When the only use of 'this' is implicitly by a dependent name, we don't
see the capture until instantiation time. Don't clobber its capture
list entry when we instantiate the ones seen at template definition time.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit cdcb44a750af3921d6883832892dd8cd5e2d22b4
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Feb 12 21:47:56 2013 -0500
PR c++/56135
* pt.c (tsubst_copy_and_build): Don't forget any new
captures that arose from use of dependent names.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index a3359ad..2aadd4d 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -14457,9 +14457,11 @@ tsubst_copy_and_build (tree t,
complete_type (type);
/* The capture list refers to closure members, so this needs to
- wait until after we finish instantiating the type. */
+ wait until after we finish instantiating the type. Also keep
+ any captures that may have been added during instantiation. */
LAMBDA_EXPR_CAPTURE_LIST (r)
- = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
+ = chainon (RECUR (LAMBDA_EXPR_CAPTURE_LIST (t)),
+ LAMBDA_EXPR_CAPTURE_LIST (r));
LAMBDA_EXPR_THIS_CAPTURE (r) = NULL_TREE;
RETURN (build_lambda_object (r));
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this8.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this8.C
new file mode 100644
index 0000000..9309a44
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this8.C
@@ -0,0 +1,39 @@
+// PR c++/56135
+// { dg-do run { target c++11 } }
+
+#include <functional>
+
+extern "C" void abort() throw();
+
+struct test {
+ template<typename T>
+ std::function<void()> broken(int x) {
+ return [=] { +x; print<T>(); };
+ }
+
+ std::function<void()> works0() {
+ return [=] { print<int>(); };
+ }
+
+ template<typename T>
+ std::function<void()> works1() {
+ return [=] { print<int>(); };
+ }
+
+ template<typename T>
+ std::function<void()> works2() {
+ return [=] { this->print<T>(); };
+ }
+
+ template<typename T>
+ void print() { if (this == NULL) abort (); }
+};
+
+int main(void) {
+ test().broken<int>(1)();
+ test().works0()();
+ test().works1<int>()();
+ test().works2<int>()();
+
+ return 0;
+}
