https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84789
--- Comment #6 from Alexandre Oliva <aoliva at gcc dot gnu.org> --- Author: aoliva Date: Fri Mar 23 01:19:14 2018 New Revision: 258792 URL: https://gcc.gnu.org/viewcvs?rev=258792&root=gcc&view=rev Log: [PR c++/84789] do not fail to resolve typename into template-independent Although resolve_typename_type always takes a template-dependent type-id, and it usually resolves it to another template-dependent type-id, it is not correct to require the latter: in declarators, template-dependent scopes may turn out to name template-independent types, as in the pr84789-2.C and pr84789-3.C testcases. The ill-formed testcase pr84789.C trips the same too-strict assert, and also gets fixed by removing the assertion on the simplified scope. However, whereas when the dependent type cannot be resolved, we get an error that suggests 'typename' is missing: pr84789.C:12:3: error: need ‘typename’ before ‘typename B<T>::A::I::I’ because ‘typename B<T>::A::I’ is a dependent scope B<T>::A::I::I i; ^~~~ when it can, we got errors that did not point at that possibility, which may be confusing: pr84789.C:9:15: error: ‘A::I’ {aka ‘int’} is not a class type B<T>::A::I::I i; // { dg-error "typename" } ^ pr84789.C:9:15: error: ‘I’ in ‘A::I’ {aka ‘int’} does not name a type Changing the parser diagnostic code that reports an invalid type name so that it does not attempt to reparse the name as a declarator gets us the superior diagnostic of a missing 'typename' keyword. for gcc/cp/ChangeLog PR c++/84789 * pt.c (resolve_typename_type): Drop assert that stopped simplification to template-independent types. Add assert to verify the initial scope is template dependent. * parser.c (cp_parser_parse_and_diagnose_invalid_type_name): Reparse the id expression as a type-name, not a declarator. for gcc/testsuite/ChangeLog PR c++/84789 * g++.dg/template/pr84789.C: New. * g++.dg/template/pr84789-2.C: New. * g++.dg/template/pr84789-3.C: New. * g++.dg/parse/dtor11.C: Accept alternate error message. Added: trunk/gcc/testsuite/g++.dg/template/pr84789-2.C trunk/gcc/testsuite/g++.dg/template/pr84789-3.C trunk/gcc/testsuite/g++.dg/template/pr84789.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/parser.c trunk/gcc/cp/pt.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/g++.dg/parse/dtor11.C
