Hi,
this ICE on valid is triggered by the existing
cpp0x/lambda/lambda-ice20.C when -Wshadow is requested. Today I
confirmed that it can be reproduced only after r251433, the "Reimplement
handling of lambdas in templates." patch: then, as part of
tsubst_lambda_expr, do_pushdecl calls check_local_shadow which in turn
checks nonlambda_method_basetype and at that time current_class_type is
null. I believe this is just something which we have to handle in the
obvious way: indeed, most other uses of LAMBDA_TYPE_P are already
checking first that the argument is non-null, see, for example, the
related current_nonlambda_class_type. Tested x86_64-linux.
Thanks, Paolo.
///////////////////////
/cp
2017-11-22 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/82293
* lambda.c (nonlambda_method_basetype): Don't use LAMBDA_TYPE_P
on a null type.
/testsuite
2017-11-22 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/82293
* g++.dg/cpp0x/lambda/lambda-ice24.C: New.
Index: cp/lambda.c
===================================================================
--- cp/lambda.c (revision 255053)
+++ cp/lambda.c (working copy)
@@ -921,7 +921,7 @@ nonlambda_method_basetype (void)
return NULL_TREE;
type = current_class_type;
- if (!LAMBDA_TYPE_P (type))
+ if (!type || !LAMBDA_TYPE_P (type))
return type;
/* Find the nearest enclosing non-lambda function. */
Index: testsuite/g++.dg/cpp0x/lambda/lambda-ice24.C
===================================================================
--- testsuite/g++.dg/cpp0x/lambda/lambda-ice24.C (nonexistent)
+++ testsuite/g++.dg/cpp0x/lambda/lambda-ice24.C (working copy)
@@ -0,0 +1,12 @@
+// PR c++/82293
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wshadow" }
+
+template <typename>
+struct S {
+ int f{[this](){return 42;}()};
+};
+
+int main(){
+ return S<int>{}.f;
+}
