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         strncpy (file_name, dl_info.dli_fname, sizeof file_name);
 149         strncpy (method_name, dl_info.dli_sname, sizeof method_name);
 150
 151        /* Don't trust dladdr() if the address is from the main program. */
 152        if (_Jv_argv == NULL || strcmp (file_name, _Jv_argv[0]) != 0)
 153          return true;
 154       }
 155   }
 156 #endif
 157
 158 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
 159   if (error)
 160     return false;
 161
 162   error |= write (f_pipe[1], hex, strlen (hex)) < 0;
 163   if (error)
 164     return false;
 165   error |= write (f_pipe[1], "\n", 1) < 0;
 166   if (error)
 167     return false;
 168
 169   error |= (fgets (method_name, sizeof method_name, b_pipe_fd) == NULL);
 170   if (error)
 171     return false;
 172   error |= (fgets (file_name, sizeof file_name, b_pipe_fd) == NULL);
 173   if (error)
 174     return false;
 175
 176   char *newline = strchr (method_name, '\n');
 177   if (newline)
 178     *newline = 0;
 179   newline = strchr (file_name, '\n');
 180   if (newline)
 181     *newline = 0;
 182
 183   return true;
 184
 185 #else
 186   return false;
 187 #endif /* defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP) */
 188 }