2018-12-29 23:27:18 +00:00
<!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" >
2019-07-28 01:26:18 +00:00
< title > Mu - 069allocate.subx< / title >
2019-07-14 16:42:36 +00:00
< meta name = "Generator" content = "Vim/8.1" >
< meta name = "plugin-version" content = "vim8.1_v1" >
2018-12-29 23:27:18 +00:00
< meta name = "syntax" content = "none" >
< meta name = "settings" content = "number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy=" >
< meta name = "colorscheme" content = "minimal-light" >
< style type = "text/css" >
<!--
pre { font-family: monospace; color: #000000; background-color: #c6c6c6; }
body { font-size:12pt; font-family: monospace; color: #000000; background-color: #c6c6c6; }
2018-12-30 08:02:42 +00:00
a { color:inherit; }
2018-12-29 23:27:18 +00:00
* { font-size:12pt; font-size: 1em; }
.subxComment { color: #005faf; }
2019-08-25 22:53:24 +00:00
.subxS2Comment { color: #8a8a8a; }
2019-09-20 18:19:30 +00:00
.subxFunction { color: #af5f00; text-decoration: underline; }
2019-07-14 16:42:36 +00:00
.LineNr { }
2019-08-25 22:53:24 +00:00
.subxS1Comment { color: #0000af; }
2019-09-20 18:19:30 +00:00
.SpecialChar { color: #d70000; }
2019-08-25 22:53:24 +00:00
.Normal { color: #000000; background-color: #c6c6c6; padding-bottom: 1px; }
2019-07-25 07:08:23 +00:00
.subxMinorFunction { color: #875f5f; }
2019-08-25 22:53:24 +00:00
.Constant { color: #008787; }
.subxTest { color: #5f8700; }
2018-12-29 23:27:18 +00:00
-->
< / style >
< script type = 'text/javascript' >
<!--
/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
var lineNum;
lineNum = window.location.hash;
lineNum = lineNum.substr(1); /* strip off '#' */
if (lineNum.indexOf('L') == -1) {
lineNum = 'L'+lineNum;
}
2019-07-14 16:42:36 +00:00
var lineElem = document.getElementById(lineNum);
2018-12-29 23:27:18 +00:00
/* Always jump to new location even if the line was hidden inside a fold, or
* we corrected the raw number to a line ID.
*/
if (lineElem) {
lineElem.scrollIntoView(true);
}
return true;
}
if ('onhashchange' in window) {
window.onhashchange = JumpToLine;
}
-->
< / script >
< / head >
< body onload = 'JumpToLine();' >
2019-07-28 01:26:18 +00:00
< a href = 'https://github.com/akkartik/mu/blob/master/069allocate.subx' > https://github.com/akkartik/mu/blob/master/069allocate.subx< / a >
2018-12-29 23:27:18 +00:00
< pre id = 'vimCodeElement' >
< span id = "L1" class = "LineNr" > 1 < / span > < span class = "subxComment" > # Helper to dynamically allocate memory on the heap.< / span >
< span id = "L2" class = "LineNr" > 2 < / span > < span class = "subxComment" > #< / span >
< span id = "L3" class = "LineNr" > 3 < / span > < span class = "subxComment" > # We'd like to be able to write tests for functions that allocate memory,< / span >
< span id = "L4" class = "LineNr" > 4 < / span > < span class = "subxComment" > # making assertions on the precise addresses used. To achieve this we'll pass< / span >
< span id = "L5" class = "LineNr" > 5 < / span > < span class = "subxComment" > # in an *allocation descriptor* to allocate from.< / span >
< span id = "L6" class = "LineNr" > 6 < / span > < span class = "subxComment" > #< / span >
< span id = "L7" class = "LineNr" > 7 < / span > < span class = "subxComment" > # Allocation descriptors are also useful outside of tests. Assembly and machine< / span >
< span id = "L8" class = "LineNr" > 8 < / span > < span class = "subxComment" > # code are of necessity unsafe languages, and one of the most insidious kinds< / span >
< span id = "L9" class = "LineNr" > 9 < / span > < span class = "subxComment" > # of bugs unsafe languages expose us to are dangling pointers to memory that< / span >
< span id = "L10" class = "LineNr" > 10 < / span > < span class = "subxComment" > # has been freed and potentially even reused for something totally different.< / span >
< span id = "L11" class = "LineNr" > 11 < / span > < span class = "subxComment" > # To reduce the odds of such " use after free" errors, SubX programs tend to not< / span >
< span id = "L12" class = "LineNr" > 12 < / span > < span class = "subxComment" > # reclaim and reuse dynamically allocated memory. (Running out of memory is far< / span >
< span id = "L13" class = "LineNr" > 13 < / span > < span class = "subxComment" > # easier to debug.) Long-running programs that want to reuse memory are mostly< / span >
< span id = "L14" class = "LineNr" > 14 < / span > < span class = "subxComment" > # on their own to be careful. However, they do get one bit of help: they can< / span >
< span id = "L15" class = "LineNr" > 15 < / span > < span class = "subxComment" > # carve out chunks of memory and then allocate from them manually using this< / span >
< span id = "L16" class = "LineNr" > 16 < / span > < span class = "subxComment" > # very same 'allocate' helper. They just need a new allocation descriptor for< / span >
< span id = "L17" class = "LineNr" > 17 < / span > < span class = "subxComment" > # their book-keeping.< / span >
< span id = "L18" class = "LineNr" > 18 < / span >
2019-09-20 18:19:30 +00:00
< span id = "L19" class = "LineNr" > 19 < / span > == data
< span id = "L20" class = "LineNr" > 20 < / span >
< span id = "L21" class = "LineNr" > 21 < / span > < span class = "subxComment" > # A default allocation descriptor for programs to use.< / span >
2019-12-09 09:26:58 +00:00
< span id = "L22" class = "LineNr" > 22 < / span > < span class = "SpecialChar" > Heap< / span > : < span class = "subxComment" > # (ref allocation-descriptor)< / span >
2019-09-20 18:19:30 +00:00
< span id = "L23" class = "LineNr" > 23 < / span > < span class = "subxComment" > # curr< / span >
< span id = "L24" class = "LineNr" > 24 < / span > 0/imm32
< span id = "L25" class = "LineNr" > 25 < / span > < span class = "subxComment" > # limit< / span >
< span id = "L26" class = "LineNr" > 26 < / span > 0/imm32
< span id = "L27" class = "LineNr" > 27 < / span >
< span id = "L28" class = "LineNr" > 28 < / span > < span class = "subxComment" > # a reasonable default< / span >
2019-12-09 09:26:58 +00:00
< span id = "L29" class = "LineNr" > 29 < / span > < span class = "SpecialChar" > Heap-size< / span > : < span class = "subxComment" > # (ref int)< / span >
2019-09-20 18:19:30 +00:00
< span id = "L30" class = "LineNr" > 30 < / span > 0x200000/imm32/2MB
2019-11-30 22:17:13 +00:00
< span id = "L31" class = "LineNr" > 31 < / span >
< span id = "L32" class = "LineNr" > 32 < / span > == code
< span id = "L33" class = "LineNr" > 33 < / span > < span class = "subxComment" > # instruction effective address register displacement immediate< / span >
< span id = "L34" class = "LineNr" > 34 < / span > < span class = "subxS1Comment" > # . op subop mod rm32 base index scale r32< / span >
< span id = "L35" class = "LineNr" > 35 < / span > < span class = "subxS1Comment" > # . 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< / span >
< span id = "L36" class = "LineNr" > 36 < / span >
< span id = "L37" class = "LineNr" > 37 < / span > < span class = "subxComment" > # Let's start initializing the default allocation descriptor.< / span >
2019-09-20 18:19:30 +00:00
< span id = "L38" class = "LineNr" > 38 < / span >
2019-11-30 22:17:13 +00:00
< span id = "L39" class = "LineNr" > 39 < / span > < span class = "SpecialChar" > Entry< / span > :
< span id = "L40" class = "LineNr" > 40 < / span > < span class = "subxComment" > # initialize heap< / span >
< span id = "L41" class = "LineNr" > 41 < / span > < span class = "subxS1Comment" > # . Heap = new-segment(Heap-size)< / span >
< span id = "L42" class = "LineNr" > 42 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L43" class = "LineNr" > 43 < / span > 68/push < span class = "SpecialChar" > < a href = '069allocate.subx.html#L22' > Heap< / a > < / span > /imm32
< span id = "L44" class = "LineNr" > 44 < / span > ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "SpecialChar" > < a href = '069allocate.subx.html#L29' > Heap-size< / a > < / span > /disp32 < span class = "subxComment" > # push *Heap-size< / span >
< span id = "L45" class = "LineNr" > 45 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L46" class = "LineNr" > 46 < / span > e8/call < a href = '053new-segment.subx.html#L41' > new-segment< / a > /disp32
< span id = "L47" class = "LineNr" > 47 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L48" class = "LineNr" > 48 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L49" class = "LineNr" > 49 < / span >
< span id = "L50" class = "LineNr" > 50 < / span > e8/call run-tests/disp32 < span class = "subxComment" > # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.< / span >
< span id = "L51" class = "LineNr" > 51 < / span > < span class = "Constant" > $array-equal-main:end< / span > :
< span id = "L52" class = "LineNr" > 52 < / span > < span class = "subxComment" > # syscall(exit, Num-test-failures)< / span >
< span id = "L53" class = "LineNr" > 53 < / span > 8b/copy 0/mod/indirect 5/rm32/.disp32 < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 3/r32/ebx < span class = "SpecialChar" > < a href = '051test.subx.html#L90' > Num-test-failures< / a > < / span > /disp32 < span class = "subxComment" > # copy *Num-test-failures to ebx< / span >
< span id = "L54" class = "LineNr" > 54 < / span > b8/copy-to-eax 1/imm32/exit
< span id = "L55" class = "LineNr" > 55 < / span > cd/syscall 0x80/imm8
< span id = "L56" class = "LineNr" > 56 < / span >
< span id = "L57" class = "LineNr" > 57 < / span > < span class = "subxComment" > # Claim the next 'n' bytes of memory starting at ad-> curr and update ad-> curr.< / span >
< span id = "L58" class = "LineNr" > 58 < / span > < span class = "subxComment" > # Abort if there isn't enough memory in 'ad'.< / span >
2020-01-03 09:36:34 +00:00
< span id = "L59" class = "LineNr" > 59 < / span > < span class = "subxFunction" > allocate< / span > : < span class = "subxComment" > # ad : (addr allocation-descriptor), n : int -> address-or-null/eax : (addr _)< / span >
2019-11-30 22:17:13 +00:00
< span id = "L60" class = "LineNr" > 60 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L61" class = "LineNr" > 61 < / span > 55/push-ebp
< span id = "L62" class = "LineNr" > 62 < / span > 89/copy 3/mod/direct 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 4/r32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy esp to ebp< / span >
< span id = "L63" class = "LineNr" > 63 < / span > < span class = "subxS1Comment" > # . save registers< / span >
< span id = "L64" class = "LineNr" > 64 < / span > 51/push-ecx
< span id = "L65" class = "LineNr" > 65 < / span > 52/push-edx
< span id = "L66" class = "LineNr" > 66 < / span > < span class = "subxComment" > # ecx = ad< / span >
< span id = "L67" class = "LineNr" > 67 < / span > 8b/copy 1/mod/*+disp8 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 1/r32/ecx 8/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # copy *(ebp+8) to ecx< / span >
< span id = "L68" class = "LineNr" > 68 < / span > < span class = "subxComment" > # save ad-> curr< / span >
< span id = "L69" class = "LineNr" > 69 < / span > 8b/copy 0/mod/indirect 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0/r32/eax < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy *ecx to eax< / span >
< span id = "L70" class = "LineNr" > 70 < / span > < span class = "subxComment" > # check if there's enough space< / span >
< span id = "L71" class = "LineNr" > 71 < / span > < span class = "subxS1Comment" > # . edx = ad-> curr + n< / span >
< span id = "L72" class = "LineNr" > 72 < / span > 89/copy 3/mod/direct 2/rm32/edx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0/r32/eax < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy eax to edx< / span >
< span id = "L73" class = "LineNr" > 73 < / span > 03/add 1/mod/*+disp8 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 2/r32/edx 0xc/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # add *(ebp+12) to edx< / span >
< span id = "L74" class = "LineNr" > 74 < / span > 3b/compare 1/mod/*+disp8 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 2/r32/edx 4/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # compare edx with *(ecx+4)< / span >
< span id = "L75" class = "LineNr" > 75 < / span > 73/jump-if-greater-or-equal-signed $allocate:abort/disp8
< span id = "L76" class = "LineNr" > 76 < / span > < span class = "Constant" > $allocate:commit< / span > :
< span id = "L77" class = "LineNr" > 77 < / span > < span class = "subxComment" > # update ad-> curr< / span >
< span id = "L78" class = "LineNr" > 78 < / span > 89/copy 0/mod/indirect 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 2/r32/edx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy edx to *ecx< / span >
< span id = "L79" class = "LineNr" > 79 < / span > < span class = "Constant" > $allocate:end< / span > :
< span id = "L80" class = "LineNr" > 80 < / span > < span class = "subxS1Comment" > # . restore registers< / span >
< span id = "L81" class = "LineNr" > 81 < / span > 5a/pop-to-edx
< span id = "L82" class = "LineNr" > 82 < / span > 59/pop-to-ecx
< span id = "L83" class = "LineNr" > 83 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L84" class = "LineNr" > 84 < / span > 89/copy 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 5/r32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy ebp to esp< / span >
< span id = "L85" class = "LineNr" > 85 < / span > 5d/pop-to-ebp
< span id = "L86" class = "LineNr" > 86 < / span > c3/return
< span id = "L87" class = "LineNr" > 87 < / span >
< span id = "L88" class = "LineNr" > 88 < / span > < span class = "Constant" > $allocate:abort< / span > :
< span id = "L89" class = "LineNr" > 89 < / span > < span class = "subxS1Comment" > # . _write(2/stderr, error)< / span >
< span id = "L90" class = "LineNr" > 90 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L91" class = "LineNr" > 91 < / span > 68/push < span class = "Constant" > " allocate: failed to allocate\n" < / span > /imm32
< span id = "L92" class = "LineNr" > 92 < / span > 68/push 2/imm32/stderr
< span id = "L93" class = "LineNr" > 93 < / span > < span class = "subxS2Comment" > # . . call< / span >
2019-12-28 08:02:29 +00:00
< span id = "L94" class = "LineNr" > 94 < / span > e8/call < a href = '050_write.subx.html#L37' > _write< / a > /disp32
2019-11-30 22:17:13 +00:00
< span id = "L95" class = "LineNr" > 95 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L96" class = "LineNr" > 96 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L97" class = "LineNr" > 97 < / span > < span class = "subxS1Comment" > # . syscall(exit, 1)< / span >
< span id = "L98" class = "LineNr" > 98 < / span > bb/copy-to-ebx 1/imm32
< span id = "L99" class = "LineNr" > 99 < / span > b8/copy-to-eax 1/imm32/exit
< span id = "L100" class = "LineNr" > 100 < / span > cd/syscall 0x80/imm8
< span id = "L101" class = "LineNr" > 101 < / span > < span class = "subxComment" > # never gets here< / span >
< span id = "L102" class = "LineNr" > 102 < / span >
< span id = "L103" class = "LineNr" > 103 < / span > < span class = "subxTest" > test-allocate-success< / span > :
< span id = "L104" class = "LineNr" > 104 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L105" class = "LineNr" > 105 < / span > 55/push-ebp
< span id = "L106" class = "LineNr" > 106 < / span > 89/copy 3/mod/direct 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 4/r32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy esp to ebp< / span >
2019-12-09 09:26:58 +00:00
< span id = "L107" class = "LineNr" > 107 < / span > < span class = "subxComment" > # var ad/ecx : (ref allocation-descriptor) = {11, 15}< / span >
2019-11-30 22:17:13 +00:00
< span id = "L108" class = "LineNr" > 108 < / span > 68/push 0xf/imm32/limit
< span id = "L109" class = "LineNr" > 109 < / span > 68/push 0xb/imm32/curr
< span id = "L110" class = "LineNr" > 110 < / span > 89/copy 3/mod/direct 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 4/r32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy esp to ecx< / span >
2019-12-09 09:26:58 +00:00
< span id = "L111" class = "LineNr" > 111 < / span > < span class = "subxComment" > # var eax : (handle byte) = allocate(ad, 3)< / span >
2019-11-30 22:17:13 +00:00
< span id = "L112" class = "LineNr" > 112 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L113" class = "LineNr" > 113 < / span > 68/push 3/imm32
< span id = "L114" class = "LineNr" > 114 < / span > 51/push-ecx
< span id = "L115" class = "LineNr" > 115 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L116" class = "LineNr" > 116 < / span > e8/call < a href = '069allocate.subx.html#L59' > allocate< / a > /disp32
< span id = "L117" class = "LineNr" > 117 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L118" class = "LineNr" > 118 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L119" class = "LineNr" > 119 < / span > < span class = "subxComment" > # check-ints-equal(eax, 11, msg)< / span >
< span id = "L120" class = "LineNr" > 120 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L121" class = "LineNr" > 121 < / span > 68/push < span class = "Constant" > " F - < a href = '069allocate.subx.html#L103' > test-allocate-success< / a > : returns current pointer of allocation descriptor" < / span > /imm32
< span id = "L122" class = "LineNr" > 122 < / span > 68/push 0xb/imm32
< span id = "L123" class = "LineNr" > 123 < / span > 50/push-eax
< span id = "L124" class = "LineNr" > 124 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L125" class = "LineNr" > 125 < / span > e8/call < a href = '051test.subx.html#L24' > check-ints-equal< / a > /disp32
< span id = "L126" class = "LineNr" > 126 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L127" class = "LineNr" > 127 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0xc/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L128" class = "LineNr" > 128 < / span > < span class = "subxComment" > # check-ints-equal(ad-> curr, 14, msg)< / span >
< span id = "L129" class = "LineNr" > 129 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L130" class = "LineNr" > 130 < / span > 68/push < span class = "Constant" > " F - < a href = '069allocate.subx.html#L103' > test-allocate-success< / a > : updates allocation descriptor" < / span > /imm32
< span id = "L131" class = "LineNr" > 131 < / span > 68/push 0xe/imm32
< span id = "L132" class = "LineNr" > 132 < / span > ff 6/subop/push 0/mod/indirect 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # push *ecx< / span >
< span id = "L133" class = "LineNr" > 133 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L134" class = "LineNr" > 134 < / span > e8/call < a href = '051test.subx.html#L24' > check-ints-equal< / a > /disp32
< span id = "L135" class = "LineNr" > 135 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L136" class = "LineNr" > 136 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0xc/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L137" class = "LineNr" > 137 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L138" class = "LineNr" > 138 < / span > 89/copy 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 5/r32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy ebp to esp< / span >
< span id = "L139" class = "LineNr" > 139 < / span > 5d/pop-to-ebp
< span id = "L140" class = "LineNr" > 140 < / span > c3/return
< span id = "L141" class = "LineNr" > 141 < / span >
< span id = "L142" class = "LineNr" > 142 < / span > < span class = "subxMinorFunction" > _pending-test-allocate-failure< / span > :
< span id = "L143" class = "LineNr" > 143 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L144" class = "LineNr" > 144 < / span > 55/push-ebp
< span id = "L145" class = "LineNr" > 145 < / span > 89/copy 3/mod/direct 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 4/r32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy esp to ebp< / span >
2019-12-09 09:26:58 +00:00
< span id = "L146" class = "LineNr" > 146 < / span > < span class = "subxComment" > # var ad/ecx : (ref allocation-descriptor) = {11, 15}< / span >
2019-11-30 22:17:13 +00:00
< span id = "L147" class = "LineNr" > 147 < / span > 68/push 0xf/imm32/limit
< span id = "L148" class = "LineNr" > 148 < / span > 68/push 0xb/imm32/curr
< span id = "L149" class = "LineNr" > 149 < / span > 89/copy 3/mod/direct 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 4/r32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy esp to ecx< / span >
2019-12-09 09:26:58 +00:00
< span id = "L150" class = "LineNr" > 150 < / span > < span class = "subxComment" > # var eax : (handle byte) = allocate(ad, 6)< / span >
2019-11-30 22:17:13 +00:00
< span id = "L151" class = "LineNr" > 151 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L152" class = "LineNr" > 152 < / span > 68/push 6/imm32
< span id = "L153" class = "LineNr" > 153 < / span > 51/push-ecx
< span id = "L154" class = "LineNr" > 154 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L155" class = "LineNr" > 155 < / span > e8/call < a href = '069allocate.subx.html#L59' > allocate< / a > /disp32
< span id = "L156" class = "LineNr" > 156 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L157" class = "LineNr" > 157 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L158" class = "LineNr" > 158 < / span > < span class = "subxComment" > # check-ints-equal(eax, 0, msg)< / span >
< span id = "L159" class = "LineNr" > 159 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L160" class = "LineNr" > 160 < / span > 68/push < span class = "Constant" > " F - test-allocate-failure: returns null" < / span > /imm32
< span id = "L161" class = "LineNr" > 161 < / span > 68/push 0/imm32
< span id = "L162" class = "LineNr" > 162 < / span > 50/push-eax
< span id = "L163" class = "LineNr" > 163 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L164" class = "LineNr" > 164 < / span > e8/call < a href = '051test.subx.html#L24' > check-ints-equal< / a > /disp32
< span id = "L165" class = "LineNr" > 165 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L166" class = "LineNr" > 166 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0xc/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L167" class = "LineNr" > 167 < / span > < span class = "subxComment" > # no change to ad-> curr< / span >
< span id = "L168" class = "LineNr" > 168 < / span > < span class = "subxS1Comment" > # . check-ints-equal(ad-> curr, 11)< / span >
< span id = "L169" class = "LineNr" > 169 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L170" class = "LineNr" > 170 < / span > 68/push < span class = "Constant" > " F - test-allocate-failure: updates allocation descriptor" < / span > /imm32
< span id = "L171" class = "LineNr" > 171 < / span > 68/push 0xb/imm32
< span id = "L172" class = "LineNr" > 172 < / span > ff 6/subop/push 0/mod/indirect 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # push *ecx< / span >
< span id = "L173" class = "LineNr" > 173 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L174" class = "LineNr" > 174 < / span > e8/call < a href = '051test.subx.html#L24' > check-ints-equal< / a > /disp32
< span id = "L175" class = "LineNr" > 175 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L176" class = "LineNr" > 176 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0xc/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L177" class = "LineNr" > 177 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L178" class = "LineNr" > 178 < / span > 89/copy 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 5/r32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy ebp to esp< / span >
< span id = "L179" class = "LineNr" > 179 < / span > 5d/pop-to-ebp
< span id = "L180" class = "LineNr" > 180 < / span > c3/return
< span id = "L181" class = "LineNr" > 181 < / span >
< span id = "L182" class = "LineNr" > 182 < / span > < span class = "subxComment" > # helper: create a nested allocation descriptor (useful for tests)< / span >
2020-01-03 09:36:34 +00:00
< span id = "L183" class = "LineNr" > 183 < / span > < span class = "subxFunction" > allocate-region< / span > : < span class = "subxComment" > # ad : (addr allocation-descriptor), n : int -> new-ad : (handle allocation-descriptor)< / span >
2019-11-30 22:17:13 +00:00
< span id = "L184" class = "LineNr" > 184 < / span > < span class = "subxS1Comment" > # . prologue< / span >
< span id = "L185" class = "LineNr" > 185 < / span > 55/push-ebp
< span id = "L186" class = "LineNr" > 186 < / span > 89/copy 3/mod/direct 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 4/r32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy esp to ebp< / span >
< span id = "L187" class = "LineNr" > 187 < / span > < span class = "subxS1Comment" > # . save registers< / span >
< span id = "L188" class = "LineNr" > 188 < / span > 51/push-ecx
< span id = "L189" class = "LineNr" > 189 < / span > < span class = "subxComment" > # eax = allocate(ad, n)< / span >
< span id = "L190" class = "LineNr" > 190 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L191" class = "LineNr" > 191 < / span > ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0xc/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # push *(ebp+12)< / span >
< span id = "L192" class = "LineNr" > 192 < / span > ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # push *(ebp+8)< / span >
< span id = "L193" class = "LineNr" > 193 < / span > < span class = "subxS2Comment" > # . . call< / span >
< span id = "L194" class = "LineNr" > 194 < / span > e8/call < a href = '069allocate.subx.html#L59' > allocate< / a > /disp32
< span id = "L195" class = "LineNr" > 195 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L196" class = "LineNr" > 196 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L197" class = "LineNr" > 197 < / span > < span class = "subxComment" > # if (eax == 0) abort< / span >
< span id = "L198" class = "LineNr" > 198 < / span > 3d/compare-eax-and 0/imm32
< span id = "L199" class = "LineNr" > 199 < / span > 74/jump-if-equal $allocate-region:abort/disp8
< span id = "L200" class = "LineNr" > 200 < / span > < span class = "subxComment" > # earmark 8 bytes at the start for a new allocation descriptor< / span >
< span id = "L201" class = "LineNr" > 201 < / span > < span class = "subxS1Comment" > # . *eax = eax + 8< / span >
< span id = "L202" class = "LineNr" > 202 < / span > 89/copy 3/mod/direct 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0/r32/eax < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy eax to ecx< / span >
< span id = "L203" class = "LineNr" > 203 < / span > 81 0/subop/add 3/mod/direct 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to ecx< / span >
< span id = "L204" class = "LineNr" > 204 < / span > 89/copy 0/mod/indirect 0/rm32/eax < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 1/r32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy ecx to *eax< / span >
< span id = "L205" class = "LineNr" > 205 < / span > < span class = "subxS1Comment" > # . *(eax+4) = eax + n< / span >
< span id = "L206" class = "LineNr" > 206 < / span > 89/copy 3/mod/direct 1/rm32/ecx < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 0/r32/eax < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy eax to ecx< / span >
< span id = "L207" class = "LineNr" > 207 < / span > 03/add 1/mod/*+disp8 5/rm32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 1/r32/ecx 0xc/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # add *(ebp+12) to ecx< / span >
< span id = "L208" class = "LineNr" > 208 < / span > 89/copy 1/mod/*+disp8 0/rm32/eax < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 1/r32/ecx 4/disp8 < span class = "Normal" > . < / span > < span class = "subxComment" > # copy ecx to *(eax+4)< / span >
< span id = "L209" class = "LineNr" > 209 < / span > < span class = "subxS1Comment" > # . restore registers< / span >
< span id = "L210" class = "LineNr" > 210 < / span > 59/pop-to-ecx
< span id = "L211" class = "LineNr" > 211 < / span > < span class = "subxS1Comment" > # . epilogue< / span >
< span id = "L212" class = "LineNr" > 212 < / span > 89/copy 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 5/r32/ebp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "subxComment" > # copy ebp to esp< / span >
< span id = "L213" class = "LineNr" > 213 < / span > 5d/pop-to-ebp
< span id = "L214" class = "LineNr" > 214 < / span > c3/return
< span id = "L215" class = "LineNr" > 215 < / span >
< span id = "L216" class = "LineNr" > 216 < / span > < span class = "subxComment" > # We could create a more general '$abort' jump target, but then we'd need to do< / span >
< span id = "L217" class = "LineNr" > 217 < / span > < span class = "subxComment" > # a conditional jump followed by loading the error message and an unconditional< / span >
< span id = "L218" class = "LineNr" > 218 < / span > < span class = "subxComment" > # jump. Or we'd need to unconditionally load the error message before a< / span >
< span id = "L219" class = "LineNr" > 219 < / span > < span class = "subxComment" > # conditional jump, even if it's unused the vast majority of the time. This way< / span >
< span id = "L220" class = "LineNr" > 220 < / span > < span class = "subxComment" > # we bloat a potentially cold segment in RAM so we can abort with a single< / span >
< span id = "L221" class = "LineNr" > 221 < / span > < span class = "subxComment" > # instruction.< / span >
< span id = "L222" class = "LineNr" > 222 < / span > < span class = "Constant" > $allocate-region:abort< / span > :
< span id = "L223" class = "LineNr" > 223 < / span > < span class = "subxS1Comment" > # . _write(2/stderr, error)< / span >
< span id = "L224" class = "LineNr" > 224 < / span > < span class = "subxS2Comment" > # . . push args< / span >
< span id = "L225" class = "LineNr" > 225 < / span > 68/push < span class = "Constant" > " allocate-region: failed to allocate\n" < / span > /imm32
< span id = "L226" class = "LineNr" > 226 < / span > 68/push 2/imm32/stderr
< span id = "L227" class = "LineNr" > 227 < / span > < span class = "subxS2Comment" > # . . call< / span >
2019-12-28 08:02:29 +00:00
< span id = "L228" class = "LineNr" > 228 < / span > e8/call < a href = '050_write.subx.html#L37' > _write< / a > /disp32
2019-11-30 22:17:13 +00:00
< span id = "L229" class = "LineNr" > 229 < / span > < span class = "subxS2Comment" > # . . discard args< / span >
< span id = "L230" class = "LineNr" > 230 < / span > 81 0/subop/add 3/mod/direct 4/rm32/esp < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > < span class = "Normal" > . < / span > 8/imm32 < span class = "subxComment" > # add to esp< / span >
< span id = "L231" class = "LineNr" > 231 < / span > < span class = "subxS1Comment" > # . syscall(exit, 1)< / span >
< span id = "L232" class = "LineNr" > 232 < / span > bb/copy-to-ebx 1/imm32
< span id = "L233" class = "LineNr" > 233 < / span > b8/copy-to-eax 1/imm32/exit
< span id = "L234" class = "LineNr" > 234 < / span > cd/syscall 0x80/imm8
< span id = "L235" class = "LineNr" > 235 < / span > < span class = "subxComment" > # never gets here< / span >
< span id = "L236" class = "LineNr" > 236 < / span >
< span id = "L237" class = "LineNr" > 237 < / span > < span class = "subxS2Comment" > # . . vim: nowrap:textwidth=0< / span >
2018-12-29 23:27:18 +00:00
< / pre >
< / body >
< / html >
<!-- vim: set foldmethod=manual : -->