re PR lto/70283 (bogus vtable mismatch warnings)

PR ipa/70283
	* ipa-devirt.c (methods_equal_p): New function.
	(compare_virtual_tables): Use it.
	* cgraph.h (symbol_table::symbol_suffix_separator): Declare.
	* cgraphclones.c (clone_function_name_1): Use
	symbol_table::symbol_suffix_separator.
	* coverage.c (build_var): Likewise.
	* symtab.c (symbol_table::symbol_suffix_separator): New.

From-SVN: r234532

gcc/ChangeLog

@@ -1,3 +1,14 @@
+2016-03-10  Jan Hubicka  <hubicka@ucw.cz>
+
+	PR ipa/70283
+	* ipa-devirt.c (methods_equal_p): New function.
+	(compare_virtual_tables): Use it.
+	* cgraph.h (symbol_table::symbol_suffix_separator): Declare.
+	* cgraphclones.c (clone_function_name_1): Use
+	symbol_table::symbol_suffix_separator.
+	* coverage.c (build_var): Likewise.
+	* symtab.c (symbol_table::symbol_suffix_separator): New.
+
 2016-03-29  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/70429

gcc/cgraph.h

@@ -2173,6 +2173,9 @@ public:
 
   FILE* GTY ((skip)) dump_file;
 
+  /* Return symbol used to separate symbol name from suffix.  */
+  static char symbol_suffix_separator ();
+
 private:
   /* Allocate new callgraph node.  */
   inline cgraph_node * allocate_cgraph_symbol (void);

gcc/cgraphclones.c

@@ -512,13 +512,7 @@ clone_function_name_1 (const char *name, const char *suffix)
   prefix = XALLOCAVEC (char, len + strlen (suffix) + 2);
   memcpy (prefix, name, len);
   strcpy (prefix + len + 1, suffix);
-#ifndef NO_DOT_IN_LABEL
-  prefix[len] = '.';
-#elif !defined NO_DOLLAR_IN_LABEL
-  prefix[len] = '$';
-#else
-  prefix[len] = '_';
-#endif
+  prefix[len] = symbol_table::symbol_suffix_separator ();
   ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix, clone_fn_id_num++);
   return get_identifier (tmp_name);
 }

gcc/coverage.c

@@ -745,11 +745,7 @@ build_var (tree fn_decl, tree type, int counter)
   else
     sprintf (buf, "__gcov%u_", counter);
   len = strlen (buf);
-#ifndef NO_DOT_IN_LABEL
-  buf[len - 1] = '.';
-#elif !defined NO_DOLLAR_IN_LABEL
-  buf[len - 1] = '$';
-#endif
+  buf[len - 1] = symbol_table::symbol_suffix_separator ();
   memcpy (buf + len, fn_name, fn_name_len + 1);
   DECL_NAME (var) = get_identifier (buf);
   TREE_STATIC (var) = 1;

gcc/ipa-devirt.c

@@ -705,6 +705,29 @@ odr_subtypes_equivalent_p (tree t1, tree t2,
   return odr_types_equivalent_p (t1, t2, false, NULL, visited, loc1, loc2);
 }
 
+/* Return true if DECL1 and DECL2 are identical methods.  Consider
+   name equivalent to name.localalias.xyz.  */
+
+static bool
+methods_equal_p (tree decl1, tree decl2)
+{
+  if (DECL_ASSEMBLER_NAME (decl1) == DECL_ASSEMBLER_NAME (decl2))
+    return true;
+  const char sep = symbol_table::symbol_suffix_separator ();
+
+  const char *name1 = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl1));
+  const char *ptr1 = strchr (name1, sep);
+  int len1 = ptr1 ? ptr1 - name1 : strlen (name1);
+
+  const char *name2 = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl2));
+  const char *ptr2 = strchr (name2, sep);
+  int len2 = ptr2 ? ptr2 - name2 : strlen (name2);
+
+  if (len1 != len2)
+    return false;
+  return !strncmp (name1, name2, len1);
+}
+
 /* Compare two virtual tables, PREVAILING and VTABLE and output ODR
    violation warnings.  */
 
@@ -758,8 +781,8 @@ compare_virtual_tables (varpool_node *prevailing, varpool_node *vtable)
 	 accept the other case.  */
       while (!end2
 	     && (end1
-	         || (DECL_ASSEMBLER_NAME (ref1->referred->decl)
-		     != DECL_ASSEMBLER_NAME (ref2->referred->decl)
+	         || (methods_equal_p (ref1->referred->decl,
+				      ref2->referred->decl)
 	             && TREE_CODE (ref1->referred->decl) == FUNCTION_DECL))
 	     && TREE_CODE (ref2->referred->decl) != FUNCTION_DECL)
 	{
@@ -785,8 +808,7 @@ compare_virtual_tables (varpool_node *prevailing, varpool_node *vtable)
 	}
       while (!end1
 	     && (end2
-	         || (DECL_ASSEMBLER_NAME (ref2->referred->decl)
-		     != DECL_ASSEMBLER_NAME (ref1->referred->decl)
+	         || (methods_equal_p (ref2->referred->decl, ref1->referred->decl)
 	             && TREE_CODE (ref2->referred->decl) == FUNCTION_DECL))
 	     && TREE_CODE (ref1->referred->decl) != FUNCTION_DECL)
 	{
@@ -823,8 +845,7 @@ compare_virtual_tables (varpool_node *prevailing, varpool_node *vtable)
 
       if (!end1 && !end2)
 	{
-	  if (DECL_ASSEMBLER_NAME (ref1->referred->decl)
-	      == DECL_ASSEMBLER_NAME (ref2->referred->decl))
+	  if (methods_equal_p (ref1->referred->decl, ref2->referred->decl))
 	    continue;
 
 	  class_type->odr_violated = true;
@@ -920,11 +941,14 @@ compare_virtual_tables (varpool_node *prevailing, varpool_node *vtable)
 		      "unit");
 	      gcc_assert (TREE_CODE (ref2->referred->decl)
 			  == FUNCTION_DECL);
-	      inform (DECL_SOURCE_LOCATION (ref1->referred->decl),
-		      "virtual method %qD", ref1->referred->decl);
-	      inform (DECL_SOURCE_LOCATION (ref2->referred->decl),
+	      inform (DECL_SOURCE_LOCATION
+			 (ref1->referred->ultimate_alias_target ()->decl),
+		      "virtual method %qD",
+		      ref1->referred->ultimate_alias_target ()->decl);
+	      inform (DECL_SOURCE_LOCATION
+			 (ref2->referred->ultimate_alias_target ()->decl),
 		      "ought to match virtual method %qD but does not",
-		      ref2->referred->decl);
+		      ref2->referred->ultimate_alias_target ()->decl);
 	    }
 	  else
 	    inform (DECL_SOURCE_LOCATION

gcc/symtab.c

@@ -2137,3 +2137,17 @@ symtab_node::definition_alignment ()
   call_for_symbol_and_aliases (get_alignment_1, &align, true);
   return align;
 }
+
+/* Return symbol used to separate symbol name from suffix.  */
+
+char 
+symbol_table::symbol_suffix_separator ()
+{
+#ifndef NO_DOT_IN_LABEL
+  return '.';
+#elif !defined NO_DOLLAR_IN_LABEL
+  return '$';
+#else
+  return '_';
+#endif
+}