Patchwork [C++] PR 44628

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Submitter Paolo Carlini
Date June 30, 2010, 6:35 p.m.
Message ID <4C2B8E61.90807@oracle.com>
Download mbox | patch
Permalink /patch/57445/
State New
Headers show

Comments

Paolo Carlini - June 30, 2010, 6:35 p.m.
Hi,

a simple patch for this P2 regression. As for the rationale behind the
additional checks: the one in cp_build_unary_op seems rather sensible
considering how many uses the function has; the other is justified
because in the caller, reference_binding, expr can be certainly
NULL_TREE in general (we already check for expr non-NULL_TREE in many
places).

Tested x86_64-linux. Ok for mainline and 4_5-branch?

Paolo.

////////////////////
/cp
2010-06-30  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/44628
	* typeck.c (cp_build_unary_op): Early return error_mark_node when
	arg is NULL_TREE too.
	* call.c (convert_class_to_reference): Return error_mark_node when
	expr is NULL_TREE.

/testsuite
2010-06-30  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/44628
	* testsuite/g++.dg/template/crash100.C: New.
Jason Merrill - June 30, 2010, 6:55 p.m.
OK.

Jason
Richard Guenther - June 30, 2010, 8:49 p.m.
On Wed, Jun 30, 2010 at 8:35 PM, Paolo Carlini <paolo.carlini@oracle.com> wrote:
> Hi,
>
> a simple patch for this P2 regression. As for the rationale behind the
> additional checks: the one in cp_build_unary_op seems rather sensible
> considering how many uses the function has; the other is justified
> because in the caller, reference_binding, expr can be certainly
> NULL_TREE in general (we already check for expr non-NULL_TREE in many
> places).
>
> Tested x86_64-linux. Ok for mainline and 4_5-branch?

The trunk was frozen when you committed this patch.

Thanks,
Richard.

> Paolo.
>
> ////////////////////
>

Patch

Index: testsuite/g++.dg/template/crash100.C
===================================================================
--- testsuite/g++.dg/template/crash100.C	(revision 0)
+++ testsuite/g++.dg/template/crash100.C	(revision 0)
@@ -0,0 +1,24 @@ 
+// PR c++/44628
+
+template <typename T>
+class Temp
+{
+  int Val;
+  public:
+  operator T&(void)  { return Val; }
+
+  virtual T& operator=(T a ) // { dg-error "overriding" }
+  {
+    Val = a;
+    return Val;
+  }
+};
+
+class Int : public Temp<int>
+{
+  public:
+  Int& operator=(int a) // { dg-error "conflicting return type" }
+  {
+    return (*this);
+  }
+};
Index: cp/typeck.c
===================================================================
--- cp/typeck.c	(revision 161612)
+++ cp/typeck.c	(working copy)
@@ -4781,7 +4781,7 @@  cp_build_unary_op (enum tree_code code, tree xarg,
   tree val;
   const char *invalid_op_diag;
 
-  if (error_operand_p (arg))
+  if (!arg || error_operand_p (arg))
     return error_mark_node;
 
   if ((invalid_op_diag
Index: cp/call.c
===================================================================
--- cp/call.c	(revision 161612)
+++ cp/call.c	(working copy)
@@ -1040,6 +1040,9 @@  convert_class_to_reference (tree reference_type, t
   struct z_candidate *cand;
   bool any_viable_p;
 
+  if (!expr)
+    return NULL;
+
   conversions = lookup_conversions (s, /*lookup_template_convs_p=*/true);
   if (!conversions)
     return NULL;