re PR middle-end/46674 (Weak alias is mistakenly optimized away)

	PR middle-end/46674
	* varasm.c (compute_visible_aliases): Handle user set
	assembler name.

	testsuite/
	PR middle-end/46674
	* gcc.dg/pr46674.c: New test.

From-SVN: r167365

gcc/ChangeLog

+2010-12-02  Jie Zhang  <jie@codesourcery.com>
+
+	PR middle-end/46674
+	* varasm.c (compute_visible_aliases): Handle user set
+	assembler name.
+
 2010-12-01  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	* config/rs6000/rs6000.c (rs6000_option_override_internal): Fix

gcc/testsuite/ChangeLog

+2010-12-02  Jie Zhang  <jie@codesourcery.com>
+
+	PR middle-end/46674
+	* gcc.dg/pr46674.c: New test.
+
 2010-12-02  Nicola Pero  <nicola.pero@meta-innovation.com>
 
 	* objc.dg/exceptions-6.m: New.

gcc/testsuite/gcc.dg/pr46674.c

+/* { dg-do compile } */
+/* { dg-require-alias "" } */
+/* { dg-options "-O2" } */
+
+int yum;
+void dessert (void) { ++yum; }
+extern void jelly (void) __asm__ ("jelly2") __attribute__ ((alias ("dessert"), weak));
+extern void wobbly (void) __attribute__ ((alias ("jelly2"), weak));
+
+/* { dg-final { scan-assembler "wobbly" } } */
+/* { dg-final { scan-assembler "jelly2" } } */

gcc/varasm.c

@@ -5525,12 +5525,21 @@ compute_visible_aliases (void)
 	{
 	  struct cgraph_node *fnode = NULL;
 	  struct varpool_node *vnode = NULL;
+	  tree asmname = DECL_ASSEMBLER_NAME (p->decl);
+	  const char *str = IDENTIFIER_POINTER (asmname);
+
+	  if (str[0] == '*')
+	    {
+	      str ++;
+	      asmname = get_identifier (str);
+	    }
+
 	  fnode = cgraph_node_for_asm (p->target);
 	  vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
 	  if ((fnode
 	       || vnode
 	       || pointer_set_contains (visible, p->target))
-	      && !pointer_set_insert (visible, DECL_ASSEMBLER_NAME (p->decl)))
+	      && !pointer_set_insert (visible, asmname))
 	    changed = true;
 	}
     }