libjava/name-finder.cc

   1 // name-finder.cc - Convert addresses to names
   2
   3 /* Copyright (C) 2000  Free Software Foundation, Inc
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 /**
  12  * @author Andrew Haley <aph@cygnus.com>
  13  * @date Jan 6  2000
  14  */
  15
  16 /* _Jv_name_finder is a class wrapper around a mechanism that can
  17    convert address of methods to their names and the names of files in
  18    which they appear.
  19
  20    Right now, the only implementation of this involves running a copy
  21    of addr2line, but at some point it is worth building this
  22    functionality into libgcj, if only for embedded systems.  */
  23
  24
  25 #ifndef _GNU_SOURCE
  26 #define _GNU_SOURCE 1
  27 #endif
  28
  29 #include <config.h>
  30
  31 #include <string.h>
  32
  33 #include <gcj/cni.h>
  34 #include <jvm.h>
  35 #include <java/lang/Object.h>
  36 #include <java-threads.h>
  37 #include <java/lang/Throwable.h>
  38 #include <java/io/PrintStream.h>
  39 #include <java/io/PrintWriter.h>
  40
  41 #include <sys/types.h>
  42
  43 #include <stdlib.h>
  44 #include <stdio.h>
  45
  46 #ifdef HAVE_UNISTD_H
  47 #include <unistd.h>
  48 #endif
  49
  50 #ifdef HAVE_DLFCN_H
  51 #include <dlfcn.h>
  52 #endif
  53
  54 #include <name-finder.h>
  55
  56 /* Create a new name finder which will perform address lookups on an
  57    executable. */
  58
  59 _Jv_name_finder::_Jv_name_finder (char *executable)
  60 {
  61 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
  62   error = 0;
  63
  64   char *argv[6];
  65   {
  66     int arg = 0;
  67 #ifdef __ia64__
  68     argv[arg++] = "addr2name.awk";
  69 #else
  70     argv[arg++] = "addr2line";
  71     argv[arg++] = "-C";
  72     argv[arg++] = "-f";
  73     argv[arg++] = "-e";
  74 #endif
  75     argv[arg++] = executable;
  76     argv[arg] = NULL;
  77   }
  78
  79   error |= pipe (f_pipe) < 0;
  80   error |= pipe (b_pipe) < 0;
  81
  82   if (error)
  83     return;
  84
  85   pid = fork ();
  86   if (pid == 0)
  87     {
  88       close (f_pipe[1]);
  89       close (b_pipe[0]);
  90       dup2 (f_pipe[0], fileno (stdin));
  91       dup2 (b_pipe[1], fileno (stdout));
  92       execvp (argv[0], argv);
  93       _exit (127);
  94     }
  95
  96   close (f_pipe [0]);
  97   close (b_pipe [1]);
  98
  99   if (pid < 0)
 100     {
 101       error |= 1;
 102       return;
 103     }
 104
 105   b_pipe_fd = fdopen (b_pipe[0], "r");
 106   error |= !b_pipe_fd;
 107 #endif
 108 }
 109
 110 /* Convert a pointer to hex. */
 111
 112 void
 113 _Jv_name_finder::toHex (void *p)
 114 {
 115   typedef unsigned word_t __attribute ((mode (word)));
 116   word_t n = (word_t) p;
 117   int digits = sizeof (void *) * 2;
 118
 119   strcpy (hex, "0x");
 120   for (int i = digits - 1; i >= 0; i--)
 121     {
 122       int digit = n % 16;
 123
 124       n /= 16;
 125       hex[i+2] = digit > 9 ? 'a' + digit - 10 : '0' + digit;
 126     }
 127   hex [digits+2] = 0;
 128 }
 129
 130 /* Given a pointer to a function or method, try to convert it into a
 131    name and the appropriate line and source file.  The caller passes
 132    the code pointer in p.
 133
 134    Returns false if the lookup fails.  Even if this happens, the field
 135    he will have been correctly filled in with the pointer.  */
 136
 137 bool
 138 _Jv_name_finder::lookup (void *p)
 139 {
 140   extern char **_Jv_argv;
 141   toHex (p);
 142
 143 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 144   {
 145     Dl_info dl_info;
 146
 147     if (dladdr (p, &dl_info))
 148       {
 149         if (dl_info.dli_fname)
 150           strncpy (file_name, dl_info.dli_fname, sizeof file_name);
 151         if (dl_info.dli_sname)
 152           strncpy (method_name, dl_info.dli_sname, sizeof method_name);
 153
 154        /* Don't trust dladdr() if the address is from the main program. */
 155        if (dl_info.dli_fname != NULL
 156            && dl_info.dli_sname != NULL
 157            && (_Jv_argv == NULL || strcmp (file_name, _Jv_argv[0]) != 0))
 158          return true;
 159       }
 160   }
 161 #endif
 162
 163 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
 164   if (error)
 165     return false;
 166
 167   error |= write (f_pipe[1], hex, strlen (hex)) < 0;
 168   if (error)
 169     return false;
 170   error |= write (f_pipe[1], "\n", 1) < 0;
 171   if (error)
 172     return false;
 173
 174   error |= (fgets (method_name, sizeof method_name, b_pipe_fd) == NULL);
 175   if (error)
 176     return false;
 177   error |= (fgets (file_name, sizeof file_name, b_pipe_fd) == NULL);
 178   if (error)
 179     return false;
 180
 181   char *newline = strchr (method_name, '\n');
 182   if (newline)
 183     *newline = 0;
 184   newline = strchr (file_name, '\n');
 185   if (newline)
 186     *newline = 0;
 187
 188   return true;
 189
 190 #else
 191   return false;
 192 #endif /* defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP) */
 193 }