From 87bde062dda425ba4dcfd059a96c24be4a5ee5a7 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 6 May 2015 22:59:54 +0000 Subject: [PATCH] compiler: Analyze escape information of interface parameters. When analyzing function calls with interface parameters, all arguments related to an interface parameter were assumed to escape via the function arguments. Now, if an argument is related to a non-escaping parameter with an interface type, the argument may be stack-allocated. From-SVN: r222865 --- gcc/go/gofrontend/escape.cc | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/gcc/go/gofrontend/escape.cc b/gcc/go/gofrontend/escape.cc index 0d8739818dd..883e69c41d0 100644 --- a/gcc/go/gofrontend/escape.cc +++ b/gcc/go/gofrontend/escape.cc @@ -586,8 +586,20 @@ Build_connection_graphs::handle_call(Named_object* object, Expression* e) // Only call expression statements are interesting // e.g. 'func(var)' for which we can show var does not escape. Call_expression* ce = e->call_expression(); - if (ce == NULL || ce->args() == NULL) + if (ce == NULL) return; + else if (ce->args() == NULL) + { + if (ce->fn()->interface_field_reference_expression() != NULL) + { + // This is a call to an interface method with no arguments. OBJECT + // must be the receiver and we assume it escapes. + Connection_node* rcvr_node = + this->gogo_->add_connection_node(object)->connection_node(); + rcvr_node->set_escape_state(Node::ESCAPE_ARG); + } + return; + } // If the function call that references OBJECT is unknown, we must be // conservative and assume every argument escapes. A function call is unknown @@ -606,6 +618,8 @@ Build_connection_graphs::handle_call(Named_object* object, Expression* e) this->gogo_->add_connection_node(arg_no)->connection_node(); arg_node->set_escape_state(Node::ESCAPE_ARG); } + else if ((*arg)->call_expression() != NULL) + this->handle_call(object, *arg); } return; } @@ -787,7 +801,6 @@ Build_connection_graphs::handle_call(Named_object* object, Expression* e) ++pos) { std::string param_name; - bool param_is_interface = false; if (*pos >= 0 && params->size() <= static_cast(*pos)) { // There were more arguments than there are parameters. This must be @@ -804,11 +817,7 @@ Build_connection_graphs::handle_call(Named_object* object, Expression* e) param_name = fntype->receiver()->name(); } else - { - param_name = params->at(*pos).name(); - param_is_interface = - (params->at(*pos).type()->interface_type() != NULL); - } + param_name = params->at(*pos).name(); if (Gogo::is_sink_name(param_name) || param_name.empty()) continue; @@ -832,11 +841,6 @@ Build_connection_graphs::handle_call(Named_object* object, Expression* e) Node* arg_node = this->gogo_->add_connection_node(object); Node* param_node = this->gogo_->add_connection_node(param_no); - - // Act conservatively when an argument is converted into an interface - // value. FIXME. - if (param_is_interface) - param_node->connection_node()->set_escape_state(Node::ESCAPE_ARG); param_node->add_edge(arg_node); } -- 2.30.2