My r11-6815 change to defer access checking when processing a base-clause removed a pair of pushclass / popclass calls that seemed to be unnecessary now that we'd also defer access checking while parsing the base-clause.
But it turns out this makes a difference in the below testcase, where we have a local class whose base clause implicitly uses the 'this' of the enclosing class. Before r11-6815, while parsing the base-clause of the local class, maybe_resolve_dummy would fail to resolve the dummy 'this' object because the current scope would be the local class. Now, since the current scope is the lambda, maybe_resolve_dummy succeeds and returns the 'this' for the enclosing class Qux. Later, during deferred instantiation of the local class, we get confused trying to resolve the access of 'a_' through this non-dummy 'this'. So this patch just reinstates the calls to pushclass / popclass that were removed in r11-6815. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? gcc/cp/ChangeLog: PR c++/100362 * parser.c (cp_parser_class_head): Reinstate calls to pushclass and popclass during parsing of the base-clause that were removed in r11-6815. gcc/testsuite/ChangeLog: PR c++/100362 * g++.dg/cpp1y/lambda-generic-100362.C: New test. --- gcc/cp/parser.c | 8 +++++- .../g++.dg/cpp1y/lambda-generic-100362.C | 25 +++++++++++++++++++ 2 files changed, 32 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-generic-100362.C diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index e1b1617da68..28752611b34 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -25683,7 +25683,13 @@ cp_parser_class_head (cp_parser* parser, until the entire list has been seen, as per [class.access.general]. */ push_deferring_access_checks (dk_deferred); if (cp_lexer_next_token_is (parser->lexer, CPP_COLON)) - bases = cp_parser_base_clause (parser); + { + if (type) + pushclass (type); + bases = cp_parser_base_clause (parser); + if (type) + popclass (); + } else bases = NULL_TREE; diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-100362.C b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-100362.C new file mode 100644 index 00000000000..283c2c9477e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-100362.C @@ -0,0 +1,25 @@ +// PR c++/100362 +// { dg-do compile { target c++14 } } + +template <class> +struct Qux { + struct A { } a_; + A f(); + + void AsyncOp() { + [](auto) { + struct local : decltype(a_) {}; + local ptr; + }(0); + + [](auto) { + struct local : decltype(f()) {}; + local ptr; + }(0); + } +}; + +void corge() { + Qux<int> qux; + qux.AsyncOp(); +} -- 2.31.1.442.g7e39198978