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 "gettext.h"
   8 #include "trace2.h"
   9
  10 static void vreportf(const char *prefix, const char *err, va_list params)
  11 {
  12         char msg[4096];
  13         char *p, *pend = msg + sizeof(msg);
  14         size_t prefix_len = strlen(prefix);
  15
  16         if (sizeof(msg) <= prefix_len) {
  17                 fprintf(stderr, "BUG!!! too long a prefix '%s'\n", prefix);
  18                 abort();
  19         }
  20         memcpy(msg, prefix, prefix_len);
  21         p = msg + prefix_len;
  22         if (vsnprintf(p, pend - p, err, params) < 0)
  23                 *p = '\0'; /* vsnprintf() failed, clip at prefix */
  24
  25         for (; p != pend - 1 && *p; p++) {
  26                 if (iscntrl(*p) && *p != '\t' && *p != '\n')
  27                         *p = '?';
  28         }
  29
  30         *(p++) = '\n'; /* we no longer need a NUL */
  31         fflush(stderr);
  32         write_in_full(2, msg, p - msg);
  33 }
  34
  35 static NORETURN void usage_builtin(const char *err, va_list params)
  36 {
  37         vreportf(_("usage: "), err, params);
  38
  39         /*
  40          * When we detect a usage error *before* the command dispatch in
  41          * cmd_main(), we don't know what verb to report.  Force it to this
  42          * to facilitate post-processing.
  43          */
  44         trace2_cmd_name("_usage_");
  45
  46         /*
  47          * Currently, the (err, params) are usually just the static usage
  48          * string which isn't very useful here.  Usually, the call site
  49          * manually calls fprintf(stderr,...) with the actual detailed
  50          * syntax error before calling usage().
  51          *
  52          * TODO It would be nice to update the call sites to pass both
  53          * the static usage string and the detailed error message.
  54          */
  55
  56         exit(129);
  57 }
  58
  59 static void die_message_builtin(const char *err, va_list params)
  60 {
  61         trace2_cmd_error_va(err, params);
  62         vreportf(_("fatal: "), err, params);
  63 }
  64
  65 /*
  66  * We call trace2_cmd_error_va() in the below functions first and
  67  * expect it to va_copy 'params' before using it (because an 'ap' can
  68  * only be walked once).
  69  */
  70 static NORETURN void die_builtin(const char *err, va_list params)
  71 {
  72         report_fn die_message_fn = get_die_message_routine();
  73
  74         die_message_fn(err, params);
  75         exit(128);
  76 }
  77
  78 static void error_builtin(const char *err, va_list params)
  79 {
  80         trace2_cmd_error_va(err, params);
  81
  82         vreportf(_("error: "), err, params);
  83 }
  84
  85 static void warn_builtin(const char *warn, va_list params)
  86 {
  87         trace2_cmd_error_va(warn, params);
  88
  89         vreportf(_("warning: "), warn, params);
  90 }
  91
  92 static int die_is_recursing_builtin(void)
  93 {
  94         static int dying;
  95         /*
  96          * Just an arbitrary number X where "a < x < b" where "a" is
  97          * "maximum number of pthreads we'll ever plausibly spawn" and
  98          * "b" is "something less than Inf", since the point is to
  99          * prevent infinite recursion.
 100          */
 101         static const int recursion_limit = 1024;
 102
 103         dying++;
 104         if (dying > recursion_limit) {
 105                 return 1;
 106         } else if (dying == 2) {
 107                 warning("die() called many times. Recursion error or racy threaded death!");
 108                 return 0;
 109         } else {
 110                 return 0;
 111         }
 112 }
 113
 114 /* If we are in a dlopen()ed .so write to a global variable would segfault
 115  * (ugh), so keep things static. */
 116 static NORETURN_PTR report_fn usage_routine = usage_builtin;
 117 static NORETURN_PTR report_fn die_routine = die_builtin;
 118 static report_fn die_message_routine = die_message_builtin;
 119 static report_fn error_routine = error_builtin;
 120 static report_fn warn_routine = warn_builtin;
 121 static int (*die_is_recursing)(void) = die_is_recursing_builtin;
 122
 123 void set_die_routine(NORETURN_PTR report_fn routine)
 124 {
 125         die_routine = routine;
 126 }
 127
 128 report_fn get_die_message_routine(void)
 129 {
 130         return die_message_routine;
 131 }
 132
 133 void set_error_routine(report_fn routine)
 134 {
 135         error_routine = routine;
 136 }
 137
 138 report_fn get_error_routine(void)
 139 {
 140         return error_routine;
 141 }
 142
 143 void set_warn_routine(report_fn routine)
 144 {
 145         warn_routine = routine;
 146 }
 147
 148 report_fn get_warn_routine(void)
 149 {
 150         return warn_routine;
 151 }
 152
 153 void set_die_is_recursing_routine(int (*routine)(void))
 154 {
 155         die_is_recursing = routine;
 156 }
 157
 158 void NORETURN usagef(const char *err, ...)
 159 {
 160         va_list params;
 161
 162         va_start(params, err);
 163         usage_routine(err, params);
 164         va_end(params);
 165 }
 166
 167 void NORETURN usage(const char *err)
 168 {
 169         usagef("%s", err);
 170 }
 171
 172 void NORETURN die(const char *err, ...)
 173 {
 174         va_list params;
 175
 176         if (die_is_recursing()) {
 177                 fputs("fatal: recursion detected in die handler\n", stderr);
 178                 exit(128);
 179         }
 180
 181         va_start(params, err);
 182         die_routine(err, params);
 183         va_end(params);
 184 }
 185
 186 static const char *fmt_with_err(char *buf, int n, const char *fmt)
 187 {
 188         char str_error[256], *err;
 189         int i, j;
 190
 191         err = strerror(errno);
 192         for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
 193                 if ((str_error[j++] = err[i++]) != '%')
 194                         continue;
 195                 if (j < sizeof(str_error) - 1) {
 196                         str_error[j++] = '%';
 197                 } else {
 198                         /* No room to double the '%', so we overwrite it with
 199                          * '\0' below */
 200                         j--;
 201                         break;
 202                 }
 203         }
 204         str_error[j] = 0;
 205         /* Truncation is acceptable here */
 206         snprintf(buf, n, "%s: %s", fmt, str_error);
 207         return buf;
 208 }
 209
 210 void NORETURN die_errno(const char *fmt, ...)
 211 {
 212         char buf[1024];
 213         va_list params;
 214
 215         if (die_is_recursing()) {
 216                 fputs("fatal: recursion detected in die_errno handler\n",
 217                         stderr);
 218                 exit(128);
 219         }
 220
 221         va_start(params, fmt);
 222         die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 223         va_end(params);
 224 }
 225
 226 #undef die_message
 227 int die_message(const char *err, ...)
 228 {
 229         va_list params;
 230
 231         va_start(params, err);
 232         die_message_routine(err, params);
 233         va_end(params);
 234         return 128;
 235 }
 236
 237 #undef die_message_errno
 238 int die_message_errno(const char *fmt, ...)
 239 {
 240         char buf[1024];
 241         va_list params;
 242
 243         va_start(params, fmt);
 244         die_message_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 245         va_end(params);
 246         return 128;
 247 }
 248
 249 #undef error_errno
 250 int error_errno(const char *fmt, ...)
 251 {
 252         char buf[1024];
 253         va_list params;
 254
 255         va_start(params, fmt);
 256         error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 257         va_end(params);
 258         return -1;
 259 }
 260
 261 #undef error
 262 int error(const char *err, ...)
 263 {
 264         va_list params;
 265
 266         va_start(params, err);
 267         error_routine(err, params);
 268         va_end(params);
 269         return -1;
 270 }
 271
 272 void warning_errno(const char *warn, ...)
 273 {
 274         char buf[1024];
 275         va_list params;
 276
 277         va_start(params, warn);
 278         warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
 279         va_end(params);
 280 }
 281
 282 void warning(const char *warn, ...)
 283 {
 284         va_list params;
 285
 286         va_start(params, warn);
 287         warn_routine(warn, params);
 288         va_end(params);
 289 }
 290
 291 /* Only set this, ever, from t/helper/, when verifying that bugs are caught. */
 292 int BUG_exit_code;
 293
 294 static void BUG_vfl_common(const char *file, int line, const char *fmt,
 295                            va_list params)
 296 {
 297         char prefix[256];
 298
 299         /* truncation via snprintf is OK here */
 300         snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
 301
 302         vreportf(prefix, fmt, params);
 303 }
 304
 305 static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
 306 {
 307         va_list params_copy;
 308         static int in_bug;
 309
 310         va_copy(params_copy, params);
 311         BUG_vfl_common(file, line, fmt, params);
 312
 313         if (in_bug)
 314                 abort();
 315         in_bug = 1;
 316
 317         trace2_cmd_error_va(fmt, params_copy);
 318
 319         if (BUG_exit_code)
 320                 exit(BUG_exit_code);
 321         abort();
 322 }
 323
 324 NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
 325 {
 326         va_list ap;
 327
 328         bug_called_must_BUG = 0;
 329
 330         va_start(ap, fmt);
 331         BUG_vfl(file, line, fmt, ap);
 332         va_end(ap);
 333 }
 334
 335 int bug_called_must_BUG;
 336 void bug_fl(const char *file, int line, const char *fmt, ...)
 337 {
 338         va_list ap;
 339
 340         bug_called_must_BUG = 1;
 341
 342         va_start(ap, fmt);
 343         BUG_vfl_common(file, line, fmt, ap);
 344         va_end(ap);
 345
 346         va_start(ap, fmt);
 347         trace2_cmd_error_va(fmt, ap);
 348         va_end(ap);
 349 }
 350
 351 #ifdef SUPPRESS_ANNOTATED_LEAKS
 352 void unleak_memory(const void *ptr, size_t len)
 353 {
 354         static struct suppressed_leak_root {
 355                 struct suppressed_leak_root *next;
 356                 char data[FLEX_ARRAY];
 357         } *suppressed_leaks;
 358         struct suppressed_leak_root *root;
 359
 360         FLEX_ALLOC_MEM(root, data, ptr, len);
 361         root->next = suppressed_leaks;
 362         suppressed_leaks = root;
 363 }
 364 #endif