re PR c++/31078 (warning: same canonical type node for different types with const strings)

2007-04-12  Douglas Gregor  <doug.gregor@gmail.com>

	PR c++/31078
	PR c++/31103
	* c-common.c (c_build_qualified_type): Set canonical type
	appropriately.  

2007-04-12  Douglas Gregor  <doug.gregor@gmail.com>

	PR c++/31078
	* g++.dg/other/pr31078.C: New.

From-SVN: r123740

gcc/ChangeLog

+2007-04-12  Douglas Gregor  <doug.gregor@gmail.com>
+
+	PR c++/31078
+	PR c++/31103
+	* c-common.c (c_build_qualified_type): Set canonical type
+	appropriately.  
+
 2007-04-12  Richard Guenther  <rguenther@suse.de>
 
 	* tree-pretty-print.c (dump_generic_node): Print ARRAY_REF

gcc/c-common.c

@@ -2894,8 +2894,26 @@ c_build_qualified_type (tree type, int type_quals)
 	}
       if (!t)
 	{
+          tree domain = TYPE_DOMAIN (type);
+
 	  t = build_variant_type_copy (type);
 	  TREE_TYPE (t) = element_type;
+
+          if (TYPE_STRUCTURAL_EQUALITY_P (element_type)
+              || (domain && TYPE_STRUCTURAL_EQUALITY_P (domain)))
+            SET_TYPE_STRUCTURAL_EQUALITY (t);
+          else if (TYPE_CANONICAL (element_type) != element_type
+                   || (domain && TYPE_CANONICAL (domain) != domain))
+            {
+              tree unqualified_canon 
+                = build_array_type (TYPE_CANONICAL (element_type),
+                                    domain? TYPE_CANONICAL (domain) 
+                                          : NULL_TREE);
+              TYPE_CANONICAL (t) 
+                = c_build_qualified_type (unqualified_canon, type_quals);
+            }
+          else
+            TYPE_CANONICAL (t) = t;
 	}
       return t;
     }

gcc/testsuite/ChangeLog

+2007-04-12  Douglas Gregor  <doug.gregor@gmail.com>
+
+	PR c++/31078
+	* g++.dg/other/pr31078.C: New.
+
 2007-04-12  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/31169

gcc/testsuite/g++.dg/other/pr31078.C

+typedef int SLONG;
+typedef char SCHAR;
+typedef short SSHORT;
+typedef char TEXT;
+typedef long ISC_STATUS;
+const SLONG gds_arg_string = 2;
+const SLONG gds_sys_request = 335544373L;
+enum jrd_blk_t
+{
+    type_str, type_dcc, type_sbm, type_smb, type_blb, type_irb, type_jrn
+};
+struct blk
+{
+};
+template < class RPT, SSHORT BLOCK_TYPE = 0 > class pool_alloc_rpt:public blk
+{
+};
+class jrn:public pool_alloc_rpt < SCHAR, type_jrn >
+{
+public:ISC_STATUS * jrn_status_vector;
+  TEXT jrn_server[1];
+};
+typedef jrn *JRN;
+extern void IBERR_build_status (ISC_STATUS *, ISC_STATUS, ...);
+static void
+error (ISC_STATUS * status_vector, JRN journal, int status, TEXT * string)
+{
+  IBERR_build_status (status_vector, gds_sys_request, gds_arg_string, string,
+		      gds_arg_string, (journal) ? journal->jrn_server : "",
+		      0);
+}