semantics.c (lambda_expr_this_capture): Fix default capture of explicit capture of 'this'.

	* semantics.c (lambda_expr_this_capture): Fix default capture
	of explicit capture of 'this'.

From-SVN: r152339

gcc/cp/ChangeLog

 2009-09-30  Jason Merrill  <jason@redhat.com>
 
+	* semantics.c (lambda_expr_this_capture): Fix default capture
+	of explicit capture of 'this'.
+
+2009-09-30  Jason Merrill  <jason@redhat.com>
+
 	* parser.c (cp_parser_lambda_expression): Don't add __ to __this.
 
 2009-09-30  Jason Merrill  <jason@redhat.com>

gcc/cp/semantics.c

@@ -5540,7 +5540,6 @@ add_default_capture (tree lambda_stack, tree id, tree initializer)
   current_class_type = saved_class_type;
 
   return member;
-
 }
 
 /* Return the capture pertaining to a use of 'this' in LAMBDA, in the form of an
@@ -5559,6 +5558,7 @@ lambda_expr_this_capture (tree lambda)
     {
       tree containing_function = TYPE_CONTEXT (TREE_TYPE (lambda));
       tree lambda_stack = tree_cons (NULL_TREE, lambda, NULL_TREE);
+      tree init = NULL_TREE;
 
       /* If we are in a lambda function, we can move out until we hit:
            1. a non-lambda function,
@@ -5569,9 +5569,20 @@ lambda_expr_this_capture (tree lambda)
           tree lambda
             = CLASSTYPE_LAMBDA_EXPR (DECL_CONTEXT (containing_function));
 
-          if (LAMBDA_EXPR_THIS_CAPTURE (lambda)
-              || LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda) == CPLD_NONE)
-            break;
+          if (LAMBDA_EXPR_THIS_CAPTURE (lambda))
+	    {
+	      /* An outer lambda has already captured 'this'.  */
+	      tree cap = LAMBDA_EXPR_THIS_CAPTURE (lambda);
+	      tree lthis
+		= cp_build_indirect_ref (DECL_ARGUMENTS (containing_function),
+					 "", tf_warning_or_error);
+	      init = finish_non_static_data_member (cap, lthis, NULL_TREE);
+	      break;
+	    }
+
+	  if (LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda) == CPLD_NONE)
+	    /* An outer lambda won't let us capture 'this'.  */
+	    break;
 
           lambda_stack = tree_cons (NULL_TREE,
                                     lambda,
@@ -5580,15 +5591,15 @@ lambda_expr_this_capture (tree lambda)
           containing_function = decl_function_context (containing_function);
         }
 
-      if (DECL_NONSTATIC_MEMBER_FUNCTION_P (containing_function))
-        {
-          this_capture = add_default_capture (lambda_stack,
-                                              /*id=*/get_identifier ("__this"),
-                                              /* First parameter is 'this'.  */
-                                              /*initializer=*/DECL_ARGUMENTS
-                                                (containing_function));
-        }
+      if (!init && DECL_NONSTATIC_MEMBER_FUNCTION_P (containing_function)
+	  && !LAMBDA_FUNCTION_P (containing_function))
+	/* First parameter is 'this'.  */
+	init = DECL_ARGUMENTS (containing_function);
 
+      if (init)
+	this_capture = add_default_capture (lambda_stack,
+					    /*id=*/get_identifier ("__this"),
+					    init);
     }
 
   if (!this_capture)

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

@@ -3,6 +3,16 @@
 
 #include <cassert>
 
+struct A {
+  int i;
+  A(): i(42) { }
+  int f() {
+    return [this]{
+      return [=]{ return i; }();
+    }();
+  }
+};
+
 int main() {
   int i = 1;
 
@@ -47,6 +57,7 @@ int main() {
 
   assert(i == 4);
 
+  assert (A().f() == 42);
+
   return 0;
 }
-