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;
  13
  14         vsnprintf(msg, sizeof(msg), err, params);
  15         for (p = msg; *p; p++) {
  16                 if (iscntrl(*p) && *p != '\t' && *p != '\n')
  17                         *p = '?';
  18         }
  19         fprintf(stderr, "%s%s\n", prefix, msg);
  20 }
  21
  22 static NORETURN void usage_builtin(const char *err, va_list params)
  23 {
  24         vreportf("usage: ", err, params);
  25         exit(129);
  26 }
  27
  28 static NORETURN void die_builtin(const char *err, va_list params)
  29 {
  30         vreportf("fatal: ", err, params);
  31         exit(128);
  32 }
  33
  34 static void error_builtin(const char *err, va_list params)
  35 {
  36         vreportf("error: ", err, params);
  37 }
  38
  39 static void warn_builtin(const char *warn, va_list params)
  40 {
  41         vreportf("warning: ", warn, params);
  42 }
  43
  44 static int die_is_recursing_builtin(void)
  45 {
  46         static int dying;
  47         /*
  48          * Just an arbitrary number X where "a < x < b" where "a" is
  49          * "maximum number of pthreads we'll ever plausibly spawn" and
  50          * "b" is "something less than Inf", since the point is to
  51          * prevent infinite recursion.
  52          */
  53         static const int recursion_limit = 1024;
  54
  55         dying++;
  56         if (dying > recursion_limit) {
  57                 return 1;
  58         } else if (dying == 2) {
  59                 warning("die() called many times. Recursion error or racy threaded death!");
  60                 return 0;
  61         } else {
  62                 return 0;
  63         }
  64 }
  65
  66 /* If we are in a dlopen()ed .so write to a global variable would segfault
  67  * (ugh), so keep things static. */
  68 static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
  69 static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
  70 static void (*error_routine)(const char *err, va_list params) = error_builtin;
  71 static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
  72 static int (*die_is_recursing)(void) = die_is_recursing_builtin;
  73
  74 void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
  75 {
  76         die_routine = routine;
  77 }
  78
  79 void set_error_routine(void (*routine)(const char *err, va_list params))
  80 {
  81         error_routine = routine;
  82 }
  83
  84 void (*get_error_routine(void))(const char *err, va_list params)
  85 {
  86         return error_routine;
  87 }
  88
  89 void set_warn_routine(void (*routine)(const char *warn, va_list params))
  90 {
  91         warn_routine = routine;
  92 }
  93
  94 void (*get_warn_routine(void))(const char *warn, va_list params)
  95 {
  96         return warn_routine;
  97 }
  98
  99 void set_die_is_recursing_routine(int (*routine)(void))
 100 {
 101         die_is_recursing = routine;
 102 }
 103
 104 void NORETURN usagef(const char *err, ...)
 105 {
 106         va_list params;
 107
 108         va_start(params, err);
 109         usage_routine(err, params);
 110         va_end(params);
 111 }
 112
 113 void NORETURN usage(const char *err)
 114 {
 115         usagef("%s", err);
 116 }
 117
 118 void NORETURN die(const char *err, ...)
 119 {
 120         va_list params;
 121
 122         if (die_is_recursing()) {
 123                 fputs("fatal: recursion detected in die handler\n", stderr);
 124                 exit(128);
 125         }
 126
 127         va_start(params, err);
 128         die_routine(err, params);
 129         va_end(params);
 130 }
 131
 132 static const char *fmt_with_err(char *buf, int n, const char *fmt)
 133 {
 134         char str_error[256], *err;
 135         int i, j;
 136
 137         err = strerror(errno);
 138         for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
 139                 if ((str_error[j++] = err[i++]) != '%')
 140                         continue;
 141                 if (j < sizeof(str_error) - 1) {
 142                         str_error[j++] = '%';
 143                 } else {
 144                         /* No room to double the '%', so we overwrite it with
 145                          * '\0' below */
 146                         j--;
 147                         break;
 148                 }
 149         }
 150         str_error[j] = 0;
 151         snprintf(buf, n, "%s: %s", fmt, str_error);
 152         return buf;
 153 }
 154
 155 void NORETURN die_errno(const char *fmt, ...)
 156 {
 157         char buf[1024];
 158         va_list params;
 159
 160         if (die_is_recursing()) {
 161                 fputs("fatal: recursion detected in die_errno handler\n",
 162                         stderr);
 163                 exit(128);
 164         }
 165
 166         va_start(params, fmt);
 167         die_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 168         va_end(params);
 169 }
 170
 171 #undef error_errno
 172 int error_errno(const char *fmt, ...)
 173 {
 174         char buf[1024];
 175         va_list params;
 176
 177         va_start(params, fmt);
 178         error_routine(fmt_with_err(buf, sizeof(buf), fmt), params);
 179         va_end(params);
 180         return -1;
 181 }
 182
 183 #undef error
 184 int error(const char *err, ...)
 185 {
 186         va_list params;
 187
 188         va_start(params, err);
 189         error_routine(err, params);
 190         va_end(params);
 191         return -1;
 192 }
 193
 194 void warning_errno(const char *warn, ...)
 195 {
 196         char buf[1024];
 197         va_list params;
 198
 199         va_start(params, warn);
 200         warn_routine(fmt_with_err(buf, sizeof(buf), warn), params);
 201         va_end(params);
 202 }
 203
 204 void warning(const char *warn, ...)
 205 {
 206         va_list params;
 207
 208         va_start(params, warn);
 209         warn_routine(warn, params);
 210         va_end(params);
 211 }
 212
 213 static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
 214 {
 215         char prefix[256];
 216
 217         /* truncation via snprintf is OK here */
 218         if (file)
 219                 snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
 220         else
 221                 snprintf(prefix, sizeof(prefix), "BUG: ");
 222
 223         vreportf(prefix, fmt, params);
 224         abort();
 225 }
 226
 227 #ifdef HAVE_VARIADIC_MACROS
 228 NORETURN void BUG_fl(const char *file, int line, const char *fmt, ...)
 229 {
 230         va_list ap;
 231         va_start(ap, fmt);
 232         BUG_vfl(file, line, fmt, ap);
 233         va_end(ap);
 234 }
 235 #else
 236 NORETURN void BUG(const char *fmt, ...)
 237 {
 238         va_list ap;
 239         va_start(ap, fmt);
 240         BUG_vfl(NULL, 0, fmt, ap);
 241         va_end(ap);
 242 }
 243 #endif