lambda_expr_this_capture assumes that we can find the fake 'this'
inserted while parsing an NSDMI, but it isn't there if we are
instantiating, rather than parsing, a generic lambda.
Tested x86_64-pc-linux-gnu, applying to trunk/7/6.
commit 9c64c953f0595e88cd911d488a415c8568934864
Author: Jason Merrill <ja...@redhat.com>
Date: Mon Feb 26 18:01:05 2018 -0500
PR c++/84520 - ICE with generic lambda in NSDMI.
* lambda.c (lambda_expr_this_capture): Don't look for fake NSDMI
'this' in a generic lambda instantiation.
diff --git a/gcc/cp/lambda.c b/gcc/cp/lambda.c
index 6a798266f12..3f77df037a2 100644
--- a/gcc/cp/lambda.c
+++ b/gcc/cp/lambda.c
@@ -758,11 +758,14 @@ lambda_expr_this_capture (tree lambda, bool add_capture_p)
lambda_stack);
if (LAMBDA_EXPR_EXTRA_SCOPE (tlambda)
+ && !COMPLETE_TYPE_P (LAMBDA_EXPR_CLOSURE (tlambda))
&& TREE_CODE (LAMBDA_EXPR_EXTRA_SCOPE (tlambda)) == FIELD_DECL)
{
/* In an NSDMI, we don't have a function to look up the decl in,
but the fake 'this' pointer that we're using for parsing is
- in scope_chain. */
+ in scope_chain. But if the closure is already complete, we're
+ in an instantiation of a generic lambda, and the fake 'this'
+ is gone. */
init = scope_chain->x_current_class_ptr;
gcc_checking_assert
(init && (TREE_TYPE (TREE_TYPE (init))
diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-nsdmi1.C
b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-nsdmi1.C
new file mode 100644
index 00000000000..89ce519d812
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-nsdmi1.C
@@ -0,0 +1,8 @@
+// PR c++/84520
+// { dg-do compile { target c++14 } }
+
+struct A
+{
+ static void foo(int);
+ void (*f)(int) = [](auto i) { foo(i); };
+};
