[patch] Fix PR c++/22604, ICE after invalid covariant return

[Volker Reichelt]

Consider the following testcase:

  struct A;

  struct B
  {
    virtual A* foo();  // { dg-error "overriding" }
  };

  struct C : B
  {
    virtual C* foo();  // { dg-error "invalid covariant" }
  };

The declaration of foo in struct C is invalid.
When updating the vtable for C the compiler fails to check for invalid
overriders in update_vtable_entry_for_fn, thus causing an ICE.

The attached patch adds the missing check and the above testcase.
In addition the patch allows us to squeeze more errors out of
g++.old-deja/g++.mike/p811.C.

Bootstrapped and regtested on i686-pc-linux-gnu.
OK for mainline and 4.0 branch (since this is a regression)?

Regards,
Volker


2005-08-05  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>

	PR c++/22604
	* class.c (update_vtable_entry_for_fn): Check for invalid overrider.

===================================================================
--- gcc/gcc/cp/class.c	1 Aug 2005 04:02:23 -0000	1.730
+++ gcc/gcc/cp/class.c	5 Aug 2005 14:50:53 -0000
@@ -1972,6 +1972,8 @@ update_vtable_entry_for_fn (tree t, tree
   if (overrider == error_mark_node)
     return;
   overrider_target = overrider_fn = TREE_PURPOSE (overrider);
+  if (DECL_INVALID_OVERRIDER_P (overrider_target))
+    return;
 
   /* Check for adjusting covariant return types.  */
   over_return = TREE_TYPE (TREE_TYPE (overrider_target));
===================================================================


2005-08-05  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>

	PR c++/22604
	* g++.dg/inherit/covariant14.C: New test.
	* g++.old-deja/g++.mike/p811.C: Add more error markers.

===================================================================
--- gcc/gcc/testsuite/g++.dg/inherit/covariant14.C	2005-06-27 13:32:40.055820328 +0200
+++ gcc/gcc/testsuite/g++.dg/inherit/covariant14.C	2005-08-05 17:12:40.000000000 +0200
@@ -0,0 +1,16 @@
+// PR c++/22604
+// ICE on invalid overrider for virtual function
+// Origin: Flash Sheridan  <flash@pobox.com>
+// { dg-do compile }
+
+struct A;
+
+struct B
+{
+  virtual A* foo();  // { dg-error "overriding" }
+};
+
+struct C : B
+{
+  virtual C* foo();  // { dg-error "invalid covariant" }
+};
===================================================================
--- gcc/gcc/testsuite/g++.old-deja/g++.mike/p811.C	1 Nov 2004 18:24:33 -0000	1.6
+++ gcc/gcc/testsuite/g++.old-deja/g++.mike/p811.C	5 Aug 2005 20:45:53 -0000
@@ -512,10 +512,10 @@ class Y {
 public:
     Y() {}
   virtual const char *stringify() = 0;
-    virtual char *stringify2() const = 0; // { dg-error "overriding" } 
+    virtual char *stringify2() const = 0; // { dg-error "overriding|virtual" } 
 };
 
-class X: public Y {
+class X: public Y { // { dg-error "pure within" }
 public:
     X(): Y() {}
     const char *stringify();		// { dg-error "candidate" }
@@ -536,7 +536,7 @@ X::stringify2()   // { dg-error "does no
 
 main()
 {
-    X x;
+    X x;  // { dg-error "abstract" }
     Y& y = x;
 
     cout << "x\n";
===================================================================