1 | // |
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2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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3 | // |
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4 | // The contents of this file are covered under the licence agreement in the |
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5 | // file "LICENCE" distributed with Cforall. |
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6 | // |
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7 | // init_once.c -- |
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8 | // |
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9 | // Author : Rob Schluntz |
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10 | // Created On : Tue Jun 14 15:43:35 2016 |
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11 | // Last Modified By : Peter A. Buhr |
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12 | // Last Modified On : Fri Sep 25 15:36:39 2020 |
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13 | // Update Count : 5 |
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14 | // |
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15 | |
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16 | // want to ensure ctor/dtor called at most once per object. |
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17 | // whole point of ctor/dtor is that you don't know what's in |
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18 | // memory when it's first called, so can't rely on member to |
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19 | // determine if this is true. instead, keep an array |
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20 | // of addresses that have been constructed and remove the element |
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21 | // when it's destructed (and vice-versa) |
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22 | |
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23 | //*** setup |
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24 | extern "C" { |
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25 | #define NULL 0 |
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26 | void * malloc(size_t); |
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27 | void free(void *); |
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28 | #define assert(cond) if (! (cond)) { printf("Assertion failed: (%s) at %s:%d\n", #cond, __FILE__, __LINE__); abort(); } |
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29 | void *memset(void *s, int c, size_t n); |
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30 | } |
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31 | |
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32 | // dummy type |
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33 | struct init_once { int * x; }; |
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34 | |
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35 | // array and operations |
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36 | // const int size = 1024; |
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37 | #define size 1024 |
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38 | struct array { |
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39 | init_once * elems[size]; |
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40 | int length; |
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41 | }; |
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42 | void remove(array * arr, init_once * x) { |
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43 | for (int i = 0; i < arr->length; i++) { |
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44 | if ( arr->elems[i] == x ) { |
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45 | arr->elems[i] = arr->elems[--arr->length]; |
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46 | return; |
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47 | } |
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48 | } |
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49 | } |
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50 | void insert(array * arr, init_once * x) { |
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51 | assert( arr->length < size ); |
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52 | arr->elems[arr->length++] = x; |
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53 | } |
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54 | int find(array * arr, init_once * x) { |
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55 | for (int i = 0; i < arr->length; i++) { |
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56 | if ( arr->elems[i] == x ) { |
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57 | return i; |
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58 | } |
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59 | } |
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60 | return -1; |
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61 | } |
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62 | void ?{}(array & arr) { |
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63 | memset(arr.elems, 0, sizeof(arr.elems)); |
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64 | arr.length = 0; |
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65 | } |
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66 | array constructed; |
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67 | array destructed; |
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68 | |
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69 | void ?{}(init_once & x) { |
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70 | assert( find( &constructed, &x ) == -1 ); |
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71 | remove( &destructed, &x ); |
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72 | insert( &constructed, &x ); |
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73 | |
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74 | x.x = (int *)malloc(sizeof(int)); |
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75 | } |
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76 | |
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77 | void ?{}(init_once & x, init_once other) { |
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78 | x{}; // reuse default ctor |
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79 | } |
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80 | |
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81 | void ^?{}(init_once & x) { |
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82 | assert( find( &destructed, &x ) == -1 ); |
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83 | remove( &constructed, &x ); |
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84 | insert( &destructed, &x ); |
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85 | |
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86 | free(x.x); |
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87 | } |
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88 | //*** end setup |
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89 | |
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90 | // test globals |
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91 | init_once x; |
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92 | init_once y = x; |
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93 | |
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94 | void static_variable() { |
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95 | static init_once x; |
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96 | } |
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97 | |
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98 | int main() { |
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99 | // local variables |
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100 | init_once x; |
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101 | init_once y = x; |
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102 | |
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103 | // block scoped variables |
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104 | { |
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105 | init_once x; |
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106 | init_once y = x; |
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107 | } |
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108 | |
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109 | // loop variables |
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110 | for (int i = 0 ; i < 10; i++) { |
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111 | init_once x; |
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112 | init_once y = x; |
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113 | } |
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114 | int i = 0; |
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115 | while (i < 10) { |
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116 | init_once x; |
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117 | init_once y = x; |
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118 | i++; |
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119 | } |
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120 | |
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121 | // declared in a switch block with a break |
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122 | for (int i = 0; i < 10; i++) { |
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123 | switch (10) { |
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124 | case 1: { |
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125 | init_once x; |
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126 | init_once y = x; |
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127 | x{}; // ensure this doesn't execute |
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128 | break; |
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129 | } |
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130 | case 10: { |
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131 | init_once x; |
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132 | init_once y = x; |
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133 | } // fall through |
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134 | default: { |
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135 | init_once x; |
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136 | init_once y = x; |
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137 | break; |
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138 | } |
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139 | } |
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140 | } |
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141 | |
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142 | // labeled break/continue |
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143 | L3: for (int k = 0; k < 10; k++) { |
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144 | init_once x; |
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145 | init_once y = x; |
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146 | L1: for (int i = 0; i < 10; i++){ |
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147 | init_once x; |
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148 | init_once y = x; |
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149 | L2: for (int j = 0; j < 10; j++) { |
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150 | init_once x; |
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151 | init_once y = x; |
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152 | |
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153 | if (i == 0) continue L1; |
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154 | if (i == 1) continue L2; |
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155 | if (i == 2) break L2; |
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156 | if (i == 3) break L1; |
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157 | if (i == 4) continue L3; |
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158 | if (i == 9) break L3; |
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159 | // if (i == 5) goto ; |
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160 | } |
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161 | } |
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162 | } |
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163 | |
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164 | // labeled break/continue with if |
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165 | LL1: for (int k = 0; k < 10; k++) { |
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166 | init_once x; |
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167 | init_once y = x; |
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168 | LL2: for (int i = 0; i < 10; i++){ |
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169 | init_once x; |
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170 | init_once y = x; |
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171 | LL3: if( i < 5) { |
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172 | init_once x; |
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173 | init_once y = x; |
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174 | |
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175 | if (i == 0) continue LL2; |
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176 | if (i == 2) break LL3; |
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177 | if (i == 3) break LL2; |
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178 | if (i == 4) continue LL1; |
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179 | } else { |
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180 | if (i == 9) break LL1; |
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181 | // if (i == 5) goto ; |
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182 | } |
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183 | } |
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184 | } |
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185 | |
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186 | // function-scoped static variable |
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187 | for (int i = 0; i < 10; i++) { |
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188 | static_variable(); |
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189 | } |
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190 | printf( "done\n" ); // non-empty .expect file |
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191 | } |
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192 | |
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193 | // Local Variables: // |
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194 | // tab-width: 4 // |
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195 | // compile-command: "cfa init_once.cfa" // |
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196 | // End: // |
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