https://gcc.gnu.org/g:074c1fc797435979c00b24aff2a4f895b8273bcf
commit r15-1224-g074c1fc797435979c00b24aff2a4f895b8273bcf Author: Jason Merrill <ja...@redhat.com> Date: Wed Jun 12 08:06:47 2024 -0400 c++: repeated export using A sample implementation of module std was breaking because the exports included 'using std::operator&' twice. Since Nathaniel's r15-964 for PR114867, the first using added an extra instance of each function that was revealed/exported by that using, resulting in duplicates for lookup_maybe_add to dedup. But if the duplicate is the first thing in the list, lookup_add doesn't make an OVERLOAD, so trying to set OVL_USING_P crashes. Fixed by using ovl_make in the case where we want to set the flag. gcc/cp/ChangeLog: * tree.cc (lookup_maybe_add): Use ovl_make when setting OVL_USING_P. gcc/testsuite/ChangeLog: * g++.dg/modules/using-21_a.C: New test. Diff: --- gcc/cp/tree.cc | 8 ++++++-- gcc/testsuite/g++.dg/modules/using-21_a.C | 11 +++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index d2a8f79ffab4..28648c14c6da 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -2526,11 +2526,15 @@ lookup_maybe_add (tree fns, tree lookup, bool deduping) predecessors onto the lookup. */ for (; fns != probe; fns = OVL_CHAIN (fns)) { - lookup = lookup_add (OVL_FUNCTION (fns), lookup); /* Propagate OVL_USING, but OVL_HIDDEN & OVL_DEDUP_P don't matter. */ if (OVL_USING_P (fns)) - OVL_USING_P (lookup) = true; + { + lookup = ovl_make (OVL_FUNCTION (fns), lookup); + OVL_USING_P (lookup) = true; + } + else + lookup = lookup_add (OVL_FUNCTION (fns), lookup); } /* And now skip this function. */ diff --git a/gcc/testsuite/g++.dg/modules/using-21_a.C b/gcc/testsuite/g++.dg/modules/using-21_a.C new file mode 100644 index 000000000000..ce6e3f920f1e --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/using-21_a.C @@ -0,0 +1,11 @@ +// { dg-additional-options "-fmodules-ts -Wno-global-module" } + +module; +namespace foo { + void baz(); +} +export module foo; +namespace foo { + export using foo::baz; + export using foo::baz; +}