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         strncpy (method_name, dl_info.dli_sname, sizeof method_name);
 151
 152        /* Don't trust dladdr() if the address is from the main program. */
 153        if (dl_info.dli_fname != NULL
 154            && (_Jv_argv == NULL || strcmp (file_name, _Jv_argv[0]) != 0))
 155          return true;
 156       }
 157   }
 158 #endif
 159
 160 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
 161   if (error)
 162     return false;
 163
 164   error |= write (f_pipe[1], hex, strlen (hex)) < 0;
 165   if (error)
 166     return false;
 167   error |= write (f_pipe[1], "\n", 1) < 0;
 168   if (error)
 169     return false;
 170
 171   error |= (fgets (method_name, sizeof method_name, b_pipe_fd) == NULL);
 172   if (error)
 173     return false;
 174   error |= (fgets (file_name, sizeof file_name, b_pipe_fd) == NULL);
 175   if (error)
 176     return false;
 177
 178   char *newline = strchr (method_name, '\n');
 179   if (newline)
 180     *newline = 0;
 181   newline = strchr (file_name, '\n');
 182   if (newline)
 183     *newline = 0;
 184
 185   return true;
 186
 187 #else
 188   return false;
 189 #endif /* defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP) */
 190 }