Update.

1998-03-09 18:21  Ulrich Drepper  <drepper@cygnus.com>

	* elf/dl-support.c (_dl_debug_bindings): Add definition.
	* elf/rtld.c (_dl_debug_bindings): Add definition.
	(process_dl_debug): Recognize bindings option.  Update help message.
	* elf/link.h (struct link_map): Add l_versyms member.
	(_dl_debug_bindings): Add declaration.
	* elf/version.c (_dl_check_map_versions): Initialize l_versyms.
	* elf/dl-object.c (_dl_new_object): Don't initialize l_rpath_dirs
	and l_reloc_result.
	* elf/dl-lookup.c (do_lookup): Define verstab from l_versyms.
	(sym_val): Remove a member, add m as link_map.
	(do_lookup): Return result appropriately.
	(_dl_lookup_symbol): If _dl_debug_bindings is defined print message.
	Call do_lookup correctly.
	(_dl_lookup_symbol_skip): Likewise.
	(_dl_lookup_versioned_symbol): Likewise.
	(_dl_lookup_versioned_symbol_skip): Likewise.

6 files changed, 100 insertions, 41 deletions

diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c
index c0f9731..c3231ac 100644
--- a/elf/dl-lookup.c
+++ b/elf/dl-lookup.c
@@ -34,8 +34,8 @@ static const char undefined_msg[] = "undefined symbol: ";
 
 struct sym_val
   {
-    ElfW(Addr) a;
     const ElfW(Sym) *s;
+    struct link_map *m;
   };
 
 
@@ -88,8 +88,8 @@ do_lookup (const char *undef_name, unsigned long int hash,
 	continue;
 
       /* Don't search the executable when resolving a copy reloc.  */
-      if (elf_machine_lookup_noexec_p (reloc_type) &&
-	  map->l_type == lt_executable)
+      if (elf_machine_lookup_noexec_p (reloc_type)
+	  && map->l_type == lt_executable)
 	continue;
 
       /* Skip objects without symbol tables.  */
@@ -98,11 +98,7 @@ do_lookup (const char *undef_name, unsigned long int hash,
 
       symtab = ((void *) map->l_addr + map->l_info[DT_SYMTAB]->d_un.d_ptr);
       strtab = ((void *) map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr);
-      if (map->l_nversions > 0 && map->l_info[VERSTAG (DT_VERSYM)] != NULL)
-	verstab = ((void *) map->l_addr
-		   + map->l_info[VERSTAG (DT_VERSYM)]->d_un.d_ptr);
-      else
-	verstab = NULL;
+      verstab = map->l_versyms;
 
       /* Search the appropriate hash bucket in this object's symbol table
 	 for a definition for the same symbol name.  */
@@ -171,7 +167,7 @@ do_lookup (const char *undef_name, unsigned long int hash,
 	    case STB_GLOBAL:
 	      /* Global definition.  Just what we need.  */
 	      result->s = sym;
-	      result->a = map->l_addr;
+	      result->m = map;
 	      return 1;
 	    case STB_WEAK:
 	      /* Weak definition.  Use this value if we don't find
@@ -179,7 +175,7 @@ do_lookup (const char *undef_name, unsigned long int hash,
 	      if (! result->s)
 		{
 		  result->s = sym;
-		  result->a = map->l_addr;
+		  result->m = map;
 		}
 	      break;
 	    default:
@@ -212,7 +208,7 @@ _dl_lookup_symbol (const char *undef_name, const ElfW(Sym) **ref,
 		   int reloc_type)
 {
   const unsigned long int hash = _dl_elf_hash (undef_name);
-  struct sym_val current_value = { 0, NULL };
+  struct sym_val current_value = { NULL, NULL };
   struct link_map **scope;
 
   /* Search the relevant loaded objects for a definition.  */
@@ -222,14 +218,24 @@ _dl_lookup_symbol (const char *undef_name, const ElfW(Sym) **ref,
 		   reference_name, NULL, NULL, reloc_type))
       break;
 
-  if (current_value.s == NULL &&
-      (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK))
-    /* We could find no value for a strong reference.  */
-    _dl_signal_error (0, reference_name,
-		      make_string (undefined_msg, undef_name));
+  if (current_value.s == NULL)
+    {
+      if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK)
+	/* We could find no value for a strong reference.  */
+	_dl_signal_error (0, reference_name,
+			  make_string (undefined_msg, undef_name));
+      *ref = NULL;
+      return 0;
+    }
+
+  if (_dl_debug_bindings)
+    _dl_debug_message ("\tbinding file ", reference_name, " to ",
+		       current_value.m->l_name[0]
+		       ? current_value.m->l_name : _dl_argv[0],
+		       ": symbol `", undef_name, "'\n", NULL);
 
   *ref = current_value.s;
-  return current_value.a;
+  return current_value.m->l_addr;
 }
 
 
@@ -245,7 +251,7 @@ _dl_lookup_symbol_skip (const char *undef_name, const ElfW(Sym) **ref,
 			struct link_map *skip_map)
 {
   const unsigned long int hash = _dl_elf_hash (undef_name);
-  struct sym_val current_value = { 0, NULL };
+  struct sym_val current_value = { NULL, NULL };
   struct link_map **scope;
   size_t i;
 
@@ -263,8 +269,20 @@ _dl_lookup_symbol_skip (const char *undef_name, const ElfW(Sym) **ref,
 		     reference_name, NULL, skip_map, 0))
 	break;
 
+  if (current_value.s == NULL)
+    {
+      *ref = NULL;
+      return 0;
+    }
+
+  if (_dl_debug_bindings)
+    _dl_debug_message ("\tbinding file ", reference_name, " to ",
+		       current_value.m->l_name[0]
+		       ? current_value.m->l_name : _dl_argv[0],
+		       ": symbol `", undef_name, "'\n", NULL);
+
   *ref = current_value.s;
-  return current_value.a;
+  return current_value.m->l_addr;
 }
 
 
@@ -281,7 +299,7 @@ _dl_lookup_versioned_symbol (const char *undef_name, const ElfW(Sym) **ref,
 			     int reloc_type)
 {
   const unsigned long int hash = _dl_elf_hash (undef_name);
-  struct sym_val current_value = { 0, NULL };
+  struct sym_val current_value = { NULL, NULL };
   struct link_map **scope;
 
   /* Search the relevant loaded objects for a definition.  */
@@ -308,15 +326,25 @@ _dl_lookup_versioned_symbol (const char *undef_name, const ElfW(Sym) **ref,
 				       ? " (no version symbols)" : ""));
     }
 
-  if (current_value.s == NULL &&
-      (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK))
-    /* We could find no value for a strong reference.  */
-    _dl_signal_error (0, reference_name,
-		      make_string (undefined_msg, undef_name,
-				   ", version ", version->name ?: NULL));
+  if (current_value.s == NULL)
+    {
+      if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK)
+	/* We could find no value for a strong reference.  */
+	_dl_signal_error (0, reference_name,
+			  make_string (undefined_msg, undef_name,
+				       ", version ", version->name ?: NULL));
+      *ref = NULL;
+      return 0;
+    }
+
+  if (_dl_debug_bindings)
+    _dl_debug_message ("\tbinding file ", reference_name, " to ",
+		       current_value.m->l_name[0]
+		       ? current_value.m->l_name : _dl_argv[0],
+		       ": symbol `", undef_name, "'\n", NULL);
 
   *ref = current_value.s;
-  return current_value.a;
+  return current_value.m->l_addr;
 }
 
 
@@ -331,7 +359,7 @@ _dl_lookup_versioned_symbol_skip (const char *undef_name,
 				  struct link_map *skip_map)
 {
   const unsigned long int hash = _dl_elf_hash (undef_name);
-  struct sym_val current_value = { 0, NULL };
+  struct sym_val current_value = { NULL, NULL };
   struct link_map **scope;
   size_t i;
 
@@ -349,19 +377,29 @@ _dl_lookup_versioned_symbol_skip (const char *undef_name,
 		     reference_name, version, skip_map, 0))
 	break;
 
-  if (current_value.s == NULL &&
-      (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK))
+  if (current_value.s == NULL)
     {
-      /* We could find no value for a strong reference.  */
-      const size_t len = strlen (undef_name);
-      char buf[sizeof undefined_msg + len];
-      __mempcpy (__mempcpy (buf, undefined_msg, sizeof undefined_msg - 1),
-		 undef_name, len + 1);
-      _dl_signal_error (0, reference_name, buf);
+      if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK)
+	{
+	  /* We could find no value for a strong reference.  */
+	  const size_t len = strlen (undef_name);
+	  char buf[sizeof undefined_msg + len];
+	  __mempcpy (__mempcpy (buf, undefined_msg, sizeof undefined_msg - 1),
+		     undef_name, len + 1);
+	  _dl_signal_error (0, reference_name, buf);
+	}
+      *ref = NULL;
+      return 0;
     }
 
+  if (_dl_debug_bindings)
+    _dl_debug_message ("\tbinding file ", reference_name, " to ",
+		       current_value.m->l_name[0]
+		       ? current_value.m->l_name : _dl_argv[0],
+		       ": symbol `", undef_name, "'\n", NULL);
+
   *ref = current_value.s;
-  return current_value.a;
+  return current_value.m->l_addr;
 }
 
 
diff --git a/elf/dl-object.c b/elf/dl-object.c
index b2dbb83..9bd600d 100644
--- a/elf/dl-object.c
+++ b/elf/dl-object.c
@@ -44,8 +44,6 @@ _dl_new_object (char *realname, const char *libname, int type)
   newname->next = NULL;
   new->l_libname = newname;
   new->l_type = type;
-  new->l_rpath_dirs = NULL;
-  new->l_reloc_result = NULL;
 
   if (_dl_loaded == NULL)
     {
diff --git a/elf/dl-support.c b/elf/dl-support.c
index 797cc99..6b6a22d 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -37,6 +37,7 @@ const char *_dl_platform;
 size_t _dl_platformlen;
 int _dl_debug_libs;
 int _dl_debug_impcalls;
+int _dl_debug_bindings;
 
 /* If nonzero print warnings about problematic situations.  */
 int _dl_verbose;
diff --git a/elf/dl-version.c b/elf/dl-version.c
index a4f77f5..f615bb0 100644
--- a/elf/dl-version.c
+++ b/elf/dl-version.c
@@ -273,6 +273,10 @@ _dl_check_map_versions (struct link_map *map, int verbose)
 	  /* Store the number of available symbols.  */
 	  map->l_nversions = ndx_high + 1;
 
+	  /* Compute the pointer to the version symbols.  */
+	  map->l_versyms = ((void *) map->l_addr
+			    + map->l_info[VERSTAG (DT_VERSYM)]->d_un.d_ptr);
+
 	  if (dyn != NULL)
 	    {
 	      ElfW(Verneed) *ent;
diff --git a/elf/link.h b/elf/link.h
index 5847945..d5e2b7f 100644
--- a/elf/link.h
+++ b/elf/link.h
@@ -197,6 +197,9 @@ struct link_map
 
     /* Collected results of relocation while profiling.  */
     ElfW(Addr) *l_reloc_result;
+
+    /* Pointer to the version information if available.  */
+    ElfW(Half) *l_versyms;
   };
 
 
@@ -248,6 +251,7 @@ extern struct link_map *_dl_profile_map;
 /* If nonzero the appropriate debug information is printed.  */
 extern int _dl_debug_libs;
 extern int _dl_debug_impcalls;
+extern int _dl_debug_bindings;
 
 /* File deccriptor to write debug messages to.  */
 extern int _dl_debug_fd;
diff --git a/elf/rtld.c b/elf/rtld.c
index c466fa2..2cb11bb 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -76,6 +76,7 @@ const char *_dl_profile_output;
 struct link_map *_dl_profile_map;
 int _dl_debug_libs;
 int _dl_debug_impcalls;
+int _dl_debug_bindings;
 
 /* Set nonzero during loading and initialization of executable and
    libraries, cleared before the executable's entry point runs.  This
@@ -928,6 +929,14 @@ process_dl_debug (char *dl_debug)
 	++dl_debug;
       if (*dl_debug != '\0')
 	{
+	  if (strncmp (dl_debug, "bindings", 8) == 0
+	      && (issep (dl_debug[8]) || dl_debug[8] == '\0'))
+	    {
+	      _dl_debug_bindings = 1;
+	      _dl_debug_impcalls = 1;
+	      any_debug = 1;
+	      dl_debug += 8;
+	    }
 	  if (strncmp (dl_debug, "libs", 4) == 0
 	      && (issep (dl_debug[4]) || dl_debug[4] == '\0'))
 	    {
@@ -942,8 +951,13 @@ process_dl_debug (char *dl_debug)
 	      _dl_sysdep_message ("\
 Valid options for the LD_DEBUG environment variable are:\n\
 \n\
-  help    display this help message and exit
-  libs    display library search paths\n", NULL);
+  bindings  display information about symbol binding\n\
+  help      display this help message and exit\n\
+  libs      display library search paths\n\
+\n\
+To direct the debugging output into a file instead of standard output\n\
+a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n",
+				  NULL);
 	      _exit (0);
 	    }
 	  else