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 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 NORETURN void die_builtin(const char *err, va_list params)
  59 {
  60         /*
  61          * We call this trace2 function first and expect it to va_copy 'params'
  62          * before using it (because an 'ap' can only be walked once).
  63          */
  64         trace2_cmd_error_va(err, params);
  65
  66         vreportf("fatal: ", err, params);
  67
  68         exit(128);
  69 }
  70
  71 static void error_builtin(const char *err, va_list params)
  72 {
  73         /*
  74          * We call this trace2 function first and expect it to va_copy 'params'
  75          * before using it (because an 'ap' can only be walked once).
  76          */
  77         trace2_cmd_error_va(err, params);
  78
  79         vreportf("error: ", err, params);
  80 }
  81
  82 static void warn_builtin(const char *warn, va_list params)
  83 {
  84         /*
  85          * We call this trace2 function first and expect it to va_copy 'params'
  86          * before using it (because an 'ap' can only be walked once).
  87          */
  88         trace2_cmd_error_va(warn, params);
  89
  90         vreportf("warning: ", warn, params);
  91 }
  92
  93 static int die_is_recursing_builtin(void)
  94 {
  95         static int dying;
  96         /*
  97          * Just an arbitrary number X where "a < x < b" where "a" is
  98          * "maximum number of pthreads we'll ever plausibly spawn" and
  99          * "b" is "something less than Inf", since the point is to
 100          * prevent infinite recursion.
 101          */
 102         static const int recursion_limit = 1024;
 103
 104         dying++;
 105         if (dying > recursion_limit) {
 106                 return 1;
 107         } else if (dying == 2) {
 108                 warning("die() called many times. Recursion error or racy threaded death!");
 109                 return 0;
 110         } else {
 111                 return 0;
 112         }
 113 }
 114
 115 /* If we are in a dlopen()ed .so write to a global variable would segfault
 116  * (ugh), so keep things static. */
 117 static NORETURN_PTR report_fn usage_routine = usage_builtin;
 118 static NORETURN_PTR report_fn die_routine = die_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 void set_error_routine(report_fn routine)
 129 {
 130         error_routine = routine;
 131 }
 132
 133 report_fn get_error_routine(void)
 134 {
 135         return error_routine;
 136 }
 137
 138 void set_warn_routine(report_fn routine)
 139 {
 140         warn_routine = routine;
 141 }
 142
 143 report_fn get_warn_routine(void)
 144 {
 145         return warn_routine;
 146 }
 147
 148 void set_die_is_recursing_routine(int (*routine)(void))
 149 {
 150         die_is_recursing = routine;
 151 }
 152
 153 void NORETURN usagef(const char *err, ...)
 154 {
 155         va_list params;
 156
 157         va_start(params, err);
 158         usage_routine(err, params);
 159         va_end(params);
 160 }
 161
 162 void NORETURN usage(const char *err)
 163 {
 164         usagef("%s", err);
 165 }
 166
 167 void NORETURN die(const char *err, ...)
 168 {
 169         va_list params;
 170
 171         if (die_is_recursing()) {
 172                 fputs("fatal: recursion detected in die handler\n", stderr);
 173                 exit(128);
 174         }
 175
 176         va_start(params, err);
 177         die_routine(err, params);
 178         va_end(params);
 179 }
 180
 181 static const char *fmt_with_err(char *buf, int n, const char *fmt)
 182 {
 183         char str_error[256], *err;
 184         int i, j;
 185
 186         err = strerror(errno);
 187         for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
 188                 if ((str_error[j++] = err[i++]) != '%')
 189                         continue;
 190                 if (j < sizeof(str_error) - 1) {
 191                         str_error[j++] = '%';
 192                 } else {
 193                         /* No room to double the '%', so we overwrite it with
 194                          * '\0' below */
 195                         j--;
 196                         break;
 197                 }
 198         }
 199         str_error[j] = 0;
 200         /* Truncation is acceptable here */
 201         snprintf(buf, n, "%s: %s", fmt, str_error);
 202         return buf;
 203 }
 204
 205 void NORETURN die_errno(const char *fmt, ...)
 206 {
 207         char buf[1024];
 208         va_list params;
 209
 210         if (die_is_recursing()) {
 211                 fputs("fatal: recursion detected in die_errno handler\n",
 212                         stderr);
 213                 exit(128);
 214         }
 215
 216         va_start(params, fmt);
 217         die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 218         va_end(params);
 219 }
 220
 221 #undef error_errno
 222 int error_errno(const char *fmt, ...)
 223 {
 224         char buf[1024];
 225         va_list params;
 226
 227         va_start(params, fmt);
 228         error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 229         va_end(params);
 230         return -1;
 231 }
 232
 233 #undef error
 234 int error(const char *err, ...)
 235 {
 236         va_list params;
 237
 238         va_start(params, err);
 239         error_routine(err, params);
 240         va_end(params);
 241         return -1;
 242 }
 243
 244 void warning_errno(const char *warn, ...)
 245 {
 246         char buf[1024];
 247         va_list params;
 248
 249         va_start(params, warn);
 250         warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
 251         va_end(params);
 252 }
 253
 254 void warning(const char *warn, ...)
 255 {
 256         va_list params;
 257
 258         va_start(params, warn);
 259         warn_routine(warn, params);
 260         va_end(params);
 261 }
 262
 263 /* Only set this, ever, from t/helper/, when verifying that bugs are caught. */
 264 int BUG_exit_code;
 265
 266 static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
 267 {
 268         char prefix[256];
 269         va_list params_copy;
 270         static int in_bug;
 271
 272         va_copy(params_copy, params);
 273
 274         /* truncation via snprintf is OK here */
 275         if (file)
 276                 snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
 277         else
 278                 snprintf(prefix, sizeof(prefix), "BUG: ");
 279
 280         vreportf(prefix, fmt, params);
 281
 282         if (in_bug)
 283                 abort();
 284         in_bug = 1;
 285
 286         trace2_cmd_error_va(fmt, params_copy);
 287
 288         if (BUG_exit_code)
 289                 exit(BUG_exit_code);
 290         abort();
 291 }
 292
 293 #ifdef HAVE_VARIADIC_MACROS
 294 NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
 295 {
 296         va_list ap;
 297         va_start(ap, fmt);
 298         BUG_vfl(file, line, fmt, ap);
 299         va_end(ap);
 300 }
 301 #else
 302 NORETURN void BUG(const char *fmt, ...)
 303 {
 304         va_list ap;
 305         va_start(ap, fmt);
 306         BUG_vfl(NULL, 0, fmt, ap);
 307         va_end(ap);
 308 }
 309 #endif
 310
 311 #ifdef SUPPRESS_ANNOTATED_LEAKS
 312 void unleak_memory(const void *ptr, size_t len)
 313 {
 314         static struct suppressed_leak_root {
 315                 struct suppressed_leak_root *next;
 316                 char data[FLEX_ARRAY];
 317         } *suppressed_leaks;
 318         struct suppressed_leak_root *root;
 319
 320         FLEX_ALLOC_MEM(root, data, ptr, len);
 321         root->next = suppressed_leaks;
 322         suppressed_leaks = root;
 323 }
 324 #endif