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         vreportf("warning: ", warn, params);
  85 }
  86
  87 static int die_is_recursing_builtin(void)
  88 {
  89         static int dying;
  90         /*
  91          * Just an arbitrary number X where "a < x < b" where "a" is
  92          * "maximum number of pthreads we'll ever plausibly spawn" and
  93          * "b" is "something less than Inf", since the point is to
  94          * prevent infinite recursion.
  95          */
  96         static const int recursion_limit = 1024;
  97
  98         dying++;
  99         if (dying > recursion_limit) {
 100                 return 1;
 101         } else if (dying == 2) {
 102                 warning("die() called many times. Recursion error or racy threaded death!");
 103                 return 0;
 104         } else {
 105                 return 0;
 106         }
 107 }
 108
 109 /* If we are in a dlopen()ed .so write to a global variable would segfault
 110  * (ugh), so keep things static. */
 111 static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
 112 static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
 113 static void (*error_routine)(const char *err, va_list params) = error_builtin;
 114 static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
 115 static int (*die_is_recursing)(void) = die_is_recursing_builtin;
 116
 117 void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
 118 {
 119         die_routine = routine;
 120 }
 121
 122 void set_error_routine(void (*routine)(const char *err, va_list params))
 123 {
 124         error_routine = routine;
 125 }
 126
 127 void (*get_error_routine(void))(const char *err, va_list params)
 128 {
 129         return error_routine;
 130 }
 131
 132 void set_warn_routine(void (*routine)(const char *warn, va_list params))
 133 {
 134         warn_routine = routine;
 135 }
 136
 137 void (*get_warn_routine(void))(const char *warn, va_list params)
 138 {
 139         return warn_routine;
 140 }
 141
 142 void set_die_is_recursing_routine(int (*routine)(void))
 143 {
 144         die_is_recursing = routine;
 145 }
 146
 147 void NORETURN usagef(const char *err, ...)
 148 {
 149         va_list params;
 150
 151         va_start(params, err);
 152         usage_routine(err, params);
 153         va_end(params);
 154 }
 155
 156 void NORETURN usage(const char *err)
 157 {
 158         usagef("%s", err);
 159 }
 160
 161 void NORETURN die(const char *err, ...)
 162 {
 163         va_list params;
 164
 165         if (die_is_recursing()) {
 166                 fputs("fatal: recursion detected in die handler\n", stderr);
 167                 exit(128);
 168         }
 169
 170         va_start(params, err);
 171         die_routine(err, params);
 172         va_end(params);
 173 }
 174
 175 static const char *fmt_with_err(char *buf, int n, const char *fmt)
 176 {
 177         char str_error[256], *err;
 178         int i, j;
 179
 180         err = strerror(errno);
 181         for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
 182                 if ((str_error[j++] = err[i++]) != '%')
 183                         continue;
 184                 if (j < sizeof(str_error) - 1) {
 185                         str_error[j++] = '%';
 186                 } else {
 187                         /* No room to double the '%', so we overwrite it with
 188                          * '\0' below */
 189                         j--;
 190                         break;
 191                 }
 192         }
 193         str_error[j] = 0;
 194         /* Truncation is acceptable here */
 195         snprintf(buf, n, "%s: %s", fmt, str_error);
 196         return buf;
 197 }
 198
 199 void NORETURN die_errno(const char *fmt, ...)
 200 {
 201         char buf[1024];
 202         va_list params;
 203
 204         if (die_is_recursing()) {
 205                 fputs("fatal: recursion detected in die_errno handler\n",
 206                         stderr);
 207                 exit(128);
 208         }
 209
 210         va_start(params, fmt);
 211         die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 212         va_end(params);
 213 }
 214
 215 #undef error_errno
 216 int error_errno(const char *fmt, ...)
 217 {
 218         char buf[1024];
 219         va_list params;
 220
 221         va_start(params, fmt);
 222         error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 223         va_end(params);
 224         return -1;
 225 }
 226
 227 #undef error
 228 int error(const char *err, ...)
 229 {
 230         va_list params;
 231
 232         va_start(params, err);
 233         error_routine(err, params);
 234         va_end(params);
 235         return -1;
 236 }
 237
 238 void warning_errno(const char *warn, ...)
 239 {
 240         char buf[1024];
 241         va_list params;
 242
 243         va_start(params, warn);
 244         warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
 245         va_end(params);
 246 }
 247
 248 void warning(const char *warn, ...)
 249 {
 250         va_list params;
 251
 252         va_start(params, warn);
 253         warn_routine(warn, params);
 254         va_end(params);
 255 }
 256
 257 /* Only set this, ever, from t/helper/, when verifying that bugs are caught. */
 258 int BUG_exit_code;
 259
 260 static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
 261 {
 262         char prefix[256];
 263
 264         /* truncation via snprintf is OK here */
 265         if (file)
 266                 snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
 267         else
 268                 snprintf(prefix, sizeof(prefix), "BUG: ");
 269
 270         vreportf(prefix, fmt, params);
 271         if (BUG_exit_code)
 272                 exit(BUG_exit_code);
 273         abort();
 274 }
 275
 276 #ifdef HAVE_VARIADIC_MACROS
 277 NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
 278 {
 279         va_list ap;
 280         va_start(ap, fmt);
 281         BUG_vfl(file, line, fmt, ap);
 282         va_end(ap);
 283 }
 284 #else
 285 NORETURN void BUG(const char *fmt, ...)
 286 {
 287         va_list ap;
 288         va_start(ap, fmt);
 289         BUG_vfl(NULL, 0, fmt, ap);
 290         va_end(ap);
 291 }
 292 #endif
 293
 294 #ifdef SUPPRESS_ANNOTATED_LEAKS
 295 void unleak_memory(const void *ptr, size_t len)
 296 {
 297         static struct suppressed_leak_root {
 298                 struct suppressed_leak_root *next;
 299                 char data[FLEX_ARRAY];
 300         } *suppressed_leaks;
 301         struct suppressed_leak_root *root;
 302
 303         FLEX_ALLOC_MEM(root, data, ptr, len);
 304         root->next = suppressed_leaks;
 305         suppressed_leaks = root;
 306 }
 307 #endif