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<div class="fragment"><div class="line"><a id="l00001" name="l00001"></a><span class="lineno"> 1</span><span class="comment">/*</span></div>
<div class="line"><a id="l00002" name="l00002"></a><span class="lineno"> 2</span><span class="comment"> * Copied from https://github.com/libbpf/usdt/</span></div>
<div class="line"><a id="l00003" name="l00003"></a><span class="lineno"> 3</span><span class="comment"> */</span></div>
<div class="line"><a id="l00004" name="l00004"></a><span class="lineno"> 4</span> </div>
<div class="line"><a id="l00005" name="l00005"></a><span class="lineno"> 5</span><span class="comment">// SPDX-License-Identifier: BSD-2-Clause</span></div>
<div class="line"><a id="l00006" name="l00006"></a><span class="lineno"> 6</span><span class="comment">/*</span></div>
<div class="line"><a id="l00007" name="l00007"></a><span class="lineno"> 7</span><span class="comment"> * This single-header library defines a collection of variadic macros for</span></div>
<div class="line"><a id="l00008" name="l00008"></a><span class="lineno"> 8</span><span class="comment"> * defining and triggering USDTs (User Statically-Defined Tracepoints):</span></div>
<div class="line"><a id="l00009" name="l00009"></a><span class="lineno"> 9</span><span class="comment"> *</span></div>
<div class="line"><a id="l00010" name="l00010"></a><span class="lineno"> 10</span><span class="comment"> * - For USDTs without associated semaphore:</span></div>
<div class="line"><a id="l00011" name="l00011"></a><span class="lineno"> 11</span><span class="comment"> * USDT(group, name, args...)</span></div>
<div class="line"><a id="l00012" name="l00012"></a><span class="lineno"> 12</span><span class="comment"> *</span></div>
<div class="line"><a id="l00013" name="l00013"></a><span class="lineno"> 13</span><span class="comment"> * - For USDTs with implicit (transparent to the user) semaphore:</span></div>
<div class="line"><a id="l00014" name="l00014"></a><span class="lineno"> 14</span><span class="comment"> * USDT_WITH_SEMA(group, name, args...)</span></div>
<div class="line"><a id="l00015" name="l00015"></a><span class="lineno"> 15</span><span class="comment"> * USDT_IS_ACTIVE(group, name)</span></div>
<div class="line"><a id="l00016" name="l00016"></a><span class="lineno"> 16</span><span class="comment"> *</span></div>
<div class="line"><a id="l00017" name="l00017"></a><span class="lineno"> 17</span><span class="comment"> * - For USDTs with explicit (user-defined and provided) semaphore:</span></div>
<div class="line"><a id="l00018" name="l00018"></a><span class="lineno"> 18</span><span class="comment"> * USDT_WITH_EXPLICIT_SEMA(sema, group, name, args...)</span></div>
<div class="line"><a id="l00019" name="l00019"></a><span class="lineno"> 19</span><span class="comment"> * USDT_SEMA_IS_ACTIVE(sema)</span></div>
<div class="line"><a id="l00020" name="l00020"></a><span class="lineno"> 20</span><span class="comment"> *</span></div>
<div class="line"><a id="l00021" name="l00021"></a><span class="lineno"> 21</span><span class="comment"> * all of which emit a NOP instruction into the instruction stream, and so</span></div>
<div class="line"><a id="l00022" name="l00022"></a><span class="lineno"> 22</span><span class="comment"> * have *zero* overhead for the surrounding code. USDTs are identified by</span></div>
<div class="line"><a id="l00023" name="l00023"></a><span class="lineno"> 23</span><span class="comment"> * a combination of `group` and `name` identifiers, which is used by external</span></div>
<div class="line"><a id="l00024" name="l00024"></a><span class="lineno"> 24</span><span class="comment"> * tracing tooling (tracers) for identifying exact USDTs of interest.</span></div>
<div class="line"><a id="l00025" name="l00025"></a><span class="lineno"> 25</span><span class="comment"> *</span></div>
<div class="line"><a id="l00026" name="l00026"></a><span class="lineno"> 26</span><span class="comment"> * USDTs can have an associated (2-byte) activity counter (USDT semaphore),</span></div>
<div class="line"><a id="l00027" name="l00027"></a><span class="lineno"> 27</span><span class="comment"> * automatically maintained by Linux kernel whenever any correctly written</span></div>
<div class="line"><a id="l00028" name="l00028"></a><span class="lineno"> 28</span><span class="comment"> * BPF-based tracer is attached to the USDT. This USDT semaphore can be used</span></div>
<div class="line"><a id="l00029" name="l00029"></a><span class="lineno"> 29</span><span class="comment"> * to check whether there is a need to do any extra data collection and</span></div>
<div class="line"><a id="l00030" name="l00030"></a><span class="lineno"> 30</span><span class="comment"> * processing for a given USDT (if necessary), and otherwise avoid extra work</span></div>
<div class="line"><a id="l00031" name="l00031"></a><span class="lineno"> 31</span><span class="comment"> * for a common case of USDT not being traced ("active").</span></div>
<div class="line"><a id="l00032" name="l00032"></a><span class="lineno"> 32</span><span class="comment"> *</span></div>
<div class="line"><a id="l00033" name="l00033"></a><span class="lineno"> 33</span><span class="comment"> * See documentation for USDT_WITH_SEMA()/USDT_IS_ACTIVE() or</span></div>
<div class="line"><a id="l00034" name="l00034"></a><span class="lineno"> 34</span><span class="comment"> * USDT_WITH_EXPLICIT_SEMA()/USDT_SEMA_IS_ACTIVE() APIs below for details on</span></div>
<div class="line"><a id="l00035" name="l00035"></a><span class="lineno"> 35</span><span class="comment"> * working with USDTs with implicitly or explicitly associated</span></div>
<div class="line"><a id="l00036" name="l00036"></a><span class="lineno"> 36</span><span class="comment"> * USDT semaphores, respectively.</span></div>
<div class="line"><a id="l00037" name="l00037"></a><span class="lineno"> 37</span><span class="comment"> *</span></div>
<div class="line"><a id="l00038" name="l00038"></a><span class="lineno"> 38</span><span class="comment"> * There is also some additional data recorded into an auxiliary note</span></div>
<div class="line"><a id="l00039" name="l00039"></a><span class="lineno"> 39</span><span class="comment"> * section. The data in the note section describes the operands, in terms of</span></div>
<div class="line"><a id="l00040" name="l00040"></a><span class="lineno"> 40</span><span class="comment"> * size and location, used by tracing tooling to know where to find USDT</span></div>
<div class="line"><a id="l00041" name="l00041"></a><span class="lineno"> 41</span><span class="comment"> * arguments. Each location is encoded as an assembler operand string.</span></div>
<div class="line"><a id="l00042" name="l00042"></a><span class="lineno"> 42</span><span class="comment"> * Tracing tools (bpftrace and BPF-based tracers, systemtap, etc) insert</span></div>
<div class="line"><a id="l00043" name="l00043"></a><span class="lineno"> 43</span><span class="comment"> * breakpoints on top of the nop, and decode the location operand-strings,</span></div>
<div class="line"><a id="l00044" name="l00044"></a><span class="lineno"> 44</span><span class="comment"> * like an assembler, to find the values being passed.</span></div>
<div class="line"><a id="l00045" name="l00045"></a><span class="lineno"> 45</span><span class="comment"> *</span></div>
<div class="line"><a id="l00046" name="l00046"></a><span class="lineno"> 46</span><span class="comment"> * The operand strings are selected by the compiler for each operand.</span></div>
<div class="line"><a id="l00047" name="l00047"></a><span class="lineno"> 47</span><span class="comment"> * They are constrained by inline-assembler codes.The default is:</span></div>
<div class="line"><a id="l00048" name="l00048"></a><span class="lineno"> 48</span><span class="comment"> *</span></div>
<div class="line"><a id="l00049" name="l00049"></a><span class="lineno"> 49</span><span class="comment"> * #define USDT_ARG_CONSTRAINT nor</span></div>
<div class="line"><a id="l00050" name="l00050"></a><span class="lineno"> 50</span><span class="comment"> *</span></div>
<div class="line"><a id="l00051" name="l00051"></a><span class="lineno"> 51</span><span class="comment"> * This is a good default if the operands tend to be integral and</span></div>
<div class="line"><a id="l00052" name="l00052"></a><span class="lineno"> 52</span><span class="comment"> * moderate in number (smaller than number of registers). In other</span></div>
<div class="line"><a id="l00053" name="l00053"></a><span class="lineno"> 53</span><span class="comment"> * cases, the compiler may report "'asm' requires impossible reload" or</span></div>
<div class="line"><a id="l00054" name="l00054"></a><span class="lineno"> 54</span><span class="comment"> * similar. In this case, consider simplifying the macro call (fewer</span></div>
<div class="line"><a id="l00055" name="l00055"></a><span class="lineno"> 55</span><span class="comment"> * and simpler operands), reduce optimization, or override the default</span></div>
<div class="line"><a id="l00056" name="l00056"></a><span class="lineno"> 56</span><span class="comment"> * constraints string via:</span></div>
<div class="line"><a id="l00057" name="l00057"></a><span class="lineno"> 57</span><span class="comment"> *</span></div>
<div class="line"><a id="l00058" name="l00058"></a><span class="lineno"> 58</span><span class="comment"> * #define USDT_ARG_CONSTRAINT g</span></div>
<div class="line"><a id="l00059" name="l00059"></a><span class="lineno"> 59</span><span class="comment"> * #include <usdt.h></span></div>
<div class="line"><a id="l00060" name="l00060"></a><span class="lineno"> 60</span><span class="comment"> *</span></div>
<div class="line"><a id="l00061" name="l00061"></a><span class="lineno"> 61</span><span class="comment"> * For some historical description of USDT v3 format (the one used by this</span></div>
<div class="line"><a id="l00062" name="l00062"></a><span class="lineno"> 62</span><span class="comment"> * library and generally recognized and assumed by BPF-based tracing tools)</span></div>
<div class="line"><a id="l00063" name="l00063"></a><span class="lineno"> 63</span><span class="comment"> * see [0]. The more formal specification can be found at [1]. Additional</span></div>
<div class="line"><a id="l00064" name="l00064"></a><span class="lineno"> 64</span><span class="comment"> * argument constraints information can be found at [2].</span></div>
<div class="line"><a id="l00065" name="l00065"></a><span class="lineno"> 65</span><span class="comment"> *</span></div>
<div class="line"><a id="l00066" name="l00066"></a><span class="lineno"> 66</span><span class="comment"> * Original SystemTap's sys/sdt.h implementation ([3]) was used as a base for</span></div>
<div class="line"><a id="l00067" name="l00067"></a><span class="lineno"> 67</span><span class="comment"> * this USDT library implementation. Current implementation differs *a lot* in</span></div>
<div class="line"><a id="l00068" name="l00068"></a><span class="lineno"> 68</span><span class="comment"> * terms of exposed user API and general usability, which was the main goal</span></div>
<div class="line"><a id="l00069" name="l00069"></a><span class="lineno"> 69</span><span class="comment"> * and focus of the reimplementation work. Nevertheless, underlying recorded</span></div>
<div class="line"><a id="l00070" name="l00070"></a><span class="lineno"> 70</span><span class="comment"> * USDT definitions are fully binary compatible and any USDT-based tooling</span></div>
<div class="line"><a id="l00071" name="l00071"></a><span class="lineno"> 71</span><span class="comment"> * should work equally well with USDTs defined by either SystemTap's or this</span></div>
<div class="line"><a id="l00072" name="l00072"></a><span class="lineno"> 72</span><span class="comment"> * library's USDT implementation.</span></div>
<div class="line"><a id="l00073" name="l00073"></a><span class="lineno"> 73</span><span class="comment"> *</span></div>
<div class="line"><a id="l00074" name="l00074"></a><span class="lineno"> 74</span><span class="comment"> * [0] https://ecos.sourceware.org/ml/systemtap/2010-q3/msg00145.html</span></div>
<div class="line"><a id="l00075" name="l00075"></a><span class="lineno"> 75</span><span class="comment"> * [1] https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation</span></div>
<div class="line"><a id="l00076" name="l00076"></a><span class="lineno"> 76</span><span class="comment"> * [2] https://gcc.gnu.org/onlinedocs/gcc/Constraints.html</span></div>
<div class="line"><a id="l00077" name="l00077"></a><span class="lineno"> 77</span><span class="comment"> * [3] https://sourceware.org/git/?p=systemtap.git;a=blob;f=includes/sys/sdt.h</span></div>
<div class="line"><a id="l00078" name="l00078"></a><span class="lineno"> 78</span><span class="comment"> */</span></div>
<div class="line"><a id="l00079" name="l00079"></a><span class="lineno"> 79</span><span class="preprocessor">#ifndef __USDT_H</span></div>
<div class="line"><a id="l00080" name="l00080"></a><span class="lineno"> 80</span><span class="preprocessor">#define __USDT_H</span></div>
<div class="line"><a id="l00081" name="l00081"></a><span class="lineno"> 81</span> </div>
<div class="line"><a id="l00082" name="l00082"></a><span class="lineno"> 82</span><span class="comment">/*</span></div>
<div class="line"><a id="l00083" name="l00083"></a><span class="lineno"> 83</span><span class="comment"> * Changelog:</span></div>
<div class="line"><a id="l00084" name="l00084"></a><span class="lineno"> 84</span><span class="comment"> *</span></div>
<div class="line"><a id="l00085" name="l00085"></a><span class="lineno"> 85</span><span class="comment"> * 0.1.0</span></div>
<div class="line"><a id="l00086" name="l00086"></a><span class="lineno"> 86</span><span class="comment"> * -----</span></div>
<div class="line"><a id="l00087" name="l00087"></a><span class="lineno"> 87</span><span class="comment"> * - Initial release</span></div>
<div class="line"><a id="l00088" name="l00088"></a><span class="lineno"> 88</span><span class="comment"> */</span></div>
<div class="line"><a id="l00089" name="l00089"></a><span class="lineno"> 89</span><span class="preprocessor">#define USDT_MAJOR_VERSION 0</span></div>
<div class="line"><a id="l00090" name="l00090"></a><span class="lineno"> 90</span><span class="preprocessor">#define USDT_MINOR_VERSION 1</span></div>
<div class="line"><a id="l00091" name="l00091"></a><span class="lineno"> 91</span><span class="preprocessor">#define USDT_PATCH_VERSION 0</span></div>
<div class="line"><a id="l00092" name="l00092"></a><span class="lineno"> 92</span> </div>
<div class="line"><a id="l00093" name="l00093"></a><span class="lineno"> 93</span><span class="comment">/* C++20 and C23 added __VA_OPT__ as a standard replacement for non-standard `##__VA_ARGS__` extension */</span></div>
<div class="line"><a id="l00094" name="l00094"></a><span class="lineno"> 94</span><span class="preprocessor">#if (defined(__STDC_VERSION__) && __STDC_VERSION__ > 201710L) || (defined(__cplusplus) && __cplusplus > 201703L)</span></div>
<div class="line"><a id="l00095" name="l00095"></a><span class="lineno"> 95</span><span class="preprocessor">#define __usdt_va_opt 1</span></div>
<div class="line"><a id="l00096" name="l00096"></a><span class="lineno"> 96</span><span class="preprocessor">#define __usdt_va_args(...) __VA_OPT__(,) __VA_ARGS__</span></div>
<div class="line"><a id="l00097" name="l00097"></a><span class="lineno"> 97</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00098" name="l00098"></a><span class="lineno"> 98</span><span class="preprocessor">#define __usdt_va_args(...) , ##__VA_ARGS__</span></div>
<div class="line"><a id="l00099" name="l00099"></a><span class="lineno"> 99</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00100" name="l00100"></a><span class="lineno"> 100</span> </div>
<div class="line"><a id="l00101" name="l00101"></a><span class="lineno"> 101</span><span class="comment">/*</span></div>
<div class="line"><a id="l00102" name="l00102"></a><span class="lineno"> 102</span><span class="comment"> * Trigger USDT with `group`:`name` identifier and pass through `args` as its</span></div>
<div class="line"><a id="l00103" name="l00103"></a><span class="lineno"> 103</span><span class="comment"> * arguments. Zero arguments are acceptable as well. No USDT semaphore is</span></div>
<div class="line"><a id="l00104" name="l00104"></a><span class="lineno"> 104</span><span class="comment"> * associated with this USDT.</span></div>
<div class="line"><a id="l00105" name="l00105"></a><span class="lineno"> 105</span><span class="comment"> *</span></div>
<div class="line"><a id="l00106" name="l00106"></a><span class="lineno"> 106</span><span class="comment"> * Such "semaphoreless" USDTs are commonly used when there is no extra data</span></div>
<div class="line"><a id="l00107" name="l00107"></a><span class="lineno"> 107</span><span class="comment"> * collection or processing needed to collect and prepare USDT arguments and</span></div>
<div class="line"><a id="l00108" name="l00108"></a><span class="lineno"> 108</span><span class="comment"> * they are just available in the surrounding code. USDT() macro will just</span></div>
<div class="line"><a id="l00109" name="l00109"></a><span class="lineno"> 109</span><span class="comment"> * record their locations in CPU registers or in memory for tracing tooling to</span></div>
<div class="line"><a id="l00110" name="l00110"></a><span class="lineno"> 110</span><span class="comment"> * be able to access them, if necessary.</span></div>
<div class="line"><a id="l00111" name="l00111"></a><span class="lineno"> 111</span><span class="comment"> */</span></div>
<div class="line"><a id="l00112" name="l00112"></a><span class="lineno"> 112</span><span class="preprocessor">#ifdef __usdt_va_opt</span></div>
<div class="line"><a id="l00113" name="l00113"></a><span class="lineno"> 113</span><span class="preprocessor">#define USDT(group, name, ...) \</span></div>
<div class="line"><a id="l00114" name="l00114"></a><span class="lineno"> 114</span><span class="preprocessor"> __usdt_probe(group, name, __usdt_sema_none, 0 __VA_OPT__(,) __VA_ARGS__)</span></div>
<div class="line"><a id="l00115" name="l00115"></a><span class="lineno"> 115</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00116" name="l00116"></a><span class="lineno"> 116</span><span class="preprocessor">#define USDT(group, name, ...) \</span></div>
<div class="line"><a id="l00117" name="l00117"></a><span class="lineno"> 117</span><span class="preprocessor"> __usdt_probe(group, name, __usdt_sema_none, 0, ##__VA_ARGS__)</span></div>
<div class="line"><a id="l00118" name="l00118"></a><span class="lineno"> 118</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00119" name="l00119"></a><span class="lineno"> 119</span> </div>
<div class="line"><a id="l00120" name="l00120"></a><span class="lineno"> 120</span><span class="comment">/*</span></div>
<div class="line"><a id="l00121" name="l00121"></a><span class="lineno"> 121</span><span class="comment"> * Trigger USDT with `group`:`name` identifier and pass through `args` as its</span></div>
<div class="line"><a id="l00122" name="l00122"></a><span class="lineno"> 122</span><span class="comment"> * arguments. Zero arguments are acceptable as well. USDT also get an</span></div>
<div class="line"><a id="l00123" name="l00123"></a><span class="lineno"> 123</span><span class="comment"> * implicitly-defined associated USDT semaphore, which will be "activated" by</span></div>
<div class="line"><a id="l00124" name="l00124"></a><span class="lineno"> 124</span><span class="comment"> * tracing tooling and can be used to check whether USDT is being actively</span></div>
<div class="line"><a id="l00125" name="l00125"></a><span class="lineno"> 125</span><span class="comment"> * observed.</span></div>
<div class="line"><a id="l00126" name="l00126"></a><span class="lineno"> 126</span><span class="comment"> *</span></div>
<div class="line"><a id="l00127" name="l00127"></a><span class="lineno"> 127</span><span class="comment"> * USDTs with semaphore are commonly used when there is a need to perform</span></div>
<div class="line"><a id="l00128" name="l00128"></a><span class="lineno"> 128</span><span class="comment"> * additional data collection and processing to prepare USDT arguments, which</span></div>
<div class="line"><a id="l00129" name="l00129"></a><span class="lineno"> 129</span><span class="comment"> * otherwise might not be necessary for the rest of application logic. In such</span></div>
<div class="line"><a id="l00130" name="l00130"></a><span class="lineno"> 130</span><span class="comment"> * case, USDT semaphore can be used to avoid unnecessary extra work. If USDT</span></div>
<div class="line"><a id="l00131" name="l00131"></a><span class="lineno"> 131</span><span class="comment"> * is not traced (which is presumed to be a common situation), the associated</span></div>
<div class="line"><a id="l00132" name="l00132"></a><span class="lineno"> 132</span><span class="comment"> * USDT semaphore is "inactive", and so there is no need to waste resources to</span></div>
<div class="line"><a id="l00133" name="l00133"></a><span class="lineno"> 133</span><span class="comment"> * prepare USDT arguments. Use USDT_IS_ACTIVE(group, name) to check whether</span></div>
<div class="line"><a id="l00134" name="l00134"></a><span class="lineno"> 134</span><span class="comment"> * USDT is "active".</span></div>
<div class="line"><a id="l00135" name="l00135"></a><span class="lineno"> 135</span><span class="comment"> *</span></div>
<div class="line"><a id="l00136" name="l00136"></a><span class="lineno"> 136</span><span class="comment"> * N.B. There is an inherent (albeit short) gap between checking whether USDT</span></div>
<div class="line"><a id="l00137" name="l00137"></a><span class="lineno"> 137</span><span class="comment"> * is active and triggering corresponding USDT, in which external tracer can</span></div>
<div class="line"><a id="l00138" name="l00138"></a><span class="lineno"> 138</span><span class="comment"> * be attached to an USDT and activate USDT semaphore after the activity check.</span></div>
<div class="line"><a id="l00139" name="l00139"></a><span class="lineno"> 139</span><span class="comment"> * If such a race occurs, tracers might miss one USDT execution. Tracers are</span></div>
<div class="line"><a id="l00140" name="l00140"></a><span class="lineno"> 140</span><span class="comment"> * expected to accommodate such possibility and this is expected to not be</span></div>
<div class="line"><a id="l00141" name="l00141"></a><span class="lineno"> 141</span><span class="comment"> * a problem for applications and tracers.</span></div>
<div class="line"><a id="l00142" name="l00142"></a><span class="lineno"> 142</span><span class="comment"> *</span></div>
<div class="line"><a id="l00143" name="l00143"></a><span class="lineno"> 143</span><span class="comment"> * N.B. Implicit USDT semaphore defined by USDT_WITH_SEMA() is contained</span></div>
<div class="line"><a id="l00144" name="l00144"></a><span class="lineno"> 144</span><span class="comment"> * within a single executable or shared library and is not shared outside</span></div>
<div class="line"><a id="l00145" name="l00145"></a><span class="lineno"> 145</span><span class="comment"> * them. I.e., if you use USDT_WITH_SEMA() with the same USDT group and name</span></div>
<div class="line"><a id="l00146" name="l00146"></a><span class="lineno"> 146</span><span class="comment"> * identifier across executable and shared library, it will work and won't</span></div>
<div class="line"><a id="l00147" name="l00147"></a><span class="lineno"> 147</span><span class="comment"> * conflict, per se, but will define independent USDT semaphores, one for each</span></div>
<div class="line"><a id="l00148" name="l00148"></a><span class="lineno"> 148</span><span class="comment"> * shared library/executable in which USDT_WITH_SEMA(group, name) is used.</span></div>
<div class="line"><a id="l00149" name="l00149"></a><span class="lineno"> 149</span><span class="comment"> * That is, if you attach to this USDT in one shared library (or executable),</span></div>
<div class="line"><a id="l00150" name="l00150"></a><span class="lineno"> 150</span><span class="comment"> * then only USDT semaphore within that shared library (or executable) will be</span></div>
<div class="line"><a id="l00151" name="l00151"></a><span class="lineno"> 151</span><span class="comment"> * updated by the kernel, while other libraries (or executable) will not see</span></div>
<div class="line"><a id="l00152" name="l00152"></a><span class="lineno"> 152</span><span class="comment"> * activated USDT semaphore. In short, it's best to use unique USDT group:name</span></div>
<div class="line"><a id="l00153" name="l00153"></a><span class="lineno"> 153</span><span class="comment"> * identifiers across different shared libraries (and, equivalently, between</span></div>
<div class="line"><a id="l00154" name="l00154"></a><span class="lineno"> 154</span><span class="comment"> * executable and shared library). This is advanced consideration and is</span></div>
<div class="line"><a id="l00155" name="l00155"></a><span class="lineno"> 155</span><span class="comment"> * rarely (if ever) seen in practice, but just to avoid surprises this is</span></div>
<div class="line"><a id="l00156" name="l00156"></a><span class="lineno"> 156</span><span class="comment"> * called out here. (Static libraries become a part of final executable, once</span></div>
<div class="line"><a id="l00157" name="l00157"></a><span class="lineno"> 157</span><span class="comment"> * linked by linker, so the above considerations don't apply to them.)</span></div>
<div class="line"><a id="l00158" name="l00158"></a><span class="lineno"> 158</span><span class="comment"> */</span></div>
<div class="line"><a id="l00159" name="l00159"></a><span class="lineno"> 159</span><span class="preprocessor">#ifdef __usdt_va_opt</span></div>
<div class="line"><a id="l00160" name="l00160"></a><span class="lineno"> 160</span><span class="preprocessor">#define USDT_WITH_SEMA(group, name, ...) \</span></div>
<div class="line"><a id="l00161" name="l00161"></a><span class="lineno"> 161</span><span class="preprocessor"> __usdt_probe(group, name, \</span></div>
<div class="line"><a id="l00162" name="l00162"></a><span class="lineno"> 162</span><span class="preprocessor"> __usdt_sema_implicit, __usdt_sema_name(group, name) \</span></div>
<div class="line"><a id="l00163" name="l00163"></a><span class="lineno"> 163</span><span class="preprocessor"> __VA_OPT__(,) __VA_ARGS__)</span></div>
<div class="line"><a id="l00164" name="l00164"></a><span class="lineno"> 164</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00165" name="l00165"></a><span class="lineno"> 165</span><span class="preprocessor">#define USDT_WITH_SEMA(group, name, ...) \</span></div>
<div class="line"><a id="l00166" name="l00166"></a><span class="lineno"> 166</span><span class="preprocessor"> __usdt_probe(group, name, \</span></div>
<div class="line"><a id="l00167" name="l00167"></a><span class="lineno"> 167</span><span class="preprocessor"> __usdt_sema_implicit, __usdt_sema_name(group, name), \</span></div>
<div class="line"><a id="l00168" name="l00168"></a><span class="lineno"> 168</span><span class="preprocessor"> ##__VA_ARGS__)</span></div>
<div class="line"><a id="l00169" name="l00169"></a><span class="lineno"> 169</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00170" name="l00170"></a><span class="lineno"> 170</span> </div>
<div class="line"><a id="l00171" name="l00171"></a><span class="lineno"> 171</span><span class="keyword">struct </span>usdt_sema { <span class="keyword">volatile</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">short</span> active; };</div>
<div class="line"><a id="l00172" name="l00172"></a><span class="lineno"> 172</span> </div>
<div class="line"><a id="l00173" name="l00173"></a><span class="lineno"> 173</span><span class="comment">/*</span></div>
<div class="line"><a id="l00174" name="l00174"></a><span class="lineno"> 174</span><span class="comment"> * Check if USDT with `group`:`name` identifier is "active" (i.e., whether it</span></div>
<div class="line"><a id="l00175" name="l00175"></a><span class="lineno"> 175</span><span class="comment"> * is attached to by external tracing tooling and is actively observed).</span></div>
<div class="line"><a id="l00176" name="l00176"></a><span class="lineno"> 176</span><span class="comment"> *</span></div>
<div class="line"><a id="l00177" name="l00177"></a><span class="lineno"> 177</span><span class="comment"> * This macro can be used to decide whether any additional and potentially</span></div>
<div class="line"><a id="l00178" name="l00178"></a><span class="lineno"> 178</span><span class="comment"> * expensive data collection or processing should be done to pass extra</span></div>
<div class="line"><a id="l00179" name="l00179"></a><span class="lineno"> 179</span><span class="comment"> * information into the given USDT. It is assumed that USDT is triggered with</span></div>
<div class="line"><a id="l00180" name="l00180"></a><span class="lineno"> 180</span><span class="comment"> * USDT_WITH_SEMA() macro which will implicitly define associated USDT</span></div>
<div class="line"><a id="l00181" name="l00181"></a><span class="lineno"> 181</span><span class="comment"> * semaphore. (If one needs more control over USDT semaphore, see</span></div>
<div class="line"><a id="l00182" name="l00182"></a><span class="lineno"> 182</span><span class="comment"> * USDT_DEFINE_SEMA() and USDT_WITH_EXPLICIT_SEMA() macros below.)</span></div>
<div class="line"><a id="l00183" name="l00183"></a><span class="lineno"> 183</span><span class="comment"> *</span></div>
<div class="line"><a id="l00184" name="l00184"></a><span class="lineno"> 184</span><span class="comment"> * N.B. Such checks are necessarily racy and speculative. Between checking</span></div>
<div class="line"><a id="l00185" name="l00185"></a><span class="lineno"> 185</span><span class="comment"> * whether USDT is active and triggering the USDT itself, tracer can be</span></div>
<div class="line"><a id="l00186" name="l00186"></a><span class="lineno"> 186</span><span class="comment"> * detached with no notification. This race should be extremely rare and worst</span></div>
<div class="line"><a id="l00187" name="l00187"></a><span class="lineno"> 187</span><span class="comment"> * case should result in one-time wasted extra data collection and processing.</span></div>
<div class="line"><a id="l00188" name="l00188"></a><span class="lineno"> 188</span><span class="comment"> */</span></div>
<div class="line"><a id="l00189" name="l00189"></a><span class="lineno"> 189</span><span class="preprocessor">#define USDT_IS_ACTIVE(group, name) ({ \</span></div>
<div class="line"><a id="l00190" name="l00190"></a><span class="lineno"> 190</span><span class="preprocessor"> extern struct usdt_sema __usdt_sema_name(group, name) \</span></div>
<div class="line"><a id="l00191" name="l00191"></a><span class="lineno"> 191</span><span class="preprocessor"> __usdt_asm_name(__usdt_sema_name(group, name)); \</span></div>
<div class="line"><a id="l00192" name="l00192"></a><span class="lineno"> 192</span><span class="preprocessor"> __usdt_sema_implicit(__usdt_sema_name(group, name)); \</span></div>
<div class="line"><a id="l00193" name="l00193"></a><span class="lineno"> 193</span><span class="preprocessor"> __usdt_sema_name(group, name).active > 0; \</span></div>
<div class="line"><a id="l00194" name="l00194"></a><span class="lineno"> 194</span><span class="preprocessor">})</span></div>
<div class="line"><a id="l00195" name="l00195"></a><span class="lineno"> 195</span> </div>
<div class="line"><a id="l00196" name="l00196"></a><span class="lineno"> 196</span><span class="comment">/*</span></div>
<div class="line"><a id="l00197" name="l00197"></a><span class="lineno"> 197</span><span class="comment"> * APIs for working with user-defined explicit USDT semaphores.</span></div>
<div class="line"><a id="l00198" name="l00198"></a><span class="lineno"> 198</span><span class="comment"> *</span></div>
<div class="line"><a id="l00199" name="l00199"></a><span class="lineno"> 199</span><span class="comment"> * This is a less commonly used advanced API for use cases in which user needs</span></div>
<div class="line"><a id="l00200" name="l00200"></a><span class="lineno"> 200</span><span class="comment"> * an explicit control over (potentially shared across multiple USDTs) USDT</span></div>
<div class="line"><a id="l00201" name="l00201"></a><span class="lineno"> 201</span><span class="comment"> * semaphore instance. This can be used when there is a group of logically</span></div>
<div class="line"><a id="l00202" name="l00202"></a><span class="lineno"> 202</span><span class="comment"> * related USDTs that all need extra data collection and processing whenever</span></div>
<div class="line"><a id="l00203" name="l00203"></a><span class="lineno"> 203</span><span class="comment"> * any of a family of related USDTs are "activated" (i.e., traced). In such</span></div>
<div class="line"><a id="l00204" name="l00204"></a><span class="lineno"> 204</span><span class="comment"> * a case, all such related USDTs will be associated with the same shared USDT</span></div>
<div class="line"><a id="l00205" name="l00205"></a><span class="lineno"> 205</span><span class="comment"> * semaphore defined with USDT_DEFINE_SEMA() and the USDTs themselves will be</span></div>
<div class="line"><a id="l00206" name="l00206"></a><span class="lineno"> 206</span><span class="comment"> * triggered with USDT_WITH_EXPLICIT_SEMA() macros, taking an explicit extra</span></div>
<div class="line"><a id="l00207" name="l00207"></a><span class="lineno"> 207</span><span class="comment"> * USDT semaphore identifier as an extra parameter.</span></div>
<div class="line"><a id="l00208" name="l00208"></a><span class="lineno"> 208</span><span class="comment"> */</span></div>
<div class="line"><a id="l00209" name="l00209"></a><span class="lineno"> 209</span> </div>
<div class="line"><a id="l00215" name="l00215"></a><span class="lineno"> 215</span><span class="preprocessor">#define USDT_SEMA(sema) __usdt_sema_##sema</span></div>
<div class="line"><a id="l00216" name="l00216"></a><span class="lineno"> 216</span> </div>
<div class="line"><a id="l00217" name="l00217"></a><span class="lineno"> 217</span><span class="comment">/*</span></div>
<div class="line"><a id="l00218" name="l00218"></a><span class="lineno"> 218</span><span class="comment"> * Define storage for user-defined USDT semaphore `sema`.</span></div>
<div class="line"><a id="l00219" name="l00219"></a><span class="lineno"> 219</span><span class="comment"> *</span></div>
<div class="line"><a id="l00220" name="l00220"></a><span class="lineno"> 220</span><span class="comment"> * Should be used only once in non-header source file to let compiler allocate</span></div>
<div class="line"><a id="l00221" name="l00221"></a><span class="lineno"> 221</span><span class="comment"> * space for the semaphore variable. Just like with any other global variable.</span></div>
<div class="line"><a id="l00222" name="l00222"></a><span class="lineno"> 222</span><span class="comment"> *</span></div>
<div class="line"><a id="l00223" name="l00223"></a><span class="lineno"> 223</span><span class="comment"> * This macro can be used anywhere where global variable declaration is</span></div>
<div class="line"><a id="l00224" name="l00224"></a><span class="lineno"> 224</span><span class="comment"> * allowed. Just like with global variable definitions, there should be only</span></div>
<div class="line"><a id="l00225" name="l00225"></a><span class="lineno"> 225</span><span class="comment"> * one definition of user-defined USDT semaphore with given `sema` identifier,</span></div>
<div class="line"><a id="l00226" name="l00226"></a><span class="lineno"> 226</span><span class="comment"> * otherwise compiler or linker will complain about duplicate variable</span></div>
<div class="line"><a id="l00227" name="l00227"></a><span class="lineno"> 227</span><span class="comment"> * definition.</span></div>
<div class="line"><a id="l00228" name="l00228"></a><span class="lineno"> 228</span><span class="comment"> *</span></div>
<div class="line"><a id="l00229" name="l00229"></a><span class="lineno"> 229</span><span class="comment"> * For C++, it is allowed to use USDT_DEFINE_SEMA() both in global namespace</span></div>
<div class="line"><a id="l00230" name="l00230"></a><span class="lineno"> 230</span><span class="comment"> * and inside namespaces (including nested namespaces). Just make sure that</span></div>
<div class="line"><a id="l00231" name="l00231"></a><span class="lineno"> 231</span><span class="comment"> * USDT_DECLARE_SEMA() is placed within the namespace where this semaphore is</span></div>
<div class="line"><a id="l00232" name="l00232"></a><span class="lineno"> 232</span><span class="comment"> * referenced, or any of its parent namespaces, so the C++ language-level</span></div>
<div class="line"><a id="l00233" name="l00233"></a><span class="lineno"> 233</span><span class="comment"> * identifier is visible to the code that needs to reference the semaphore.</span></div>
<div class="line"><a id="l00234" name="l00234"></a><span class="lineno"> 234</span><span class="comment"> * At the lowest layer, USDT semaphores have global naming and visibility</span></div>
<div class="line"><a id="l00235" name="l00235"></a><span class="lineno"> 235</span><span class="comment"> * (they have a corresponding `__usdt_sema_<name>` symbol, which can be linked</span></div>
<div class="line"><a id="l00236" name="l00236"></a><span class="lineno"> 236</span><span class="comment"> * against from C or C++ code, if necessary). To keep it simple, putting</span></div>
<div class="line"><a id="l00237" name="l00237"></a><span class="lineno"> 237</span><span class="comment"> * USDT_DECLARE_SEMA() declarations into global namespaces is the simplest</span></div>
<div class="line"><a id="l00238" name="l00238"></a><span class="lineno"> 238</span><span class="comment"> * no-brainer solution. All these aspects are irrelevant for plain C, because</span></div>
<div class="line"><a id="l00239" name="l00239"></a><span class="lineno"> 239</span><span class="comment"> * C doesn't have namespaces and everything is always in the global namespace.</span></div>
<div class="line"><a id="l00240" name="l00240"></a><span class="lineno"> 240</span><span class="comment"> *</span></div>
<div class="line"><a id="l00241" name="l00241"></a><span class="lineno"> 241</span><span class="comment"> * N.B. Due to USDT metadata being recorded in non-allocatable ELF note</span></div>
<div class="line"><a id="l00242" name="l00242"></a><span class="lineno"> 242</span><span class="comment"> * section, it has limitations when it comes to relocations, which, in</span></div>
<div class="line"><a id="l00243" name="l00243"></a><span class="lineno"> 243</span><span class="comment"> * practice, means that it's not possible to correctly share USDT semaphores</span></div>
<div class="line"><a id="l00244" name="l00244"></a><span class="lineno"> 244</span><span class="comment"> * between main executable and shared libraries, or even between multiple</span></div>
<div class="line"><a id="l00245" name="l00245"></a><span class="lineno"> 245</span><span class="comment"> * shared libraries. USDT semaphore has to be contained to individual shared</span></div>
<div class="line"><a id="l00246" name="l00246"></a><span class="lineno"> 246</span><span class="comment"> * library or executable to avoid unpleasant surprises with half-working USDT</span></div>
<div class="line"><a id="l00247" name="l00247"></a><span class="lineno"> 247</span><span class="comment"> * semaphores. We enforce this by marking semaphore ELF symbols as having</span></div>
<div class="line"><a id="l00248" name="l00248"></a><span class="lineno"> 248</span><span class="comment"> * a hidden visibility. This is quite an advanced use case and consideration</span></div>
<div class="line"><a id="l00249" name="l00249"></a><span class="lineno"> 249</span><span class="comment"> * and for most users this should have no consequences whatsoever.</span></div>
<div class="line"><a id="l00250" name="l00250"></a><span class="lineno"> 250</span><span class="comment"> */</span></div>
<div class="line"><a id="l00251" name="l00251"></a><span class="lineno"> 251</span><span class="preprocessor">#define USDT_DEFINE_SEMA(sema) \</span></div>
<div class="line"><a id="l00252" name="l00252"></a><span class="lineno"> 252</span><span class="preprocessor"> struct usdt_sema __usdt_sema_sec USDT_SEMA(sema) \</span></div>
<div class="line"><a id="l00253" name="l00253"></a><span class="lineno"> 253</span><span class="preprocessor"> __usdt_asm_name(USDT_SEMA(sema)) \</span></div>
<div class="line"><a id="l00254" name="l00254"></a><span class="lineno"> 254</span><span class="preprocessor"> __attribute__((visibility("hidden"))) = { 0 }</span></div>
<div class="line"><a id="l00255" name="l00255"></a><span class="lineno"> 255</span> </div>
<div class="line"><a id="l00256" name="l00256"></a><span class="lineno"> 256</span><span class="comment">/*</span></div>
<div class="line"><a id="l00257" name="l00257"></a><span class="lineno"> 257</span><span class="comment"> * Declare extern reference to user-defined USDT semaphore `sema`.</span></div>
<div class="line"><a id="l00258" name="l00258"></a><span class="lineno"> 258</span><span class="comment"> *</span></div>
<div class="line"><a id="l00259" name="l00259"></a><span class="lineno"> 259</span><span class="comment"> * Refers to a variable defined in another compilation unit by</span></div>
<div class="line"><a id="l00260" name="l00260"></a><span class="lineno"> 260</span><span class="comment"> * USDT_DEFINE_SEMA() and allows to use the same USDT semaphore across</span></div>
<div class="line"><a id="l00261" name="l00261"></a><span class="lineno"> 261</span><span class="comment"> * multiple compilation units (i.e., .c and .cpp files).</span></div>
<div class="line"><a id="l00262" name="l00262"></a><span class="lineno"> 262</span><span class="comment"> *</span></div>
<div class="line"><a id="l00263" name="l00263"></a><span class="lineno"> 263</span><span class="comment"> * See USDT_DEFINE_SEMA() notes above for C++ language usage peculiarities.</span></div>
<div class="line"><a id="l00264" name="l00264"></a><span class="lineno"> 264</span><span class="comment"> */</span></div>
<div class="line"><a id="l00265" name="l00265"></a><span class="lineno"> 265</span><span class="preprocessor">#define USDT_DECLARE_SEMA(sema) \</span></div>
<div class="line"><a id="l00266" name="l00266"></a><span class="lineno"> 266</span><span class="preprocessor"> extern struct usdt_sema USDT_SEMA(sema) __usdt_asm_name(USDT_SEMA(sema))</span></div>
<div class="line"><a id="l00267" name="l00267"></a><span class="lineno"> 267</span> </div>
<div class="line"><a id="l00268" name="l00268"></a><span class="lineno"> 268</span><span class="comment">/*</span></div>
<div class="line"><a id="l00269" name="l00269"></a><span class="lineno"> 269</span><span class="comment"> * Check if user-defined USDT semaphore `sema` is "active" (i.e., whether it</span></div>
<div class="line"><a id="l00270" name="l00270"></a><span class="lineno"> 270</span><span class="comment"> * is attached to by external tracing tooling and is actively observed).</span></div>
<div class="line"><a id="l00271" name="l00271"></a><span class="lineno"> 271</span><span class="comment"> *</span></div>
<div class="line"><a id="l00272" name="l00272"></a><span class="lineno"> 272</span><span class="comment"> * This macro can be used to decide whether any additional and potentially</span></div>
<div class="line"><a id="l00273" name="l00273"></a><span class="lineno"> 273</span><span class="comment"> * expensive data collection or processing should be done to pass extra</span></div>
<div class="line"><a id="l00274" name="l00274"></a><span class="lineno"> 274</span><span class="comment"> * information into USDT(s) associated with USDT semaphore `sema`.</span></div>
<div class="line"><a id="l00275" name="l00275"></a><span class="lineno"> 275</span><span class="comment"> *</span></div>
<div class="line"><a id="l00276" name="l00276"></a><span class="lineno"> 276</span><span class="comment"> * N.B. Such checks are necessarily racy. Between checking the state of USDT</span></div>
<div class="line"><a id="l00277" name="l00277"></a><span class="lineno"> 277</span><span class="comment"> * semaphore and triggering associated USDT(s), the active tracer might attach</span></div>
<div class="line"><a id="l00278" name="l00278"></a><span class="lineno"> 278</span><span class="comment"> * or detach. This race should be extremely rare and worst case should result</span></div>
<div class="line"><a id="l00279" name="l00279"></a><span class="lineno"> 279</span><span class="comment"> * in one-time missed USDT event or wasted extra data collection and</span></div>
<div class="line"><a id="l00280" name="l00280"></a><span class="lineno"> 280</span><span class="comment"> * processing. USDT-using tracers should be written with this in mind and is</span></div>
<div class="line"><a id="l00281" name="l00281"></a><span class="lineno"> 281</span><span class="comment"> * not a concern of the application defining USDTs with associated semaphore.</span></div>
<div class="line"><a id="l00282" name="l00282"></a><span class="lineno"> 282</span><span class="comment"> */</span></div>
<div class="line"><a id="l00283" name="l00283"></a><span class="lineno"> 283</span><span class="preprocessor">#define USDT_SEMA_IS_ACTIVE(sema) (USDT_SEMA(sema).active > 0)</span></div>
<div class="line"><a id="l00284" name="l00284"></a><span class="lineno"> 284</span> </div>
<div class="line"><a id="l00285" name="l00285"></a><span class="lineno"> 285</span><span class="comment">/*</span></div>
<div class="line"><a id="l00286" name="l00286"></a><span class="lineno"> 286</span><span class="comment"> * Invoke USDT specified by `group` and `name` identifiers and associate</span></div>
<div class="line"><a id="l00287" name="l00287"></a><span class="lineno"> 287</span><span class="comment"> * explicitly user-defined semaphore `sema` with it. Pass through `args` as</span></div>
<div class="line"><a id="l00288" name="l00288"></a><span class="lineno"> 288</span><span class="comment"> * USDT arguments. `args` are optional and zero arguments are acceptable.</span></div>
<div class="line"><a id="l00289" name="l00289"></a><span class="lineno"> 289</span><span class="comment"> *</span></div>
<div class="line"><a id="l00290" name="l00290"></a><span class="lineno"> 290</span><span class="comment"> * Semaphore is defined with the help of USDT_DEFINE_SEMA() macro and can be</span></div>
<div class="line"><a id="l00291" name="l00291"></a><span class="lineno"> 291</span><span class="comment"> * checked whether active with USDT_SEMA_IS_ACTIVE().</span></div>
<div class="line"><a id="l00292" name="l00292"></a><span class="lineno"> 292</span><span class="comment"> */</span></div>
<div class="line"><a id="l00293" name="l00293"></a><span class="lineno"> 293</span><span class="preprocessor">#ifdef __usdt_va_opt</span></div>
<div class="line"><a id="l00294" name="l00294"></a><span class="lineno"> 294</span><span class="preprocessor">#define USDT_WITH_EXPLICIT_SEMA(sema, group, name, ...) \</span></div>
<div class="line"><a id="l00295" name="l00295"></a><span class="lineno"> 295</span><span class="preprocessor"> __usdt_probe(group, name, __usdt_sema_explicit, USDT_SEMA(sema), ##__VA_ARGS__)</span></div>
<div class="line"><a id="l00296" name="l00296"></a><span class="lineno"> 296</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00297" name="l00297"></a><span class="lineno"> 297</span><span class="preprocessor">#define USDT_WITH_EXPLICIT_SEMA(sema, group, name, ...) \</span></div>
<div class="line"><a id="l00298" name="l00298"></a><span class="lineno"> 298</span><span class="preprocessor"> __usdt_probe(group, name, __usdt_sema_explicit, USDT_SEMA(sema) __VA_OPT__(,) __VA_ARGS__)</span></div>
<div class="line"><a id="l00299" name="l00299"></a><span class="lineno"> 299</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00300" name="l00300"></a><span class="lineno"> 300</span> </div>
<div class="line"><a id="l00301" name="l00301"></a><span class="lineno"> 301</span><span class="comment">/*</span></div>
<div class="line"><a id="l00302" name="l00302"></a><span class="lineno"> 302</span><span class="comment"> * Adjustable implementation aspects</span></div>
<div class="line"><a id="l00303" name="l00303"></a><span class="lineno"> 303</span><span class="comment"> */</span></div>
<div class="line"><a id="l00304" name="l00304"></a><span class="lineno"> 304</span><span class="preprocessor">#ifndef USDT_ARG_CONSTRAINT</span></div>
<div class="line"><a id="l00305" name="l00305"></a><span class="lineno"> 305</span><span class="preprocessor">#if defined __powerpc__</span></div>
<div class="line"><a id="l00306" name="l00306"></a><span class="lineno"> 306</span><span class="preprocessor">#define USDT_ARG_CONSTRAINT nZr</span></div>
<div class="line"><a id="l00307" name="l00307"></a><span class="lineno"> 307</span><span class="preprocessor">#elif defined __arm__</span></div>
<div class="line"><a id="l00308" name="l00308"></a><span class="lineno"> 308</span><span class="preprocessor">#define USDT_ARG_CONSTRAINT g</span></div>
<div class="line"><a id="l00309" name="l00309"></a><span class="lineno"> 309</span><span class="preprocessor">#elif defined __loongarch__</span></div>
<div class="line"><a id="l00310" name="l00310"></a><span class="lineno"> 310</span><span class="preprocessor">#define USDT_ARG_CONSTRAINT nmr</span></div>
<div class="line"><a id="l00311" name="l00311"></a><span class="lineno"> 311</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00312" name="l00312"></a><span class="lineno"> 312</span><span class="preprocessor">#define USDT_ARG_CONSTRAINT nor</span></div>
<div class="line"><a id="l00313" name="l00313"></a><span class="lineno"> 313</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00314" name="l00314"></a><span class="lineno"> 314</span><span class="preprocessor">#endif </span><span class="comment">/* USDT_ARG_CONSTRAINT */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00315" name="l00315"></a><span class="lineno"> 315</span> </div>
<div class="line"><a id="l00316" name="l00316"></a><span class="lineno"> 316</span><span class="preprocessor">#ifndef USDT_NOP</span></div>
<div class="line"><a id="l00317" name="l00317"></a><span class="lineno"> 317</span><span class="preprocessor">#if defined(__ia64__) || defined(__s390__) || defined(__s390x__)</span></div>
<div class="line"><a id="l00318" name="l00318"></a><span class="lineno"> 318</span><span class="preprocessor">#define USDT_NOP nop 0</span></div>
<div class="line"><a id="l00319" name="l00319"></a><span class="lineno"> 319</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00320" name="l00320"></a><span class="lineno"> 320</span><span class="preprocessor">#define USDT_NOP nop</span></div>
<div class="line"><a id="l00321" name="l00321"></a><span class="lineno"> 321</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00322" name="l00322"></a><span class="lineno"> 322</span><span class="preprocessor">#endif </span><span class="comment">/* USDT_NOP */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00323" name="l00323"></a><span class="lineno"> 323</span> </div>
<div class="line"><a id="l00324" name="l00324"></a><span class="lineno"> 324</span><span class="comment">/*</span></div>
<div class="line"><a id="l00325" name="l00325"></a><span class="lineno"> 325</span><span class="comment"> * Implementation details</span></div>
<div class="line"><a id="l00326" name="l00326"></a><span class="lineno"> 326</span><span class="comment"> */</span></div>
<div class="line"><a id="l00327" name="l00327"></a><span class="lineno"> 327</span><span class="comment">/* USDT name for implicitly-defined USDT semaphore, derived from group:name */</span></div>
<div class="line"><a id="l00328" name="l00328"></a><span class="lineno"> 328</span><span class="preprocessor">#define __usdt_sema_name(group, name) __usdt_sema_##group##__##name</span></div>
<div class="line"><a id="l00329" name="l00329"></a><span class="lineno"> 329</span><span class="comment">/* ELF section into which USDT semaphores are put */</span></div>
<div class="line"><a id="l00330" name="l00330"></a><span class="lineno"> 330</span><span class="preprocessor">#define __usdt_sema_sec __attribute__((section(".probes")))</span></div>
<div class="line"><a id="l00331" name="l00331"></a><span class="lineno"> 331</span> </div>
<div class="line"><a id="l00332" name="l00332"></a><span class="lineno"> 332</span><span class="preprocessor">#define __usdt_concat(a, b) a ## b</span></div>
<div class="line"><a id="l00333" name="l00333"></a><span class="lineno"> 333</span><span class="preprocessor">#define __usdt_apply(fn, n) __usdt_concat(fn, n)</span></div>
<div class="line"><a id="l00334" name="l00334"></a><span class="lineno"> 334</span> </div>
<div class="line"><a id="l00335" name="l00335"></a><span class="lineno"> 335</span><span class="preprocessor">#ifndef __usdt_nth</span></div>
<div class="line"><a id="l00336" name="l00336"></a><span class="lineno"> 336</span><span class="preprocessor">#define __usdt_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, N, ...) N</span></div>
<div class="line"><a id="l00337" name="l00337"></a><span class="lineno"> 337</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00338" name="l00338"></a><span class="lineno"> 338</span> </div>
<div class="line"><a id="l00339" name="l00339"></a><span class="lineno"> 339</span><span class="preprocessor">#ifndef __usdt_narg</span></div>
<div class="line"><a id="l00340" name="l00340"></a><span class="lineno"> 340</span><span class="preprocessor">#ifdef __usdt_va_opt</span></div>
<div class="line"><a id="l00341" name="l00341"></a><span class="lineno"> 341</span><span class="preprocessor">#define __usdt_narg(...) __usdt_nth(_ __VA_OPT__(,) __VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)</span></div>
<div class="line"><a id="l00342" name="l00342"></a><span class="lineno"> 342</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00343" name="l00343"></a><span class="lineno"> 343</span><span class="preprocessor">#define __usdt_narg(...) __usdt_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)</span></div>
<div class="line"><a id="l00344" name="l00344"></a><span class="lineno"> 344</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00345" name="l00345"></a><span class="lineno"> 345</span><span class="preprocessor">#endif </span><span class="comment">/* __usdt_narg */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00346" name="l00346"></a><span class="lineno"> 346</span> </div>
<div class="line"><a id="l00347" name="l00347"></a><span class="lineno"> 347</span><span class="preprocessor">#define __usdt_hash #</span></div>
<div class="line"><a id="l00348" name="l00348"></a><span class="lineno"> 348</span><span class="preprocessor">#define __usdt_str_(x) #x</span></div>
<div class="line"><a id="l00349" name="l00349"></a><span class="lineno"> 349</span><span class="preprocessor">#define __usdt_str(x) __usdt_str_(x)</span></div>
<div class="line"><a id="l00350" name="l00350"></a><span class="lineno"> 350</span> </div>
<div class="line"><a id="l00351" name="l00351"></a><span class="lineno"> 351</span><span class="preprocessor">#ifndef __usdt_asm_name</span></div>
<div class="line"><a id="l00352" name="l00352"></a><span class="lineno"> 352</span><span class="preprocessor">#define __usdt_asm_name(name) __asm__(__usdt_str(name))</span></div>
<div class="line"><a id="l00353" name="l00353"></a><span class="lineno"> 353</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00354" name="l00354"></a><span class="lineno"> 354</span> </div>
<div class="line"><a id="l00355" name="l00355"></a><span class="lineno"> 355</span><span class="preprocessor">#define __usdt_asm1(a) __usdt_str(a) "\n"</span></div>
<div class="line"><a id="l00356" name="l00356"></a><span class="lineno"> 356</span><span class="preprocessor">#define __usdt_asm2(a,b) __usdt_str(a) "," __usdt_str(b) "\n"</span></div>
<div class="line"><a id="l00357" name="l00357"></a><span class="lineno"> 357</span><span class="preprocessor">#define __usdt_asm3(a,b,c) __usdt_str(a) "," __usdt_str(b) "," __usdt_str(c) "\n"</span></div>
<div class="line"><a id="l00358" name="l00358"></a><span class="lineno"> 358</span><span class="preprocessor">#define __usdt_asm5(a,b,c,d,e) __usdt_str(a) "," __usdt_str(b) "," __usdt_str(c) "," \</span></div>
<div class="line"><a id="l00359" name="l00359"></a><span class="lineno"> 359</span><span class="preprocessor"> __usdt_str(d) "," __usdt_str(e) "\n"</span></div>
<div class="line"><a id="l00360" name="l00360"></a><span class="lineno"> 360</span> </div>
<div class="line"><a id="l00361" name="l00361"></a><span class="lineno"> 361</span><span class="preprocessor">#ifdef __LP64__</span></div>
<div class="line"><a id="l00362" name="l00362"></a><span class="lineno"> 362</span><span class="preprocessor">#define __usdt_asm_addr .8byte</span></div>
<div class="line"><a id="l00363" name="l00363"></a><span class="lineno"> 363</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00364" name="l00364"></a><span class="lineno"> 364</span><span class="preprocessor">#define __usdt_asm_addr .4byte</span></div>
<div class="line"><a id="l00365" name="l00365"></a><span class="lineno"> 365</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00366" name="l00366"></a><span class="lineno"> 366</span> </div>
<div class="line"><a id="l00367" name="l00367"></a><span class="lineno"> 367</span><span class="preprocessor">#define __usdt_asm_strz_(x) __usdt_asm1(.asciz #x)</span></div>
<div class="line"><a id="l00368" name="l00368"></a><span class="lineno"> 368</span><span class="preprocessor">#define __usdt_asm_strz(x) __usdt_asm_strz_(x)</span></div>
<div class="line"><a id="l00369" name="l00369"></a><span class="lineno"> 369</span><span class="preprocessor">#define __usdt_asm_str_(x) __usdt_asm1(.ascii #x)</span></div>
<div class="line"><a id="l00370" name="l00370"></a><span class="lineno"> 370</span><span class="preprocessor">#define __usdt_asm_str(x) __usdt_asm_str_(x)</span></div>
<div class="line"><a id="l00371" name="l00371"></a><span class="lineno"> 371</span> </div>
<div class="line"><a id="l00372" name="l00372"></a><span class="lineno"> 372</span><span class="comment">/* "semaphoreless" USDT case */</span></div>
<div class="line"><a id="l00373" name="l00373"></a><span class="lineno"> 373</span><span class="preprocessor">#ifndef __usdt_sema_none</span></div>
<div class="line"><a id="l00374" name="l00374"></a><span class="lineno"> 374</span><span class="preprocessor">#define __usdt_sema_none(sema)</span></div>
<div class="line"><a id="l00375" name="l00375"></a><span class="lineno"> 375</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00376" name="l00376"></a><span class="lineno"> 376</span> </div>
<div class="line"><a id="l00377" name="l00377"></a><span class="lineno"> 377</span><span class="comment">/* implicitly defined __usdt_sema__group__name semaphore (using weak symbols) */</span></div>
<div class="line"><a id="l00378" name="l00378"></a><span class="lineno"> 378</span><span class="preprocessor">#ifndef __usdt_sema_implicit</span></div>
<div class="line"><a id="l00379" name="l00379"></a><span class="lineno"> 379</span><span class="preprocessor">#define __usdt_sema_implicit(sema) \</span></div>
<div class="line"><a id="l00380" name="l00380"></a><span class="lineno"> 380</span><span class="preprocessor"> __asm__ __volatile__ ( \</span></div>
<div class="line"><a id="l00381" name="l00381"></a><span class="lineno"> 381</span><span class="preprocessor"> __usdt_asm1(.ifndef sema) \</span></div>
<div class="line"><a id="l00382" name="l00382"></a><span class="lineno"> 382</span><span class="preprocessor"> __usdt_asm3( .pushsection .probes, "aw", "progbits") \</span></div>
<div class="line"><a id="l00383" name="l00383"></a><span class="lineno"> 383</span><span class="preprocessor"> __usdt_asm1( .weak sema) \</span></div>
<div class="line"><a id="l00384" name="l00384"></a><span class="lineno"> 384</span><span class="preprocessor"> __usdt_asm1( .hidden sema) \</span></div>
<div class="line"><a id="l00385" name="l00385"></a><span class="lineno"> 385</span><span class="preprocessor"> __usdt_asm1( .align 2) \</span></div>
<div class="line"><a id="l00386" name="l00386"></a><span class="lineno"> 386</span><span class="preprocessor"> __usdt_asm1(sema:) \</span></div>
<div class="line"><a id="l00387" name="l00387"></a><span class="lineno"> 387</span><span class="preprocessor"> __usdt_asm1( .zero 2) \</span></div>
<div class="line"><a id="l00388" name="l00388"></a><span class="lineno"> 388</span><span class="preprocessor"> __usdt_asm2( .type sema, @object) \</span></div>
<div class="line"><a id="l00389" name="l00389"></a><span class="lineno"> 389</span><span class="preprocessor"> __usdt_asm2( .size sema, 2) \</span></div>
<div class="line"><a id="l00390" name="l00390"></a><span class="lineno"> 390</span><span class="preprocessor"> __usdt_asm1( .popsection) \</span></div>
<div class="line"><a id="l00391" name="l00391"></a><span class="lineno"> 391</span><span class="preprocessor"> __usdt_asm1(.endif) \</span></div>
<div class="line"><a id="l00392" name="l00392"></a><span class="lineno"> 392</span><span class="preprocessor"> );</span></div>
<div class="line"><a id="l00393" name="l00393"></a><span class="lineno"> 393</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00394" name="l00394"></a><span class="lineno"> 394</span> </div>
<div class="line"><a id="l00395" name="l00395"></a><span class="lineno"> 395</span><span class="comment">/* externally defined semaphore using USDT_DEFINE_SEMA() and passed explicitly by user */</span></div>
<div class="line"><a id="l00396" name="l00396"></a><span class="lineno"> 396</span><span class="preprocessor">#ifndef __usdt_sema_explicit</span></div>
<div class="line"><a id="l00397" name="l00397"></a><span class="lineno"> 397</span><span class="preprocessor">#define __usdt_sema_explicit(sema) \</span></div>
<div class="line"><a id="l00398" name="l00398"></a><span class="lineno"> 398</span><span class="preprocessor"> __asm__ __volatile__ ("" :: "m" (sema));</span></div>
<div class="line"><a id="l00399" name="l00399"></a><span class="lineno"> 399</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00400" name="l00400"></a><span class="lineno"> 400</span> </div>
<div class="line"><a id="l00401" name="l00401"></a><span class="lineno"> 401</span><span class="comment">/* main USDT definition (nop and .note.stapsdt metadata) */</span></div>
<div class="line"><a id="l00402" name="l00402"></a><span class="lineno"> 402</span><span class="preprocessor">#define __usdt_probe(group, name, sema_def, sema, ...) do { \</span></div>
<div class="line"><a id="l00403" name="l00403"></a><span class="lineno"> 403</span><span class="preprocessor"> sema_def(sema) \</span></div>
<div class="line"><a id="l00404" name="l00404"></a><span class="lineno"> 404</span><span class="preprocessor"> __asm__ __volatile__ ( \</span></div>
<div class="line"><a id="l00405" name="l00405"></a><span class="lineno"> 405</span><span class="preprocessor"> __usdt_asm1(990: USDT_NOP) \</span></div>
<div class="line"><a id="l00406" name="l00406"></a><span class="lineno"> 406</span><span class="preprocessor"> __usdt_asm3( .pushsection .note.stapsdt, "", "note") \</span></div>
<div class="line"><a id="l00407" name="l00407"></a><span class="lineno"> 407</span><span class="preprocessor"> __usdt_asm1( .balign 4) \</span></div>
<div class="line"><a id="l00408" name="l00408"></a><span class="lineno"> 408</span><span class="preprocessor"> __usdt_asm3( .4byte 992f-991f,994f-993f,3) \</span></div>
<div class="line"><a id="l00409" name="l00409"></a><span class="lineno"> 409</span><span class="preprocessor"> __usdt_asm1(991: .asciz "stapsdt") \</span></div>
<div class="line"><a id="l00410" name="l00410"></a><span class="lineno"> 410</span><span class="preprocessor"> __usdt_asm1(992: .balign 4) \</span></div>
<div class="line"><a id="l00411" name="l00411"></a><span class="lineno"> 411</span><span class="preprocessor"> __usdt_asm1(993: __usdt_asm_addr 990b) \</span></div>
<div class="line"><a id="l00412" name="l00412"></a><span class="lineno"> 412</span><span class="preprocessor"> __usdt_asm1( __usdt_asm_addr _.stapsdt.base) \</span></div>
<div class="line"><a id="l00413" name="l00413"></a><span class="lineno"> 413</span><span class="preprocessor"> __usdt_asm1( __usdt_asm_addr sema) \</span></div>
<div class="line"><a id="l00414" name="l00414"></a><span class="lineno"> 414</span><span class="preprocessor"> __usdt_asm_strz(group) \</span></div>
<div class="line"><a id="l00415" name="l00415"></a><span class="lineno"> 415</span><span class="preprocessor"> __usdt_asm_strz(name) \</span></div>
<div class="line"><a id="l00416" name="l00416"></a><span class="lineno"> 416</span><span class="preprocessor"> __usdt_asm_args(__VA_ARGS__) \</span></div>
<div class="line"><a id="l00417" name="l00417"></a><span class="lineno"> 417</span><span class="preprocessor"> __usdt_asm1( .ascii "\0") \</span></div>
<div class="line"><a id="l00418" name="l00418"></a><span class="lineno"> 418</span><span class="preprocessor"> __usdt_asm1(994: .balign 4) \</span></div>
<div class="line"><a id="l00419" name="l00419"></a><span class="lineno"> 419</span><span class="preprocessor"> __usdt_asm1( .popsection) \</span></div>
<div class="line"><a id="l00420" name="l00420"></a><span class="lineno"> 420</span><span class="preprocessor"> __usdt_asm1(.ifndef _.stapsdt.base) \</span></div>
<div class="line"><a id="l00421" name="l00421"></a><span class="lineno"> 421</span><span class="preprocessor"> __usdt_asm5( .pushsection .stapsdt.base,"aG","progbits",.stapsdt.base,comdat)\</span></div>
<div class="line"><a id="l00422" name="l00422"></a><span class="lineno"> 422</span><span class="preprocessor"> __usdt_asm1( .weak _.stapsdt.base) \</span></div>
<div class="line"><a id="l00423" name="l00423"></a><span class="lineno"> 423</span><span class="preprocessor"> __usdt_asm1( .hidden _.stapsdt.base) \</span></div>
<div class="line"><a id="l00424" name="l00424"></a><span class="lineno"> 424</span><span class="preprocessor"> __usdt_asm1(_.stapsdt.base:) \</span></div>
<div class="line"><a id="l00425" name="l00425"></a><span class="lineno"> 425</span><span class="preprocessor"> __usdt_asm1( .space 1) \</span></div>
<div class="line"><a id="l00426" name="l00426"></a><span class="lineno"> 426</span><span class="preprocessor"> __usdt_asm2( .size _.stapsdt.base, 1) \</span></div>
<div class="line"><a id="l00427" name="l00427"></a><span class="lineno"> 427</span><span class="preprocessor"> __usdt_asm1( .popsection) \</span></div>
<div class="line"><a id="l00428" name="l00428"></a><span class="lineno"> 428</span><span class="preprocessor"> __usdt_asm1(.endif) \</span></div>
<div class="line"><a id="l00429" name="l00429"></a><span class="lineno"> 429</span><span class="preprocessor"> :: __usdt_asm_ops(__VA_ARGS__) \</span></div>
<div class="line"><a id="l00430" name="l00430"></a><span class="lineno"> 430</span><span class="preprocessor"> ); \</span></div>
<div class="line"><a id="l00431" name="l00431"></a><span class="lineno"> 431</span><span class="preprocessor">} while (0)</span></div>
<div class="line"><a id="l00432" name="l00432"></a><span class="lineno"> 432</span> </div>
<div class="line"><a id="l00433" name="l00433"></a><span class="lineno"> 433</span><span class="comment">/*</span></div>
<div class="line"><a id="l00434" name="l00434"></a><span class="lineno"> 434</span><span class="comment"> * NB: gdb PR24541 highlighted an unspecified corner of the sdt.h</span></div>
<div class="line"><a id="l00435" name="l00435"></a><span class="lineno"> 435</span><span class="comment"> * operand note format.</span></div>
<div class="line"><a id="l00436" name="l00436"></a><span class="lineno"> 436</span><span class="comment"> *</span></div>
<div class="line"><a id="l00437" name="l00437"></a><span class="lineno"> 437</span><span class="comment"> * The named register may be a longer or shorter (!) alias for the</span></div>
<div class="line"><a id="l00438" name="l00438"></a><span class="lineno"> 438</span><span class="comment"> * storage where the value in question is found. For example, on</span></div>
<div class="line"><a id="l00439" name="l00439"></a><span class="lineno"> 439</span><span class="comment"> * i386, 64-bit value may be put in register pairs, and a register</span></div>
<div class="line"><a id="l00440" name="l00440"></a><span class="lineno"> 440</span><span class="comment"> * name stored would identify just one of them. Previously, gcc was</span></div>
<div class="line"><a id="l00441" name="l00441"></a><span class="lineno"> 441</span><span class="comment"> * asked to emit the %w[id] (16-bit alias of some registers holding</span></div>
<div class="line"><a id="l00442" name="l00442"></a><span class="lineno"> 442</span><span class="comment"> * operands), even when a wider 32-bit value was used.</span></div>
<div class="line"><a id="l00443" name="l00443"></a><span class="lineno"> 443</span><span class="comment"> *</span></div>
<div class="line"><a id="l00444" name="l00444"></a><span class="lineno"> 444</span><span class="comment"> * Bottom line: the byte-width given before the @ sign governs. If</span></div>
<div class="line"><a id="l00445" name="l00445"></a><span class="lineno"> 445</span><span class="comment"> * there is a mismatch between that width and that of the named</span></div>
<div class="line"><a id="l00446" name="l00446"></a><span class="lineno"> 446</span><span class="comment"> * register, then a sys/sdt.h note consumer may need to employ</span></div>
<div class="line"><a id="l00447" name="l00447"></a><span class="lineno"> 447</span><span class="comment"> * architecture-specific heuristics to figure out where the compiler</span></div>
<div class="line"><a id="l00448" name="l00448"></a><span class="lineno"> 448</span><span class="comment"> * has actually put the complete value.</span></div>
<div class="line"><a id="l00449" name="l00449"></a><span class="lineno"> 449</span><span class="comment"> */</span></div>
<div class="line"><a id="l00450" name="l00450"></a><span class="lineno"> 450</span><span class="preprocessor">#if defined(__powerpc__) || defined(__powerpc64__)</span></div>
<div class="line"><a id="l00451" name="l00451"></a><span class="lineno"> 451</span><span class="preprocessor">#define __usdt_argref(id) %I[id]%[id]</span></div>
<div class="line"><a id="l00452" name="l00452"></a><span class="lineno"> 452</span><span class="preprocessor">#elif defined(__i386__)</span></div>
<div class="line"><a id="l00453" name="l00453"></a><span class="lineno"> 453</span><span class="preprocessor">#define __usdt_argref(id) %k[id] </span><span class="comment">/* gcc.gnu.org/PR80115 sourceware.org/PR24541 */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00454" name="l00454"></a><span class="lineno"> 454</span><span class="preprocessor">#else</span></div>
<div class="line"><a id="l00455" name="l00455"></a><span class="lineno"> 455</span><span class="preprocessor">#define __usdt_argref(id) %[id]</span></div>
<div class="line"><a id="l00456" name="l00456"></a><span class="lineno"> 456</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00457" name="l00457"></a><span class="lineno"> 457</span> </div>
<div class="line"><a id="l00458" name="l00458"></a><span class="lineno"> 458</span><span class="preprocessor">#define __usdt_asm_arg(n) __usdt_asm_str(%c[__usdt_asz##n]) \</span></div>
<div class="line"><a id="l00459" name="l00459"></a><span class="lineno"> 459</span><span class="preprocessor"> __usdt_asm1(.ascii "@") \</span></div>
<div class="line"><a id="l00460" name="l00460"></a><span class="lineno"> 460</span><span class="preprocessor"> __usdt_asm_str(__usdt_argref(__usdt_aval##n))</span></div>
<div class="line"><a id="l00461" name="l00461"></a><span class="lineno"> 461</span> </div>
<div class="line"><a id="l00462" name="l00462"></a><span class="lineno"> 462</span><span class="preprocessor">#define __usdt_asm_args0 </span><span class="comment">/* no arguments */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00463" name="l00463"></a><span class="lineno"> 463</span><span class="preprocessor">#define __usdt_asm_args1 __usdt_asm_arg(1)</span></div>
<div class="line"><a id="l00464" name="l00464"></a><span class="lineno"> 464</span><span class="preprocessor">#define __usdt_asm_args2 __usdt_asm_args1 __usdt_asm1(.ascii " ") __usdt_asm_arg(2)</span></div>
<div class="line"><a id="l00465" name="l00465"></a><span class="lineno"> 465</span><span class="preprocessor">#define __usdt_asm_args3 __usdt_asm_args2 __usdt_asm1(.ascii " ") __usdt_asm_arg(3)</span></div>
<div class="line"><a id="l00466" name="l00466"></a><span class="lineno"> 466</span><span class="preprocessor">#define __usdt_asm_args4 __usdt_asm_args3 __usdt_asm1(.ascii " ") __usdt_asm_arg(4)</span></div>
<div class="line"><a id="l00467" name="l00467"></a><span class="lineno"> 467</span><span class="preprocessor">#define __usdt_asm_args5 __usdt_asm_args4 __usdt_asm1(.ascii " ") __usdt_asm_arg(5)</span></div>
<div class="line"><a id="l00468" name="l00468"></a><span class="lineno"> 468</span><span class="preprocessor">#define __usdt_asm_args6 __usdt_asm_args5 __usdt_asm1(.ascii " ") __usdt_asm_arg(6)</span></div>
<div class="line"><a id="l00469" name="l00469"></a><span class="lineno"> 469</span><span class="preprocessor">#define __usdt_asm_args7 __usdt_asm_args6 __usdt_asm1(.ascii " ") __usdt_asm_arg(7)</span></div>
<div class="line"><a id="l00470" name="l00470"></a><span class="lineno"> 470</span><span class="preprocessor">#define __usdt_asm_args8 __usdt_asm_args7 __usdt_asm1(.ascii " ") __usdt_asm_arg(8)</span></div>
<div class="line"><a id="l00471" name="l00471"></a><span class="lineno"> 471</span><span class="preprocessor">#define __usdt_asm_args9 __usdt_asm_args8 __usdt_asm1(.ascii " ") __usdt_asm_arg(9)</span></div>
<div class="line"><a id="l00472" name="l00472"></a><span class="lineno"> 472</span><span class="preprocessor">#define __usdt_asm_args10 __usdt_asm_args9 __usdt_asm1(.ascii " ") __usdt_asm_arg(10)</span></div>
<div class="line"><a id="l00473" name="l00473"></a><span class="lineno"> 473</span><span class="preprocessor">#define __usdt_asm_args11 __usdt_asm_args10 __usdt_asm1(.ascii " ") __usdt_asm_arg(11)</span></div>
<div class="line"><a id="l00474" name="l00474"></a><span class="lineno"> 474</span><span class="preprocessor">#define __usdt_asm_args12 __usdt_asm_args11 __usdt_asm1(.ascii " ") __usdt_asm_arg(12)</span></div>
<div class="line"><a id="l00475" name="l00475"></a><span class="lineno"> 475</span><span class="preprocessor">#define __usdt_asm_args(...) __usdt_apply(__usdt_asm_args, __usdt_narg(__VA_ARGS__))</span></div>
<div class="line"><a id="l00476" name="l00476"></a><span class="lineno"> 476</span> </div>
<div class="line"><a id="l00477" name="l00477"></a><span class="lineno"> 477</span><span class="preprocessor">#define __usdt_is_arr(x) (__builtin_classify_type(x) == 14 || __builtin_classify_type(x) == 5)</span></div>
<div class="line"><a id="l00478" name="l00478"></a><span class="lineno"> 478</span><span class="preprocessor">#define __usdt_arg_size(x) (__usdt_is_arr(x) ? sizeof(void *) : sizeof(x))</span></div>
<div class="line"><a id="l00479" name="l00479"></a><span class="lineno"> 479</span> </div>
<div class="line"><a id="l00480" name="l00480"></a><span class="lineno"> 480</span><span class="comment">/*</span></div>
<div class="line"><a id="l00481" name="l00481"></a><span class="lineno"> 481</span><span class="comment"> * We can't use __builtin_choose_expr() in C++, so fall back to table-based</span></div>
<div class="line"><a id="l00482" name="l00482"></a><span class="lineno"> 482</span><span class="comment"> * signedness determination for known types, utilizing templates magic.</span></div>
<div class="line"><a id="l00483" name="l00483"></a><span class="lineno"> 483</span><span class="comment"> */</span></div>
<div class="line"><a id="l00484" name="l00484"></a><span class="lineno"> 484</span><span class="preprocessor">#ifdef __cplusplus</span></div>
<div class="line"><a id="l00485" name="l00485"></a><span class="lineno"> 485</span> </div>
<div class="line"><a id="l00486" name="l00486"></a><span class="lineno"> 486</span><span class="preprocessor">#define __usdt_is_signed(x) (!__usdt_is_arr(x) && __usdt_t<__typeof(x)>::is_signed)</span></div>
<div class="line"><a id="l00487" name="l00487"></a><span class="lineno"> 487</span> </div>
<div class="line"><a id="l00488" name="l00488"></a><span class="lineno"> 488</span><span class="preprocessor">#include <cstddef></span></div>
<div class="line"><a id="l00489" name="l00489"></a><span class="lineno"> 489</span> </div>
<div class="line"><a id="l00490" name="l00490"></a><span class="lineno"> 490</span><span class="keyword">template</span><<span class="keyword">typename</span> T> <span class="keyword">struct </span>__usdt_t { <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">bool</span> is_signed = <span class="keyword">false</span>; };</div>
<div class="line"><a id="l00491" name="l00491"></a><span class="lineno"> 491</span><span class="keyword">template</span><<span class="keyword">typename</span> A> <span class="keyword">struct </span>__usdt_t<A[]> : <span class="keyword">public</span> __usdt_t<A *> {};</div>
<div class="line"><a id="l00492" name="l00492"></a><span class="lineno"> 492</span><span class="keyword">template</span><<span class="keyword">typename</span> A, <span class="keywordtype">size_t</span> N> <span class="keyword">struct </span>__usdt_t<A[N]> : <span class="keyword">public</span> __usdt_t<A *> {};</div>
<div class="line"><a id="l00493" name="l00493"></a><span class="lineno"> 493</span> </div>
<div class="line"><a id="l00494" name="l00494"></a><span class="lineno"> 494</span><span class="preprocessor">#define __usdt_def_signed(T) \</span></div>
<div class="line"><a id="l00495" name="l00495"></a><span class="lineno"> 495</span><span class="preprocessor">template<> struct __usdt_t<T> { static const bool is_signed = true; }; \</span></div>
<div class="line"><a id="l00496" name="l00496"></a><span class="lineno"> 496</span><span class="preprocessor">template<> struct __usdt_t<const T> { static const bool is_signed = true; }; \</span></div>
<div class="line"><a id="l00497" name="l00497"></a><span class="lineno"> 497</span><span class="preprocessor">template<> struct __usdt_t<volatile T> { static const bool is_signed = true; }; \</span></div>
<div class="line"><a id="l00498" name="l00498"></a><span class="lineno"> 498</span><span class="preprocessor">template<> struct __usdt_t<const volatile T> { static const bool is_signed = true; }</span></div>
<div class="line"><a id="l00499" name="l00499"></a><span class="lineno"> 499</span><span class="preprocessor">#define __usdt_maybe_signed(T) \</span></div>
<div class="line"><a id="l00500" name="l00500"></a><span class="lineno"> 500</span><span class="preprocessor">template<> struct __usdt_t<T> { static const bool is_signed = (T)-1 < (T)1; }; \</span></div>
<div class="line"><a id="l00501" name="l00501"></a><span class="lineno"> 501</span><span class="preprocessor">template<> struct __usdt_t<const T> { static const bool is_signed = (T)-1 < (T)1; }; \</span></div>
<div class="line"><a id="l00502" name="l00502"></a><span class="lineno"> 502</span><span class="preprocessor">template<> struct __usdt_t<volatile T> { static const bool is_signed = (T)-1 < (T)1; }; \</span></div>
<div class="line"><a id="l00503" name="l00503"></a><span class="lineno"> 503</span><span class="preprocessor">template<> struct __usdt_t<const volatile T> { static const bool is_signed = (T)-1 < (T)1; }</span></div>
<div class="line"><a id="l00504" name="l00504"></a><span class="lineno"> 504</span> </div>
<div class="line"><a id="l00505" name="l00505"></a><span class="lineno"> 505</span>__usdt_def_signed(<span class="keywordtype">signed</span> <span class="keywordtype">char</span>);</div>
<div class="line"><a id="l00506" name="l00506"></a><span class="lineno"> 506</span>__usdt_def_signed(<span class="keywordtype">short</span>);</div>
<div class="line"><a id="l00507" name="l00507"></a><span class="lineno"> 507</span>__usdt_def_signed(<span class="keywordtype">int</span>);</div>
<div class="line"><a id="l00508" name="l00508"></a><span class="lineno"> 508</span>__usdt_def_signed(<span class="keywordtype">long</span>);</div>
<div class="line"><a id="l00509" name="l00509"></a><span class="lineno"> 509</span>__usdt_def_signed(<span class="keywordtype">long</span> <span class="keywordtype">long</span>);</div>
<div class="line"><a id="l00510" name="l00510"></a><span class="lineno"> 510</span>__usdt_maybe_signed(<span class="keywordtype">char</span>);</div>
<div class="line"><a id="l00511" name="l00511"></a><span class="lineno"> 511</span>__usdt_maybe_signed(<span class="keywordtype">wchar_t</span>);</div>
<div class="line"><a id="l00512" name="l00512"></a><span class="lineno"> 512</span> </div>
<div class="line"><a id="l00513" name="l00513"></a><span class="lineno"> 513</span><span class="preprocessor">#else </span><span class="comment">/* !__cplusplus */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00514" name="l00514"></a><span class="lineno"> 514</span> </div>
<div class="line"><a id="l00515" name="l00515"></a><span class="lineno"> 515</span><span class="preprocessor">#define __usdt_is_inttype(x) (__builtin_classify_type(x) >= 1 && __builtin_classify_type(x) <= 4)</span></div>
<div class="line"><a id="l00516" name="l00516"></a><span class="lineno"> 516</span><span class="preprocessor">#define __usdt_inttype(x) __typeof(__builtin_choose_expr(__usdt_is_inttype(x), (x), 0U))</span></div>
<div class="line"><a id="l00517" name="l00517"></a><span class="lineno"> 517</span><span class="preprocessor">#define __usdt_is_signed(x) ((__usdt_inttype(x))-1 < (__usdt_inttype(x))1)</span></div>
<div class="line"><a id="l00518" name="l00518"></a><span class="lineno"> 518</span> </div>
<div class="line"><a id="l00519" name="l00519"></a><span class="lineno"> 519</span><span class="preprocessor">#endif </span><span class="comment">/* __cplusplus */</span><span class="preprocessor"></span></div>
<div class="line"><a id="l00520" name="l00520"></a><span class="lineno"> 520</span> </div>
<div class="line"><a id="l00521" name="l00521"></a><span class="lineno"> 521</span><span class="preprocessor">#define __usdt_asm_op(n, x) \</span></div>
<div class="line"><a id="l00522" name="l00522"></a><span class="lineno"> 522</span><span class="preprocessor"> [__usdt_asz##n] "n" ((__usdt_is_signed(x) ? (int)-1 : 1) * (int)__usdt_arg_size(x)), \</span></div>
<div class="line"><a id="l00523" name="l00523"></a><span class="lineno"> 523</span><span class="preprocessor"> [__usdt_aval##n] __usdt_str(USDT_ARG_CONSTRAINT)(x)</span></div>
<div class="line"><a id="l00524" name="l00524"></a><span class="lineno"> 524</span> </div>
<div class="line"><a id="l00525" name="l00525"></a><span class="lineno"> 525</span><span class="preprocessor">#define __usdt_asm_ops0() [__usdt_dummy] "g" (0)</span></div>
<div class="line"><a id="l00526" name="l00526"></a><span class="lineno"> 526</span><span class="preprocessor">#define __usdt_asm_ops1(x) __usdt_asm_op(1, x)</span></div>
<div class="line"><a id="l00527" name="l00527"></a><span class="lineno"> 527</span><span class="preprocessor">#define __usdt_asm_ops2(a,x) __usdt_asm_ops1(a), __usdt_asm_op(2, x)</span></div>
<div class="line"><a id="l00528" name="l00528"></a><span class="lineno"> 528</span><span class="preprocessor">#define __usdt_asm_ops3(a,b,x) __usdt_asm_ops2(a,b), __usdt_asm_op(3, x)</span></div>
<div class="line"><a id="l00529" name="l00529"></a><span class="lineno"> 529</span><span class="preprocessor">#define __usdt_asm_ops4(a,b,c,x) __usdt_asm_ops3(a,b,c), __usdt_asm_op(4, x)</span></div>
<div class="line"><a id="l00530" name="l00530"></a><span class="lineno"> 530</span><span class="preprocessor">#define __usdt_asm_ops5(a,b,c,d,x) __usdt_asm_ops4(a,b,c,d), __usdt_asm_op(5, x)</span></div>
<div class="line"><a id="l00531" name="l00531"></a><span class="lineno"> 531</span><span class="preprocessor">#define __usdt_asm_ops6(a,b,c,d,e,x) __usdt_asm_ops5(a,b,c,d,e), __usdt_asm_op(6, x)</span></div>
<div class="line"><a id="l00532" name="l00532"></a><span class="lineno"> 532</span><span class="preprocessor">#define __usdt_asm_ops7(a,b,c,d,e,f,x) __usdt_asm_ops6(a,b,c,d,e,f), __usdt_asm_op(7, x)</span></div>
<div class="line"><a id="l00533" name="l00533"></a><span class="lineno"> 533</span><span class="preprocessor">#define __usdt_asm_ops8(a,b,c,d,e,f,g,x) __usdt_asm_ops7(a,b,c,d,e,f,g), __usdt_asm_op(8, x)</span></div>
<div class="line"><a id="l00534" name="l00534"></a><span class="lineno"> 534</span><span class="preprocessor">#define __usdt_asm_ops9(a,b,c,d,e,f,g,h,x) __usdt_asm_ops8(a,b,c,d,e,f,g,h), __usdt_asm_op(9, x)</span></div>
<div class="line"><a id="l00535" name="l00535"></a><span class="lineno"> 535</span><span class="preprocessor">#define __usdt_asm_ops10(a,b,c,d,e,f,g,h,i,x) __usdt_asm_ops9(a,b,c,d,e,f,g,h,i), __usdt_asm_op(10, x)</span></div>
<div class="line"><a id="l00536" name="l00536"></a><span class="lineno"> 536</span><span class="preprocessor">#define __usdt_asm_ops11(a,b,c,d,e,f,g,h,i,j,x) __usdt_asm_ops10(a,b,c,d,e,f,g,h,i,j), __usdt_asm_op(11, x)</span></div>
<div class="line"><a id="l00537" name="l00537"></a><span class="lineno"> 537</span><span class="preprocessor">#define __usdt_asm_ops12(a,b,c,d,e,f,g,h,i,j,k,x) __usdt_asm_ops11(a,b,c,d,e,f,g,h,i,j,k), __usdt_asm_op(12, x)</span></div>
<div class="line"><a id="l00538" name="l00538"></a><span class="lineno"> 538</span><span class="preprocessor">#define __usdt_asm_ops(...) __usdt_apply(__usdt_asm_ops, __usdt_narg(__VA_ARGS__))(__VA_ARGS__)</span></div>
<div class="line"><a id="l00539" name="l00539"></a><span class="lineno"> 539</span> </div>
<div class="line"><a id="l00540" name="l00540"></a><span class="lineno"> 540</span><span class="preprocessor">#endif </span><span class="comment">/* __USDT_H */</span><span class="preprocessor"></span></div>
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