re PR c++/43856 ([C++0x] gcc-4.5.0 fails to transform id-expression into class…

re PR c++/43856 ([C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement)

	PR c++/43856
	* name-lookup.c (qualify_lookup): Disqualify lambda op().
	* class.c (current_nonlambda_class_type): New fn.
	* semantics.c (nonlambda_method_basetype): New.
	* cp-tree.h: Declare them.
	* tree.c (maybe_dummy_object): Handle implicit 'this' capture.

From-SVN: r158807

gcc/cp/ChangeLog

 2010-04-27  Jason Merrill  <jason@redhat.com>
 
+	PR c++/43856
+	* name-lookup.c (qualify_lookup): Disqualify lambda op().
+	* class.c (current_nonlambda_class_type): New fn.
+	* semantics.c (nonlambda_method_basetype): New.
+	* cp-tree.h: Declare them.
+	* tree.c (maybe_dummy_object): Handle implicit 'this' capture.
+
 	* semantics.c (baselink_for_fns): Correct BASELINK_BINFO.
 
 	PR c++/43875

gcc/cp/class.c

@@ -5971,6 +5971,34 @@ currently_open_derived_class (tree t)
   return NULL_TREE;
 }
 
+/* Returns the innermost class type which is not a lambda closure type.  */
+
+tree
+current_nonlambda_class_type (void)
+{
+  int i;
+
+  /* We start looking from 1 because entry 0 is from global scope,
+     and has no type.  */
+  for (i = current_class_depth; i > 0; --i)
+    {
+      tree c;
+      if (i == current_class_depth)
+	c = current_class_type;
+      else
+	{
+	  if (current_class_stack[i].hidden)
+	    break;
+	  c = current_class_stack[i].type;
+	}
+      if (!c)
+	continue;
+      if (!LAMBDA_TYPE_P (c))
+	return c;
+    }
+  return NULL_TREE;
+}
+
 /* When entering a class scope, all enclosing class scopes' names with
    static meaning (static variables, static functions, types and
    enumerators) have to be visible.  This recursive function calls

gcc/cp/cp-tree.h

@@ -4580,6 +4580,7 @@ extern void resort_type_method_vec		(void *, void *,
 extern bool add_method				(tree, tree, tree);
 extern bool currently_open_class		(tree);
 extern tree currently_open_derived_class	(tree);
+extern tree current_nonlambda_class_type	(void);
 extern tree finish_struct			(tree, tree);
 extern void finish_struct_1			(tree);
 extern int resolves_to_fixed_type_p		(tree, int *);
@@ -5212,6 +5213,7 @@ extern tree add_capture                         (tree, tree, tree, bool, bool);
 extern tree add_default_capture                 (tree, tree, tree);
 extern void register_capture_members		(tree);
 extern tree lambda_expr_this_capture            (tree);
+extern tree nonlambda_method_basetype		(void);
 extern void maybe_add_lambda_conv_op            (tree);
 
 /* in tree.c */

gcc/cp/name-lookup.c

@@ -3807,6 +3807,10 @@ qualify_lookup (tree val, int flags)
   if (cp_unevaluated_operand && TREE_CODE (val) == FIELD_DECL
       && DECL_NORMAL_CAPTURE_P (val))
     return false;
+  /* None of the lookups that use qualify_lookup want the op() from the
+     lambda; they want the one from the enclosing class.  */
+  if (TREE_CODE (val) == FUNCTION_DECL && LAMBDA_FUNCTION_P (val))
+    return false;
   return true;
 }
 

gcc/cp/semantics.c

@@ -5869,6 +5869,32 @@ lambda_expr_this_capture (tree lambda)
   return result;
 }
 
+/* Returns the method basetype of the innermost non-lambda function, or
+   NULL_TREE if none.  */
+
+tree
+nonlambda_method_basetype (void)
+{
+  tree fn, type;
+  if (!current_class_ref)
+    return NULL_TREE;
+
+  type = current_class_type;
+  if (!LAMBDA_TYPE_P (type))
+    return type;
+
+  /* Find the nearest enclosing non-lambda function.  */
+  fn = TYPE_NAME (type);
+  do
+    fn = decl_function_context (fn);
+  while (fn && LAMBDA_FUNCTION_P (fn));
+
+  if (!fn || !DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
+    return NULL_TREE;
+
+  return TYPE_METHOD_BASETYPE (TREE_TYPE (fn));
+}
+
 /* If the closure TYPE has a static op(), also add a conversion to function
    pointer.  */
 

gcc/cp/tree.c

@@ -2293,11 +2293,11 @@ maybe_dummy_object (tree type, tree* binfop)
 {
   tree decl, context;
   tree binfo;
+  tree current = current_nonlambda_class_type ();
 
-  if (current_class_type
-      && (binfo = lookup_base (current_class_type, type,
-			       ba_unique | ba_quiet, NULL)))
-    context = current_class_type;
+  if (current
+      && (binfo = lookup_base (current, type, ba_any, NULL)))
+    context = current;
   else
     {
       /* Reference from a nested class member function.  */
@@ -2315,6 +2315,13 @@ maybe_dummy_object (tree type, tree* binfop)
       && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (current_class_ref)),
 		      current_class_type))
     decl = current_class_ref;
+  else if (current != current_class_type
+	   && context == nonlambda_method_basetype ())
+    /* In a lambda, need to go through 'this' capture.  */
+    decl = (cp_build_indirect_ref
+	    ((lambda_expr_this_capture
+	      (CLASSTYPE_LAMBDA_EXPR (current_class_type))),
+	     RO_NULL, tf_warning_or_error));
   else
     decl = build_dummy_object (context);
 

gcc/testsuite/ChangeLog

 2010-04-27  Jason Merrill  <jason@redhat.com>
 
+	PR c++/43856
+	* g++.dg/cpp0x/lambda/lambda-this2.C: New.
+
 	PR c++/43875
 	* g++.dg/cpp0x/lambda/lambda-deduce2.C: New.
 

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this2.C

+// PR c++/43856
+// Test for implicit 'this' capture via rewriting.
+// { dg-options "-std=c++0x" }
+
+struct S1 {
+  int operator()(int);
+  int i;
+  void g();
+  void f() {
+    [=]() {
+      i;
+      g();
+      operator()(42);
+    };
+  }
+};