ifhub/inform7
1
0
Fork 0
mirror of https://github.com/ganelson/inform.git synced 2024-07-05 16:44:21 +03:00
Code Issues Projects Releases Wiki Activity
inform7/docs/final-module/2-cg.html
Graham Nelson 40a6d193c3 First attempts at hybrid C-Inform programming
2021-09-09 23:06:55 +01:00

330 lines
65 KiB
HTML
Raw Blame History

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Code Generation</title>
<link href="../docs-assets/Breadcrumbs.css" rel="stylesheet" rev="stylesheet" type="text/css">
<meta name="viewport" content="width=device-width initial-scale=1">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta http-equiv="Content-Language" content="en-gb">
<link href="../docs-assets/Contents.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Progress.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Navigation.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Fonts.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Base.css" rel="stylesheet" rev="stylesheet" type="text/css">
<script>
function togglePopup(material_id) {
var popup = document.getElementById(material_id);
popup.classList.toggle("show");
}
</script>
<link href="../docs-assets/Popups.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Colours.css" rel="stylesheet" rev="stylesheet" type="text/css">
</head>
<body class="commentary-font">
<nav role="navigation">
<h1><a href="../index.html">
<img src="../docs-assets/Inform.png" height=72">
</a></h1>
<ul><li><a href="../compiler.html">compiler tools</a></li>
<li><a href="../other.html">other tools</a></li>
<li><a href="../extensions.html">extensions and kits</a></li>
<li><a href="../units.html">unit test tools</a></li>
</ul><h2>Compiler Webs</h2><ul>
<li><a href="../inbuild/index.html">inbuild</a></li>
<li><a href="../inform7/index.html">inform7</a></li>
<li><a href="../inter/index.html">inter</a></li>
</ul><h2>Inbuild Modules</h2><ul>
<li><a href="../supervisor-module/index.html">supervisor</a></li>
</ul><h2>Inform7 Modules</h2><ul>
<li><a href="../core-module/index.html">core</a></li>
<li><a href="../assertions-module/index.html">assertions</a></li>
<li><a href="../values-module/index.html">values</a></li>
<li><a href="../knowledge-module/index.html">knowledge</a></li>
<li><a href="../imperative-module/index.html">imperative</a></li>
<li><a href="../runtime-module/index.html">runtime</a></li>
<li><a href="../if-module/index.html">if</a></li>
<li><a href="../multimedia-module/index.html">multimedia</a></li>
<li><a href="../index-module/index.html">index</a></li>
</ul><h2>Inter Modules</h2><ul>
<li><a href="../bytecode-module/index.html">bytecode</a></li>
<li><a href="../building-module/index.html">building</a></li>
<li><a href="../pipeline-module/index.html">pipeline</a></li>
<li><a href="index.html"><span class="selectedlink">final</span></a></li>
</ul><h2>Services</h2><ul>
<li><a href="../arch-module/index.html">arch</a></li>
<li><a href="../calculus-module/index.html">calculus</a></li>
<li><a href="../html-module/index.html">html</a></li>
<li><a href="../inflections-module/index.html">inflections</a></li>
<li><a href="../kinds-module/index.html">kinds</a></li>
<li><a href="../linguistics-module/index.html">linguistics</a></li>
<li><a href="../problems-module/index.html">problems</a></li>
<li><a href="../syntax-module/index.html">syntax</a></li>
<li><a href="../words-module/index.html">words</a></li>
<li><a href="../../../inweb/docs/foundation-module/index.html">foundation</a></li>
</ul>
</nav>
<main role="main">
<!--Weave of 'Code Generation' generated by Inweb-->
<div class="breadcrumbs">
<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../compiler.html">Inter Modules</a></li><li><a href="index.html">final</a></li><li><a href="index.html#2">Chapter 2: Mechanism</a></li><li><b>Code Generation</b></li></ul></div>
<p class="purpose">To generate final code from intermediate code.</p>
<ul class="toc"><li><a href="2-cg.html#SP1">&#167;1. Pipeline stage</a></li><li><a href="2-cg.html#SP2">&#167;2. Generations</a></li><li><a href="2-cg.html#SP8">&#167;8. </a></li><li><a href="2-cg.html#SP10">&#167;10. Marking</a></li></ul><hr class="tocbar">
<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>&#167;1. Pipeline stage. </b></p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::create_pipeline_stage</span><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">CodeGen::Stage::new</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="string-syntax">"generate"</span><span class="plain-syntax">, </span><a href="2-cg.html#SP1" class="function-link"><span class="function-syntax">CodeGen::run_pipeline_stage</span></a><span class="plain-syntax">, </span><span class="identifier-syntax">TEXT_OUT_STAGE_ARG</span><span class="plain-syntax">, </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::run_pipeline_stage</span><span class="plain-syntax">(</span><span class="identifier-syntax">pipeline_step</span><span class="plain-syntax"> *</span><span class="identifier-syntax">step</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">target_argument</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"no target specified"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">which</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Str::len</span><span class="plain-syntax">(</span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">package_argument</span><span class="plain-syntax">) &gt; </span><span class="constant-syntax">0</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">which</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Inter::Packages::by_url</span><span class="plain-syntax">(</span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">repository</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">package_argument</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">which</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"Arg %S\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">package_argument</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"no such package name"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax"> =</span>
<span class="plain-syntax"> </span><a href="2-cg.html#SP2" class="function-link"><span class="function-syntax">CodeGen::new_generation</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">step</span><span class="plain-syntax">, </span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">repository</span><span class="plain-syntax">, </span><span class="identifier-syntax">which</span><span class="plain-syntax">, </span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">target_argument</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="2-ft.html#SP3" class="function-link"><span class="function-syntax">CodeGen::Targets::begin_generation</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">) == </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><a href="2-cg.html#SP8" class="function-link"><span class="function-syntax">CodeGen::generate</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-ft.html#SP3" class="function-link"><span class="function-syntax">CodeGen::Targets::end_generation</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-cg.html#SP4" class="function-link"><span class="function-syntax">CodeGen::write</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">step</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">text_out_file</span><span class="plain-syntax">, </span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>&#167;2. Generations. </b>A "generation" is a single act of translating inter code into final code.
That final code will be a text file written in some other programming
language, though probably a low-level one.
</p>
<p class="commentary">The "target" of a generation is the final language: for example, Inform 6.
</p>
<p class="commentary">During a generation, textual output is assembled as a set of "segments".
Different targets may need different segments. This is all to facilitate
rearranging content as necessary to get it to compile in the target language:
for example, one might need to have all constants defined first, then all
arrays, and one could do this by creating two segments, one to accumulate
the constants in, one to accumulate the arrays.
</p>
<p class="commentary">At any given time, a generation has a "current" segment, to which output
is being written. Ome segment is special: the temporary one, which is used
only when assembling other material, and not for the final output.
</p>
<pre class="definitions code-font"><span class="definition-keyword">enum</span> <span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax"> </span><span class="identifier-syntax">from</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">MAX_CG_SEGMENTS</span><span class="plain-syntax"> </span><span class="constant-syntax">100</span>
</pre>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="identifier-syntax">pipeline_step</span><span class="plain-syntax"> *</span><span class="identifier-syntax">from_step</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="identifier-syntax">inter_tree</span><span class="plain-syntax"> *</span><span class="identifier-syntax">from</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="reserved-syntax">code_generation_target</span><span class="plain-syntax"> *</span><span class="identifier-syntax">target</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="identifier-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">just_this_package</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="identifier-syntax">segments</span><span class="plain-syntax">[</span><span class="constant-syntax">MAX_CG_SEGMENTS</span><span class="plain-syntax">];</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="identifier-syntax">linked_list</span><span class="plain-syntax"> *</span><span class="identifier-syntax">segment_sequence</span><span class="plain-syntax">; </span><span class="comment-syntax"> of </span><span class="extract"><span class="extract-syntax">generated_segment</span></span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="identifier-syntax">current_segment</span><span class="plain-syntax">; </span><span class="comment-syntax"> an entry in that array, or null</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">temporarily_diverted</span><span class="plain-syntax">; </span><span class="comment-syntax"> to the temporary segment</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">target_specific_data</span><span class="plain-syntax">; </span><span class="comment-syntax"> depending on the target generated to</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">CLASS_DEFINITION</span>
<span class="plain-syntax">} </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax">;</span>
<span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="function-syntax">CodeGen::new_generation</span><button class="popup" onclick="togglePopup('usagePopup1')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup1">Usage of <span class="code-font"><span class="function-syntax">CodeGen::new_generation</span></span>:<br/><a href="2-cg.html#SP1">&#167;1</a><br/>Frame Control - <a href="2-fc.html#SP2">&#167;2</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">pipeline_step</span><span class="plain-syntax"> *</span><span class="identifier-syntax">step</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree</span><span class="plain-syntax"> *</span><span class="identifier-syntax">I</span><span class="plain-syntax">,</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">just</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation_target</span><span class="plain-syntax"> *</span><span class="identifier-syntax">target</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax"> = </span><span class="identifier-syntax">CREATE</span><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from_step</span><span class="plain-syntax"> = </span><span class="identifier-syntax">step</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax"> = </span><span class="identifier-syntax">I</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">target</span><span class="plain-syntax"> = </span><span class="identifier-syntax">target</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">just</span><span class="plain-syntax">) </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">just_this_package</span><span class="plain-syntax"> = </span><span class="identifier-syntax">just</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">just_this_package</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Site::main_package</span><span class="plain-syntax">(</span><span class="identifier-syntax">I</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">current_segment</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segment_sequence</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NEW_LINKED_LIST</span><span class="plain-syntax">(</span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">i</span><span class="plain-syntax">&lt;</span><span class="constant-syntax">MAX_CG_SEGMENTS</span><span class="plain-syntax">; </span><span class="identifier-syntax">i</span><span class="plain-syntax">++) </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">] = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<ul class="endnotetexts"><li>The structure code_generation is accessed in 2/fc, 2/cal, 2/iap, 2/vrb, 2/ft, 3/fti, 3/fbi, 3/fi, 4/fi6, 5/fnc, 5/cnm, 5/cmm, 5/cpc, 5/ccn, 5/com, 5/clt and here.</li></ul>
<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>&#167;3. </b>At present, at least, a "segment" is nothing more than a wrapper for a text.
But we abstract it in case it's ever useful for it to be more.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">generated_code</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">CLASS_DEFINITION</span>
<span class="plain-syntax">} </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax">;</span>
<span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="function-syntax">CodeGen::new_segment</span><button class="popup" onclick="togglePopup('usagePopup2')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup2">Usage of <span class="code-font"><span class="function-syntax">CodeGen::new_segment</span></span>:<br/><a href="2-cg.html#SP6">&#167;6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="identifier-syntax">seg</span><span class="plain-syntax"> = </span><span class="identifier-syntax">CREATE</span><span class="plain-syntax">(</span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">seg</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">generated_code</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Str::new</span><span class="plain-syntax">();</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">seg</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::create_segments</span><button class="popup" onclick="togglePopup('usagePopup3')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup3">Usage of <span class="code-font"><span class="function-syntax">CodeGen::create_segments</span></span>:<br/>Generating Inform 6 - <a href="4-fi6.html#SP3">&#167;3</a><br/>Final C - <a href="5-fnc.html#SP5">&#167;5</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">data</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">codes</span><span class="plain-syntax">[]) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segment_sequence</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NEW_LINKED_LIST</span><span class="plain-syntax">(</span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">codes</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">] &gt;= </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">i</span><span class="plain-syntax">++) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">codes</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">] &gt;= </span><span class="constant-syntax">MAX_CG_SEGMENTS</span><span class="plain-syntax">) ||</span>
<span class="plain-syntax"> (</span><span class="identifier-syntax">codes</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">] == </span><span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax">)) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"bad segment sequence"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="identifier-syntax">codes</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">]] = </span><a href="2-cg.html#SP3" class="function-link"><span class="function-syntax">CodeGen::new_segment</span></a><span class="plain-syntax">();</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">ADD_TO_LINKED_LIST</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="identifier-syntax">codes</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">]], </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax">, </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segment_sequence</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">target_specific_data</span><span class="plain-syntax"> = </span><span class="identifier-syntax">data</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<ul class="endnotetexts"><li>The structure generated_segment is private to this section.</li></ul>
<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>&#167;4. </b>And then all we do is concatenate them in order:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::write</span><button class="popup" onclick="togglePopup('usagePopup4')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup4">Usage of <span class="code-font"><span class="function-syntax">CodeGen::write</span></span>:<br/><a href="2-cg.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">OUTPUT_STREAM</span><span class="plain-syntax">, </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="identifier-syntax">seg</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER_LINKED_LIST</span><span class="plain-syntax">(</span><span class="identifier-syntax">seg</span><span class="plain-syntax">, </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax">, </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segment_sequence</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"%S"</span><span class="plain-syntax">, </span><span class="identifier-syntax">seg</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">generated_code</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP5" class="paragraph-anchor"></a><b>&#167;5. </b>Here we switch the output, by changing the segment selection. This must
always be done in a way which is then undone, restoring the previous state:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="function-syntax">CodeGen::select</span><button class="popup" onclick="togglePopup('usagePopup5')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup5">Usage of <span class="code-font"><span class="function-syntax">CodeGen::select</span></span>:<br/>Frame Control - <a href="2-fc.html#SP1">&#167;1</a><br/>Constants and Literals - <a href="2-cal.html#SP2">&#167;2</a><br/>Instances and Properties - <a href="2-iap.html#SP1">&#167;1</a>, <a href="2-iap.html#SP4_5">&#167;4.5</a>, <a href="2-iap.html#SP4_6">&#167;4.6</a>, <a href="2-iap.html#SP5">&#167;5</a>, <a href="2-iap.html#SP6">&#167;6</a><br/>Generating Inform 6 - <a href="4-fi6.html#SP3">&#167;3</a>, <a href="4-fi6.html#SP7">&#167;7</a>, <a href="4-fi6.html#SP8">&#167;8</a>, <a href="4-fi6.html#SP10">&#167;10</a><br/>Final C - <a href="5-fnc.html#SP5">&#167;5</a><br/>C Global Variables - <a href="5-cgv.html#SP1">&#167;1</a>, <a href="5-cgv.html#SP2">&#167;2</a><br/>C Memory Model - <a href="5-cmm.html#SP3">&#167;3</a>, <a href="5-cmm.html#SP4">&#167;4</a>, <a href="5-cmm.html#SP10_2">&#167;10.2</a>, <a href="5-cmm.html#SP11">&#167;11</a>, <a href="5-cmm.html#SP14">&#167;14</a><br/>C Object Model - <a href="5-com.html#SP1_3">&#167;1.3</a>, <a href="5-com.html#SP4">&#167;4</a>, <a href="5-com.html#SP7">&#167;7</a>, <a href="5-com.html#SP8">&#167;8</a>, <a href="5-com.html#SP1_4">&#167;1.4</a>, <a href="5-com.html#SP1_5">&#167;1.5</a>, <a href="5-com.html#SP1_6">&#167;1.6</a>, <a href="5-com.html#SP10">&#167;10</a><br/>C Function Model - <a href="5-cfm.html#SP1">&#167;1</a><br/>C Literals - <a href="5-clt.html#SP1">&#167;1</a>, <a href="5-clt.html#SP2">&#167;2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="identifier-syntax">saved</span><span class="plain-syntax"> = </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">current_segment</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">i</span><span class="plain-syntax"> &lt; </span><span class="constant-syntax">0</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">i</span><span class="plain-syntax"> &gt;= </span><span class="constant-syntax">MAX_CG_SEGMENTS</span><span class="plain-syntax">)) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"out of range"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"poorly timed selection"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">current_segment</span><span class="plain-syntax"> = </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">];</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">saved</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::deselect</span><button class="popup" onclick="togglePopup('usagePopup6')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup6">Usage of <span class="code-font"><span class="function-syntax">CodeGen::deselect</span></span>:<br/>Frame Control - <a href="2-fc.html#SP1">&#167;1</a><br/>Constants and Literals - <a href="2-cal.html#SP2">&#167;2</a><br/>Instances and Properties - <a href="2-iap.html#SP1">&#167;1</a>, <a href="2-iap.html#SP4_5">&#167;4.5</a>, <a href="2-iap.html#SP4_6">&#167;4.6</a>, <a href="2-iap.html#SP5">&#167;5</a>, <a href="2-iap.html#SP6">&#167;6</a><br/>Generating Inform 6 - <a href="4-fi6.html#SP3">&#167;3</a>, <a href="4-fi6.html#SP7">&#167;7</a>, <a href="4-fi6.html#SP8">&#167;8</a>, <a href="4-fi6.html#SP10">&#167;10</a><br/>Final C - <a href="5-fnc.html#SP5">&#167;5</a><br/>C Global Variables - <a href="5-cgv.html#SP1">&#167;1</a>, <a href="5-cgv.html#SP2">&#167;2</a><br/>C Memory Model - <a href="5-cmm.html#SP3">&#167;3</a>, <a href="5-cmm.html#SP4">&#167;4</a>, <a href="5-cmm.html#SP10_2">&#167;10.2</a>, <a href="5-cmm.html#SP11">&#167;11</a>, <a href="5-cmm.html#SP14">&#167;14</a><br/>C Object Model - <a href="5-com.html#SP1_3">&#167;1.3</a>, <a href="5-com.html#SP4">&#167;4</a>, <a href="5-com.html#SP7">&#167;7</a>, <a href="5-com.html#SP8">&#167;8</a>, <a href="5-com.html#SP1_4">&#167;1.4</a>, <a href="5-com.html#SP1_5">&#167;1.5</a>, <a href="5-com.html#SP1_6">&#167;1.6</a>, <a href="5-com.html#SP10">&#167;10</a><br/>C Function Model - <a href="5-cfm.html#SP1">&#167;1</a><br/>C Literals - <a href="5-clt.html#SP1">&#167;1</a>, <a href="5-clt.html#SP2">&#167;2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="reserved-syntax">generated_segment</span><span class="plain-syntax"> *</span><span class="identifier-syntax">saved</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"poorly timed deselection"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">current_segment</span><span class="plain-syntax"> = </span><span class="identifier-syntax">saved</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP6" class="paragraph-anchor"></a><b>&#167;6. </b>The procedure for selecting the temporary segment is different, because
we also have to direct it to a given text.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::select_temporary</span><button class="popup" onclick="togglePopup('usagePopup7')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup7">Usage of <span class="code-font"><span class="function-syntax">CodeGen::select_temporary</span></span>:<br/>Frame Control - <a href="2-fc.html#SP1">&#167;1</a>, <a href="2-fc.html#SP2">&#167;2</a><br/>Constants and Literals - <a href="2-cal.html#SP2">&#167;2</a><br/>Instances and Properties - <a href="2-iap.html#SP5_8_5_1_1">&#167;5.8.5.1.1</a>, <a href="2-iap.html#SP5_11_1">&#167;5.11.1</a>, <a href="2-iap.html#SP8">&#167;8</a><br/>C Global Variables - <a href="5-cgv.html#SP2">&#167;2</a><br/>C Assembly - <a href="5-cas.html#SP3">&#167;3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">T</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax">] == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax">] = </span><a href="2-cg.html#SP3" class="function-link"><span class="function-syntax">CodeGen::new_segment</span></a><span class="plain-syntax">();</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax">]-&gt;</span><span class="element-syntax">generated_code</span><span class="plain-syntax"> = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> }</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"nested temporary cgs"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax"> = </span><span class="identifier-syntax">TRUE</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax">]-&gt;</span><span class="element-syntax">generated_code</span><span class="plain-syntax"> = </span><span class="identifier-syntax">T</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::deselect_temporary</span><button class="popup" onclick="togglePopup('usagePopup8')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup8">Usage of <span class="code-font"><span class="function-syntax">CodeGen::deselect_temporary</span></span>:<br/>Frame Control - <a href="2-fc.html#SP1">&#167;1</a>, <a href="2-fc.html#SP2">&#167;2</a><br/>Constants and Literals - <a href="2-cal.html#SP2">&#167;2</a><br/>Instances and Properties - <a href="2-iap.html#SP5_8_5_1_1">&#167;5.8.5.1.1</a>, <a href="2-iap.html#SP5_11_1">&#167;5.11.1</a>, <a href="2-iap.html#SP8">&#167;8</a><br/>C Global Variables - <a href="5-cgv.html#SP2">&#167;2</a><br/>C Assembly - <a href="5-cas.html#SP3">&#167;3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax"> = </span><span class="identifier-syntax">FALSE</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP7" class="paragraph-anchor"></a><b>&#167;7. </b>Note that temporary selections take precedence over the regular selection.
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="function-syntax">CodeGen::current</span><button class="popup" onclick="togglePopup('usagePopup9')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup9">Usage of <span class="code-font"><span class="function-syntax">CodeGen::current</span></span>:<br/>Frame Control - <a href="2-fc.html#SP2">&#167;2</a>, <a href="2-fc.html#SP3">&#167;3</a><br/>Constants and Literals - <a href="2-cal.html#SP2">&#167;2</a><br/>Instances and Properties - <a href="2-iap.html#SP4_6">&#167;4.6</a>, <a href="2-iap.html#SP5">&#167;5</a>, <a href="2-iap.html#SP6">&#167;6</a>, <a href="2-iap.html#SP8">&#167;8</a><br/>Generating Inform 6 - <a href="4-fi6.html#SP3">&#167;3</a>, <a href="4-fi6.html#SP4">&#167;4</a>, <a href="4-fi6.html#SP5">&#167;5</a>, <a href="4-fi6.html#SP6">&#167;6</a>, <a href="4-fi6.html#SP7">&#167;7</a>, <a href="4-fi6.html#SP8">&#167;8</a>, <a href="4-fi6.html#SP9">&#167;9</a>, <a href="4-fi6.html#SP10">&#167;10</a><br/>Final C - <a href="5-fnc.html#SP5">&#167;5</a><br/>C Namespace - <a href="5-cnm.html#SP3">&#167;3</a><br/>C References - <a href="5-crf.html#SP4">&#167;4</a><br/>C Global Variables - <a href="5-cgv.html#SP1">&#167;1</a>, <a href="5-cgv.html#SP2">&#167;2</a><br/>C Memory Model - <a href="5-cmm.html#SP3">&#167;3</a>, <a href="5-cmm.html#SP4">&#167;4</a>, <a href="5-cmm.html#SP10_2">&#167;10.2</a>, <a href="5-cmm.html#SP11">&#167;11</a>, <a href="5-cmm.html#SP12">&#167;12</a>, <a href="5-cmm.html#SP14">&#167;14</a>, <a href="5-cmm.html#SP15">&#167;15</a><br/>C Assembly - <a href="5-cas.html#SP3">&#167;3</a><br/>C Program Control - <a href="5-cpc.html#SP1">&#167;1</a>, <a href="5-cpc.html#SP2">&#167;2</a><br/>C Arithmetic - <a href="5-car.html#SP1">&#167;1</a><br/>C Conditions - <a href="5-ccn.html#SP1">&#167;1</a>, <a href="5-ccn.html#SP2">&#167;2</a><br/>C Object Model - <a href="5-com.html#SP1_3">&#167;1.3</a>, <a href="5-com.html#SP4">&#167;4</a>, <a href="5-com.html#SP7">&#167;7</a>, <a href="5-com.html#SP8">&#167;8</a>, <a href="5-com.html#SP1_4">&#167;1.4</a>, <a href="5-com.html#SP1_5">&#167;1.5</a>, <a href="5-com.html#SP1_6">&#167;1.6</a>, <a href="5-com.html#SP10">&#167;10</a>, <a href="5-com.html#SP11">&#167;11</a><br/>C Function Model - <a href="5-cfm.html#SP1">&#167;1</a><br/>C Literals - <a href="5-clt.html#SP1">&#167;1</a>, <a href="5-clt.html#SP2">&#167;2</a>, <a href="5-clt.html#SP3">&#167;3</a>, <a href="5-clt.html#SP4">&#167;4</a><br/>C Input-Output Model - <a href="5-cim.html#SP2">&#167;2</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">temporarily_diverted</span><span class="plain-syntax">)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">segments</span><span class="plain-syntax">[</span><span class="constant-syntax">temporary_I7CGS</span><span class="plain-syntax">]-&gt;</span><span class="element-syntax">generated_code</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">current_segment</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">current_segment</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">generated_code</span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP8" class="paragraph-anchor"></a><b>&#167;8. </b>Actual generation happens in three phases:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::generate</span><button class="popup" onclick="togglePopup('usagePopup10')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup10">Usage of <span class="code-font"><span class="function-syntax">CodeGen::generate</span></span>:<br/><a href="2-cg.html#SP1">&#167;1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="2-cg.html#SP8_1" class="named-paragraph-link"><span class="named-paragraph">Phase one - preparation</span><span class="named-paragraph-number">8.1</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="2-cg.html#SP8_2" class="named-paragraph-link"><span class="named-paragraph">Phase two - traverse</span><span class="named-paragraph-number">8.2</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="2-cg.html#SP8_3" class="named-paragraph-link"><span class="named-paragraph">Phase three - consolidation</span><span class="named-paragraph-number">8.3</span></a></span><span class="plain-syntax">;</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP8_1" class="paragraph-anchor"></a><b>&#167;8.1. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Phase one - preparation</span><span class="named-paragraph-number">8.1</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">InterTree::traverse</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">, </span><a href="2-cg.html#SP10" class="function-link"><span class="function-syntax">CodeGen::clear_transients</span></a><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, </span><span class="identifier-syntax">PACKAGE_IST</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-fc.html#SP1" class="function-link"><span class="function-syntax">CodeGen::FC::prepare</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-cal.html#SP1" class="function-link"><span class="function-syntax">CodeGen::CL::prepare</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-vrb.html#SP1" class="function-link"><span class="function-syntax">CodeGen::Var::prepare</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-iap.html#SP1" class="function-link"><span class="function-syntax">CodeGen::IP::prepare</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="2-cg.html#SP8">&#167;8</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP8_2" class="paragraph-anchor"></a><b>&#167;8.2. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Phase two - traverse</span><span class="named-paragraph-number">8.2</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><span class="identifier-syntax">InterTree::traverse_root_only</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">, </span><a href="2-cg.html#SP9" class="function-link"><span class="function-syntax">CodeGen::pragma</span></a><span class="plain-syntax">, </span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">PRAGMA_IST</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">InterTree::traverse</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">, </span><a href="2-fc.html#SP1" class="function-link"><span class="function-syntax">CodeGen::FC::pre_iterate</span></a><span class="plain-syntax">, </span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, -</span><span class="identifier-syntax">PACKAGE_IST</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">InterTree::traverse</span><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">-&gt;</span><span class="element-syntax">from</span><span class="plain-syntax">, </span><a href="2-fc.html#SP1" class="function-link"><span class="function-syntax">CodeGen::FC::iterate</span></a><span class="plain-syntax">, </span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, -</span><span class="identifier-syntax">PACKAGE_IST</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="2-cg.html#SP8">&#167;8</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP8_3" class="paragraph-anchor"></a><b>&#167;8.3. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Phase three - consolidation</span><span class="named-paragraph-number">8.3</span></span><span class="comment-syntax"> =</span>
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="plain-syntax"> </span><a href="2-iap.html#SP1" class="function-link"><span class="function-syntax">CodeGen::IP::write_properties</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-cal.html#SP2" class="function-link"><span class="function-syntax">CodeGen::CL::sort_literals</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">);</span>
</pre>
<ul class="endnotetexts"><li>This code is used in <a href="2-cg.html#SP8">&#167;8</a>.</li></ul>
<p class="commentary firstcommentary"><a id="SP9" class="paragraph-anchor"></a><b>&#167;9. </b></p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::pragma</span><button class="popup" onclick="togglePopup('usagePopup11')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup11">Usage of <span class="code-font"><span class="function-syntax">CodeGen::pragma</span></span>:<br/><a href="2-cg.html#SP8_2">&#167;8.2</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_tree</span><span class="plain-syntax"> *</span><span class="identifier-syntax">I</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">state</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *</span><span class="identifier-syntax">gen</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">code_generation</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">state</span><span class="plain-syntax">;</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">target_symbol</span><span class="plain-syntax"> = </span><span class="identifier-syntax">InterSymbolsTables::symbol_from_frame_data</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="identifier-syntax">TARGET_PRAGMA_IFLD</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">target_symbol</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"bad pragma"</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_ti</span><span class="plain-syntax"> </span><span class="identifier-syntax">ID</span><span class="plain-syntax"> = </span><span class="identifier-syntax">P</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">W</span><span class="plain-syntax">.</span><span class="identifier-syntax">data</span><span class="plain-syntax">[</span><span class="identifier-syntax">TEXT_PRAGMA_IFLD</span><span class="plain-syntax">];</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">S</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Inode::ID_to_text</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="identifier-syntax">ID</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><a href="2-ft.html#SP13" class="function-link"><span class="function-syntax">CodeGen::Targets::offer_pragma</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">gen</span><span class="plain-syntax">, </span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="identifier-syntax">target_symbol</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">symbol_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">S</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP10" class="paragraph-anchor"></a><b>&#167;10. Marking. </b>We use a transient flag on symbols, but abstract that here:
</p>
<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::marked</span><button class="popup" onclick="togglePopup('usagePopup12')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup12">Usage of <span class="code-font"><span class="function-syntax">CodeGen::marked</span></span>:<br/>Instances and Properties - <a href="2-iap.html#SP5_8_4">&#167;5.8.4</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">symb_name</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">Inter::Symbols::get_flag</span><span class="plain-syntax">(</span><span class="identifier-syntax">symb_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">TRAVERSE_MARK_BIT</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::mark</span><button class="popup" onclick="togglePopup('usagePopup13')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup13">Usage of <span class="code-font"><span class="function-syntax">CodeGen::mark</span></span>:<br/>Instances and Properties - <a href="2-iap.html#SP5_8_4">&#167;5.8.4</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">symb_name</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Inter::Symbols::set_flag</span><span class="plain-syntax">(</span><span class="identifier-syntax">symb_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">TRAVERSE_MARK_BIT</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::unmark</span><button class="popup" onclick="togglePopup('usagePopup14')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup14">Usage of <span class="code-font"><span class="function-syntax">CodeGen::unmark</span></span>:<br/>Instances and Properties - <a href="2-iap.html#SP5_8">&#167;5.8</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_symbol</span><span class="plain-syntax"> *</span><span class="identifier-syntax">symb_name</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Inter::Symbols::clear_flag</span><span class="plain-syntax">(</span><span class="identifier-syntax">symb_name</span><span class="plain-syntax">, </span><span class="identifier-syntax">TRAVERSE_MARK_BIT</span><span class="plain-syntax">);</span>
<span class="plain-syntax">}</span>
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">CodeGen::clear_transients</span><button class="popup" onclick="togglePopup('usagePopup15')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup15">Usage of <span class="code-font"><span class="function-syntax">CodeGen::clear_transients</span></span>:<br/><a href="2-cg.html#SP8_1">&#167;8.1</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">inter_tree</span><span class="plain-syntax"> *</span><span class="identifier-syntax">I</span><span class="plain-syntax">, </span><span class="identifier-syntax">inter_tree_node</span><span class="plain-syntax"> *</span><span class="identifier-syntax">P</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">state</span><span class="plain-syntax">) {</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_package</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pack</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Inter::Package::defined_by_frame</span><span class="plain-syntax">(</span><span class="identifier-syntax">P</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">inter_symbols_table</span><span class="plain-syntax"> *</span><span class="identifier-syntax">T</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Inter::Packages::scope</span><span class="plain-syntax">(</span><span class="identifier-syntax">pack</span><span class="plain-syntax">);</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">i</span><span class="function-syntax">&lt;T-&gt;</span><span class="identifier-syntax">size</span><span class="plain-syntax">; </span><span class="identifier-syntax">i</span><span class="plain-syntax">++)</span>
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">T</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">symbol_array</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">])</span>
<span class="plain-syntax"> </span><span class="identifier-syntax">Inter::Symbols::clear_transient_flags</span><span class="plain-syntax">(</span><span class="identifier-syntax">T</span><span class="plain-syntax">-&gt;</span><span class="identifier-syntax">symbol_array</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">]);</span>
<span class="plain-syntax">}</span>
</pre>
<nav role="progress"><div class="progresscontainer">
<ul class="progressbar"><li class="progressprev"><a href="1-fm.html">&#10094;</a></li><li class="progresschapter"><a href="1-fm.html">1</a></li><li class="progresscurrentchapter">2</li><li class="progresscurrent">cg</li><li class="progresssection"><a href="2-fc.html">fc</a></li><li class="progresssection"><a href="2-cal.html">cal</a></li><li class="progresssection"><a href="2-iap.html">iap</a></li><li class="progresssection"><a href="2-vrb.html">vrb</a></li><li class="progresssection"><a href="2-ft.html">ft</a></li><li class="progresschapter"><a href="3-fti.html">3</a></li><li class="progresschapter"><a href="4-fi6.html">4</a></li><li class="progresschapter"><a href="5-fnc.html">5</a></li><li class="progressnext"><a href="2-fc.html">&#10095;</a></li></ul></div>
</nav><!--End of weave-->
</main>
</body>
</html>
Reference in a new issue View git blame Copy permalink