https://gcc.gnu.org/g:cf22e30f0cfae65dd012966cab657583e2be667e
commit r16-5977-gcf22e30f0cfae65dd012966cab657583e2be667e Author: Nathaniel Shead <[email protected]> Date: Sun Dec 7 23:17:15 2025 +1100 c++: Non-inline temploid friends should still be COMDAT [PR122819] Modules allow temploid friends to no longer be implicitly inline, as functions defined in a class body will not be implicitly inline if attached to a named module. This requires us to clean up linkage handling a little bit, mostly by replacing usages of 'DECL_TEMPLATE_INSTANTIATION' with 'DECL_TEMPLOID_INSTANTIATION' when determining if an entity has vague linkage. PR c++/122819 gcc/cp/ChangeLog: * decl.cc (start_preparsed_function): Use DECL_TEMPLOID_INSTANTIATION instead of DECL_TEMPLATE_INSTANTIATION to check vague linkage. * decl2.cc (vague_linkage_p): Likewise. (c_parse_final_cleanups): Simplify condition. * semantics.cc (expand_or_defer_fn_1): Also check for temploid friend functions. gcc/testsuite/ChangeLog: * g++.dg/modules/tpl-friend-22.C: New test. Signed-off-by: Nathaniel Shead <[email protected]> Reviewed-by: Jason Merrill <[email protected]> Diff: --- gcc/cp/decl.cc | 6 +++--- gcc/cp/decl2.cc | 5 ++--- gcc/cp/semantics.cc | 4 +++- gcc/testsuite/g++.dg/modules/tpl-friend-22.C | 24 ++++++++++++++++++++++++ 4 files changed, 32 insertions(+), 7 deletions(-) diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 74c862ec1c7d..31081b390fae 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -19750,7 +19750,7 @@ start_preparsed_function (tree decl1, tree attrs, int flags) } } - bool honor_interface = (!DECL_TEMPLATE_INSTANTIATION (decl1) + bool honor_interface = (!DECL_TEMPLOID_INSTANTIATION (decl1) /* Implicitly-defined methods (like the destructor for a class in which no destructor is explicitly declared) must not be defined @@ -19781,7 +19781,7 @@ start_preparsed_function (tree decl1, tree attrs, int flags) else if (!finfo->interface_unknown && honor_interface) { if (DECL_DECLARED_INLINE_P (decl1) - || DECL_TEMPLATE_INSTANTIATION (decl1)) + || DECL_TEMPLOID_INSTANTIATION (decl1)) { DECL_EXTERNAL (decl1) = (finfo->interface_only @@ -19823,7 +19823,7 @@ start_preparsed_function (tree decl1, tree attrs, int flags) DECL_EXTERNAL (decl1) = 0; if ((DECL_DECLARED_INLINE_P (decl1) - || DECL_TEMPLATE_INSTANTIATION (decl1)) + || DECL_TEMPLOID_INSTANTIATION (decl1)) && ! DECL_INTERFACE_KNOWN (decl1)) DECL_DEFER_OUTPUT (decl1) = 1; else diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc index 8ec9740c8a9e..01bf26b1e4f8 100644 --- a/gcc/cp/decl2.cc +++ b/gcc/cp/decl2.cc @@ -2510,7 +2510,7 @@ vague_linkage_p (tree decl) || (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl)) || (DECL_LANG_SPECIFIC (decl) - && DECL_TEMPLATE_INSTANTIATION (decl)) + && DECL_TEMPLOID_INSTANTIATION (decl)) || (VAR_P (decl) && DECL_INLINE_VAR_P (decl))) return true; else if (DECL_FUNCTION_SCOPE_P (decl)) @@ -5850,8 +5850,7 @@ c_parse_final_cleanups (void) && !(header_module_p () && (DECL_DEFAULTED_FN (decl) || decl_tls_wrapper_p (decl))) /* Don't complain if the template was defined. */ - && !((DECL_TEMPLATE_INSTANTIATION (decl) - || DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (decl)) + && !(DECL_TEMPLOID_INSTANTIATION (decl) && DECL_INITIAL (DECL_TEMPLATE_RESULT (template_for_substitution (decl)))) && warning_at (DECL_SOURCE_LOCATION (decl), 0, diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index 331db16f76de..b32ab2f0d2b7 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -5537,7 +5537,9 @@ expand_or_defer_fn_1 (tree fn) of the compilation. Until that point, we do not want the back end to output them -- but we do want it to see the bodies of these functions so that it can inline them as appropriate. */ - if (DECL_DECLARED_INLINE_P (fn) || DECL_IMPLICIT_INSTANTIATION (fn)) + if (DECL_DECLARED_INLINE_P (fn) + || DECL_IMPLICIT_INSTANTIATION (fn) + || DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (fn)) { if (DECL_INTERFACE_KNOWN (fn)) /* We've already made a decision as to how this function will diff --git a/gcc/testsuite/g++.dg/modules/tpl-friend-22.C b/gcc/testsuite/g++.dg/modules/tpl-friend-22.C new file mode 100644 index 000000000000..a77d1cbecad8 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-friend-22.C @@ -0,0 +1,24 @@ +// PR c++/122819 +// { dg-do compile { target *-*-*gnu* } } +// { dg-additional-options "-fmodules" } + +export module M; + +template <typename T> struct S; +void foo(S<float>); + +template <typename T> struct S { + friend void foo(S) {} +}; + +void foo(S<double>); + +void use() { + foo(S<int>{}); + foo(S<float>{}); + foo(S<double>{}); +} + +// { dg-final { scan-assembler "_ZW1M3fooS_1SIiE,comdat" } } +// { dg-final { scan-assembler "_ZW1M3fooS_1SIfE,comdat" } } +// { dg-final { scan-assembler "_ZW1M3fooS_1SIdE,comdat" } }
