usage.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "git-compat-util.h"
   7 #include "cache.h"
   8
   9 static void vreportf(const char *prefix, const char *err, va_list params)
  10 {
  11         char msg[4096];
  12         char *p, *pend = msg + sizeof(msg);
  13         size_t prefix_len = strlen(prefix);
  14
  15         if (sizeof(msg) <= prefix_len) {
  16                 fprintf(stderr, "BUG!!! too long a prefix '%s'\n", prefix);
  17                 abort();
  18         }
  19         memcpy(msg, prefix, prefix_len);
  20         p = msg + prefix_len;
  21         if (vsnprintf(p, pend - p, err, params) < 0)
  22                 *p = '\0'; /* vsnprintf() failed, clip at prefix */
  23
  24         for (; p != pend - 1 && *p; p++) {
  25                 if (iscntrl(*p) && *p != '\t' && *p != '\n')
  26                         *p = '?';
  27         }
  28
  29         *(p++) = '\n'; /* we no longer need a NUL */
  30         fflush(stderr);
  31         write_in_full(2, msg, p - msg);
  32 }
  33
  34 static NORETURN void usage_builtin(const char *err, va_list params)
  35 {
  36         vreportf("usage: ", err, params);
  37
  38         /*
  39          * When we detect a usage error *before* the command dispatch in
  40          * cmd_main(), we don't know what verb to report.  Force it to this
  41          * to facilitate post-processing.
  42          */
  43         trace2_cmd_name("_usage_");
  44
  45         /*
  46          * Currently, the (err, params) are usually just the static usage
  47          * string which isn't very useful here.  Usually, the call site
  48          * manually calls fprintf(stderr,...) with the actual detailed
  49          * syntax error before calling usage().
  50          *
  51          * TODO It would be nice to update the call sites to pass both
  52          * the static usage string and the detailed error message.
  53          */
  54
  55         exit(129);
  56 }
  57
  58 static void die_message_builtin(const char *err, va_list params)
  59 {
  60         trace2_cmd_error_va(err, params);
  61         vreportf("fatal: ", err, params);
  62 }
  63
  64 /*
  65  * We call trace2_cmd_error_va() in the below functions first and
  66  * expect it to va_copy 'params' before using it (because an 'ap' can
  67  * only be walked once).
  68  */
  69 static NORETURN void die_builtin(const char *err, va_list params)
  70 {
  71         report_fn die_message_fn = get_die_message_routine();
  72
  73         die_message_fn(err, params);
  74         exit(128);
  75 }
  76
  77 static void error_builtin(const char *err, va_list params)
  78 {
  79         trace2_cmd_error_va(err, params);
  80
  81         vreportf("error: ", err, params);
  82 }
  83
  84 static void warn_builtin(const char *warn, va_list params)
  85 {
  86         trace2_cmd_error_va(warn, params);
  87
  88         vreportf("warning: ", warn, params);
  89 }
  90
  91 static int die_is_recursing_builtin(void)
  92 {
  93         static int dying;
  94         /*
  95          * Just an arbitrary number X where "a < x < b" where "a" is
  96          * "maximum number of pthreads we'll ever plausibly spawn" and
  97          * "b" is "something less than Inf", since the point is to
  98          * prevent infinite recursion.
  99          */
 100         static const int recursion_limit = 1024;
 101
 102         dying++;
 103         if (dying > recursion_limit) {
 104                 return 1;
 105         } else if (dying == 2) {
 106                 warning("die() called many times. Recursion error or racy threaded death!");
 107                 return 0;
 108         } else {
 109                 return 0;
 110         }
 111 }
 112
 113 /* If we are in a dlopen()ed .so write to a global variable would segfault
 114  * (ugh), so keep things static. */
 115 static NORETURN_PTR report_fn usage_routine = usage_builtin;
 116 static NORETURN_PTR report_fn die_routine = die_builtin;
 117 static report_fn die_message_routine = die_message_builtin;
 118 static report_fn error_routine = error_builtin;
 119 static report_fn warn_routine = warn_builtin;
 120 static int (*die_is_recursing)(void) = die_is_recursing_builtin;
 121
 122 void set_die_routine(NORETURN_PTR report_fn routine)
 123 {
 124         die_routine = routine;
 125 }
 126
 127 report_fn get_die_message_routine(void)
 128 {
 129         return die_message_routine;
 130 }
 131
 132 void set_error_routine(report_fn routine)
 133 {
 134         error_routine = routine;
 135 }
 136
 137 report_fn get_error_routine(void)
 138 {
 139         return error_routine;
 140 }
 141
 142 void set_warn_routine(report_fn routine)
 143 {
 144         warn_routine = routine;
 145 }
 146
 147 report_fn get_warn_routine(void)
 148 {
 149         return warn_routine;
 150 }
 151
 152 void set_die_is_recursing_routine(int (*routine)(void))
 153 {
 154         die_is_recursing = routine;
 155 }
 156
 157 void NORETURN usagef(const char *err, ...)
 158 {
 159         va_list params;
 160
 161         va_start(params, err);
 162         usage_routine(err, params);
 163         va_end(params);
 164 }
 165
 166 void NORETURN usage(const char *err)
 167 {
 168         usagef("%s", err);
 169 }
 170
 171 void NORETURN die(const char *err, ...)
 172 {
 173         va_list params;
 174
 175         if (die_is_recursing()) {
 176                 fputs("fatal: recursion detected in die handler\n", stderr);
 177                 exit(128);
 178         }
 179
 180         va_start(params, err);
 181         die_routine(err, params);
 182         va_end(params);
 183 }
 184
 185 static const char *fmt_with_err(char *buf, int n, const char *fmt)
 186 {
 187         char str_error[256], *err;
 188         int i, j;
 189
 190         err = strerror(errno);
 191         for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
 192                 if ((str_error[j++] = err[i++]) != '%')
 193                         continue;
 194                 if (j < sizeof(str_error) - 1) {
 195                         str_error[j++] = '%';
 196                 } else {
 197                         /* No room to double the '%', so we overwrite it with
 198                          * '\0' below */
 199                         j--;
 200                         break;
 201                 }
 202         }
 203         str_error[j] = 0;
 204         /* Truncation is acceptable here */
 205         snprintf(buf, n, "%s: %s", fmt, str_error);
 206         return buf;
 207 }
 208
 209 void NORETURN die_errno(const char *fmt, ...)
 210 {
 211         char buf[1024];
 212         va_list params;
 213
 214         if (die_is_recursing()) {
 215                 fputs("fatal: recursion detected in die_errno handler\n",
 216                         stderr);
 217                 exit(128);
 218         }
 219
 220         va_start(params, fmt);
 221         die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 222         va_end(params);
 223 }
 224
 225 #undef die_message
 226 int die_message(const char *err, ...)
 227 {
 228         va_list params;
 229
 230         va_start(params, err);
 231         die_message_routine(err, params);
 232         va_end(params);
 233         return 128;
 234 }
 235
 236 #undef die_message_errno
 237 int die_message_errno(const char *fmt, ...)
 238 {
 239         char buf[1024];
 240         va_list params;
 241
 242         va_start(params, fmt);
 243         die_message_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 244         va_end(params);
 245         return 128;
 246 }
 247
 248 #undef error_errno
 249 int error_errno(const char *fmt, ...)
 250 {
 251         char buf[1024];
 252         va_list params;
 253
 254         va_start(params, fmt);
 255         error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 256         va_end(params);
 257         return -1;
 258 }
 259
 260 #undef error
 261 int error(const char *err, ...)
 262 {
 263         va_list params;
 264
 265         va_start(params, err);
 266         error_routine(err, params);
 267         va_end(params);
 268         return -1;
 269 }
 270
 271 void warning_errno(const char *warn, ...)
 272 {
 273         char buf[1024];
 274         va_list params;
 275
 276         va_start(params, warn);
 277         warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
 278         va_end(params);
 279 }
 280
 281 void warning(const char *warn, ...)
 282 {
 283         va_list params;
 284
 285         va_start(params, warn);
 286         warn_routine(warn, params);
 287         va_end(params);
 288 }
 289
 290 /* Only set this, ever, from t/helper/, when verifying that bugs are caught. */
 291 int BUG_exit_code;
 292
 293 static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
 294 {
 295         char prefix[256];
 296         va_list params_copy;
 297         static int in_bug;
 298
 299         va_copy(params_copy, params);
 300
 301         /* truncation via snprintf is OK here */
 302         snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
 303
 304         vreportf(prefix, fmt, params);
 305
 306         if (in_bug)
 307                 abort();
 308         in_bug = 1;
 309
 310         trace2_cmd_error_va(fmt, params_copy);
 311
 312         if (BUG_exit_code)
 313                 exit(BUG_exit_code);
 314         abort();
 315 }
 316
 317 NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
 318 {
 319         va_list ap;
 320         va_start(ap, fmt);
 321         BUG_vfl(file, line, fmt, ap);
 322         va_end(ap);
 323 }
 324
 325 #ifdef SUPPRESS_ANNOTATED_LEAKS
 326 void unleak_memory(const void *ptr, size_t len)
 327 {
 328         static struct suppressed_leak_root {
 329                 struct suppressed_leak_root *next;
 330                 char data[FLEX_ARRAY];
 331         } *suppressed_leaks;
 332         struct suppressed_leak_root *root;
 333
 334         FLEX_ALLOC_MEM(root, data, ptr, len);
 335         root->next = suppressed_leaks;
 336         suppressed_leaks = root;
 337 }
 338 #endif