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<h1>/home/pvrabec/openscap/openscap-0.5.7/src/common/assume.h</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="preprocessor">#pragma once</span>
<a name="l00002"></a>00002 <span class="preprocessor"></span><span class="preprocessor">#ifndef ASSUME_H</span>
<a name="l00003"></a>00003 <span class="preprocessor"></span><span class="preprocessor">#define ASSUME_H</span>
<a name="l00004"></a>00004 <span class="preprocessor"></span>
<a name="l00005"></a>00005 <span class="preprocessor">#include <stdio.h></span>
<a name="l00006"></a>00006 <span class="preprocessor">#include <stdlib.h></span>
<a name="l00007"></a>00007
<a name="l00008"></a>00008 <span class="comment">/*</span>
<a name="l00009"></a>00009 <span class="comment"> * Note: the term "terminate" used in the following text means a call to abort()</span>
<a name="l00010"></a>00010 <span class="comment"> * in the case the code was compiled without NDEBUG defined. The retval</span>
<a name="l00011"></a>00011 <span class="comment"> * argument is ignored in that case. In the other case (NDEBUG is defined)</span>
<a name="l00012"></a>00012 <span class="comment"> * terminate means that `return (retval)' is used instead of aborting the</span>
<a name="l00013"></a>00013 <span class="comment"> * program. This is because we are in a library and taking down a program</span>
<a name="l00014"></a>00014 <span class="comment"> * from inside a library function isn't safe.</span>
<a name="l00015"></a>00015 <span class="comment"> * Unless ASSUME_VERBOSE is defined during compilation time, assume won't</span>
<a name="l00016"></a>00016 <span class="comment"> * emit any messages to stderr. In debugging mode (i.e. when NDEBUG is</span>
<a name="l00017"></a>00017 <span class="comment"> * undefined) the error message is always written to stderr.</span>
<a name="l00018"></a>00018 <span class="comment"> *</span>
<a name="l00019"></a>00019 <span class="comment"> * Usage:</span>
<a name="l00020"></a>00020 <span class="comment"> *</span>
<a name="l00021"></a>00021 <span class="comment"> * 1. assume(expr, retval)</span>
<a name="l00022"></a>00022 <span class="comment"> *</span>
<a name="l00023"></a>00023 <span class="comment"> * Check whether expr is true, terminate if not.</span>
<a name="l00024"></a>00024 <span class="comment"> *</span>
<a name="l00025"></a>00025 <span class="comment"> * 2. assume(expr, retval, f_branch)</span>
<a name="l00026"></a>00026 <span class="comment"> * </span>
<a name="l00027"></a>00027 <span class="comment"> * Check whether expr is true, execute f_branch if not and terminate. The break</span>
<a name="l00028"></a>00028 <span class="comment"> * statement can be used to skip the termination.</span>
<a name="l00029"></a>00029 <span class="comment"> * </span>
<a name="l00030"></a>00030 <span class="comment"> * 3. assume(expr, retval, f_branch, t_branch)</span>
<a name="l00031"></a>00031 <span class="comment"> *</span>
<a name="l00032"></a>00032 <span class="comment"> * Check whether expr is true, execute f_branch if not and terminate. If expr</span>
<a name="l00033"></a>00033 <span class="comment"> * is true, then execute t_branch.</span>
<a name="l00034"></a>00034 <span class="comment"> * </span>
<a name="l00035"></a>00035 <span class="comment"> */</span>
<a name="l00036"></a>00036
<a name="l00037"></a>00037 <span class="preprocessor">#define __LB(l, ...) l</span>
<a name="l00038"></a>00038 <span class="preprocessor"></span><span class="preprocessor">#define __RB(l, ...) __VA_ARGS__</span>
<a name="l00039"></a>00039 <span class="preprocessor"></span>
<a name="l00040"></a>00040 <span class="preprocessor">#include <sys/cdefs.h></span>
<a name="l00041"></a>00041 <span class="preprocessor">#define __XCB(a, b) __CONCAT(a, b)</span>
<a name="l00042"></a>00042 <span class="preprocessor"></span><span class="preprocessor">#define __XCA(a, b) __XCB(a, __XCB(b, __XCB(atcg </span><span class="comment">/* random strign */</span>,a)))
<a name="l00043"></a>00043
<a name="l00044"></a>00044 <span class="preprocessor">#define __emitmsg_fp stderr</span>
<a name="l00045"></a>00045 <span class="preprocessor"></span>
<a name="l00046"></a>00046 <span class="comment">/*</span>
<a name="l00047"></a>00047 <span class="comment"> * == Implementation note #1 ==</span>
<a name="l00048"></a>00048 <span class="comment"> * We use ftrylockfile here because it's better to drop the message than to</span>
<a name="l00049"></a>00049 <span class="comment"> * cause a deadlock.</span>
<a name="l00050"></a>00050 <span class="comment"> */</span>
<a name="l00051"></a>00051 <span class="preprocessor">#define __atomic_emitmsg(...) \</span>
<a name="l00052"></a>00052 <span class="preprocessor"> do { \</span>
<a name="l00053"></a>00053 <span class="preprocessor"> if (ftrylockfile(__emitmsg_fp) == 0) { \</span>
<a name="l00054"></a>00054 <span class="preprocessor"> fprintf (stderr, __VA_ARGS__); \</span>
<a name="l00055"></a>00055 <span class="preprocessor"> funlockfile(__emitmsg_fp); \</span>
<a name="l00056"></a>00056 <span class="preprocessor"> } \</span>
<a name="l00057"></a>00057 <span class="preprocessor"> } while (0)</span>
<a name="l00058"></a>00058 <span class="preprocessor"></span>
<a name="l00059"></a>00059 <span class="preprocessor">#ifndef NDEBUG</span>
<a name="l00060"></a>00060 <span class="preprocessor"></span><span class="preprocessor"># define __terminate(retval) abort()</span>
<a name="l00061"></a>00061 <span class="preprocessor"></span><span class="preprocessor"># define __emitmsg(...) __atomic_emitmsg (__VA_ARGS__)</span>
<a name="l00062"></a>00062 <span class="preprocessor"></span><span class="preprocessor">#else</span>
<a name="l00063"></a>00063 <span class="preprocessor"></span><span class="preprocessor"># define __terminate(retval) return(retval)</span>
<a name="l00064"></a>00064 <span class="preprocessor"></span><span class="preprocessor"># ifdef ASSUME_VERBOSE</span>
<a name="l00065"></a>00065 <span class="preprocessor"></span><span class="preprocessor"># define __emitmsg(...) __atomic_emitmsg (__VA_ARGS__)</span>
<a name="l00066"></a>00066 <span class="preprocessor"></span><span class="preprocessor"># else</span>
<a name="l00067"></a>00067 <span class="preprocessor"></span><span class="preprocessor"># define __emitmsg(...) while(0)</span>
<a name="l00068"></a>00068 <span class="preprocessor"></span><span class="preprocessor"># endif </span><span class="comment">/* ASSUME_VERBOSE */</span>
<a name="l00069"></a>00069 <span class="preprocessor">#endif </span><span class="comment">/* NDEBUG */</span>
<a name="l00070"></a>00070
<a name="l00071"></a>00071 <span class="preprocessor">#define __assume(expr, exprstr, retval, ...) \</span>
<a name="l00072"></a>00072 <span class="preprocessor"> do { \</span>
<a name="l00073"></a>00073 <span class="preprocessor"> int __XCA(__cont, __LINE__) = 1; \</span>
<a name="l00074"></a>00074 <span class="preprocessor"> if (!(expr)) { \</span>
<a name="l00075"></a>00075 <span class="preprocessor"> __emitmsg ("%s:%d (%s): Assumption `%s' not fulfilled!\n", __FILE__, __LINE__, __PRETTY_FUNCTION__, exprstr); \</span>
<a name="l00076"></a>00076 <span class="preprocessor"> do {__LB(__VA_ARGS__)} while((__XCA(__cont, __LINE__) = 0)); \</span>
<a name="l00077"></a>00077 <span class="preprocessor"> if (__XCA(__cont, __LINE__) == 0) __terminate(retval); \</span>
<a name="l00078"></a>00078 <span class="preprocessor"> } else { \</span>
<a name="l00079"></a>00079 <span class="preprocessor"> do {__RB(__VA_ARGS__)} while(0); \</span>
<a name="l00080"></a>00080 <span class="preprocessor"> } \</span>
<a name="l00081"></a>00081 <span class="preprocessor"> } while (0)</span>
<a name="l00082"></a>00082 <span class="preprocessor"></span>
<a name="l00083"></a>00083 <span class="preprocessor">#if defined(__GNUC__)</span>
<a name="l00084"></a>00084 <span class="preprocessor"></span><span class="preprocessor"># define assume(expr, retval, ...) __assume(__builtin_expect(expr, 1), #expr, retval, __VA_ARGS__)</span>
<a name="l00085"></a>00085 <span class="preprocessor"></span><span class="preprocessor">#else</span>
<a name="l00086"></a>00086 <span class="preprocessor"></span><span class="preprocessor"># define assume(expr, retval, ...) __assume(expr, #expr, retval, __VA_ARGS__)</span>
<a name="l00087"></a>00087 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00088"></a>00088 <span class="preprocessor"></span>
<a name="l00092"></a>00092 <span class="preprocessor">#define assume_r(...) assume(__VA_ARGS__)</span>
<a name="l00093"></a>00093 <span class="preprocessor"></span>
<a name="l00097"></a>00097 <span class="preprocessor">#ifndef NDEBUG</span>
<a name="l00098"></a>00098 <span class="preprocessor"></span><span class="preprocessor"># define assume_d(...) assume(__VA_ARGS__)</span>
<a name="l00099"></a>00099 <span class="preprocessor"></span><span class="preprocessor">#else</span>
<a name="l00100"></a>00100 <span class="preprocessor"></span><span class="preprocessor"># define assume_d(...) while(0)</span>
<a name="l00101"></a>00101 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00102"></a>00102 <span class="preprocessor"></span>
<a name="l00103"></a>00103 <span class="preprocessor">#endif </span><span class="comment">/* ASSUME_H */</span>
</pre></div></div>
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