re PR middle-end/55709 (Infinite loop in pointer_set_insert compiling cp/pt.c)

	PR middle-end/55709
	Forward port from 4.7 branch:
	2012-04-10  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>

	PR middle-end/52894
	* varasm.c (process_pending_assemble_externals): Set
	pending_assemble_externals_processed true.
	(assemble_external): Call assemble_external_real if the pending
	assemble externals have been processed.

From-SVN: r194538

gcc/ChangeLog

+2012-12-16  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+
+	PR middle-end/55709
+	Forward port from 4.7 branch:
+	2012-04-10  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+
+	PR middle-end/52894
+	* varasm.c (process_pending_assemble_externals): Set
+	pending_assemble_externals_processed true.
+	(assemble_external): Call assemble_external_real if the pending
+	assemble externals have been processed.
+
 2012-12-16  Eric Botcazou  <ebotcazou@adacore.com>
 	    Tomash Brechko  <tomash.brechko@gmail.com>
 

gcc/varasm.c

@@ -2088,6 +2088,11 @@ contains_pointers_p (tree type)
    it all the way to final.  See PR 17982 for further discussion.  */
 static GTY(()) tree pending_assemble_externals;
 
+/* Some targets delay some output to final using TARGET_ASM_FILE_END.
+   As a result, assemble_external can be called after the list of externals
+   is processed and the pointer set destroyed.  */
+static bool pending_assemble_externals_processed;
+
 #ifdef ASM_OUTPUT_EXTERNAL
 /* Avoid O(external_decls**2) lookups in the pending_assemble_externals
    TREE_LIST in assemble_external.  */
@@ -2144,6 +2149,7 @@ process_pending_assemble_externals (void)
     assemble_external_real (TREE_VALUE (list));
 
   pending_assemble_externals = 0;
+  pending_assemble_externals_processed = true;
   pointer_set_destroy (pending_assemble_externals_set);
 #endif
 }
@@ -2196,6 +2202,12 @@ assemble_external (tree decl ATTRIBUTE_UNUSED)
     weak_decls = tree_cons (NULL, decl, weak_decls);
 
 #ifdef ASM_OUTPUT_EXTERNAL
+  if (pending_assemble_externals_processed)
+    {
+      assemble_external_real (decl);
+      return;
+    }
+
   if (! pointer_set_insert (pending_assemble_externals_set, decl))
     pending_assemble_externals = tree_cons (NULL, decl,
 					    pending_assemble_externals);