https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111710
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Nathaniel Shead <nsh...@gcc.gnu.org>: https://gcc.gnu.org/g:3685fae23bb00898749dfc155212c9c5cd3a0980 commit r14-9232-g3685fae23bb00898749dfc155212c9c5cd3a0980 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Fri Feb 16 15:52:48 2024 +1100 c++: Support lambdas attached to more places in modules [PR111710] The fix for PR107398 weakened the restrictions that lambdas must belong to namespace scope. However this was not sufficient: we also need to allow lambdas attached to FIELD_DECLs, PARM_DECLs, and TYPE_DECLs. For field decls we key the lambda to its class rather than the field itself. Otherwise we can run into issues when deduplicating the lambda's TYPE_DECL, because when loading its context we load the containing field before we've deduplicated the keyed lambda, causing mismatches; by keying to the class instead we defer checking keyed declarations until deduplication has completed. Additionally, by [basic.link] p15.2 a lambda defined anywhere in a class-specifier should not be TU-local, which includes base-class declarations, so ensure that lambdas declared there are keyed appropriately as well. Because this now requires 'DECL_MODULE_KEYED_DECLS_P' to be checked on a fairly large number of different kinds of DECLs, and that in general it's safe to just get 'false' as a result of a check on an unexpected DECL type, this patch also removes the tree checking from the accessor. Finally, to handle deduplicating templated lambda fields, we need to ensure that we can determine that two lambdas from different field decls match, so we ensure that we also deduplicate LAMBDA_EXPRs on stream in. PR c++/111710 gcc/cp/ChangeLog: * cp-tree.h (DECL_MODULE_KEYED_DECLS_P): Remove tree checking. (struct lang_decl_base): Update comments and fix whitespace. * module.cc (trees_out::lang_decl_bools): Always write module_keyed_decls_p flag... (trees_in::lang_decl_bools): ...and always read it. (trees_out::decl_value): Handle all kinds of keyed decls. (trees_in::decl_value): Likewise. (trees_in::tree_value): Deduplicate LAMBDA_EXPRs. (maybe_key_decl): Also support lambdas attached to fields, parameters, and types. Key lambdas attached to fields to their class. (trees_out::get_merge_kind): Likewise. (trees_out::key_mergeable): Likewise. (trees_in::key_mergeable): Support keyed decls in a TYPE_DECL container. * parser.cc (cp_parser_class_head): Start a lambda scope when parsing base classes. gcc/testsuite/ChangeLog: * g++.dg/modules/lambda-7.h: New test. * g++.dg/modules/lambda-7_a.H: New test. * g++.dg/modules/lambda-7_b.C: New test. * g++.dg/modules/lambda-7_c.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Patrick Palka <ppa...@redhat.com> Reviewed-by: Jason Merrill <ja...@redhat.com>
