| Message ID | 20210503164808.155944-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: base-clause parsing and implicit 'this' [PR100362] | expand |
On 5/3/21 12:48 PM, Patrick Palka wrote: > 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? OK for trunk and 11.2. > 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(); > +} >
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(); +}