re PR c++/27666 (ICE with volatile in conditional expression)

	PR c++/27666
	* call.c (build_conditional_expr): Robustify.
	PR c++/27666
	* g++.dg/expr/cond9.C: New test.

From-SVN: r114702

gcc/cp/ChangeLog

 2006-06-15  Mark Mitchell  <mark@codesourcery.com>
 
+	PR c++/27666
+	* call.c (build_conditional_expr): Robustify.
+
 	PR c++/27640
 	* pt.c (instantiate_template): Set processing_template_decl to
 	zero while performing substitutions.

gcc/cp/call.c

@@ -3322,12 +3322,21 @@ build_conditional_expr (tree arg1, tree arg2, tree arg3)
 	  arg2 = convert_like (conv2, arg2);
 	  arg2 = convert_from_reference (arg2);
 	  arg2_type = TREE_TYPE (arg2);
+	  /* Even if CONV2 is a valid conversion, the result of the
+	     conversion may be invalid.  For example, if ARG3 has type
+	     "volatile X", and X does not have a copy constructor
+	     accepting a "volatile X&", then even if ARG2 can be
+	     converted to X, the conversion will fail.  */
+	  if (error_operand_p (arg2))
+	    result = error_mark_node;
 	}
       else if (conv3 && (!conv3->bad_p || !conv2))
 	{
 	  arg3 = convert_like (conv3, arg3);
 	  arg3 = convert_from_reference (arg3);
 	  arg3_type = TREE_TYPE (arg3);
+	  if (error_operand_p (arg3))
+	    result = error_mark_node;
 	}
 
       /* Free all the conversions we allocated.  */

gcc/testsuite/ChangeLog

 2006-06-15  Mark Mitchell  <mark@codesourcery.com>
 
+	PR c++/27666
+	* g++.dg/expr/cond9.C: New test.
+
 	PR c++/27640
 	* g++.dg/template/ctor7.C: New test.
 

gcc/testsuite/g++.dg/expr/cond9.C

+// PR c++/27666
+
+struct A { // { dg-error "A" }
+  A(int); // { dg-error "A" }
+};
+
+void foo(volatile A a) { 
+  1 ? a : 0; // { dg-error "match|temporary" }
+  1 ? 0 : a; // { dg-error "match|temporary" }
+}