re PR c++/12909 (ambiguity in mangling vector types)

	PR c++/12909
	* cgraph.h (varpool_node): Add extra_name field.
	* varpool.c (varpool_extra_name_alias): New.
	(varpool_assemble_decl): Emit extra name aliases.
	(varpool_mark_needed_node): Look past an extra name alias.
cp/
	* mangle.c (mangle_decl): Handle VAR_DECL, too.

From-SVN: r157203

gcc/ChangeLog

+2010-03-03  Jason Merrill  <jason@redhat.com>
+
+	PR c++/12909
+	* cgraph.h (varpool_node): Add extra_name field.
+	* varpool.c (varpool_extra_name_alias): New.
+	(varpool_assemble_decl): Emit extra name aliases.
+	(varpool_mark_needed_node): Look past an extra name alias.
+
 2010-03-03  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config.gcc (sparc64-*-solaris2*, sparc-*-solaris2*): Merge into...

gcc/cgraph.h

@@ -361,6 +361,9 @@ struct GTY((chain_next ("%h.next"))) varpool_node {
   struct varpool_node *next;
   /* Pointer to the next function in varpool_nodes_queue.  */
   struct varpool_node *next_needed;
+  /* For normal nodes a pointer to the first extra name alias.  For alias
+     nodes a pointer to the normal node.  */
+  struct varpool_node *extra_name;
   /* Ordering of all cgraph nodes.  */
   int order;
 
@@ -379,7 +382,8 @@ struct GTY((chain_next ("%h.next"))) varpool_node {
   unsigned output : 1;
   /* Set when function is visible by other units.  */
   unsigned externally_visible : 1;
-  /* Set for aliases once they got through assemble_alias.  */
+  /* Set for aliases once they got through assemble_alias.  Also set for
+     extra name aliases in varpool_extra_name_alias.  */
   unsigned alias : 1;
 };
 
@@ -574,6 +578,7 @@ bool varpool_assemble_decl (struct varpool_node *node);
 bool varpool_analyze_pending_decls (void);
 void varpool_remove_unreferenced_decls (void);
 void varpool_empty_needed_queue (void);
+bool varpool_extra_name_alias (tree, tree);
 const char * varpool_node_name (struct varpool_node *node);
 
 /* Walk all reachable static variables.  */

gcc/cp/mangle.c

@@ -3070,9 +3070,6 @@ mangle_decl (const tree decl)
 	inform (DECL_SOURCE_LOCATION (decl), "-fabi-version=4 (or =0) "
 		"avoids this error with a change in vector mangling");
 
-      if (TREE_CODE (decl) != FUNCTION_DECL)
-	return;
-
       save_ver = flag_abi_version;
       flag_abi_version = 0;
       id2 = mangle_decl_string (decl);
@@ -3085,7 +3082,10 @@ mangle_decl (const tree decl)
       DECL_VISIBILITY (alias) = DECL_VISIBILITY (decl);
       if (vague_linkage_p (decl))
 	DECL_WEAK (alias) = 1;
-      cgraph_same_body_alias (alias, decl);
+      if (TREE_CODE (decl) == FUNCTION_DECL)
+	cgraph_same_body_alias (alias, decl);
+      else
+	varpool_extra_name_alias (alias, decl);
     }
 #endif
 }

gcc/testsuite/g++.dg/abi/mangle40.C

@@ -3,6 +3,7 @@
 // { dg-options "-mavx -Wabi -fabi-version=2" }
 // { dg-final { scan-assembler "weak\[^\n\]*_Z1fIDv4_fEvT_" } }
 // { dg-final { scan-assembler "weak\[^\n\]*_Z1fIU8__vectorfEvT_" } }
+// { dg-final { scan-assembler "weak\[^\n\]*_ZN1AIDv4_fE1tE" } }
 // { dg-final { scan-assembler "weak\[^\n\]*_ZN1AIU8__vectorfE1tE" } }
 
 #include <x86intrin.h>

gcc/varpool.c

@@ -207,6 +207,8 @@ varpool_enqueue_needed_node (struct varpool_node *node)
 void
 varpool_mark_needed_node (struct varpool_node *node)
 {
+  if (node->alias && node->extra_name)
+    node = node->extra_name;
   if (!node->needed && node->finalized
       && !TREE_ASM_WRITTEN (node->decl))
     varpool_enqueue_needed_node (node);
@@ -383,9 +385,22 @@ varpool_assemble_decl (struct varpool_node *node)
       assemble_variable (decl, 0, 1, 0);
       if (TREE_ASM_WRITTEN (decl))
 	{
+	  struct varpool_node *alias;
+
 	  node->next_needed = varpool_assembled_nodes_queue;
 	  varpool_assembled_nodes_queue = node;
 	  node->finalized = 1;
+
+	  /* Also emit any extra name aliases.  */
+	  for (alias = node->extra_name; alias; alias = alias->next)
+	    {
+	      /* Update linkage fields in case they've changed.  */
+	      DECL_WEAK (alias->decl) = DECL_WEAK (decl);
+	      TREE_PUBLIC (alias->decl) = TREE_PUBLIC (decl);
+	      DECL_VISIBILITY (alias->decl) = DECL_VISIBILITY (decl);
+	      assemble_alias (alias->decl, DECL_ASSEMBLER_NAME (decl));
+	    }
+
 	  return true;
 	}
     }
@@ -507,4 +522,40 @@ add_new_static_var (tree type)
   return new_node->decl;
 }
 
+/* Attempt to mark ALIAS as an alias to DECL.  Return TRUE if successful.
+   Extra name aliases are output whenever DECL is output.  */
+
+bool
+varpool_extra_name_alias (tree alias, tree decl)
+{
+  struct varpool_node key, *alias_node, *decl_node, **slot;
+
+#ifndef ASM_OUTPUT_DEF
+  /* If aliases aren't supported by the assembler, fail.  */
+  return false;
+#endif
+
+  gcc_assert (TREE_CODE (decl) == VAR_DECL);
+  gcc_assert (TREE_CODE (alias) == VAR_DECL);
+  /* Make sure the hash table has been created.  */
+  decl_node = varpool_node (decl);
+
+  key.decl = alias;
+
+  slot = (struct varpool_node **) htab_find_slot (varpool_hash, &key, INSERT);
+
+  /* If the varpool_node has been already created, fail.  */
+  if (*slot)
+    return false;
+
+  alias_node = GGC_CNEW (struct varpool_node);
+  alias_node->decl = alias;
+  alias_node->alias = 1;
+  alias_node->extra_name = decl_node;
+  alias_node->next = decl_node->extra_name;
+  decl_node->extra_name = alias_node;
+  *slot = alias_node;
+  return true;
+}
+
 #include "gt-varpool.h"