 70     # var ed/eax : (ref exit-descriptor)
 71     81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # subtract from esp
 72     89/copy                         3/mod/direct    0/rm32/eax    .           .             .           4/r32/esp   .               .                 # copy esp to eax
 73     # configure ed to really exit()
 74     # . ed->target = 0
 75     c7          0/subop/copy        0/mod/direct    0/rm32/eax    .           .             .           .           .               0/imm32           # copy to *eax
 76     # compile(Stdin, 1/stdout, 2/stderr, ed)
 77     # . . push args
 78     50/push-eax/ed
 79     68/push  2/imm32/stderr
 80     68/push  1/imm32/stdout
 81     68/push  Stdin/imm32
 82     # . . call
 83     e8/call  compile/disp32
 84     # . . discard args
 85     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
 86     # syscall(exit, 0)
 87     bb/copy-to-ebx  0/imm32
 88 $main:end:
 89     b8/copy-to-eax  1/imm32/exit
 90     cd/syscall  0x80/imm8
 91 
 92 # the main entry point
 93 compile:  # in : (address buffered-file), out : fd or (address stream byte), err : fd or (address stream byte), ed : (address exit-descriptor)
 94     # . prologue
 95     55/push-ebp
 96     89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
 97     # . save registers
 98     50/push-eax
 99     51/push-ecx
100     # prime the pump
101     # . Look = get-char(in)
102     # . . push args
103     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8      .                    # push *(ebp+8)
104     # . . call
105     e8/call  get-char/disp32
106     # . . discard args
107     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
108     # var num/ecx : (ref stream byte 7)
109     # Numbers can be 32 bits or 8 hex bytes long. One of them will be in 'Look', so we need space for 7 bytes.
110     # Sizing the stream just right buys us overflow-handling for free inside 'get-num'.
111     # Add 12 bytes for 'read', 'write' and 'length' fields, for a total of 19 bytes, or 0x13 in hex.
112     # The stack pointer is no longer aligned, so dump_stack() can be misleading past this point.
113     81          5/subop/subtract    3/mod/direct    4/rm32/esp    .           .             .           .           .               0x13/imm32        # subtract from esp
114     89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
115     # initialize the stream
116     # . num->length = 7
117     c7          0/subop/copy        1/mod/*+disp8   1/rm32/ecx    .           .             .           .           8/disp8         7/imm32           # copy to *(ecx+8)
118     # . clear-stream(num)
119     # . . push args
120     51/push-ecx
121     # . . call
122     e8/call  clear-stream/disp32
123     # . . discard args
124     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
125     # read a digit from 'in' into 'num'
126     # . get-num(in, num, err, ed)
127     # . . push args
128     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x14/disp8      .                 # push *(ebp+20)
129     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0x10/disp8      .                 # push *(ebp+16)
130     51/push-ecx/num
131     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8      .                    # push *(ebp+8)
132     # . . call
133     e8/call  get-num/disp32
134     # . . discard args
135     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
136     # render 'num' into the following template on 'out':
137     #   bb/copy-to-ebx  _num_
138     #   b8/copy-to-eax  1/imm32/exit
139     #   cd/syscall  0x80/imm8
140     #
141     # . write(out, "bb/copy-to-ebx  ")
142     # . . push args
143     68/push  "bb/copy-to-ebx  "/imm32
144     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .          
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - chessboard.mu</title>
<meta name="Generator" content="Vim/7.4">
<meta name="plugin-version" content="vim7.4_v2">
<meta name="syntax" content="none">
<meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color: #080808; }
* { font-size: 12pt; font-size: 1em; }
.muRecipe { color: #ff8700; }
.muData { color: #ffff00; }
.Special { color: #c00000; }
.muScenario { color: #00af00; }
.Delimiter { color: #800080; }
.Comment { color: #9090ff; }
.Constant { color: #00a0a0; }
.SalientComment { color: #00ffff; }
.CommentedCode { color: #6c6c6c; }
.muControl { color: #c0a020; }
-->
</style>

<script type='text/javascript'>
<!--

-->
</script>
</head>
<body>
<pre id='vimCodeElement'>
<span class="Comment"># Chessboard program: you type in moves in algebraic notation, and it'll</span>
<span class="Comment"># display the position after each move.</span>

<span class="muRecipe">def</span> main [
  open-console  <span class="Comment"># take control of screen, keyboard and mouse</span>

  <span class="Comment"># The chessboard function takes keyboard and screen objects as 'ingredients'.</span>
  <span class="Comment">#</span>
  <span class="Comment"># In mu it is good form (though not required) to explicitly show the</span>
  <span class="Comment"># hardware you rely on.</span>
  <span class="Comment">#</span>
  <span class="Comment"># Here the console and screen are both 0, which usually indicates real</span>
  <span class="Comment"># hardware rather than a fake for testing as you'll see below.</span>
  chessboard <span class="Constant">0/screen</span>, <span class="Constant">0/console</span>

  close-console  <span class="Comment"># clean up screen, keyboard and mouse</span>
]

<span class="SalientComment">## But enough about mu. Here's what it looks like to run the chessboard program.</span>

<span class="muScenario">scenario</span> print-board-and-read-move [
  trace-until <span class="Constant">100/app</span>
  <span class="Comment"># we'll make the screen really wide because the program currently prints out a long line</span>
  assume-screen <span class="Constant">120/width</span>, <span class="Constant">20/height</span>
  <span class="Comment"># initialize keyboard to type in a move</span>
  assume-console [
    type <span class="Constant">[a2-a4</span>
<span class="Constant">]</span>
  ]
  run [
    <span class="Constant">local-scope</span>
    screen:address:screen, console:address:console<span class="Special"> &lt;- </span>chessboard screen:address:screen, console:address:console
    <span class="Comment"># icon for the cursor</span>
    cursor-icon:character<span class="Special"> &lt;- </span>copy <span class="Constant">9251/␣</span>
    screen<span class="Special"> &lt;- </span>print screen, cursor-icon
  ]
  screen-should-contain [
  <span class="Comment">#            1         2         3         4         5         6         7         8         9         10        11</span>
  <span class="Comment">#  012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789</span>
   <span class="Constant"> .Stupid text-mode chessboard. White pieces in uppercase; black pieces in lowercase. No checking for legal moves.         .</span>
   <span class="Constant"> .                                                                                                                        .</span>
   <span class="Constant"> .8 | r n b q k b n r                                                                                                     .</span>
   <span class="Constant"> .7 | p p p p p p p p                                                                                                     .</span>
   <span class="Constant"> .6 |                                                                                                                     .</span>
   <span class="Constant"> .5 |                                                                                                                     .</span>
   <span class="Constant"> .4 | P                                                                                                                   .</span>
   <span class="Constant"> .3 |                                                                                                                     .</span>
   <span class="Constant"> .2 |   P P P P P P P                                                                                                     .</span>
   <span class="Constant"> .1 | R N B Q K B N R                                                                                                     .</span>
   <span class="Constant"> .  +----------------                                                                                                     .</span>
   <span class="Constant"> .    a b c d e f g h                                                                                                     .</span>
   <span class="Constant"> .                                                                                                                        .</span>
   <span class="Constant"> .Type in your move as &lt;from square&gt;-&lt;to square&gt;. For example: 'a2-a4'. Then press &lt;enter&gt;.                               .</span>
   <span class="Constant"> .                                                                                                                        .</span>
   <span class="Constant"> .Hit 'q' to exit.                                                                                                        .</span>
   <span class="Constant"> .                                                                                                                        .</span>
   <span class="Constant"> .move: ␣                                                                                                                 .</span>
   <span class="Constant"> .                                                                                                                        .</span>
   <span class="Constant"> .                                                                                                                        .</span>
  ]
]

<span class="SalientComment">## Here's how 'chessboard' is implemented.</span>

<span class="muRecipe">def</span> chessboard screen:address:screen, console:address:console<span class="muRecipe"> -&gt; </span>screen:address:screen, console:address:console [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  board:address:array:address:array:character<span class="Special"> &lt;- </span>initial-position
  <span class="Comment"># hook up stdin</span>
  stdin-in:address:source:character, stdin-out:address:sink:character<span class="Special"> &lt;- </span>new-channel <span class="Constant">10/capacity</span>
  start-running send-keys-to-channel, console, stdin-out, screen
  <span class="Comment"># buffer lines in stdin</span>
  buffered-stdin-in:address:source:character, buffered-stdin-out:address:sink:character<span class="Special"> &lt;- </span>new-channel <span class="Constant">10/capacity</span>
  start-running buffer-lines, stdin-in, buffered-stdin-out
  <span class="Delimiter">{</span>
    print screen, <span class="Constant">[Stupid text-mode chessboard. White pieces in uppercase; black pieces in lowercase. No checking for legal moves.</span>
<span class="Constant">]</span>
    cursor-to-next-line screen
    print-board screen, board
    cursor-to-next-line screen
    print screen, <span class="Constant">[Type in your move as &lt;from square&gt;-&lt;to square&gt;. For example: 'a2-a4'. Then press &lt;enter&gt;.</span>
<span class="Constant">]</span>
    cursor-to-next-line screen
    print screen <span class="Constant">[Hit 'q' to exit.</span>
<span class="Constant">]</span>
    <span class="Delimiter">{</span>
      cursor-to-next-line screen
      screen<span class="Special"> &lt;- </span>print screen, <span class="Constant">[move: ]</span>
      m:address:move, quit:boolean, error:boolean<span class="Special"> &lt;- </span>read-move buffered-stdin-in, screen
      <span class="muControl">break-if</span> quit, <span class="Constant">+quit:label</span>
      buffered-stdin-in<span class="Special"> &lt;- </span>clear buffered-stdin-in  <span class="Comment"># cleanup after error. todo: test this?</span>
      <span class="muControl">loop-if</span> error
    <span class="Delimiter">}</span>
    board<span class="Special"> &lt;- </span>make-move board, m
    screen<span class="Special"> &lt;- </span>clear-screen screen
    <span class="muControl">loop</span>
  <span class="Delimiter">}</span>
<span class="Constant">  +quit</span>
]

<span class="SalientComment">## a board is an array of files, a file is an array of characters (squares)</span>

<span class="muRecipe">def</span> new-board initial-position:address:array:character<span class="muRecipe"> -&gt; </span>board:address:array:address:array:character [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  <span class="Comment"># assert(length(initial-position) == 64)</span>
  len:number<span class="Special"> &lt;- </span>length *initial-position
  correct-length?:boolean<span class="Special"> &lt;- </span>equal len, <span class="Constant">64</span>
  assert correct-length?, <span class="Constant">[chessboard had incorrect size]</span>
  <span class="Comment"># board is an array of pointers to files; file is an array of characters</span>
  board<span class="Special"> &lt;- </span>new <span class="Delimiter">{</span>(address array character): type<span class="Delimiter">}</span>, <span class="Constant">8</span>
  col:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
  <span class="Delimiter">{</span>
    done?:boolean<span class="Special"> &lt;- </span>equal col, <span class="Constant">8</span>
    <span class="muControl">break-if</span> done?
    file:address:array:character<span class="Special"> &lt;- </span>new-file initial-position, col
    *board<span class="Special"> &lt;- </span>put-index *board, col, file
    col<span class="Special"> &lt;- </span>add col, <span class="Constant">1</span>
    <span class="muControl">loop</span>
  <span class="Delimiter">}</span>
]

<span class="muRecipe">def</span> new-file position:address:array:character, index:number<span class="muRecipe"> -&gt; </span>result:address:array:character [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  index<span class="Special"> &lt;- </span>multiply index, <span class="Constant">8</span>
  result<span class="Special"> &lt;- </span>new <span class="Constant">character:type</span>, <span class="Constant">8</span>
  row:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
  <span class="Delimiter">{</span>
    done?:boolean<span class="Special"> &lt;- </span>equal row, <span class="Constant">8</span>
    <span class="muControl">break-if</span> done?
    square:character<span class="Special"> &lt;- </span>index *position, index
    *result<span class="Special"> &lt;- </span>put-index *result, row, square
    row<span class="Special"> &lt;- </span>add row, <span class="Constant">1</span>
    index<span class="Special"> &lt;- </span>add index, <span class="Constant">1</span>
    <span class="muControl">loop</span>
  <span class="Delimiter">}</span>
]

<span class="muRecipe">def</span> print-board screen:address:screen, board:address:array:address:array:character<span class="muRecipe"> -&gt; </span>screen:address:screen [
  <span class="Constant">local-scope</span>
  <span class="Constant">load-ingredients</span>
  row:number<span class="Special"> &lt;- </span>copy <span class="Constant">7</span>  <span class="Comment"># start printing from the top of the board</span>
  space:character<span class="Special"> &lt;- </span>copy <span class="Constant">32/space</span>
  <span class="Comment"># print each row</span>
  <span class="Delimiter">{</span>
    done?:boolean<span class="Special"> &lt;- </span>lesser-than row, <span class="Constant">0</span>
    <span class="muControl">break-if</span> done?
    <span class="Comment"># print rank number as a legend</span>
    rank:number<span class="Special"> &lt;- </span>add row, <span class="Constant">1</span>
    print-integer screen, rank
    print screen, <span class="Constant">[ | ]</span>
    <span class="Comment"># print each square in the row</span>
    col:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
    <span class="Delimiter">{</span>
      done?:boolean<span class="Special"> &lt;- </span>equal col:number, <span class="Constant">8</span>
      <span class="muControl">break-if</span> done?:boolean
      f:address:array:character<span class="Special"> &lt;- </span>index *board, col
      c:character<span class="Special"> &lt;- </span>index *f, row
      print screen, c
      print screen, space
      col<span class="Special"> &lt;- </span>add col, <span class="Constant">1</span>
      <span class="muControl">loop</span>
    <span class="Delimiter">}</span>
    row<span class="Special"> &lt;- </span>subtract row, <span class="Constant">1</span>
    cursor-to-next-line screen
    <span class="muControl">loop</span>
  <span class="Delimiter">}</span>
  <span class="Comment"># print file letters as legend</span>
  print screen, <span class="Constant">[  +----------------]</span>
  cursor-to-next-line screen
  print screen, <span class="Constant">[    a b c d e f g h]</span>
  cursor-to-next-line screen
]

<span class="muRecipe">def</span> initial-position<span class="muRecipe"> -&gt; </span>board:address:array:address:array:character [
  <span class="Constant">local-scope</span>
  <span class="Comment"># layout in memory (in raster order):</span>
  <span class="Comment">#   R P _ _ _ _ p r</span>
  <span class="Comment">#   N P _ _ _ _ p n</span>
  <span class="Comment">#   B P _ _ _ _ p b</span>
  <span class="Comment">#   Q P _ _ _ _ p q</span>
  <span class="Comment">#   K P _ _ _ _ p k</span>
  <span class="Comment">#   B P _ _ _ _ p B</span>
  <span class="Comment">#   N P _ _ _ _ p n</span>
  <span class="Comment">#   R P _ _ _ _ p r</span>
  initial-position:address:array:character<span class="Special"> &lt;- </span>new-array <span class="Constant">82/R</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">114/r</span>, <span class="Constant">78/N</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">110/n</span>, <span class="Constant">66/B</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">98/b</span>, <span class="Constant">81/Q</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">113/q</span>, <span class="Constant">75/K</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">107/k</span>, <span class="Constant">66/B</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">98/b</span>, <span class="Constant">78/N</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">110/n</span>, <span class="Constant">82/R</span>, <span class="Constant">80/P</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">32/blank</span>, <span class="Constant">112/p</span>, <span class="Constant">114/r</span>
<span class="CommentedCode">#?       82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 114/r,</span>
<span class="CommentedCode">#?       78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n,</span>
<span class="CommentedCode">#?       66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b, </span>
<span class="CommentedCode">#?       81/Q, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 113/q,</span>
<span class="CommentedCode">#?       75/K, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 107/k,</span>
<span class="CommentedCode">#?       66/B, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 98/b,</span>
<span class="CommentedCode">#?       78/N, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p, 110/n,</span>
<span class="CommentedCode">#?       82/R, 80/P, 32/blank, 32/blank, 32/blank, 32/blank, 112/p