re PR c++/34935 (ICE with attribute may_alias)

2008-01-31  Douglas Gregor  <doug.gregor@gmail.com>
           Jakub Jelinek  <jakub@redhat.com>

       PR c++/34935
       PR c++/34936
       * typeck.c (structural_comptypes): Handle comparisons of
       VOID_TYPE, BOOLEAN_TYPE, INTEGER_TYPE, FIXED_POINT_TYPE, and
       REAL_TYPE nodes.
       * mangle.c (write_builtin_type): Map down to the canonical type,
       which will be one of the predefined type nodes.

2008-01-31  Douglas Gregor  <doug.gregor@gmail.com>
           Jakub Jelinek  <jakub@redhat.com>

       PR c++/34935
       PR c++/34936
       * g++.dg/ext/alias-canon.C: New.
       * g++.dg/ext/alias-mangle.C: New.
	

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r131984

gcc/cp/ChangeLog

+2008-01-31  Douglas Gregor  <doug.gregor@gmail.com>
+           Jakub Jelinek  <jakub@redhat.com>
+
+       PR c++/34935
+       PR c++/34936
+       * typeck.c (structural_comptypes): Handle comparisons of
+       VOID_TYPE, BOOLEAN_TYPE, INTEGER_TYPE, FIXED_POINT_TYPE, and
+       REAL_TYPE nodes.
+       * mangle.c (write_builtin_type): Map down to the canonical type,
+       which will be one of the predefined type nodes.
+
 2008-01-29  Michael Meissner  <michael.meissner@amd.com>
 
 	PR 35004

gcc/cp/mangle.c

@@ -1768,6 +1768,9 @@ write_CV_qualifiers_for_type (const tree type)
 static void
 write_builtin_type (tree type)
 {
+  if (TYPE_CANONICAL (type))
+    type = TYPE_CANONICAL (type);
+
   switch (TREE_CODE (type))
     {
     case VOID_TYPE:

gcc/cp/typeck.c

@@ -977,6 +977,30 @@ structural_comptypes (tree t1, tree t2, int strict)
   /* Compare the types.  Break out if they could be the same.  */
   switch (TREE_CODE (t1))
     {
+    case VOID_TYPE:
+    case BOOLEAN_TYPE:
+      /* All void and bool types are the same.  */
+      break;
+
+    case INTEGER_TYPE:
+    case FIXED_POINT_TYPE:
+    case REAL_TYPE:
+      /* With these nodes, we can't determine type equivalence by
+	 looking at what is stored in the nodes themselves, because
+	 two nodes might have different TYPE_MAIN_VARIANTs but still
+	 represent the same type.  For example, wchar_t and int could
+	 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE,
+	 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs
+	 and are distinct types. On the other hand, int and the
+	 following typedef
+
+           typedef int INT __attribute((may_alias));
+
+	 have identical properties, different TYPE_MAIN_VARIANTs, but
+	 represent the same type.  The canonical type system keeps
+	 track of equivalence in this case, so we fall back on it.  */
+      return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
+
     case TEMPLATE_TEMPLATE_PARM:
     case BOUND_TEMPLATE_TEMPLATE_PARM:
       if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)

gcc/testsuite/ChangeLog

+2008-01-31  Douglas Gregor  <doug.gregor@gmail.com>
+           Jakub Jelinek  <jakub@redhat.com>
+
+       PR c++/34935
+       PR c++/34936
+       * g++.dg/ext/alias-canon.C: New.
+       * g++.dg/ext/alias-mangle.C: New.
+
 2008-01-30  Jan Hubicka  <jh@suse.cz>
 
 	* gcc.c-torture/execute/pr34982.c: Add forgotten return 0.

gcc/testsuite/g++.dg/ext/alias-canon.C

+// PR c++/34935
+/* { dg-do compile } */
+/* { dg-final { scan-assembler "_Z1fi" } } */
+/* { dg-final { scan-assembler "_Z1fb" } } */
+/* { dg-final { scan-assembler "_Z1fd" } } */
+/* { dg-final { scan-assembler "_Z1ff" } } */
+/* { dg-final { scan-assembler "_Z1fw" } } */
+
+typedef int INT __attribute((may_alias));
+
+void f(int);
+void f(INT) { }
+
+typedef bool BOOL __attribute((may_alias));
+
+void f(bool);
+void f(BOOL) { }
+
+typedef float FLOAT __attribute((may_alias));
+
+void f(float);
+void f(FLOAT) { }
+
+typedef double DOUBLE __attribute((may_alias));
+
+void f(double);
+void f(DOUBLE) {}
+
+typedef wchar_t WCHAR_T __attribute((may_alias));
+
+void f(wchar_t);
+void f(WCHAR_T) {}
+
+void test()
+{
+  f(0);
+  f(true);
+  f(1.0f);
+  f(1.0);
+  f(L'f');
+}

gcc/testsuite/g++.dg/ext/alias-mangle.C

+// PR c++/34936
+// { dg-do compile }
+/* { dg-final { scan-assembler "_ZN1AIdEC1Ev" } } */
+typedef double X __attribute((may_alias)) ;
+
+template<typename> struct A
+{
+  A();
+};
+
+A<X> a;