1 | /* |
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2 | * malloc routines with failure handling. |
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3 | * |
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4 | * Usage: |
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5 | * |
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6 | * extern xmalloc_handler_t memory_error; |
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7 | * extern const char *string; |
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8 | * char *buffer; |
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9 | * va_list args; |
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10 | * |
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11 | * xmalloc_error_handler = memory_error; |
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12 | * buffer = xmalloc(1024); |
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13 | * xrealloc(buffer, 2048); |
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14 | * free(buffer); |
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15 | * buffer = xcalloc(1024); |
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16 | * free(buffer); |
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17 | * buffer = xstrdup(string); |
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18 | * free(buffer); |
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19 | * buffer = xstrndup(string, 25); |
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20 | * free(buffer); |
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21 | * xasprintf(&buffer, "%s", "some string"); |
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22 | * free(buffer); |
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23 | * xvasprintf(&buffer, "%s", args); |
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24 | * |
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25 | * xmalloc, xcalloc, xrealloc, and xstrdup behave exactly like their C library |
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26 | * counterparts without the leading x except that they will never return NULL. |
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27 | * Instead, on error, they call xmalloc_error_handler, passing it the name of |
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28 | * the function whose memory allocation failed, the amount of the allocation, |
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29 | * and the file and line number where the allocation function was invoked |
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30 | * (from __FILE__ and __LINE__). This function may do whatever it wishes, |
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31 | * such as some action to free up memory or a call to sleep to hope that |
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32 | * system resources return. If the handler returns, the interrupted memory |
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33 | * allocation function will try its allocation again (calling the handler |
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34 | * again if it still fails). |
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35 | * |
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36 | * xstrndup behaves like xstrdup but only copies the given number of |
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37 | * characters. It allocates an additional byte over its second argument and |
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38 | * always nul-terminates the string. |
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39 | * |
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40 | * xasprintf and xvasprintf behave just like their GNU glibc library |
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41 | * implementations except that they do the same checking as described above. |
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42 | * xasprintf will only be able to provide accurate file and line information |
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43 | * on systems that support variadic macros. |
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44 | * |
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45 | * The default error handler, if none is set by the caller, prints an error |
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46 | * message to stderr and exits with exit status 1. An error handler must take |
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47 | * a const char * (function name), size_t (bytes allocated), const char * |
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48 | * (file), and int (line). |
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49 | * |
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50 | * xmalloc will return a pointer to a valid memory region on an xmalloc of 0 |
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51 | * bytes, ensuring this by allocating space for one character instead of 0 |
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52 | * bytes. |
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53 | * |
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54 | * The functions defined here are actually x_malloc, x_realloc, etc. The |
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55 | * header file defines macros named xmalloc, etc. that pass the file name and |
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56 | * line number to these functions. |
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57 | * |
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58 | * Copyright (c) 2004, 2005, 2006 |
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59 | * by Internet Systems Consortium, Inc. ("ISC") |
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60 | * Copyright (c) 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, |
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61 | * 2002, 2003 by The Internet Software Consortium and Rich Salz |
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62 | * |
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63 | * See LICENSE for licensing terms. |
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64 | */ |
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65 | |
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66 | #include <config.h> |
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67 | #include <portable/system.h> |
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68 | |
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69 | #include <errno.h> |
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70 | |
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71 | #include <util/util.h> |
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72 | |
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73 | |
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74 | /* |
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75 | * The default error handler. |
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76 | */ |
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77 | void |
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78 | xmalloc_fail(const char *function, size_t size, const char *file, int line) |
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79 | { |
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80 | sysdie("failed to %s %lu bytes at %s line %d", function, |
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81 | (unsigned long) size, file, line); |
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82 | } |
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83 | |
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84 | /* Assign to this variable to choose a handler other than the default. */ |
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85 | xmalloc_handler_type xmalloc_error_handler = xmalloc_fail; |
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86 | |
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87 | |
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88 | void * |
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89 | x_malloc(size_t size, const char *file, int line) |
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90 | { |
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91 | void *p; |
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92 | size_t real_size; |
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93 | |
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94 | real_size = (size > 0) ? size : 1; |
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95 | p = malloc(real_size); |
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96 | while (p == NULL) { |
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97 | (*xmalloc_error_handler)("malloc", size, file, line); |
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98 | p = malloc(real_size); |
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99 | } |
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100 | return p; |
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101 | } |
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102 | |
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103 | |
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104 | void * |
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105 | x_calloc(size_t n, size_t size, const char *file, int line) |
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106 | { |
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107 | void *p; |
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108 | |
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109 | n = (n > 0) ? n : 1; |
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110 | size = (size > 0) ? size : 1; |
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111 | p = calloc(n, size); |
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112 | while (p == NULL) { |
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113 | (*xmalloc_error_handler)("calloc", n * size, file, line); |
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114 | p = calloc(n, size); |
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115 | } |
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116 | return p; |
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117 | } |
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118 | |
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119 | |
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120 | void * |
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121 | x_realloc(void *p, size_t size, const char *file, int line) |
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122 | { |
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123 | void *newp; |
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124 | |
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125 | newp = realloc(p, size); |
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126 | while (newp == NULL && size > 0) { |
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127 | (*xmalloc_error_handler)("realloc", size, file, line); |
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128 | newp = realloc(p, size); |
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129 | } |
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130 | return newp; |
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131 | } |
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132 | |
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133 | |
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134 | char * |
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135 | x_strdup(const char *s, const char *file, int line) |
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136 | { |
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137 | char *p; |
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138 | size_t len; |
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139 | |
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140 | len = strlen(s) + 1; |
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141 | p = malloc(len); |
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142 | while (p == NULL) { |
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143 | (*xmalloc_error_handler)("strdup", len, file, line); |
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144 | p = malloc(len); |
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145 | } |
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146 | memcpy(p, s, len); |
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147 | return p; |
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148 | } |
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149 | |
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150 | |
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151 | char * |
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152 | x_strndup(const char *s, size_t size, const char *file, int line) |
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153 | { |
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154 | char *p; |
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155 | |
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156 | p = malloc(size + 1); |
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157 | while (p == NULL) { |
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158 | (*xmalloc_error_handler)("strndup", size + 1, file, line); |
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159 | p = malloc(size + 1); |
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160 | } |
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161 | memcpy(p, s, size); |
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162 | p[size] = '\0'; |
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163 | return p; |
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164 | } |
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165 | |
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166 | |
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167 | int |
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168 | x_vasprintf(char **strp, const char *fmt, va_list args, const char *file, |
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169 | int line) |
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170 | { |
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171 | va_list args_copy; |
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172 | int status; |
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173 | |
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174 | va_copy(args_copy, args); |
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175 | status = vasprintf(strp, fmt, args_copy); |
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176 | va_end(args_copy); |
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177 | while (status < 0 && errno == ENOMEM) { |
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178 | va_copy(args_copy, args); |
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179 | status = vsnprintf(NULL, 0, fmt, args_copy); |
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180 | va_end(args_copy); |
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181 | (*xmalloc_error_handler)("vasprintf", status + 1, file, line); |
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182 | va_copy(args_copy, args); |
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183 | status = vasprintf(strp, fmt, args_copy); |
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184 | va_end(args_copy); |
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185 | } |
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186 | return status; |
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187 | } |
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188 | |
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189 | |
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190 | #if HAVE_C99_VAMACROS || HAVE_GNU_VAMACROS |
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191 | int |
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192 | x_asprintf(char **strp, const char *file, int line, const char *fmt, ...) |
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193 | { |
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194 | va_list args, args_copy; |
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195 | int status; |
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196 | |
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197 | va_start(args, fmt); |
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198 | va_copy(args_copy, args); |
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199 | status = vasprintf(strp, fmt, args_copy); |
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200 | va_end(args_copy); |
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201 | while (status < 0 && errno == ENOMEM) { |
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202 | va_copy(args_copy, args); |
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203 | status = vsnprintf(NULL, 0, fmt, args_copy); |
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204 | va_end(args_copy); |
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205 | (*xmalloc_error_handler)("asprintf", status + 1, file, line); |
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206 | va_copy(args_copy, args); |
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207 | status = vasprintf(strp, fmt, args_copy); |
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208 | va_end(args_copy); |
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209 | } |
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210 | return status; |
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211 | } |
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212 | #else /* !(HAVE_C99_VAMACROS || HAVE_GNU_VAMACROS) */ |
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213 | int |
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214 | x_asprintf(char **strp, const char *fmt, ...) |
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215 | { |
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216 | va_list args, args_copy; |
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217 | int status; |
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218 | |
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219 | va_start(args, fmt); |
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220 | va_copy(args_copy, args); |
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221 | status = vasprintf(strp, fmt, args_copy); |
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222 | va_end(args_copy); |
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223 | while (status < 0 && errno == ENOMEM) { |
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224 | va_copy(args_copy, args); |
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225 | status = vsnprintf(NULL, 0, fmt, args_copy); |
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226 | va_end(args_copy); |
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227 | (*xmalloc_error_handler)("asprintf", status + 1, __FILE__, __LINE__); |
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228 | va_copy(args_copy, args); |
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229 | status = vasprintf(strp, fmt, args_copy); |
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230 | va_end(args_copy); |
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231 | } |
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232 | return status; |
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233 | } |
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234 | #endif /* !(HAVE_C99_VAMACROS || HAVE_GNU_VAMACROS) */ |
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