openwrt/toolchain/gdb/patches/620-debian_static-thread-db.patch

   1 Status: submitted similar patch 2004-12-08
   2
   3 This patch cleans up the initialization of thread_db.  It works for static
   4 binaries now.  The vsyscall patches hide this problem, since new static
   5 binaries will load the vsyscall DSO and then trigger thread_db; but
   6 this is still a good cleanup.
   7
   8 Index: gdb-6.3/gdb/thread-db.c
   9 ===================================================================
  10 --- gdb-6.3.orig/gdb/thread-db.c        2004-10-08 16:29:56.000000000 -0400
  11 +++ gdb-6.3/gdb/thread-db.c     2004-11-10 00:19:30.626530413 -0500
  12 @@ -34,6 +34,7 @@
  13  #include "target.h"
  14  #include "regcache.h"
  15  #include "solib-svr4.h"
  16 +#include "observer.h"
  17
  18  #ifdef HAVE_GNU_LIBC_VERSION_H
  19  #include <gnu/libc-version.h>
  20 @@ -627,59 +628,49 @@ check_thread_signals (void)
  21  #endif
  22  }
  23
  24 +/* Check whether thread_db is usable.  This function is called when
  25 +   an inferior is created (or otherwise acquired, e.g. attached to)
  26 +   and when new shared libraries are loaded into a running process.  */
  27 +
  28  static void
  29 -thread_db_new_objfile (struct objfile *objfile)
  30 +check_for_thread_db (void)
  31  {
  32    td_err_e err;
  33 +  static int already_loaded;
  34
  35    /* First time through, report that libthread_db was successfuly
  36       loaded.  Can't print this in in thread_db_load as, at that stage,
  37 -     the interpreter and it's console haven't started.  The real
  38 -     problem here is that libthread_db is loaded too early - it should
  39 -     only be loaded when there is a program to debug.  */
  40 -  {
  41 -    static int dejavu;
  42 -    if (!dejavu)
  43 -      {
  44 -       Dl_info info;
  45 -       const char *library = NULL;
  46 -       /* Try dladdr.  */
  47 -       if (dladdr ((*td_ta_new_p), &info) != 0)
  48 -         library = info.dli_fname;
  49 -       /* Try dlinfo?  */
  50 -       if (library == NULL)
  51 -         /* Paranoid - don't let a NULL path slip through.  */
  52 -         library = LIBTHREAD_DB_SO;
  53 -       printf_unfiltered ("Using host libthread_db library \"%s\".\n",
  54 -                          library);
  55 -       dejavu = 1;
  56 -      }
  57 -  }
  58 +     the interpreter and it's console haven't started.  */
  59
  60 -  /* Don't attempt to use thread_db on targets which can not run
  61 -     (core files).  */
  62 -  if (objfile == NULL || !target_has_execution)
  63 +  if (!already_loaded)
  64      {
  65 -      /* All symbols have been discarded.  If the thread_db target is
  66 -         active, deactivate it now.  */
  67 -      if (using_thread_db)
  68 -       {
  69 -         gdb_assert (proc_handle.pid == 0);
  70 -         unpush_target (&thread_db_ops);
  71 -         using_thread_db = 0;
  72 -       }
  73 +      Dl_info info;
  74 +      const char *library = NULL;
  75 +      if (dladdr ((*td_ta_new_p), &info) != 0)
  76 +       library = info.dli_fname;
  77 +
  78 +      /* Try dlinfo?  */
  79
  80 -      goto quit;
  81 +      if (library == NULL)
  82 +       /* Paranoid - don't let a NULL path slip through.  */
  83 +       library = LIBTHREAD_DB_SO;
  84 +
  85 +      printf_unfiltered ("Using host libthread_db library \"%s\".\n",
  86 +                        library);
  87 +      already_loaded = 1;
  88      }
  89
  90    if (using_thread_db)
  91      /* Nothing to do.  The thread library was already detected and the
  92         target vector was already activated.  */
  93 -    goto quit;
  94 +    return;
  95 +
  96 +  /* Don't attempt to use thread_db on targets which can not run
  97 +     (executables not running yet, core files) for now.  */
  98 +  if (!target_has_execution)
  99 +    return;
 100
 101 -  /* Initialize the structure that identifies the child process.  Note
 102 -     that at this point there is no guarantee that we actually have a
 103 -     child process.  */
 104 +  /* Initialize the structure that identifies the child process.  */
 105    proc_handle.pid = GET_PID (inferior_ptid);
 106
 107    /* Now attempt to open a connection to the thread library.  */
 108 @@ -706,12 +697,24 @@ thread_db_new_objfile (struct objfile *o
 109                thread_db_err_str (err));
 110        break;
 111      }
 112 +}
 113 +
 114 +static void
 115 +thread_db_new_objfile (struct objfile *objfile)
 116 +{
 117 +  if (objfile != NULL)
 118 +    check_for_thread_db ();
 119
 120 -quit:
 121    if (target_new_objfile_chain)
 122      target_new_objfile_chain (objfile);
 123  }
 124
 125 +static void
 126 +check_for_thread_db_observer (struct target_ops *target, int from_tty)
 127 +{
 128 +  check_for_thread_db ();
 129 +}
 130 +
 131  /* Attach to a new thread.  This function is called when we receive a
 132     TD_CREATE event or when we iterate over all threads and find one
 133     that wasn't already in our list.  */
 134 @@ -1366,5 +1369,8 @@ _initialize_thread_db (void)
 135        /* Add ourselves to objfile event chain.  */
 136        target_new_objfile_chain = deprecated_target_new_objfile_hook;
 137        deprecated_target_new_objfile_hook = thread_db_new_objfile;
 138 +
 139 +      /* Register ourselves for the new inferior observer.  */
 140 +      observer_attach_inferior_created (check_for_thread_db_observer);
 141      }
 142  }
 143 Index: gdb-6.3/gdb/Makefile.in
 144 ===================================================================
 145 --- gdb-6.3.orig/gdb/Makefile.in        2004-11-09 23:04:57.000000000 -0500
 146 +++ gdb-6.3/gdb/Makefile.in     2004-11-10 00:19:26.440347022 -0500
 147 @@ -2626,7 +2626,8 @@ thread.o: thread.c $(defs_h) $(symtab_h)
 148         $(gdbcmd_h) $(regcache_h) $(gdb_h) $(gdb_string_h) $(ui_out_h)
 149  thread-db.o: thread-db.c $(defs_h) $(gdb_assert_h) $(gdb_proc_service_h) \
 150         $(gdb_thread_db_h) $(bfd_h) $(gdbthread_h) $(inferior_h) \
 151 -       $(symfile_h) $(objfiles_h) $(target_h) $(regcache_h) $(solib_svr4_h)
 152 +       $(symfile_h) $(objfiles_h) $(target_h) $(regcache_h) $(solib_svr4_h) \
 153 +       $(observer_h)
 154  top.o: top.c $(defs_h) $(gdbcmd_h) $(call_cmds_h) $(cli_cmds_h) \
 155         $(cli_script_h) $(cli_setshow_h) $(cli_decode_h) $(symtab_h) \
 156         $(inferior_h) $(target_h) $(breakpoint_h) $(gdbtypes_h) \