https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116568
--- Comment #1 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:9016c5ac94c55714d001309ef640710f9d512254 commit r15-6378-g9016c5ac94c55714d001309ef640710f9d512254 Author: Nathaniel Shead <nathanielosh...@gmail.com> Date: Tue Oct 8 20:50:38 2024 +1100 c++/modules: Detect exposures of TU-local entities Currently, the modules streaming code implements some checks for declarations in the CMI that reference (some kinds of) internal-linkage entities, and errors if so. This patch expands on that support to implement the logic for exposures of TU-local entities as defined in [basic.link] since P1815. This will cause some code that previously errored in modules to start compiling; for instance, template specialisations of internal linkage functions. However, some code that previously appeared valid will with this patch no longer compile, notably some kinds of usages of internal linkage functions included from the GMF. This appears to be related to P2808 and FR-025, however as yet there doesn't appear to be consensus for changing these rules so I've implemented them as-is. This patch leaves a couple of things out. In particular, a couple of the rules for what is a TU-local entity currently seem to me to be redundant; I've left them as FIXMEs to be handled once I can find testcases that aren't adequately supported by the other logic here. Additionally, there are some exceptions for when naming a TU-local entity is not always an exposure; I've left support for this to a follow-up patch for easier review, as it has broader implications for streaming. TU-local lambdas are also not yet properly implemented, due to other bugs with regards to LAMBDA_TYPE_EXTRA_SCOPE not being set in all cases that it probably should be (see also PR c++/116568). We can revisit this once that issue has been fixed. Finally, this patch makes a couple of small adjustments to the modules streaming logic to prune any leftover TU-local deps (that aren't erroneous exposures). This is required for this patch to ensure that later stages don't get confused by any leftover TU-local entities floating around. gcc/cp/ChangeLog: * tree.cc (decl_linkage): Treat DECL_SELF_REFERENCE_P like DECL_IMPLICIT_TYPEDEF_P. * name-lookup.cc (do_namespace_alias): Fix linkage. * module.cc (DB_IS_INTERNAL_BIT): Rename to... (DB_TU_LOCAL_BIT): ...this. (DB_REFS_INTERNAL_BIT): Rename to... (DB_EXPOSURE_BIT): ...this. (depset::hash::is_internal): Rename to... (depset::hash::is_tu_local): ...this. (depset::hash::refs_internal): Rename to... (depset::hash::is_exposure): ...this. (depset::hash::is_tu_local_entity): New function. (depset::hash::has_tu_local_tmpl_arg): New function. (depset::hash::is_tu_local_value): New function. (depset::hash::make_dependency): Check for TU-local entities. (depset::hash::add_dependency): Make current an exposure whenever it references a TU-local entity. (depset::hash::add_binding_entity): Don't create bindings for any TU-local entity. (depset::hash::finalize_dependencies): Rename flags and adjust diagnostic messages to report exposures of TU-local entities. (depset::tarjan::connect): Don't include any TU-local depsets. (depset::hash::connect): Likewise. gcc/testsuite/ChangeLog: * g++.dg/modules/block-decl-2.C: Adjust messages. * g++.dg/modules/internal-1.C: Adjust messages, remove XFAILs. * g++.dg/modules/linkage-2.C: Adjust messages, remove XFAILS. * g++.dg/modules/internal-3.C: New test. * g++.dg/modules/internal-4_a.H: New test. * g++.dg/modules/internal-4_b.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> Reviewed-by: Jason Merrill <ja...@redhat.com>
