5806

1 files changed, 63 insertions, 43 deletions

diff --git a/html/050_write.subx.html b/html/050_write.subx.html
index be9724da..71734034 100644
--- a/html/050_write.subx.html
+++ b/html/050_write.subx.html
@@ -70,50 +70,70 @@ if ('onhashchange' in window) {
 <span id="L11" class="LineNr">11 </span>    b8/copy-to-eax  1/imm32/exit
 <span id="L12" class="LineNr">12 </span>    cd/syscall  0x80/imm8
 <span id="L13" class="LineNr">13 </span>
-<span id="L14" class="LineNr">14 </span><span class="subxMinorFunction">_write</span>:  <span class="subxComment"># fd : int, s : (address array byte)</span>
-<span id="L15" class="LineNr">15 </span>    <span class="subxS1Comment"># . prologue</span>
-<span id="L16" class="LineNr">16 </span>    55/push-ebp
-<span id="L17" class="LineNr">17 </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="L18" class="LineNr">18 </span>    <span class="subxS1Comment"># . save registers</span>
-<span id="L19" class="LineNr">19 </span>    50/push-eax
-<span id="L20" class="LineNr">20 </span>    51/push-ecx
-<span id="L21" class="LineNr">21 </span>    52/push-edx
-<span id="L22" class="LineNr">22 </span>    53/push-ebx
-<span id="L23" class="LineNr">23 </span>    <span class="subxComment"># syscall(write, fd, (data) s+4, (size) *s)</span>
-<span id="L24" class="LineNr">24 </span>    <span class="subxS1Comment"># . fd : ebx</span>
-<span id="L25" class="LineNr">25 </span>    8b/copy                         1/mod/*+disp8   5/rm32/ebp   <span class="Normal"> . </span>         <span class="Normal"> . </span>           <span class="Normal"> . </span>          3/r32/ebx   8/disp8        <span class="Normal"> . </span>                <span class="subxComment"># copy *(ebp+8) to ebx</span>
-<span id="L26" class="LineNr">26 </span>    <span class="subxS1Comment"># . data : ecx = s+4</span>
-<span id="L27" class="LineNr">27 </span>    8b/copy                         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"># copy *(ebp+12) to ecx</span>
-<span id="L28" class="LineNr">28 </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>              4/imm32           <span class="subxComment"># add to ecx</span>
-<span id="L29" class="LineNr">29 </span>    <span class="subxS1Comment"># . size : edx = *s</span>
-<span id="L30" class="LineNr">30 </span>    8b/copy                         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"># copy *(ebp+12) to edx</span>
-<span id="L31" class="LineNr">31 </span>    8b/copy                         0/mod/indirect  2/rm32/edx   <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 edx</span>
-<span id="L32" class="LineNr">32 </span>    <span class="subxS1Comment"># . syscall</span>
-<span id="L33" class="LineNr">33 </span>    b8/copy-to-eax  4/imm32/write
-<span id="L34" class="LineNr">34 </span>    cd/syscall  0x80/imm8
-<span id="L35" class="LineNr">35 </span>    <span class="subxComment"># if (eax &lt; 0) abort</span>
-<span id="L36" class="LineNr">36 </span>    3d/compare-eax-with  0/imm32
-<span id="L37" class="LineNr">37 </span>    0f 8c/jump-if-lesser  $_write:abort/disp32
-<span id="L38" class="LineNr">38 </span><span class="Constant">$_write:end</span>:
-<span id="L39" class="LineNr">39 </span>    <span class="subxS1Comment"># . restore registers</span>
-<span id="L40" class="LineNr">40 </span>    5b/pop-to-ebx
-<span id="L41" class="LineNr">41 </span>    5a/pop-to-edx
-<span id="L42" class="LineNr">42 </span>    59/pop-to-ecx
-<span id="L43" class="LineNr">43 </span>    58/pop-to-eax
-<span id="L44" class="LineNr">44 </span>    <span class="subxS1Comment"># . epilogue</span>
-<span id="L45" class="LineNr">45 </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="L46" class="LineNr">46 </span>    5d/pop-to-ebp
-<span id="L47" class="LineNr">47 </span>    c3/return
-<span id="L48" class="LineNr">48 </span>
-<span id="L49" class="LineNr">49 </span><span class="Constant">$_write:abort</span>:
-<span id="L50" class="LineNr">50 </span>    <span class="subxComment"># can't write a message here for risk of an infinite loop, so we'll use a special exit code instead</span>
-<span id="L51" class="LineNr">51 </span>    <span class="subxS1Comment"># . syscall(exit, 255)</span>
-<span id="L52" class="LineNr">52 </span>    bb/copy-to-ebx  0xff/imm32
-<span id="L53" class="LineNr">53 </span>    b8/copy-to-eax  1/imm32/exit
+<span id="L14" class="LineNr">14 </span><span class="subxComment"># Since this is the first file of SubX code, a note about type comments.</span>
+<span id="L15" class="LineNr">15 </span><span class="subxComment"># Eventually we'll build a slightly higher-level safe language atop SubX.</span>
+<span id="L16" class="LineNr">16 </span><span class="subxComment"># Even though we don't have the safe language yet, we'll start thinking in</span>
+<span id="L17" class="LineNr">17 </span><span class="subxComment"># terms of the higher-level types in comments.</span>
+<span id="L18" class="LineNr">18 </span><span class="subxComment">#</span>
+<span id="L19" class="LineNr">19 </span><span class="subxComment"># Mu will have two kinds of addresses:</span>
+<span id="L20" class="LineNr">20 </span><span class="subxComment">#   - 'ref' which is used to point to a unique element, because machine</span>
+<span id="L21" class="LineNr">21 </span><span class="subxComment">#     code can't store large types in registers.</span>
+<span id="L22" class="LineNr">22 </span><span class="subxComment">#   - 'handle' which can point to a heap allocation, different heap allocations</span>
+<span id="L23" class="LineNr">23 </span><span class="subxComment">#     at different times, or even at times nothing at all.</span>
+<span id="L24" class="LineNr">24 </span><span class="subxComment">#</span>
+<span id="L25" class="LineNr">25 </span><span class="subxComment"># The type 'address' can be obtained from either a ref or handle, but it can</span>
+<span id="L26" class="LineNr">26 </span><span class="subxComment"># only be stored on the stack (say to pass objects by reference).</span>
+<span id="L27" class="LineNr">27 </span><span class="subxComment"># Conversely, a ref can't be copied into another ref, only to an address (which</span>
+<span id="L28" class="LineNr">28 </span><span class="subxComment"># by construction has a shorter lifetime).</span>
+<span id="L29" class="LineNr">29 </span><span class="subxComment">#</span>
+<span id="L30" class="LineNr">30 </span><span class="subxComment"># Beginnings of a lattice of types:</span>
+<span id="L31" class="LineNr">31 </span><span class="subxComment">#   You can convert a ref or handle to an address, but not the other way around.</span>
+<span id="L32" class="LineNr">32 </span><span class="subxComment">#   You can convert addresses to ints, but not the other way around.</span>
+<span id="L33" class="LineNr">33 </span>
+<span id="L34" class="LineNr">34 </span><span class="subxMinorFunction">_write</span>:  <span class="subxComment"># fd : int, s : (address array byte)</span>
+<span id="L35" class="LineNr">35 </span>    <span class="subxS1Comment"># . prologue</span>
+<span id="L36" class="LineNr">36 </span>    55/push-ebp
+<span id="L37" class="LineNr">37 </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="L38" class="LineNr">38 </span>    <span class="subxS1Comment"># . save registers</span>
+<span id="L39" class="LineNr">39 </span>    50/push-eax
+<span id="L40" class="LineNr">40 </span>    51/push-ecx
+<span id="L41" class="LineNr">41 </span>    52/push-edx
+<span id="L42" class="LineNr">42 </span>    53/push-ebx
+<span id="L43" class="LineNr">43 </span>    <span class="subxComment"># syscall(write, fd, (data) s+4, (size) *s)</span>
+<span id="L44" class="LineNr">44 </span>    <span class="subxS1Comment"># . fd : ebx</span>
+<span id="L45" class="LineNr">45 </span>    8b/copy                         1/mod/*+disp8   5/rm32/ebp   <span class="Normal"> . </span>         <span class="Normal"> . </span>           <span class="Normal"> . </span>          3/r32/ebx   8/disp8        <span class="Normal"> . </span>                <span class="subxComment"># copy *(ebp+8) to ebx</span>
+<span id="L46" class="LineNr">46 </span>    <span class="subxS1Comment"># . data : ecx = s+4</span>
+<span id="L47" class="LineNr">47 </span>    8b/copy                         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"># copy *(ebp+12) to ecx</span>
+<span id="L48" class="LineNr">48 </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>              4/imm32           <span class="subxComment"># add to ecx</span>
+<span id="L49" class="LineNr">49 </span>    <span class="subxS1Comment"># . size : edx = *s</span>
+<span id="L50" class="LineNr">50 </span>    8b/copy                         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"># copy *(ebp+12) to edx</span>
+<span id="L51" class="LineNr">51 </span>    8b/copy                         0/mod/indirect  2/rm32/edx   <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 edx</span>
+<span id="L52" class="LineNr">52 </span>    <span class="subxS1Comment"># . syscall</span>
+<span id="L53" class="LineNr">53 </span>    b8/copy-to-eax  4/imm32/write
 <span id="L54" class="LineNr">54 </span>    cd/syscall  0x80/imm8
-<span id="L55" class="LineNr">55 </span>    <span class="subxComment"># never gets here</span>
-<span id="L56" class="LineNr">56 </span>
-<span id="L57" class="LineNr">57 </span><span class="subxS2Comment"># . . vim&#0058;nowrap:textwidth=0</span>
+<span id="L55" class="LineNr">55 </span>    <span class="subxComment"># if (eax &lt; 0) abort</span>
+<span id="L56" class="LineNr">56 </span>    3d/compare-eax-with  0/imm32
+<span id="L57" class="LineNr">57 </span>    0f 8c/jump-if-lesser  $_write:abort/disp32
+<span id="L58" class="LineNr">58 </span><span class="Constant">$_write:end</span>:
+<span id="L59" class="LineNr">59 </span>    <span class="subxS1Comment"># . restore registers</span>
+<span id="L60" class="LineNr">60 </span>    5b/pop-to-ebx
+<span id="L61" class="LineNr">61 </span>    5a/pop-to-edx
+<span id="L62" class="LineNr">62 </span>    59/pop-to-ecx
+<span id="L63" class="LineNr">63 </span>    58/pop-to-eax
+<span id="L64" class="LineNr">64 </span>    <span class="subxS1Comment"># . epilogue</span>
+<span id="L65" class="LineNr">65 </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="L66" class="LineNr">66 </span>    5d/pop-to-ebp
+<span id="L67" class="LineNr">67 </span>    c3/return
+<span id="L68" class="LineNr">68 </span>
+<span id="L69" class="LineNr">69 </span><span class="Constant">$_write:abort</span>:
+<span id="L70" class="LineNr">70 </span>    <span class="subxComment"># can't write a message here for risk of an infinite loop, so we'll use a special exit code instead</span>
+<span id="L71" class="LineNr">71 </span>    <span class="subxS1Comment"># . syscall(exit, 255)</span>
+<span id="L72" class="LineNr">72 </span>    bb/copy-to-ebx  0xff/imm32
+<span id="L73" class="LineNr">73 </span>    b8/copy-to-eax  1/imm32/exit
+<span id="L74" class="LineNr">74 </span>    cd/syscall  0x80/imm8
+<span id="L75" class="LineNr">75 </span>    <span class="subxComment"># never gets here</span>
+<span id="L76" class="LineNr">76 </span>
+<span id="L77" class="LineNr">77 </span><span class="subxS2Comment"># . . vim&#0058;nowrap:textwidth=0</span>
 </pre>
 </body>
 </html>