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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.8.14"/> <meta name="viewport" content="width=device-width, initial-scale=1"/> <title>Ruby: missing/alloca.c Source File</title> <link href="../../tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="../../jquery.js"></script> <script type="text/javascript" src="../../dynsections.js"></script> <link href="../../doxygen.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="top"><!-- do not remove this div, it is closed by doxygen! --> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td id="projectalign" style="padding-left: 0.5em;"> <div id="projectname">Ruby  <span id="projectnumber">2.1.10p492(2016-04-01revision54464)</span> </div> </td> </tr> </tbody> </table> </div> <!-- end header part --> <!-- Generated by Doxygen 1.8.14 --> <script type="text/javascript" src="../../menudata.js"></script> <script type="text/javascript" src="../../menu.js"></script> <script type="text/javascript"> /* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ $(function() { initMenu('../../',false,false,'search.php','Search'); }); /* @license-end */</script> <div id="main-nav"></div> <div id="nav-path" class="navpath"> <ul> <li class="navelem"><a class="el" href="../../dir_f3bfeebb553c3f6ecfb19202628b4493.html">missing</a></li> </ul> </div> </div><!-- top --> <div class="header"> <div class="headertitle"> <div class="title">alloca.c</div> </div> </div><!--header--> <div class="contents"> <a href="../../d7/d55/alloca_8c.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">/* alloca -- (mostly) portable public-domain implementation -- D A Gwyn</span></div><div class="line"><a name="l00002"></a><span class="lineno"> 2</span> <span class="comment"></span></div><div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment"> last edit: 86/05/30 rms</span></div><div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment"> include config.h, since on VMS it renames some symbols.</span></div><div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment"> Use xmalloc instead of malloc.</span></div><div class="line"><a name="l00006"></a><span class="lineno"> 6</span> <span class="comment"></span></div><div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="comment"> This implementation of the PWB library alloca() function,</span></div><div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment"> which is used to allocate space off the run-time stack so</span></div><div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="comment"> that it is automatically reclaimed upon procedure exit,</span></div><div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="comment"> was inspired by discussions with J. Q. Johnson of Cornell.</span></div><div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="comment"></span></div><div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="comment"> It should work under any C implementation that uses an</span></div><div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="comment"> actual procedure stack (as opposed to a linked list of</span></div><div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="comment"> frames). There are some preprocessor constants that can</span></div><div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="comment"> be defined when compiling for your specific system, for</span></div><div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="comment"> improved efficiency; however, the defaults should be okay.</span></div><div class="line"><a name="l00017"></a><span class="lineno"> 17</span> <span class="comment"></span></div><div class="line"><a name="l00018"></a><span class="lineno"> 18</span> <span class="comment"> The general concept of this implementation is to keep</span></div><div class="line"><a name="l00019"></a><span class="lineno"> 19</span> <span class="comment"> track of all alloca()-allocated blocks, and reclaim any</span></div><div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="comment"> that are found to be deeper in the stack than the current</span></div><div class="line"><a name="l00021"></a><span class="lineno"> 21</span> <span class="comment"> invocation. This heuristic does not reclaim storage as</span></div><div class="line"><a name="l00022"></a><span class="lineno"> 22</span> <span class="comment"> soon as it becomes invalid, but it will do so eventually.</span></div><div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="comment"></span></div><div class="line"><a name="l00024"></a><span class="lineno"> 24</span> <span class="comment"> As a special case, alloca(0) reclaims storage without</span></div><div class="line"><a name="l00025"></a><span class="lineno"> 25</span> <span class="comment"> allocating any. It is a good idea to use alloca(0) in</span></div><div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="comment"> your main control loop, etc. to force garbage collection.</span></div><div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="comment">*/</span></div><div class="line"><a name="l00028"></a><span class="lineno"> 28</span> <span class="preprocessor">#ifndef lint</span></div><div class="line"><a name="l00029"></a><span class="lineno"><a class="line" href="../../d7/d55/alloca_8c.html#aadfeb057aee4d307770f7655fd26be05"> 29</a></span> <span class="keyword">static</span> <span class="keywordtype">char</span> <a class="code" href="../../d7/d55/alloca_8c.html#aadfeb057aee4d307770f7655fd26be05">SCCSid</a>[] = <span class="stringliteral">"@(#)alloca.c 1.1"</span>; <span class="comment">/* for the "what" utility */</span></div><div class="line"><a name="l00030"></a><span class="lineno"> 30</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00031"></a><span class="lineno"> 31</span> </div><div class="line"><a name="l00032"></a><span class="lineno"> 32</span> <span class="preprocessor">#include "ruby/config.h"</span></div><div class="line"><a name="l00033"></a><span class="lineno"><a class="line" href="../../d7/d55/alloca_8c.html#a6ef94e467ce5a88943bde2180e939962"> 33</a></span> <span class="preprocessor">#define X3J11 1 </span><span class="comment">/* config.h should contain void if needed */</span><span class="preprocessor"></span></div><div class="line"><a name="l00034"></a><span class="lineno"> 34</span> </div><div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="preprocessor">#ifdef C_ALLOCA</span></div><div class="line"><a name="l00036"></a><span class="lineno"> 36</span> </div><div class="line"><a name="l00037"></a><span class="lineno"> 37</span> <span class="preprocessor">#ifdef emacs</span></div><div class="line"><a name="l00038"></a><span class="lineno"> 38</span> <span class="preprocessor">#ifdef static</span></div><div class="line"><a name="l00039"></a><span class="lineno"> 39</span> <span class="comment">/* actually, only want this if static is defined as ""</span></div><div class="line"><a name="l00040"></a><span class="lineno"> 40</span> <span class="comment"> -- this is for usg, in which emacs must undefine static</span></div><div class="line"><a name="l00041"></a><span class="lineno"> 41</span> <span class="comment"> in order to make unexec workable</span></div><div class="line"><a name="l00042"></a><span class="lineno"> 42</span> <span class="comment"> */</span></div><div class="line"><a name="l00043"></a><span class="lineno"> 43</span> <span class="preprocessor">#ifndef STACK_DIRECTION</span></div><div class="line"><a name="l00044"></a><span class="lineno"> 44</span> you</div><div class="line"><a name="l00045"></a><span class="lineno"> 45</span> lose</div><div class="line"><a name="l00046"></a><span class="lineno"> 46</span> -- must know STACK_DIRECTION at compile-time</div><div class="line"><a name="l00047"></a><span class="lineno"> 47</span> <span class="preprocessor">#endif </span><span class="comment">/* STACK_DIRECTION undefined */</span><span class="preprocessor"></span></div><div class="line"><a name="l00048"></a><span class="lineno"> 48</span> <span class="preprocessor">#endif </span><span class="comment">/* static */</span><span class="preprocessor"></span></div><div class="line"><a name="l00049"></a><span class="lineno"> 49</span> <span class="preprocessor">#endif </span><span class="comment">/* emacs */</span><span class="preprocessor"></span></div><div class="line"><a name="l00050"></a><span class="lineno"> 50</span> </div><div class="line"><a name="l00051"></a><span class="lineno"> 51</span> <span class="preprocessor">#ifdef X3J11</span></div><div class="line"><a name="l00052"></a><span class="lineno"> 52</span> <span class="keyword">typedef</span> <span class="keywordtype">void</span> *pointer; <span class="comment">/* generic pointer type */</span></div><div class="line"><a name="l00053"></a><span class="lineno"> 53</span> <span class="preprocessor">#else</span></div><div class="line"><a name="l00054"></a><span class="lineno"> 54</span> <span class="keyword">typedef</span> <span class="keywordtype">char</span> *pointer; <span class="comment">/* generic pointer type */</span></div><div class="line"><a name="l00055"></a><span class="lineno"> 55</span> <span class="preprocessor">#endif </span><span class="comment">/* X3J11 */</span><span class="preprocessor"></span></div><div class="line"><a name="l00056"></a><span class="lineno"> 56</span> </div><div class="line"><a name="l00057"></a><span class="lineno"> 57</span> <span class="preprocessor">#ifndef NULL</span></div><div class="line"><a name="l00058"></a><span class="lineno"> 58</span> <span class="preprocessor">#define NULL 0 </span><span class="comment">/* null pointer constant */</span><span class="preprocessor"></span></div><div class="line"><a name="l00059"></a><span class="lineno"> 59</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00060"></a><span class="lineno"> 60</span> </div><div class="line"><a name="l00061"></a><span class="lineno"> 61</span> <span class="preprocessor">#define xmalloc ruby_xmalloc</span></div><div class="line"><a name="l00062"></a><span class="lineno"> 62</span> <span class="preprocessor">#define xfree ruby_xfree</span></div><div class="line"><a name="l00063"></a><span class="lineno"> 63</span> </div><div class="line"><a name="l00064"></a><span class="lineno"> 64</span> <span class="keyword">extern</span> <span class="keywordtype">void</span> <a class="code" href="../../d8/db0/defines_8h.html#a6ff69f8866ae756cb246b3eebf7a4fce">xfree</a>();</div><div class="line"><a name="l00065"></a><span class="lineno"> 65</span> <span class="keyword">extern</span> pointer <a class="code" href="../../d8/db0/defines_8h.html#a6af5faec3f9662b20ffc9903f923dec0">xmalloc</a>();</div><div class="line"><a name="l00066"></a><span class="lineno"> 66</span> </div><div class="line"><a name="l00067"></a><span class="lineno"> 67</span> <span class="comment">/*</span></div><div class="line"><a name="l00068"></a><span class="lineno"> 68</span> <span class="comment"> Define STACK_DIRECTION if you know the direction of stack</span></div><div class="line"><a name="l00069"></a><span class="lineno"> 69</span> <span class="comment"> growth for your system; otherwise it will be automatically</span></div><div class="line"><a name="l00070"></a><span class="lineno"> 70</span> <span class="comment"> deduced at run-time.</span></div><div class="line"><a name="l00071"></a><span class="lineno"> 71</span> <span class="comment"></span></div><div class="line"><a name="l00072"></a><span class="lineno"> 72</span> <span class="comment"> STACK_DIRECTION > 0 => grows toward higher addresses</span></div><div class="line"><a name="l00073"></a><span class="lineno"> 73</span> <span class="comment"> STACK_DIRECTION < 0 => grows toward lower addresses</span></div><div class="line"><a name="l00074"></a><span class="lineno"> 74</span> <span class="comment"> STACK_DIRECTION = 0 => direction of growth unknown</span></div><div class="line"><a name="l00075"></a><span class="lineno"> 75</span> <span class="comment">*/</span></div><div class="line"><a name="l00076"></a><span class="lineno"> 76</span> </div><div class="line"><a name="l00077"></a><span class="lineno"> 77</span> <span class="preprocessor">#ifndef STACK_DIRECTION</span></div><div class="line"><a name="l00078"></a><span class="lineno"> 78</span> <span class="preprocessor">#define STACK_DIRECTION 0 </span><span class="comment">/* direction unknown */</span><span class="preprocessor"></span></div><div class="line"><a name="l00079"></a><span class="lineno"> 79</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00080"></a><span class="lineno"> 80</span> </div><div class="line"><a name="l00081"></a><span class="lineno"> 81</span> <span class="preprocessor">#if STACK_DIRECTION != 0</span></div><div class="line"><a name="l00082"></a><span class="lineno"> 82</span> </div><div class="line"><a name="l00083"></a><span class="lineno"> 83</span> <span class="preprocessor">#define STACK_DIR STACK_DIRECTION </span><span class="comment">/* known at compile-time */</span><span class="preprocessor"></span></div><div class="line"><a name="l00084"></a><span class="lineno"> 84</span> </div><div class="line"><a name="l00085"></a><span class="lineno"> 85</span> <span class="preprocessor">#else </span><span class="comment">/* STACK_DIRECTION == 0; need run-time code */</span><span class="preprocessor"></span></div><div class="line"><a name="l00086"></a><span class="lineno"> 86</span> </div><div class="line"><a name="l00087"></a><span class="lineno"> 87</span> <span class="keyword">static</span> <span class="keywordtype">int</span> stack_dir; <span class="comment">/* 1 or -1 once known */</span></div><div class="line"><a name="l00088"></a><span class="lineno"> 88</span> <span class="preprocessor">#define STACK_DIR stack_dir</span></div><div class="line"><a name="l00089"></a><span class="lineno"> 89</span> </div><div class="line"><a name="l00090"></a><span class="lineno"> 90</span> <span class="keyword">static</span> <span class="keywordtype">void</span></div><div class="line"><a name="l00091"></a><span class="lineno"> 91</span> find_stack_direction (<span class="comment">/* void */</span>)</div><div class="line"><a name="l00092"></a><span class="lineno"> 92</span> {</div><div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  <span class="keyword">static</span> <span class="keywordtype">char</span> *addr = <a class="code" href="../../d4/db0/__sdbm_8c.html#a070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>; <span class="comment">/* address of first</span></div><div class="line"><a name="l00094"></a><span class="lineno"> 94</span> <span class="comment"> `dummy', once known */</span></div><div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  <span class="keyword">auto</span> <span class="keywordtype">char</span> dummy; <span class="comment">/* to get stack address */</span></div><div class="line"><a name="l00096"></a><span class="lineno"> 96</span> </div><div class="line"><a name="l00097"></a><span class="lineno"> 97</span>  <span class="keywordflow">if</span> (addr == <a class="code" href="../../d4/db0/__sdbm_8c.html#a070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>)</div><div class="line"><a name="l00098"></a><span class="lineno"> 98</span>  { <span class="comment">/* initial entry */</span></div><div class="line"><a name="l00099"></a><span class="lineno"> 99</span>  addr = &dummy;</div><div class="line"><a name="l00100"></a><span class="lineno"> 100</span> </div><div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  find_stack_direction (); <span class="comment">/* recurse once */</span></div><div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  }</div><div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  <span class="keywordflow">else</span> <span class="comment">/* second entry */</span></div><div class="line"><a name="l00104"></a><span class="lineno"> 104</span>  <span class="keywordflow">if</span> (&dummy > addr)</div><div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  stack_dir = 1; <span class="comment">/* stack grew upward */</span></div><div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  <span class="keywordflow">else</span></div><div class="line"><a name="l00107"></a><span class="lineno"> 107</span>  stack_dir = -1; <span class="comment">/* stack grew downward */</span></div><div class="line"><a name="l00108"></a><span class="lineno"> 108</span> }</div><div class="line"><a name="l00109"></a><span class="lineno"> 109</span> </div><div class="line"><a name="l00110"></a><span class="lineno"> 110</span> <span class="preprocessor">#endif </span><span class="comment">/* STACK_DIRECTION == 0 */</span><span class="preprocessor"></span></div><div class="line"><a name="l00111"></a><span class="lineno"> 111</span> </div><div class="line"><a name="l00112"></a><span class="lineno"> 112</span> <span class="comment">/*</span></div><div class="line"><a name="l00113"></a><span class="lineno"> 113</span> <span class="comment"> An "alloca header" is used to:</span></div><div class="line"><a name="l00114"></a><span class="lineno"> 114</span> <span class="comment"> (a) chain together all alloca()ed blocks;</span></div><div class="line"><a name="l00115"></a><span class="lineno"> 115</span> <span class="comment"> (b) keep track of stack depth.</span></div><div class="line"><a name="l00116"></a><span class="lineno"> 116</span> <span class="comment"></span></div><div class="line"><a name="l00117"></a><span class="lineno"> 117</span> <span class="comment"> It is very important that sizeof(header) agree with malloc()</span></div><div class="line"><a name="l00118"></a><span class="lineno"> 118</span> <span class="comment"> alignment chunk size. The following default should work okay.</span></div><div class="line"><a name="l00119"></a><span class="lineno"> 119</span> <span class="comment">*/</span></div><div class="line"><a name="l00120"></a><span class="lineno"> 120</span> </div><div class="line"><a name="l00121"></a><span class="lineno"> 121</span> <span class="preprocessor">#ifndef ALIGN_SIZE</span></div><div class="line"><a name="l00122"></a><span class="lineno"> 122</span> <span class="preprocessor">#define ALIGN_SIZE sizeof(double)</span></div><div class="line"><a name="l00123"></a><span class="lineno"> 123</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00124"></a><span class="lineno"> 124</span> </div><div class="line"><a name="l00125"></a><span class="lineno"> 125</span> <span class="keyword">typedef</span> <span class="keyword">union </span>hdr</div><div class="line"><a name="l00126"></a><span class="lineno"> 126</span> {</div><div class="line"><a name="l00127"></a><span class="lineno"> 127</span>  <span class="keywordtype">char</span> align[ALIGN_SIZE]; <span class="comment">/* to force sizeof(header) */</span></div><div class="line"><a name="l00128"></a><span class="lineno"> 128</span>  <span class="keyword">struct</span></div><div class="line"><a name="l00129"></a><span class="lineno"> 129</span>  {</div><div class="line"><a name="l00130"></a><span class="lineno"> 130</span>  <span class="keyword">union </span>hdr *next; <span class="comment">/* for chaining headers */</span></div><div class="line"><a name="l00131"></a><span class="lineno"> 131</span>  <span class="keywordtype">char</span> *deep; <span class="comment">/* for stack depth measure */</span></div><div class="line"><a name="l00132"></a><span class="lineno"> 132</span>  } h;</div><div class="line"><a name="l00133"></a><span class="lineno"> 133</span> } header;</div><div class="line"><a name="l00134"></a><span class="lineno"> 134</span> </div><div class="line"><a name="l00135"></a><span class="lineno"> 135</span> <span class="comment">/*</span></div><div class="line"><a name="l00136"></a><span class="lineno"> 136</span> <span class="comment"> alloca( size ) returns a pointer to at least `size' bytes of</span></div><div class="line"><a name="l00137"></a><span class="lineno"> 137</span> <span class="comment"> storage which will be automatically reclaimed upon exit from</span></div><div class="line"><a name="l00138"></a><span class="lineno"> 138</span> <span class="comment"> the procedure that called alloca(). Originally, this space</span></div><div class="line"><a name="l00139"></a><span class="lineno"> 139</span> <span class="comment"> was supposed to be taken from the current stack frame of the</span></div><div class="line"><a name="l00140"></a><span class="lineno"> 140</span> <span class="comment"> caller, but that method cannot be made to work for some</span></div><div class="line"><a name="l00141"></a><span class="lineno"> 141</span> <span class="comment"> implementations of C, for example under Gould's UTX/32.</span></div><div class="line"><a name="l00142"></a><span class="lineno"> 142</span> <span class="comment">*/</span></div><div class="line"><a name="l00143"></a><span class="lineno"> 143</span> </div><div class="line"><a name="l00144"></a><span class="lineno"> 144</span> <span class="keyword">static</span> header *last_alloca_header = <a class="code" href="../../d4/db0/__sdbm_8c.html#a070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>; <span class="comment">/* -> last alloca header */</span></div><div class="line"><a name="l00145"></a><span class="lineno"> 145</span> </div><div class="line"><a name="l00146"></a><span class="lineno"> 146</span> pointer</div><div class="line"><a name="l00147"></a><span class="lineno"> 147</span> <a class="code" href="../../de/de6/ruby_2ruby_8h.html#a871651237a27c4f7bac0c12882b08b93">alloca</a> (<a class="code" href="../../d5/db5/encoding_8c.html#a439227feff9d7f55384e8780cfc2eb82">size</a>) <span class="comment">/* returns pointer to storage */</span></div><div class="line"><a name="l00148"></a><span class="lineno"> 148</span>  <span class="keywordtype">unsigned</span> <a class="code" href="../../d5/db5/encoding_8c.html#a439227feff9d7f55384e8780cfc2eb82">size</a>; <span class="comment">/* # bytes to allocate */</span></div><div class="line"><a name="l00149"></a><span class="lineno"> 149</span> {</div><div class="line"><a name="l00150"></a><span class="lineno"> 150</span>  <span class="keyword">auto</span> <span class="keywordtype">char</span> probe; <span class="comment">/* probes stack depth: */</span></div><div class="line"><a name="l00151"></a><span class="lineno"> 151</span>  <span class="keyword">register</span> <span class="keywordtype">char</span> *depth = &probe;</div><div class="line"><a name="l00152"></a><span class="lineno"> 152</span> </div><div class="line"><a name="l00153"></a><span class="lineno"> 153</span> <span class="preprocessor">#if STACK_DIRECTION == 0</span></div><div class="line"><a name="l00154"></a><span class="lineno"> 154</span>  <span class="keywordflow">if</span> (STACK_DIR == 0) <span class="comment">/* unknown growth direction */</span></div><div class="line"><a name="l00155"></a><span class="lineno"> 155</span>  find_stack_direction ();</div><div class="line"><a name="l00156"></a><span class="lineno"> 156</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00157"></a><span class="lineno"> 157</span> </div><div class="line"><a name="l00158"></a><span class="lineno"> 158</span>  <span class="comment">/* Reclaim garbage, defined as all alloca()ed storage that</span></div><div class="line"><a name="l00159"></a><span class="lineno"> 159</span> <span class="comment"> was allocated from deeper in the stack than currently. */</span></div><div class="line"><a name="l00160"></a><span class="lineno"> 160</span>  {</div><div class="line"><a name="l00161"></a><span class="lineno"> 161</span>  <span class="keyword">register</span> header *hp; <span class="comment">/* traverses linked list */</span></div><div class="line"><a name="l00162"></a><span class="lineno"> 162</span> </div><div class="line"><a name="l00163"></a><span class="lineno"> 163</span>  <span class="keywordflow">for</span> (hp = last_alloca_header; hp != <a class="code" href="../../d4/db0/__sdbm_8c.html#a070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>;)</div><div class="line"><a name="l00164"></a><span class="lineno"> 164</span>  <span class="keywordflow">if</span> (STACK_DIR > 0 && hp->h.deep > depth</div><div class="line"><a name="l00165"></a><span class="lineno"> 165</span>  || STACK_DIR < 0 && hp->h.deep < depth)</div><div class="line"><a name="l00166"></a><span class="lineno"> 166</span>  {</div><div class="line"><a name="l00167"></a><span class="lineno"> 167</span>  <span class="keyword">register</span> header *np = hp->h.next;</div><div class="line"><a name="l00168"></a><span class="lineno"> 168</span> </div><div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  <a class="code" href="../../d8/db0/defines_8h.html#a6ff69f8866ae756cb246b3eebf7a4fce">xfree</a> ((pointer) hp); <span class="comment">/* collect garbage */</span></div><div class="line"><a name="l00170"></a><span class="lineno"> 170</span> </div><div class="line"><a name="l00171"></a><span class="lineno"> 171</span>  hp = np; <span class="comment">/* -> next header */</span></div><div class="line"><a name="l00172"></a><span class="lineno"> 172</span>  }</div><div class="line"><a name="l00173"></a><span class="lineno"> 173</span>  <span class="keywordflow">else</span></div><div class="line"><a name="l00174"></a><span class="lineno"> 174</span>  <span class="keywordflow">break</span>; <span class="comment">/* rest are not deeper */</span></div><div class="line"><a name="l00175"></a><span class="lineno"> 175</span> </div><div class="line"><a name="l00176"></a><span class="lineno"> 176</span>  last_alloca_header = hp; <span class="comment">/* -> last valid storage */</span></div><div class="line"><a name="l00177"></a><span class="lineno"> 177</span>  }</div><div class="line"><a name="l00178"></a><span class="lineno"> 178</span> </div><div class="line"><a name="l00179"></a><span class="lineno"> 179</span>  <span class="keywordflow">if</span> (<a class="code" href="../../d5/db5/encoding_8c.html#a439227feff9d7f55384e8780cfc2eb82">size</a> == 0)</div><div class="line"><a name="l00180"></a><span class="lineno"> 180</span>  <span class="keywordflow">return</span> <a class="code" href="../../d4/db0/__sdbm_8c.html#a070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>; <span class="comment">/* no allocation required */</span></div><div class="line"><a name="l00181"></a><span class="lineno"> 181</span> </div><div class="line"><a name="l00182"></a><span class="lineno"> 182</span>  <span class="comment">/* Allocate combined header + user data storage. */</span></div><div class="line"><a name="l00183"></a><span class="lineno"> 183</span> </div><div class="line"><a name="l00184"></a><span class="lineno"> 184</span>  {</div><div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  <span class="keyword">register</span> pointer <span class="keyword">new</span> = <a class="code" href="../../d8/db0/defines_8h.html#a6af5faec3f9662b20ffc9903f923dec0">xmalloc</a> (<span class="keyword">sizeof</span> (header) + <a class="code" href="../../d5/db5/encoding_8c.html#a439227feff9d7f55384e8780cfc2eb82">size</a>);</div><div class="line"><a name="l00186"></a><span class="lineno"> 186</span>  <span class="comment">/* address of header */</span></div><div class="line"><a name="l00187"></a><span class="lineno"> 187</span> </div><div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  ((header *)<span class="keyword">new</span>)->h.next = last_alloca_header;</div><div class="line"><a name="l00189"></a><span class="lineno"> 189</span>  ((header *)<span class="keyword">new</span>)->h.deep = depth;</div><div class="line"><a name="l00190"></a><span class="lineno"> 190</span> </div><div class="line"><a name="l00191"></a><span class="lineno"> 191</span>  last_alloca_header = (header *)<span class="keyword">new</span>;</div><div class="line"><a name="l00192"></a><span class="lineno"> 192</span> </div><div class="line"><a name="l00193"></a><span class="lineno"> 193</span>  <span class="comment">/* User storage begins just after header. */</span></div><div class="line"><a name="l00194"></a><span class="lineno"> 194</span> </div><div class="line"><a name="l00195"></a><span class="lineno"> 195</span>  <span class="keywordflow">return</span> (pointer)((<span class="keywordtype">char</span> *)<span class="keyword">new</span> + <span class="keyword">sizeof</span>(header));</div><div class="line"><a name="l00196"></a><span class="lineno"> 196</span>  }</div><div class="line"><a name="l00197"></a><span class="lineno"> 197</span> }</div><div class="line"><a name="l00198"></a><span class="lineno"> 198</span> </div><div class="line"><a name="l00199"></a><span class="lineno"> 199</span> <span class="preprocessor">#endif</span></div><div class="ttc" id="encoding_8c_html_a439227feff9d7f55384e8780cfc2eb82"><div class="ttname"><a href="../../d5/db5/encoding_8c.html#a439227feff9d7f55384e8780cfc2eb82">size</a></div><div class="ttdeci">int size</div><div class="ttdef"><b>Definition:</b> <a href="../../d5/db5/encoding_8c_source.html#l00049">encoding.c:49</a></div></div> <div class="ttc" id="defines_8h_html_a6af5faec3f9662b20ffc9903f923dec0"><div class="ttname"><a href="../../d8/db0/defines_8h.html#a6af5faec3f9662b20ffc9903f923dec0">xmalloc</a></div><div class="ttdeci">#define xmalloc</div><div class="ttdef"><b>Definition:</b> <a href="../../d8/db0/defines_8h_source.html#l00108">defines.h:108</a></div></div> <div class="ttc" id="alloca_8c_html_aadfeb057aee4d307770f7655fd26be05"><div class="ttname"><a href="../../d7/d55/alloca_8c.html#aadfeb057aee4d307770f7655fd26be05">SCCSid</a></div><div class="ttdeci">static char SCCSid[]</div><div class="ttdef"><b>Definition:</b> <a href="../../d7/d55/alloca_8c_source.html#l00029">alloca.c:29</a></div></div> <div class="ttc" id="ruby_2ruby_8h_html_a871651237a27c4f7bac0c12882b08b93"><div class="ttname"><a href="../../de/de6/ruby_2ruby_8h.html#a871651237a27c4f7bac0c12882b08b93">alloca</a></div><div class="ttdeci">RUBY_SYMBOL_EXPORT_BEGIN void * alloca()</div></div> <div class="ttc" id="defines_8h_html_a6ff69f8866ae756cb246b3eebf7a4fce"><div class="ttname"><a href="../../d8/db0/defines_8h.html#a6ff69f8866ae756cb246b3eebf7a4fce">xfree</a></div><div class="ttdeci">void void xfree(void *)</div></div> <div class="ttc" id="__sdbm_8c_html_a070d2ce7b6bb7e5c05602aa8c308d0c4"><div class="ttname"><a href="../../d4/db0/__sdbm_8c.html#a070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a></div><div class="ttdeci">#define NULL</div><div class="ttdef"><b>Definition:</b> <a href="../../d4/db0/__sdbm_8c_source.html#l00102">_sdbm.c:102</a></div></div> </div><!-- fragment --></div><!-- contents --> <!-- start footer part --> <hr class="footer"/><address class="footer"><small> Generated by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="../../doxygen.png" alt="doxygen"/> </a> 1.8.14 </small></address> </body> </html>
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