re PR c++/26696 (ICE with statement forming unused static member function reference)

        PR c++/26696
        * cvt.c (convert_to_void): Replace a subexpression with no side
        effects with void_zero_node.
        * tree.c (is_overloaded_fn): Look through COMPONENT_REF.
        (get_first_fn): Ditto.
        * decl.c (grokdeclarator): No need to look through COMPONENT_REF.

From-SVN: r116724

gcc/cp/ChangeLog

+2006-09-06  Jason Merrill  <jason@redhat.com>
+
+	PR c++/26696
+	* cvt.c (convert_to_void): Replace a subexpression with no side 
+	effects with void_zero_node.
+	* tree.c (is_overloaded_fn): Look through COMPONENT_REF.
+	(get_first_fn): Ditto.
+	* decl.c (grokdeclarator): No need to look through COMPONENT_REF.
+
 2006-09-05  Jason Merrill  <jason@redhat.com>
 
 	PR c++/26571

gcc/cp/cvt.c

@@ -960,6 +960,8 @@ convert_to_void (tree expr, const char *implicit)
 	}
       expr = build1 (CONVERT_EXPR, void_type_node, expr);
     }
+  if (! TREE_SIDE_EFFECTS (expr))
+    expr = void_zero_node;
   return expr;
 }
 

gcc/cp/decl.c

@@ -7014,8 +7014,6 @@ grokdeclarator (const cp_declarator *declarator,
 		  tree fns = TREE_OPERAND (decl, 0);
 
 		  dname = fns;
-		  if (TREE_CODE (dname) == COMPONENT_REF)
-		    dname = TREE_OPERAND (dname, 1);
 		  if (TREE_CODE (dname) != IDENTIFIER_NODE)
 		    {
 		      gcc_assert (is_overloaded_fn (dname));

gcc/cp/tree.c

@@ -853,7 +853,8 @@ int
 is_overloaded_fn (tree x)
 {
   /* A baselink is also considered an overloaded function.  */
-  if (TREE_CODE (x) == OFFSET_REF)
+  if (TREE_CODE (x) == OFFSET_REF
+      || TREE_CODE (x) == COMPONENT_REF)
     x = TREE_OPERAND (x, 1);
   if (BASELINK_P (x))
     x = BASELINK_FUNCTIONS (x);
@@ -880,6 +881,8 @@ get_first_fn (tree from)
 {
   gcc_assert (is_overloaded_fn (from));
   /* A baselink is also considered an overloaded function.  */
+  if (TREE_CODE (from) == COMPONENT_REF)
+    from = TREE_OPERAND (from, 1);
   if (BASELINK_P (from))
     from = BASELINK_FUNCTIONS (from);
   return OVL_CURRENT (from);

gcc/testsuite/g++.dg/other/component1.C

@@ -23,7 +23,7 @@ void Foo () {
   c.f;		        // { dg-error "statement cannot resolve" "" }
   c.f<int>;		// { dg-error "statement cannot resolve" "" }
   
-  c.g == 1;		// { dg-error "invalid use of" "" }
-  c.f == 1;		// { dg-error "invalid use of" "" }
-  c.f<int> == 1;	// { dg-error "invalid use of" "" }
+  c.g == 1;		// { dg-error "invalid" "" }
+  c.f == 1;		// { dg-error "invalid" "" }
+  c.f<int> == 1;	// { dg-error "invalid" "" }
 }

gcc/testsuite/g++.dg/warn/noeffect8.C

+// PR c++/26696
+
+struct A
+{
+  static void f() {}
+}; 
+
+int main() 
+{
+  A a; 
+  a.f;    			// { dg-warning "not call" }
+}