libgfortran/runtime/backtrace.c

   1 /* Copyright (C) 2006, 2007, 2009, 2011 Free Software Foundation, Inc.
   2    Contributed by François-Xavier Coudert
   3
   4 This file is part of the GNU Fortran runtime library (libgfortran).
   5
   6 Libgfortran is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 Libgfortran is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 Under Section 7 of GPL version 3, you are granted additional
  17 permissions described in the GCC Runtime Library Exception, version
  18 3.1, as published by the Free Software Foundation.
  19
  20 You should have received a copy of the GNU General Public License and
  21 a copy of the GCC Runtime Library Exception along with this program;
  22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 <http://www.gnu.org/licenses/>.  */
  24
  25 #include "libgfortran.h"
  26
  27 #include <string.h>
  28
  29 #ifdef HAVE_STDLIB_H
  30 #include <stdlib.h>
  31 #endif
  32
  33 #ifdef HAVE_INTTYPES_H
  34 #include <inttypes.h>
  35 #endif
  36
  37 #ifdef HAVE_UNISTD_H
  38 #include <unistd.h>
  39 #endif
  40
  41 #ifdef HAVE_EXECINFO_H
  42 #include <execinfo.h>
  43 #endif
  44
  45 #ifdef HAVE_SYS_WAIT_H
  46 #include <sys/wait.h>
  47 #endif
  48
  49 #include <ctype.h>
  50
  51
  52 /* Macros for common sets of capabilities: can we fork and exec, can
  53    we use glibc-style backtrace functions, and can we use pipes.  */
  54 #define CAN_FORK (defined(HAVE_FORK) && defined(HAVE_EXECVP) \
  55                   && defined(HAVE_WAIT))
  56 #define GLIBC_BACKTRACE (defined(HAVE_BACKTRACE) \
  57                          && defined(HAVE_BACKTRACE_SYMBOLS))
  58 #define CAN_PIPE (CAN_FORK && defined(HAVE_PIPE) \
  59                   && defined(HAVE_DUP2) && defined(HAVE_FDOPEN) \
  60                   && defined(HAVE_CLOSE))
  61
  62
  63 #if GLIBC_BACKTRACE && CAN_PIPE
  64 static char *
  65 local_strcasestr (const char *s1, const char *s2)
  66 {
  67 #ifdef HAVE_STRCASESTR
  68   return strcasestr (s1, s2);
  69 #else
  70
  71   const char *p = s1;
  72   const size_t len = strlen (s2);
  73   const char u = *s2, v = isupper((int) *s2) ? tolower((int) *s2)
  74                                   : (islower((int) *s2) ? toupper((int) *s2)
  75                                                         : *s2);
  76
  77   while (1)
  78     {
  79       while (*p != u && *p != v && *p)
  80         p++;
  81       if (*p == 0)
  82         return NULL;
  83       if (strncasecmp (p, s2, len) == 0)
  84         return (char *)p;
  85     }
  86 #endif
  87 }
  88 #endif
  89
  90
  91 #if GLIBC_BACKTRACE
  92 static void
  93 dump_glibc_backtrace (int depth, char *str[])
  94 {
  95   int i;
  96
  97   for (i = 0; i < depth; i++)
  98     {
  99       estr_write ("  + ");
 100       estr_write (str[i]);
 101       estr_write ("\n");
 102     }
 103
 104   free (str);
 105 }
 106 #endif
 107
 108 /* show_backtrace displays the backtrace, currently obtained by means of
 109    the glibc backtrace* functions.  */
 110 void
 111 show_backtrace (void)
 112 {
 113 #if GLIBC_BACKTRACE
 114
 115 #define DEPTH 50
 116 #define BUFSIZE 1024
 117
 118   void *trace[DEPTH];
 119   char **str;
 120   int depth;
 121
 122   depth = backtrace (trace, DEPTH);
 123   if (depth <= 0)
 124     return;
 125
 126   str = backtrace_symbols (trace, depth);
 127
 128 #if CAN_PIPE
 129
 130 #ifndef STDIN_FILENO
 131 #define STDIN_FILENO 0
 132 #endif
 133
 134 #ifndef STDOUT_FILENO
 135 #define STDOUT_FILENO 1
 136 #endif
 137
 138 #ifndef STDERR_FILENO
 139 #define STDERR_FILENO 2
 140 #endif
 141
 142   /* We attempt to extract file and line information from addr2line.  */
 143   do
 144   {
 145     /* Local variables.  */
 146     int f[2], pid, line, i;
 147     FILE *output;
 148     char addr_buf[DEPTH][GFC_XTOA_BUF_SIZE], func[BUFSIZE], file[BUFSIZE];
 149     char *p, *end;
 150     const char *addr[DEPTH];
 151
 152     /* Write the list of addresses in hexadecimal format.  */
 153     for (i = 0; i < depth; i++)
 154       addr[i] = gfc_xtoa ((GFC_UINTEGER_LARGEST) (intptr_t) trace[i], addr_buf[i],
 155                       sizeof (addr_buf[i]));
 156
 157     /* Don't output an error message if something goes wrong, we'll simply
 158        fall back to the pstack and glibc backtraces.  */
 159     if (pipe (f) != 0)
 160       break;
 161     if ((pid = fork ()) == -1)
 162       break;
 163
 164     if (pid == 0)
 165       {
 166         /* Child process.  */
 167 #define NUM_FIXEDARGS 5
 168         char *arg[DEPTH+NUM_FIXEDARGS+1];
 169
 170         close (f[0]);
 171         close (STDIN_FILENO);
 172         close (STDERR_FILENO);
 173
 174         if (dup2 (f[1], STDOUT_FILENO) == -1)
 175           _exit (0);
 176         close (f[1]);
 177
 178         arg[0] = (char *) "addr2line";
 179         arg[1] = (char *) "-e";
 180         arg[2] = full_exe_path ();
 181         arg[3] = (char *) "-f";
 182         arg[4] = (char *) "-s";
 183         for (i = 0; i < depth; i++)
 184           arg[NUM_FIXEDARGS+i] = (char *) addr[i];
 185         arg[NUM_FIXEDARGS+depth] = NULL;
 186         execvp (arg[0], arg);
 187         _exit (0);
 188 #undef NUM_FIXEDARGS
 189       }
 190
 191     /* Father process.  */
 192     close (f[1]);
 193     wait (NULL);
 194     output = fdopen (f[0], "r");
 195     i = -1;
 196
 197     if (fgets (func, sizeof(func), output))
 198       {
 199         estr_write ("\nBacktrace for this error:\n");
 200
 201         do
 202           {
 203             if (! fgets (file, sizeof(file), output))
 204               goto fallback;
 205
 206             i++;
 207
 208             for (p = func; *p != '\n' && *p != '\r'; p++)
 209               ;
 210
 211             *p = '\0';
 212
 213             /* Try to recognize the internal libgfortran functions.  */
 214             if (strncasecmp (func, "*_gfortran", 10) == 0
 215                 || strncasecmp (func, "_gfortran", 9) == 0
 216                 || strcmp (func, "main") == 0 || strcmp (func, "_start") == 0
 217                 || strcmp (func, "_gfortrani_handler") == 0)
 218               continue;
 219
 220             if (local_strcasestr (str[i], "libgfortran.so") != NULL
 221                 || local_strcasestr (str[i], "libgfortran.dylib") != NULL
 222                 || local_strcasestr (str[i], "libgfortran.a") != NULL)
 223               continue;
 224
 225             /* If we only have the address, use the glibc backtrace.  */
 226             if (func[0] == '?' && func[1] == '?' && file[0] == '?'
 227                 && file[1] == '?')
 228               {
 229                 estr_write ("  + ");
 230                 estr_write (str[i]);
 231                 estr_write ("\n");
 232                 continue;
 233               }
 234
 235             /* Extract the line number.  */
 236             for (end = NULL, p = file; *p; p++)
 237               if (*p == ':')
 238                 end = p;
 239             if (end != NULL)
 240               {
 241                 *end = '\0';
 242                 line = atoi (++end);
 243               }
 244             else
 245               line = -1;
 246
 247             if (strcmp (func, "MAIN__") == 0)
 248               estr_write ("  + in the main program\n");
 249             else
 250               {
 251                 estr_write ("  + function ");
 252                 estr_write (func);
 253                 estr_write (" (0x");
 254                 estr_write (addr[i]);
 255                 estr_write (")\n");
 256               }
 257
 258             if (line <= 0 && strcmp (file, "??") == 0)
 259               continue;
 260
 261             if (line <= 0)
 262               {
 263                 estr_write ("    from file ");
 264                 estr_write (file);
 265                 estr_write ("\n");
 266               }
 267             else
 268               st_printf ("    at line %d of file %s\n", line, file);
 269           }
 270         while (fgets (func, sizeof(func), output));
 271
 272         free (str);
 273         return;
 274
 275 fallback:
 276         estr_write ("** Something went wrong while running addr2line. **\n"
 277                     "** Falling back  to a simpler  backtrace scheme. **\n");
 278       }
 279     }
 280   while (0);
 281
 282 #undef DEPTH
 283 #undef BUFSIZE
 284
 285 #endif
 286 #endif
 287
 288 #if CAN_FORK && defined(HAVE_GETPPID)
 289   /* Try to call pstack.  */
 290   do
 291   {
 292     /* Local variables.  */
 293     int pid;
 294
 295     /* Don't output an error message if something goes wrong, we'll simply
 296        fall back to the pstack and glibc backtraces.  */
 297     if ((pid = fork ()) == -1)
 298       break;
 299
 300     if (pid == 0)
 301       {
 302         /* Child process.  */
 303 #define NUM_ARGS 2
 304         char *arg[NUM_ARGS+1];
 305         char buf[20];
 306
 307         estr_write ("\nBacktrace for this error:\n");
 308         arg[0] = (char *) "pstack";
 309         snprintf (buf, sizeof(buf), "%d", (int) getppid ());
 310         arg[1] = buf;
 311         arg[2] = NULL;
 312         execvp (arg[0], arg);
 313 #undef NUM_ARGS
 314
 315         /* pstack didn't work, so we fall back to dumping the glibc
 316            backtrace if we can.  */
 317 #if GLIBC_BACKTRACE
 318         dump_glibc_backtrace (depth, str);
 319 #else
 320         estr_write ("  unable to produce a backtrace, sorry!\n");
 321 #endif
 322
 323         _exit (0);
 324       }
 325
 326     /* Father process.  */
 327     wait (NULL);
 328     return;
 329   }
 330   while(0);
 331 #endif
 332
 333 #if GLIBC_BACKTRACE
 334   /* Fallback to the glibc backtrace.  */
 335   estr_write ("\nBacktrace for this error:\n");
 336   dump_glibc_backtrace (depth, str);
 337 #endif
 338 }