libjava/name-finder.cc

   1 // name-finder.cc - Convert addresses to names
   2
   3 /* Copyright (C) 2000, 2002  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   // Initialize file descriptors so that shutdown works properly.
  65   f_pipe[0] = -1;
  66   f_pipe[1] = -1;
  67   b_pipe[0] = -1;
  68   b_pipe[1] = -1;
  69   b_pipe_fd = NULL;
  70
  71   char *argv[6];
  72   {
  73     int arg = 0;
  74 #ifdef __ia64__
  75     argv[arg++] = "addr2name.awk";
  76 #else
  77     argv[arg++] = "addr2line";
  78     argv[arg++] = "-C";
  79     argv[arg++] = "-f";
  80     argv[arg++] = "-e";
  81 #endif
  82     argv[arg++] = executable;
  83     argv[arg] = NULL;
  84   }
  85
  86   error |= pipe (f_pipe) < 0;
  87   error |= pipe (b_pipe) < 0;
  88
  89   if (error)
  90     return;
  91
  92   pid = fork ();
  93   if (pid == 0)
  94     {
  95       close (f_pipe[1]);
  96       close (b_pipe[0]);
  97       dup2 (f_pipe[0], fileno (stdin));
  98       dup2 (b_pipe[1], fileno (stdout));
  99       execvp (argv[0], argv);
 100       _exit (127);
 101     }
 102
 103   // Close child end of pipes.  Set local descriptors to -1 so we
 104   // don't try to close the fd again.
 105   close (f_pipe [0]);
 106   f_pipe[0] = -1;
 107   close (b_pipe [1]);
 108   b_pipe[1] = -1;
 109
 110   if (pid < 0)
 111     {
 112       error |= 1;
 113       return;
 114     }
 115
 116   b_pipe_fd = fdopen (b_pipe[0], "r");
 117   error |= !b_pipe_fd;
 118
 119   if (! error)
 120     {
 121       // Don't try to close the fd twice.
 122       b_pipe[0] = -1;
 123     }
 124 #endif
 125 }
 126
 127 /* Convert a pointer to hex. */
 128
 129 void
 130 _Jv_name_finder::toHex (void *p)
 131 {
 132   typedef unsigned word_t __attribute ((mode (word)));
 133   word_t n = (word_t) p;
 134   int digits = sizeof (void *) * 2;
 135
 136   strcpy (hex, "0x");
 137   for (int i = digits - 1; i >= 0; i--)
 138     {
 139       int digit = n % 16;
 140
 141       n /= 16;
 142       hex[i+2] = digit > 9 ? 'a' + digit - 10 : '0' + digit;
 143     }
 144   hex [digits+2] = 0;
 145 }
 146
 147 /* Given a pointer to a function or method, try to convert it into a
 148    name and the appropriate line and source file.  The caller passes
 149    the code pointer in p.
 150
 151    Returns false if the lookup fails.  Even if this happens, the field
 152    he will have been correctly filled in with the pointer.  */
 153
 154 bool
 155 _Jv_name_finder::lookup (void *p)
 156 {
 157   extern char **_Jv_argv;
 158   toHex (p);
 159
 160 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 161   {
 162     Dl_info dl_info;
 163
 164     if (dladdr (p, &dl_info))
 165       {
 166         if (dl_info.dli_fname)
 167           strncpy (file_name, dl_info.dli_fname, sizeof file_name);
 168         if (dl_info.dli_sname)
 169           strncpy (method_name, dl_info.dli_sname, sizeof method_name);
 170
 171        /* Don't trust dladdr() if the address is from the main program. */
 172        if (dl_info.dli_fname != NULL
 173            && dl_info.dli_sname != NULL
 174            && (_Jv_argv == NULL || strcmp (file_name, _Jv_argv[0]) != 0))
 175          return true;
 176       }
 177   }
 178 #endif
 179
 180 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
 181   if (error)
 182     return false;
 183
 184   error |= write (f_pipe[1], hex, strlen (hex)) < 0;
 185   if (error)
 186     return false;
 187   error |= write (f_pipe[1], "\n", 1) < 0;
 188   if (error)
 189     return false;
 190
 191   error |= (fgets (method_name, sizeof method_name, b_pipe_fd) == NULL);
 192   if (error)
 193     return false;
 194   error |= (fgets (file_name, sizeof file_name, b_pipe_fd) == NULL);
 195   if (error)
 196     return false;
 197
 198   char *newline = strchr (method_name, '\n');
 199   if (newline)
 200     *newline = 0;
 201   newline = strchr (file_name, '\n');
 202   if (newline)
 203     *newline = 0;
 204
 205   return true;
 206
 207 #else
 208   return false;
 209 #endif /* defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP) */
 210 }