[patch] Backport memory leak fix to 7.1

[Sami Wagiaalla <swagiaal at redhat dot com>]

this is a combination of the patches posted
here http://sourceware.org/ml/gdb-patches/2010-03/msg00124.html
and here http://sourceware.org/ml/gdb-patches/2010-03/msg00475.html
and commited to HEAD

   2010-03-22  Sami Wagiaalla  <swagiaal@redhat.com>
   
   	PR Breakpoints/11408:
   	* cp-namespace.c (cp_add_using): Deleted.
   	(cp_add_using_directive): Use obstack allocations.
   	Merged the function cp_add_using into this one.
   	Added 'struct obstack *' argument.
   	(cp_scan_for_anonymous_namespaces): Updated.
   	* cp-support.h: Updated.
   	* dwarf2read.c (read_import_statement): Updated.
   	(read_namespace): Updated.
   	* buildsym.c (finish_block): Reset using_directives pointer
   	after block initialization.
   
   2010-03-22  Sami Wagiaalla  <swagiaal@redhat.com>
   
   	* gdb.cp/gdb2384-base.h: Created 'namespace B'.
   	* gdb.cp/gdb2384-base.cc: Use 'namespace B'.

diff --git a/gdb/buildsym.c b/gdb/buildsym.c
index ff2c9b1..35e4663 100644
--- a/gdb/buildsym.c
+++ b/gdb/buildsym.c
@@ -387,6 +387,7 @@ finish_block (struct symbol *symbol, struct pending **listhead,
    }

  block_set_using (block, using_directives, &objfile->objfile_obstack);
+  using_directives = NULL;

  record_pending_block (objfile, block, opblock);

diff --git a/gdb/cp-namespace.c b/gdb/cp-namespace.c
index 5e894d4..7593475 100644
--- a/gdb/cp-namespace.c
+++ b/gdb/cp-namespace.c
@@ -117,7 +117,8 @@ cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
		 anonymous namespace.  So add symbols in it to the
		 namespace given by the previous component if there is
		 one, or to the global namespace if there isn't.  */
-	      cp_add_using_directive (dest, src, NULL);
+	      cp_add_using_directive (dest, src, NULL,
+	                              &SYMBOL_SYMTAB (symbol)->objfile->objfile_obstack);
	    }
	  /* The "+ 2" is for the "::".  */
	  previous_component = next_component + 2;
@@ -128,11 +129,18 @@ cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
    }
}

-/* Add a using directive to using_list. If the using directive in question
-   has already been added, don't add it twice.  */
+
+/* Add a using directive to using_directives.  If the using directive in
+   question has already been added, don't add it twice.
+   Create a new struct using_direct which imports the namespace SRC into the
+   scope DEST.  ALIAS is the name of the imported namespace in the current
+   scope.  If ALIAS is NULL then the namespace is known by its original name.
+   The arguments are copied into newly allocated memory so they can be 
+   temporaries.  */

void
-cp_add_using_directive (const char *dest, const char *src, const char *alias)
+cp_add_using_directive (const char *dest, const char *src, const char *alias,
+                        struct obstack *obstack)
{
  struct using_direct *current;
  struct using_direct *new;
@@ -142,12 +150,23 @@ cp_add_using_directive (const char *dest, const char *src, const char *alias)
  for (current = using_directives; current != NULL; current = current->next)
    {
      if (strcmp (current->import_src, src) == 0
-          && strcmp (current->import_dest, dest) == 0)
+          && strcmp (current->import_dest, dest) == 0
+          && ((alias == NULL && current->alias == NULL)
+              || (alias != NULL && current->alias != NULL
+        	  && strcmp (alias, current->alias) == 0)))
	return;
    }

-  using_directives = cp_add_using (dest, src, alias, using_directives);
+  new = OBSTACK_ZALLOC (obstack, struct using_direct);

+  new->import_src = obsavestring (src, strlen (src), obstack);
+  new->import_dest = obsavestring (dest, strlen (dest), obstack);
+
+  if (alias != NULL)
+    new->alias = obsavestring (alias, strlen (alias), obstack);
+
+  new->next = using_directives;
+  using_directives = new;
}

/* Record the namespace that the function defined by SYMBOL was
@@ -198,36 +217,6 @@ cp_is_anonymous (const char *namespace)
	  != NULL);
}

-/* Create a new struct using direct which imports the namespace SRC into the
-   scope DEST.  ALIAS is the name of the imported namespace in the current
-   scope.  If ALIAS is NULL then the namespace is known by its original name.
-   Set its next member in the linked list to NEXT; allocate all memory
-   using xmalloc.  It copies the strings, so NAME can be a temporary
-   string.  */
-
-struct using_direct *
-cp_add_using (const char *dest,
-              const char *src,
-              const char *alias,
-	      struct using_direct *next)
-{
-  struct using_direct *retval;
-
-  retval = xmalloc (sizeof (struct using_direct));
-  retval->import_src = savestring (src, strlen(src));
-  retval->import_dest = savestring (dest, strlen(dest));
-
-  if (alias != NULL)
-    retval->alias = savestring (alias, strlen (alias));
-  else
-    retval->alias = NULL;
-
-  retval->next = next;
-  retval->searched = 0;
-
-  return retval;
-}
-
/* The C++-specific version of name lookup for static and global
   names.  This makes sure that names get looked for in all namespaces
   that are in scope.  NAME is the natural name of the symbol that
diff --git a/gdb/cp-support.h b/gdb/cp-support.h
index a6a9af1..3921a5f 100644
--- a/gdb/cp-support.h
+++ b/gdb/cp-support.h
@@ -90,12 +90,8 @@ extern int cp_is_anonymous (const char *namespace);

extern void cp_add_using_directive (const char *dest,
                                    const char *src,
-                                    const char *alias);
-
-extern struct using_direct *cp_add_using (const char *dest,
-                                          const char *src,
-                                          const char *alias,
-					  struct using_direct *next);
+                                    const char *alias,
+                                    struct obstack *obstack);

extern void cp_initialize_namespace (void);

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index b144dc1..6345a9c 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -3470,10 +3470,10 @@ read_import_statement (struct die_info *die, struct dwarf2_cu *cu)
      strcpy (canonical_name, imported_name);
    }

-  using_directives = cp_add_using (import_prefix,
-                                   canonical_name,
-                                   import_alias,
-                                   using_directives);
+  cp_add_using_directive (import_prefix,
+                          canonical_name,
+                          import_alias,
+                          &cu->objfile->objfile_obstack);
}

static void
@@ -5632,7 +5632,8 @@ read_namespace (struct die_info *die, struct dwarf2_cu *cu)
      if (is_anonymous)
	{
	  const char *previous_prefix = determine_prefix (die, cu);
-	  cp_add_using_directive (previous_prefix, TYPE_NAME (type), NULL);
+	  cp_add_using_directive (previous_prefix, TYPE_NAME (type), NULL,
+	                          &objfile->objfile_obstack);
	}
    }

diff --git a/gdb/testsuite/gdb.cp/gdb2384-base.cc b/gdb/testsuite/gdb.cp/gdb2384-base.cc
index 09ed04e..b58f30d 100644
--- a/gdb/testsuite/gdb.cp/gdb2384-base.cc
+++ b/gdb/testsuite/gdb.cp/gdb2384-base.cc
@@ -23,6 +23,8 @@ base::base (int _x)
{
}

+using namespace B;
+
int
base::meth ()
{
diff --git a/gdb/testsuite/gdb.cp/gdb2384-base.h b/gdb/testsuite/gdb.cp/gdb2384-base.h
index b09701e..981943c 100644
--- a/gdb/testsuite/gdb.cp/gdb2384-base.h
+++ b/gdb/testsuite/gdb.cp/gdb2384-base.h
@@ -16,6 +16,10 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */

+namespace B{
+  int x;
+}
+
class base
{
 public:

Attachment: memoryleak.patch
Description: Text document