libjava/name-finder.cc

   1 // name-finder.cc - Convert addresses to names
   2
   3 /* Copyright (C) 2000  Red Hat 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   unsigned long long n = (unsigned long long)p;
 116   int digits = sizeof (void *) * 2;
 117
 118   strcpy (hex, "0x");
 119   for (int i = digits - 1; i >= 0; i--)
 120     {
 121       int digit = n % 16;
 122
 123       n /= 16;
 124       hex[i+2] = digit > 9 ? 'a' + digit - 10 : '0' + digit;
 125     }
 126   hex [digits+2] = 0;
 127 }
 128
 129 /* Given a pointer to a function or method, try to convert it into a
 130    name and the appropriate line and source file.  The caller passes
 131    the code pointer in p.
 132
 133    Returns false if the lookup fails.  Even if this happens, the field
 134    he will have been correctly filled in with the pointer.  */
 135
 136 bool
 137 _Jv_name_finder::lookup (void *p)
 138 {
 139   extern char **_Jv_argv;
 140   toHex (p);
 141
 142 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 143   {
 144     Dl_info dl_info;
 145
 146     if (dladdr (p, &dl_info))
 147       {
 148         if (dl_info.dli_fname)
 149           strncpy (file_name, dl_info.dli_fname, sizeof file_name);
 150         if (dl_info.dli_sname)
 151           strncpy (method_name, dl_info.dli_sname, sizeof method_name);
 152
 153        /* Don't trust dladdr() if the address is from the main program. */
 154        if (dl_info.dli_fname != NULL
 155            && dl_info.dli_sname != NULL
 156            && (_Jv_argv == NULL || strcmp (file_name, _Jv_argv[0]) != 0))
 157          return true;
 158       }
 159   }
 160 #endif
 161
 162 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
 163   if (error)
 164     return false;
 165
 166   error |= write (f_pipe[1], hex, strlen (hex)) < 0;
 167   if (error)
 168     return false;
 169   error |= write (f_pipe[1], "\n", 1) < 0;
 170   if (error)
 171     return false;
 172
 173   error |= (fgets (method_name, sizeof method_name, b_pipe_fd) == NULL);
 174   if (error)
 175     return false;
 176   error |= (fgets (file_name, sizeof file_name, b_pipe_fd) == NULL);
 177   if (error)
 178     return false;
 179
 180   char *newline = strchr (method_name, '\n');
 181   if (newline)
 182     *newline = 0;
 183   newline = strchr (file_name, '\n');
 184   if (newline)
 185     *newline = 0;
 186
 187   return true;
 188
 189 #else
 190   return false;
 191 #endif /* defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP) */
 192 }