libbacktrace/print.c

   1 /* print.c -- Print the current backtrace.
   2    Copyright (C) 2012-2024 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor, Google.
   4
   5 Redistribution and use in source and binary forms, with or without
   6 modification, are permitted provided that the following conditions are
   7 met:
   8
   9     (1) Redistributions of source code must retain the above copyright
  10     notice, this list of conditions and the following disclaimer.
  11
  12     (2) Redistributions in binary form must reproduce the above copyright
  13     notice, this list of conditions and the following disclaimer in
  14     the documentation and/or other materials provided with the
  15     distribution.
  16
  17     (3) The name of the author may not be used to
  18     endorse or promote products derived from this software without
  19     specific prior written permission.
  20
  21 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  23 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  24 DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  25 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  26 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  27 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  29 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30 IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31 POSSIBILITY OF SUCH DAMAGE.  */
  32
  33 #include "config.h"
  34
  35 #include <stdio.h>
  36 #include <string.h>
  37 #include <sys/types.h>
  38
  39 #include "backtrace.h"
  40 #include "internal.h"
  41
  42 /* Passed to callbacks.  */
  43
  44 struct print_data
  45 {
  46   struct backtrace_state *state;
  47   FILE *f;
  48 };
  49
  50 /* Print errors to stderr.  */
  51
  52 static void
  53 error_callback (void *data, const char *msg, int errnum)
  54 {
  55   struct print_data *pdata = (struct print_data *) data;
  56
  57   if (pdata->state->filename != NULL)
  58     fprintf (stderr, "%s: ", pdata->state->filename);
  59   fprintf (stderr, "libbacktrace: %s", msg);
  60   if (errnum > 0)
  61     fprintf (stderr, ": %s", strerror (errnum));
  62   fputc ('\n', stderr);
  63 }
  64
  65 /* Print one level of a backtrace if we couldn't get a file or function name.
  66    Use syminfo to try to get a symbol name.  */
  67
  68 static void print_syminfo_callback (void *data, uintptr_t pc,
  69                                     const char *symname, uintptr_t symval,
  70                                     uintptr_t symsize ATTRIBUTE_UNUSED)
  71 {
  72   struct print_data *pdata = (struct print_data *) data;
  73
  74   if (symname == NULL)
  75     fprintf (pdata->f, "0x%lx ???\n\t???:0\n", (unsigned long) pc);
  76   else
  77     fprintf (pdata->f, "0x%lx ???\n\t%s+0x%lx:0\n",
  78              (unsigned long) pc,
  79              symname,
  80              (unsigned long) (pc - symval));
  81 }
  82
  83 /* Print one level of a backtrace.  */
  84
  85 static int
  86 print_callback (void *data, uintptr_t pc, const char *filename, int lineno,
  87                 const char *function)
  88 {
  89   struct print_data *pdata = (struct print_data *) data;
  90
  91   if (function == NULL && filename == NULL)
  92     {
  93       backtrace_syminfo (pdata->state, pc, print_syminfo_callback,
  94                          error_callback, data);
  95       return 0;
  96     }
  97
  98   fprintf (pdata->f, "0x%lx %s\n\t%s:%d\n",
  99            (unsigned long) pc,
 100            function == NULL ? "???" : function,
 101            filename == NULL ? "???" : filename,
 102            lineno);
 103   return 0;
 104 }
 105
 106 /* Print a backtrace.  */
 107
 108 void __attribute__((noinline))
 109 backtrace_print (struct backtrace_state *state, int skip, FILE *f)
 110 {
 111   struct print_data data;
 112
 113   data.state = state;
 114   data.f = f;
 115   backtrace_full (state, skip + 1, print_callback, error_callback,
 116                   (void *) &data);
 117 }