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     argv[arg++] = "addr2line";
  68     argv[arg++] = "-C";
  69     argv[arg++] = "-f";
  70     argv[arg++] = "-e";
  71     argv[arg++] = executable;
  72     argv[arg] = NULL;
  73   }
  74
  75   error |= pipe (f_pipe) < 0;
  76   error |= pipe (b_pipe) < 0;
  77
  78   if (error)
  79     return;
  80
  81   pid = fork ();
  82   if (pid == 0)
  83     {
  84       close (f_pipe[1]);
  85       close (b_pipe[0]);
  86       dup2 (f_pipe[0], fileno (stdin));
  87       dup2 (b_pipe[1], fileno (stdout));
  88       execvp (argv[0], argv);
  89       _exit (127);
  90     }
  91
  92   close (f_pipe [0]);
  93   close (b_pipe [1]);
  94
  95   if (pid < 0)
  96     {
  97       error |= 1;
  98       return;
  99     }
 100
 101   b_pipe_fd = fdopen (b_pipe[0], "r");
 102   error |= !b_pipe_fd;
 103 #endif
 104 }
 105
 106 /* Convert a pointer to hex. */
 107
 108 void
 109 _Jv_name_finder::toHex (void *p)
 110 {
 111   unsigned long long n = (unsigned long long)p;
 112   int digits = sizeof (void *) * 2;
 113
 114   strcpy (hex, "0x");
 115   for (int i = digits - 1; i >= 0; i--)
 116     {
 117       int digit = n % 16;
 118
 119       n /= 16;
 120       hex[i+2] = digit > 9 ? 'a' + digit - 10 : '0' + digit;
 121     }
 122   hex [digits+2] = 0;
 123 }
 124
 125 /* Given a pointer to a function or method, try to convert it into a
 126    name and the appropriate line and source file.  The caller passes
 127    the code pointer in p.
 128
 129    Returns false if the lookup fails.  Even if this happens, the field
 130    he will have been correctly filled in with the pointer.  */
 131
 132 bool
 133 _Jv_name_finder::lookup (void *p)
 134 {
 135   toHex (p);
 136
 137 #if defined (HAVE_DLFCN_H) && defined (HAVE_DLADDR)
 138   {
 139     Dl_info dl_info;
 140
 141     if (dladdr (p, &dl_info))
 142       {
 143         strncpy (file_name, dl_info.dli_fname, sizeof file_name);
 144         strncpy (method_name, dl_info.dli_sname, sizeof method_name);
 145         return true;
 146       }
 147   }
 148 #endif
 149
 150 #if defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP)
 151   if (error)
 152     return false;
 153
 154   error |= write (f_pipe[1], hex, strlen (hex)) < 0;
 155   if (error)
 156     return false;
 157   error |= write (f_pipe[1], "\n", 1) < 0;
 158   if (error)
 159     return false;
 160
 161   error |= (fgets (method_name, sizeof method_name, b_pipe_fd) == NULL);
 162   if (error)
 163     return false;
 164   error |= (fgets (file_name, sizeof file_name, b_pipe_fd) == NULL);
 165   if (error)
 166     return false;
 167
 168   char *newline = strchr (method_name, '\n');
 169   if (newline)
 170     *newline = 0;
 171   newline = strchr (file_name, '\n');
 172   if (newline)
 173     *newline = 0;
 174
 175   return true;
 176
 177 #else
 178   return false;
 179 #endif /* defined (HAVE_PIPE) && defined (HAVE_FORK) && defined (HAVE_EXECVP) */
 180 }