4521

author: Kartik Agaram <vc@akkartik.com> 2018-08-13 21:25:22 -0700
committer: Kartik Agaram <vc@akkartik.com> 2018-08-13 21:25:22 -0700
commit: 7328af20a1921d9258a60803ee5367da97a6082e (patch)
tree: e809d6cff85f290073a71982a5d24255848678ac /html/subx/028translate.cc.html
parent: 5cec03b41425940ff5fa73c10ea8fb402a3b5ffa (diff)
download: mu-7328af20a1921d9258a60803ee5367da97a6082e.tar.gz
1 files changed, 223 insertions, 0 deletions
diff --git a/html/subx/028translate.cc.html b/html/subx/028translate.cc.html
new file mode 100644
index 00000000..0838b51a
--- /dev/null
+++ b/html/subx/028translate.cc.html
@@ -0,0 +1,223 @@
+<!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 - subx/028translate.cc</title>
+<meta name="Generator" content="Vim/7.4">
+<meta name="plugin-version" content="vim7.4_v2">
+<meta name="syntax" content="cpp">
+<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
+<meta name="colorscheme" content="minimal">
+<style type="text/css">
+<!--
+pre { white-space: pre-wrap; font-family: monospace; color: #aaaaaa; background-color: #080808; }
+body { font-size: 12pt; font-family: monospace; color: #aaaaaa; background-color: #080808; }
+a { color:#eeeeee; text-decoration: none; }
+a:hover { text-decoration: underline; }
+* { font-size: 12pt; font-size: 1em; }
+.Constant { color: #00a0a0; }
+.SalientComment { color: #00ffff; }
+.Comment { color: #9090ff; }
+.Comment a { color:#0000ee; text-decoration:underline; }
+.Delimiter { color: #800080; }
+.LineNr { color: #444444; }
+.Identifier { color: #c0a020; }
+.Normal { color: #aaaaaa; background-color: #080808; padding-bottom: 1px; }
+.cSpecial { color: #008000; }
+-->
+</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;
+  }
+  lineElem = document.getElementById(lineNum);
+  /* 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();'>
+<pre id='vimCodeElement'>
+<span id="L1" class="LineNr">  1 </span><span class="Comment">//: The bedrock level 1 of abstraction is now done, and we're going to start</span>
+<span id="L2" class="LineNr">  2 </span><span class="Comment">//: building levels above it that make programming in x86 machine code a</span>
+<span id="L3" class="LineNr">  3 </span><span class="Comment">//: little more ergonomic.</span>
+<span id="L4" class="LineNr">  4 </span><span class="Comment">//:</span>
+<span id="L5" class="LineNr">  5 </span><span class="Comment">//: All levels will be &quot;pass through by default&quot;. Whatever they don't</span>
+<span id="L6" class="LineNr">  6 </span><span class="Comment">//: understand they will silently pass through to lower levels.</span>
+<span id="L7" class="LineNr">  7 </span><span class="Comment">//:</span>
+<span id="L8" class="LineNr">  8 </span><span class="Comment">//: Since raw hex bytes of machine code are always possible to inject, SubX is</span>
+<span id="L9" class="LineNr">  9 </span><span class="Comment">//: not a language, and we aren't building a compiler. This is something</span>
+<span id="L10" class="LineNr"> 10 </span><span class="Comment">//: deliberately leakier. Levels are more for improving auditing, checks and</span>
+<span id="L11" class="LineNr"> 11 </span><span class="Comment">//: error messages rather than for hiding low-level details.</span>
+<span id="L12" class="LineNr"> 12 </span>
+<span id="L13" class="LineNr"> 13 </span><span class="Comment">//: Translator workflow: read 'source' file. Run a series of transforms on it,</span>
+<span id="L14" class="LineNr"> 14 </span><span class="Comment">//: each passing through what it doesn't understand. The final program should</span>
+<span id="L15" class="LineNr"> 15 </span><span class="Comment">//: be just machine code, suitable to write to an ELF binary.</span>
+<span id="L16" class="LineNr"> 16 </span><span class="Comment">//:</span>
+<span id="L17" class="LineNr"> 17 </span><span class="Comment">//: Higher levels usually transform code on the basis of metadata.</span>
+<span id="L18" class="LineNr"> 18 </span>
+<span id="L19" class="LineNr"> 19 </span><span class="Delimiter">:(before &quot;End Main&quot;)</span>
+<span id="L20" class="LineNr"> 20 </span><span class="Normal">if</span> <span class="Delimiter">(</span><a href='001help.cc.html#L89'>is_equal</a><span class="Delimiter">(</span>argv[<span class="Constant">1</span>]<span class="Delimiter">,</span> <span class="Constant">&quot;translate&quot;</span><span class="Delimiter">))</span> <span class="Delimiter">{</span>
+<span id="L21" class="LineNr"> 21 </span>  <a href='003trace.cc.html#L245'>START_TRACING_UNTIL_END_OF_SCOPE</a><span class="Delimiter">;</span>
+<span id="L22" class="LineNr"> 22 </span>  assert<span class="Delimiter">(</span>argc &gt; <span class="Constant">3</span><span class="Delimiter">);</span>
+<span id="L23" class="LineNr"> 23 </span>  <a href='011run.cc.html#L96'>program</a> p<span class="Delimiter">;</span>
+<span id="L24" class="LineNr"> 24 </span>  ifstream fin<span class="Delimiter">(</span>argv[<span class="Constant">2</span>]<span class="Delimiter">);</span>
+<span id="L25" class="LineNr"> 25 </span>  <span class="Normal">if</span> <span class="Delimiter">(</span>!fin<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L26" class="LineNr"> 26 </span>    cerr &lt;&lt; <span class="Constant">&quot;could not open &quot;</span> &lt;&lt; argv[<span class="Constant">2</span>] &lt;&lt; <span class="cSpecial">'\n'</span><span class="Delimiter">;</span>
+<span id="L27" class="LineNr"> 27 </span>    <span class="Identifier">return</span> <span class="Constant">1</span><span class="Delimiter">;</span>
+<span id="L28" class="LineNr"> 28 </span>  <span class="Delimiter">}</span>
+<span id="L29" class="LineNr"> 29 </span>  <a href='011run.cc.html#L125'>parse</a><span class="Delimiter">(</span>fin<span class="Delimiter">,</span> p<span class="Delimiter">);</span>
+<span id="L30" class="LineNr"> 30 </span>  <span class="Normal">if</span> <span class="Delimiter">(</span><a href='003trace.cc.html#L217'>trace_contains_errors</a><span class="Delimiter">())</span> <span class="Identifier">return</span> <span class="Constant">1</span><span class="Delimiter">;</span>
+<span id="L31" class="LineNr"> 31 </span>  <a href='011run.cc.html#L186'>transform</a><span class="Delimiter">(</span>p<span class="Delimiter">);</span>
+<span id="L32" class="LineNr"> 32 </span>  <span class="Normal">if</span> <span class="Delimiter">(</span><a href='003trace.cc.html#L217'>trace_contains_errors</a><span class="Delimiter">())</span> <span class="Identifier">return</span> <span class="Constant">1</span><span class="Delimiter">;</span>
+<span id="L33" class="LineNr"> 33 </span>  <a href='028translate.cc.html#L40'>save_elf</a><span class="Delimiter">(</span>p<span class="Delimiter">,</span> argv[<span class="Constant">3</span>]<span class="Delimiter">);</span>
+<span id="L34" class="LineNr"> 34 </span>  <span class="Normal">if</span> <span class="Delimiter">(</span><a href='003trace.cc.html#L217'>trace_contains_errors</a><span class="Delimiter">())</span> unlink<span class="Delimiter">(</span>argv[<span class="Constant">3</span>]<span class="Delimiter">);</span>
+<span id="L35" class="LineNr"> 35 </span>  <span class="Identifier">return</span> <span class="Constant">0</span><span class="Delimiter">;</span>
+<span id="L36" class="LineNr"> 36 </span><span class="Delimiter">}</span>
+<span id="L37" class="LineNr"> 37 </span>
+<span id="L38" class="LineNr"> 38 </span><span class="Delimiter">:(code)</span>
+<span id="L39" class="LineNr"> 39 </span><span class="Comment">// write out a program to a bare-bones ELF file</span>
+<span id="L40" class="LineNr"> 40 </span><span class="Normal">void</span> <a href='028translate.cc.html#L40'>save_elf</a><span class="Delimiter">(</span><span class="Normal">const</span> program&amp; p<span class="Delimiter">,</span> <span class="Normal">const</span> <span class="Normal">char</span>* filename<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L41" class="LineNr"> 41 </span>  ofstream out<span class="Delimiter">(</span>filename<span class="Delimiter">,</span> ios::binary<span class="Delimiter">);</span>
+<span id="L42" class="LineNr"> 42 </span>  <a href='028translate.cc.html#L48'>write_elf_header</a><span class="Delimiter">(</span>out<span class="Delimiter">,</span> p<span class="Delimiter">);</span>
+<span id="L43" class="LineNr"> 43 </span>  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">size_t</span> i = <span class="Constant">0</span><span class="Delimiter">;</span>  i &lt; p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>size<span class="Delimiter">();</span>  ++i<span class="Delimiter">)</span>
+<span id="L44" class="LineNr"> 44 </span>    <a href='028translate.cc.html#L141'>write_segment</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">),</span> out<span class="Delimiter">);</span>
+<span id="L45" class="LineNr"> 45 </span>  out<span class="Delimiter">.</span>close<span class="Delimiter">();</span>
+<span id="L46" class="LineNr"> 46 </span><span class="Delimiter">}</span>
+<span id="L47" class="LineNr"> 47 </span>
+<span id="L48" class="LineNr"> 48 </span><span class="Normal">void</span> <a href='028translate.cc.html#L48'>write_elf_header</a><span class="Delimiter">(</span>ostream&amp; out<span class="Delimiter">,</span> <span class="Normal">const</span> program&amp; p<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L49" class="LineNr"> 49 </span>  <span class="Normal">char</span> c = <span class="cSpecial">'\0'</span><span class="Delimiter">;</span>
+<span id="L50" class="LineNr"> 50 </span><span class="Comment">#define O(X)  c = (X); out.write(&amp;c, sizeof(c))</span>
+<span id="L51" class="LineNr"> 51 </span><span class="Comment">// host is required to be little-endian</span>
+<span id="L52" class="LineNr"> 52 </span><span class="Comment">#define emit(X)  out.write(reinterpret_cast&lt;const char*&gt;(&amp;X), sizeof(X))</span>
+<span id="L53" class="LineNr"> 53 </span>  <span class="SalientComment">//// ehdr</span>
+<span id="L54" class="LineNr"> 54 </span>  <span class="Comment">// e_ident</span>
+<span id="L55" class="LineNr"> 55 </span>  O<span class="Delimiter">(</span><span class="Constant">0x7f</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Comment">/*</span><span class="Comment">E</span><span class="Comment">*/</span><span class="Constant">0x45</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Comment">/*</span><span class="Comment">L</span><span class="Comment">*/</span><span class="Constant">0x4c</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Comment">/*</span><span class="Comment">F</span><span class="Comment">*/</span><span class="Constant">0x46</span><span class="Delimiter">);</span>
+<span id="L56" class="LineNr"> 56 </span>    O<span class="Delimiter">(</span><span class="Constant">0x1</span><span class="Delimiter">);</span>  <span class="Comment">// 32-bit format</span>
+<span id="L57" class="LineNr"> 57 </span>    O<span class="Delimiter">(</span><span class="Constant">0x1</span><span class="Delimiter">);</span>  <span class="Comment">// little-endian</span>
+<span id="L58" class="LineNr"> 58 </span>    O<span class="Delimiter">(</span><span class="Constant">0x1</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Constant">0x0</span><span class="Delimiter">);</span>
+<span id="L59" class="LineNr"> 59 </span>  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">size_t</span> i = <span class="Constant">0</span><span class="Delimiter">;</span>  i &lt; <span class="Constant">8</span><span class="Delimiter">;</span>  ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span> O<span class="Delimiter">(</span><span class="Constant">0x0</span><span class="Delimiter">);</span> <span class="Delimiter">}</span>
+<span id="L60" class="LineNr"> 60 </span>  <span class="Comment">// e_type</span>
+<span id="L61" class="LineNr"> 61 </span>  O<span class="Delimiter">(</span><span class="Constant">0x02</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Constant">0x00</span><span class="Delimiter">);</span>
+<span id="L62" class="LineNr"> 62 </span>  <span class="Comment">// e_machine</span>
+<span id="L63" class="LineNr"> 63 </span>  O<span class="Delimiter">(</span><span class="Constant">0x03</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Constant">0x00</span><span class="Delimiter">);</span>
+<span id="L64" class="LineNr"> 64 </span>  <span class="Comment">// e_version</span>
+<span id="L65" class="LineNr"> 65 </span>  O<span class="Delimiter">(</span><span class="Constant">0x01</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Constant">0x00</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Constant">0x00</span><span class="Delimiter">);</span> O<span class="Delimiter">(</span><span class="Constant">0x00</span><span class="Delimiter">);</span>
+<span id="L66" class="LineNr"> 66 </span>  <span class="Comment">// e_entry</span>
+<span id="L67" class="LineNr"> 67 </span>  <span class="Normal">int</span> e_entry = p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span><a href='011run.cc.html#L105'>start</a><span class="Delimiter">;</span>  <span class="Comment">// convention</span>
+<span id="L68" class="LineNr"> 68 </span>  emit<span class="Delimiter">(</span>e_entry<span class="Delimiter">);</span>
+<span id="L69" class="LineNr"> 69 </span>  <span class="Comment">// e_phoff -- immediately after ELF header</span>
+<span id="L70" class="LineNr"> 70 </span>  <span class="Normal">int</span> e_phoff = <span class="Constant">0x34</span><span class="Delimiter">;</span>
+<span id="L71" class="LineNr"> 71 </span>  emit<span class="Delimiter">(</span>e_phoff<span class="Delimiter">);</span>
+<span id="L72" class="LineNr"> 72 </span>  <span class="Comment">// e_shoff; unused</span>
+<span id="L73" class="LineNr"> 73 </span>  <span class="Normal">int</span> dummy32 = <span class="Constant">0</span><span class="Delimiter">;</span>
+<span id="L74" class="LineNr"> 74 </span>  emit<span class="Delimiter">(</span>dummy32<span class="Delimiter">);</span>
+<span id="L75" class="LineNr"> 75 </span>  <span class="Comment">// e_flags; unused</span>
+<span id="L76" class="LineNr"> 76 </span>  emit<span class="Delimiter">(</span>dummy32<span class="Delimiter">);</span>
+<span id="L77" class="LineNr"> 77 </span>  <span class="Comment">// e_ehsize</span>
+<span id="L78" class="LineNr"> 78 </span>  <span class="Normal">uint16_t</span> e_ehsize = <span class="Constant">0x34</span><span class="Delimiter">;</span>
+<span id="L79" class="LineNr"> 79 </span>  emit<span class="Delimiter">(</span>e_ehsize<span class="Delimiter">);</span>
+<span id="L80" class="LineNr"> 80 </span>  <span class="Comment">// e_phentsize</span>
+<span id="L81" class="LineNr"> 81 </span>  <span class="Normal">uint16_t</span> e_phentsize = <span class="Constant">0x20</span><span class="Delimiter">;</span>
+<span id="L82" class="LineNr"> 82 </span>  emit<span class="Delimiter">(</span>e_phentsize<span class="Delimiter">);</span>
+<span id="L83" class="LineNr"> 83 </span>  <span class="Comment">// e_phnum</span>
+<span id="L84" class="LineNr"> 84 </span>  <span class="Normal">uint16_t</span> e_phnum = <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">);</span>
+<span id="L85" class="LineNr"> 85 </span>  emit<span class="Delimiter">(</span>e_phnum<span class="Delimiter">);</span>
+<span id="L86" class="LineNr"> 86 </span>  <span class="Comment">// e_shentsize</span>
+<span id="L87" class="LineNr"> 87 </span>  <span class="Normal">uint16_t</span> dummy16 = <span class="Constant">0x0</span><span class="Delimiter">;</span>
+<span id="L88" class="LineNr"> 88 </span>  emit<span class="Delimiter">(</span>dummy16<span class="Delimiter">);</span>
+<span id="L89" class="LineNr"> 89 </span>  <span class="Comment">// e_shnum</span>
+<span id="L90" class="LineNr"> 90 </span>  emit<span class="Delimiter">(</span>dummy16<span class="Delimiter">);</span>
+<span id="L91" class="LineNr"> 91 </span>  <span class="Comment">// e_shstrndx</span>
+<span id="L92" class="LineNr"> 92 </span>  emit<span class="Delimiter">(</span>dummy16<span class="Delimiter">);</span>
+<span id="L93" class="LineNr"> 93 </span>
+<span id="L94" class="LineNr"> 94 </span>  <span class="Normal">uint32_t</span> p_offset = <span class="Comment">/*</span><span class="Comment">size of ehdr</span><span class="Comment">*/</span><span class="Constant">0x34</span> + <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">)</span>*<span class="Constant">0x20</span><span class="Comment">/*</span><span class="Comment">size of each phdr</span><span class="Comment">*/</span><span class="Delimiter">;</span>
+<span id="L95" class="LineNr"> 95 </span>  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span>  i &lt; <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">);</span>  ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L96" class="LineNr"> 96 </span>    <span class="SalientComment">//// phdr</span>
+<span id="L97" class="LineNr"> 97 </span>    <span class="Comment">// p_type</span>
+<span id="L98" class="LineNr"> 98 </span>    <span class="Normal">uint32_t</span> p_type = <span class="Constant">0x1</span><span class="Delimiter">;</span>
+<span id="L99" class="LineNr"> 99 </span>    emit<span class="Delimiter">(</span>p_type<span class="Delimiter">);</span>
+<span id="L100" class="LineNr">100 </span>    <span class="Comment">// p_offset</span>
+<span id="L101" class="LineNr">101 </span>    emit<span class="Delimiter">(</span>p_offset<span class="Delimiter">);</span>
+<span id="L102" class="LineNr">102 </span>    <span class="Comment">// p_vaddr</span>
+<span id="L103" class="LineNr">103 </span>    emit<span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L105'>start</a><span class="Delimiter">);</span>
+<span id="L104" class="LineNr">104 </span>    <span class="Comment">// p_paddr</span>
+<span id="L105" class="LineNr">105 </span>    emit<span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L105'>start</a><span class="Delimiter">);</span>
+<span id="L106" class="LineNr">106 </span>    <span class="Comment">// p_filesz</span>
+<span id="L107" class="LineNr">107 </span>    <span class="Normal">uint32_t</span> size = <a href='028translate.cc.html#L151'>size_of</a><span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">));</span>
+<span id="L108" class="LineNr">108 </span>    assert<span class="Delimiter">(</span>size &lt; <a href='012elf.cc.html#L105'>SEGMENT_SIZE</a><span class="Delimiter">);</span>
+<span id="L109" class="LineNr">109 </span>    emit<span class="Delimiter">(</span>size<span class="Delimiter">);</span>
+<span id="L110" class="LineNr">110 </span>    <span class="Comment">// p_memsz</span>
+<span id="L111" class="LineNr">111 </span>    emit<span class="Delimiter">(</span>size<span class="Delimiter">);</span>
+<span id="L112" class="LineNr">112 </span>    <span class="Comment">// p_flags</span>
+<span id="L113" class="LineNr">113 </span>    <span class="Normal">uint32_t</span> p_flags = <span class="Delimiter">(</span>i == <span class="Constant">0</span><span class="Delimiter">)</span> ? <span class="Comment">/*</span><span class="Comment">r-x</span><span class="Comment">*/</span><span class="Constant">0x5</span> : <span class="Comment">/*</span><span class="Comment">rw-</span><span class="Comment">*/</span><span class="Constant">0x6</span><span class="Delimiter">;</span>  <span class="Comment">// convention: only first segment is code</span>
+<span id="L114" class="LineNr">114 </span>    emit<span class="Delimiter">(</span>p_flags<span class="Delimiter">);</span>
+<span id="L115" class="LineNr">115 </span>
+<span id="L116" class="LineNr">116 </span>    <span class="Comment">// p_align</span>
+<span id="L117" class="LineNr">117 </span>    <span class="Comment">// &quot;As the system creates or augments a process image, it logically copies</span>
+<span id="L118" class="LineNr">118 </span>    <span class="Comment">// a file's segment to a virtual memory segment.  When—and if— the system</span>
+<span id="L119" class="LineNr">119 </span>    <span class="Comment">// physically reads the file depends on the program's execution behavior,</span>
+<span id="L120" class="LineNr">120 </span>    <span class="Comment">// system load, and so on.  A process does not require a physical page</span>
+<span id="L121" class="LineNr">121 </span>    <span class="Comment">// unless it references the logical page during execution, and processes</span>
+<span id="L122" class="LineNr">122 </span>    <span class="Comment">// commonly leave many pages unreferenced. Therefore delaying physical</span>
+<span id="L123" class="LineNr">123 </span>    <span class="Comment">// reads frequently obviates them, improving system performance. To obtain</span>
+<span id="L124" class="LineNr">124 </span>    <span class="Comment">// this efficiency in practice, executable and shared object files must</span>
+<span id="L125" class="LineNr">125 </span>    <span class="Comment">// have segment images whose file offsets and virtual addresses are</span>
+<span id="L126" class="LineNr">126 </span>    <span class="Comment">// congruent, modulo the page size.&quot; -- <a href="http://refspecs.linuxbase.org/elf/elf.pdf">http://refspecs.linuxbase.org/elf/elf.pdf</a> (page 95)</span>
+<span id="L127" class="LineNr">127 </span>    <span class="Normal">uint32_t</span> p_align = <span class="Constant">0x1000</span><span class="Delimiter">;</span>  <span class="Comment">// default page size on linux</span>
+<span id="L128" class="LineNr">128 </span>    emit<span class="Delimiter">(</span>p_align<span class="Delimiter">);</span>
+<span id="L129" class="LineNr">129 </span>    <span class="Normal">if</span> <span class="Delimiter">(</span>p_offset % p_align != p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L105'>start</a> % p_align<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L130" class="LineNr">130 </span>      <a href='003trace.cc.html#L203'>raise</a> &lt;&lt; <span class="Constant">&quot;segment starting at 0x&quot;</span> &lt;&lt; <a href='010---vm.cc.html#L260'>HEXWORD</a> &lt;&lt; p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L105'>start</a> &lt;&lt; <span class="Constant">&quot; is improperly aligned; alignment for p_offset &quot;</span> &lt;&lt; p_offset &lt;&lt; <span class="Constant">&quot; should be &quot;</span> &lt;&lt; <span class="Delimiter">(</span>p_offset % p_align<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot; but is &quot;</span> &lt;&lt; <span class="Delimiter">(</span>p<span class="Delimiter">.</span><a href='011run.cc.html#L97'>segments</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L105'>start</a> % p_align<span class="Delimiter">)</span> &lt;&lt; <span class="cSpecial">'\n'</span> &lt;&lt; <a href='003trace.cc.html#L222'>end</a><span class="Delimiter">();</span>
+<span id="L131" class="LineNr">131 </span>      <span class="Identifier">return</span><span class="Delimiter">;</span>
+<span id="L132" class="LineNr">132 </span>    <span class="Delimiter">}</span>
+<span id="L133" class="LineNr">133 </span>
+<span id="L134" class="LineNr">134 </span>    <span class="Comment">// prepare for next segment</span>
+<span id="L135" class="LineNr">135 </span>    p_offset += size<span class="Delimiter">;</span>
+<span id="L136" class="LineNr">136 </span>  <span class="Delimiter">}</span>
+<span id="L137" class="LineNr">137 </span><span class="Comment">#undef O</span>
+<span id="L138" class="LineNr">138 </span><span class="Comment">#undef emit</span>
+<span id="L139" class="LineNr">139 </span><span class="Delimiter">}</span>
+<span id="L140" class="LineNr">140 </span>
+<span id="L141" class="LineNr">141 </span><span class="Normal">void</span> <a href='028translate.cc.html#L141'>write_segment</a><span class="Delimiter">(</span><span class="Normal">const</span> segment&amp; s<span class="Delimiter">,</span> ostream&amp; out<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L142" class="LineNr">142 </span>  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span>  i &lt; <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L106'>lines</a><span class="Delimiter">);</span>  ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L143" class="LineNr">143 </span>    <span class="Normal">const</span> vector&lt;word&gt;&amp; w = s<span class="Delimiter">.</span><a href='011run.cc.html#L106'>lines</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L111'>words</a><span class="Delimiter">;</span>
+<span id="L144" class="LineNr">144 </span>    <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> j = <span class="Constant">0</span><span class="Delimiter">;</span>  j &lt; <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>w<span class="Delimiter">);</span>  ++j<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L145" class="LineNr">145 </span>      <span class="Normal">uint8_t</span> x = <a href='011run.cc.html#L222'>hex_byte</a><span class="Delimiter">(</span>w<span class="Delimiter">.</span>at<span class="Delimiter">(</span>j<span class="Delimiter">).</span><a href='011run.cc.html#L118'>data</a><span class="Delimiter">);</span>  <span class="Comment">// we're done with metadata by this point</span>
+<span id="L146" class="LineNr">146 </span>      out<span class="Delimiter">.</span>write<span class="Delimiter">(</span><span class="Normal">reinterpret_cast</span>&lt;<span class="Normal">const</span> <span class="Normal">char</span>*&gt;<span class="Delimiter">(</span>&amp;x<span class="Delimiter">),</span> <span class="Comment">/*</span><span class="Comment">sizeof(byte)</span><span class="Comment">*/</span><span class="Constant">1</span><span class="Delimiter">);</span>
+<span id="L147" class="LineNr">147 </span>    <span class="Delimiter">}</span>
+<span id="L148" class="LineNr">148 </span>  <span class="Delimiter">}</span>
+<span id="L149" class="LineNr">149 </span><span class="Delimiter">}</span>
+<span id="L150" class="LineNr">150 </span>
+<span id="L151" class="LineNr">151 </span><span class="Normal">uint32_t</span> <a href='028translate.cc.html#L151'>size_of</a><span class="Delimiter">(</span><span class="Normal">const</span> segment&amp; s<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+<span id="L152" class="LineNr">152 </span>  <span class="Normal">uint32_t</span> sum = <span class="Constant">0</span><span class="Delimiter">;</span>
+<span id="L153" class="LineNr">153 </span>  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span>  i &lt; <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L106'>lines</a><span class="Delimiter">);</span>  ++i<span class="Delimiter">)</span>
+<span id="L154" class="LineNr">154 </span>    sum += <a href='001help.cc.html#L157'>SIZE</a><span class="Delimiter">(</span>s<span class="Delimiter">.</span><a href='011run.cc.html#L106'>lines</a><span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span><a href='011run.cc.html#L111'>words</a><span class="Delimiter">);</span>
+<span id="L155" class="LineNr">155 </span>  <span class="Identifier">return</span> sum<span class="Delimiter">;</span>
+<span id="L156" class="LineNr">156 </span><span class="Delimiter">}</span>
+<span id="L157" class="LineNr">157 </span>
+<span id="L158" class="LineNr">158 </span><span class="Delimiter">:(before &quot;End Includes&quot;)</span>
+<span id="L159" class="LineNr">159 </span><span class="Normal">using</span> std::ios<span class="Delimiter">;</span>
+</pre>
+</body>
+</html>
+<!-- vim: set foldmethod=manual : -->
author	Kartik Agaram <vc@akkartik.com>	2018-08-13 21:25:22 -0700
committer	Kartik Agaram <vc@akkartik.com>	2018-08-13 21:25:22 -0700
commit	7328af20a1921d9258a60803ee5367da97a6082e (patch)
tree	e809d6cff85f290073a71982a5d24255848678ac /html/subx/028translate.cc.html
parent	5cec03b41425940ff5fa73c10ea8fb402a3b5ffa (diff)
download	mu-7328af20a1921d9258a60803ee5367da97a6082e.tar.gz