From 0ba3e5ff14a48f1fb7ca53cb86194e08d5b5da66 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Thu, 6 Mar 2025 17:58:14 +0100 Subject: [PATCH] c++: Fix up instantiation of pointer/reference/array types with attributes [PR119138] My r15-7822 PR118787 change unfortunately broke build on x86_64-w64-mingw32. The reduced testcase below shows what is going on. va_list on this target is char * with extra (non-dependent) attributes on it. Before my r15-7822 change, instantiation of such type used the fast path and just returned t, but as it has non-NULL TYPE_ATTRIBUTES, it now falls through, builds a pointer type and then calls apply_late_template_attributes. And in there triggers a bug, that function has been written for types with RECORD_TYPE/UNION_TYPE (or ENUMERAL_TYPE?) in mind, where we call apply_late_template_attributes with ATTR_FLAG_TYPE_IN_PLACE and can just apply the non-dependent attributes directly to TYPE_ATTRIBUTES. That is wrong for shared types like {POINTER,REFERENCE,ARRAY}_TYPE etc., we should just force cp_build_type_attribute_variant to build a variant type for the non-dependent attributes and then process dependent attributes (which given attr_flag will DTRT already). The second change in the patch is an optimization, we can actually return back to returning t even when TYPE_ATTRIBUTES is non-NULL, as long as it is non-dependent (dependent attributes are stored first, so it is enough to check the first attribute). 2025-03-06 Jakub Jelinek PR c++/119138 * pt.cc (apply_late_template_attributes): Set p to NULL if ATTR_FLAG_TYPE_IN_PLACE is not set in attr_flags. (tsubst) : Reuse original type even if TYPE_ATTRIBUTES is non-NULL, but all the attributes are non-dependent. * g++.dg/template/pr119138.C: New test. --- gcc/cp/pt.cc | 9 ++++++--- gcc/testsuite/g++.dg/template/pr119138.C | 16 ++++++++++++++++ 2 files changed, 22 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/template/pr119138.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index c09a934580f..2775af7701b 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -12393,7 +12393,8 @@ apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags, to our attributes parameter. */ gcc_assert (*p == attributes); } - else if (FUNC_OR_METHOD_TYPE_P (*decl_p)) + else if (FUNC_OR_METHOD_TYPE_P (*decl_p) + || (attr_flags & ATTR_FLAG_TYPE_IN_PLACE) == 0) p = NULL; else { @@ -16867,7 +16868,8 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl) { if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE - && TYPE_ATTRIBUTES (t) == NULL_TREE) + && (TYPE_ATTRIBUTES (t) == NULL_TREE + || !ATTR_IS_DEPENDENT (TYPE_ATTRIBUTES (t)))) return t; /* [temp.deduct] @@ -17029,7 +17031,8 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl) it will obviously be the same as T. */ if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t) - && TYPE_ATTRIBUTES (t) == NULL_TREE) + && (TYPE_ATTRIBUTES (t) == NULL_TREE + || !ATTR_IS_DEPENDENT (TYPE_ATTRIBUTES (t)))) return t; /* These checks should match the ones in create_array_type_for_decl. diff --git a/gcc/testsuite/g++.dg/template/pr119138.C b/gcc/testsuite/g++.dg/template/pr119138.C new file mode 100644 index 00000000000..b0893872f2c --- /dev/null +++ b/gcc/testsuite/g++.dg/template/pr119138.C @@ -0,0 +1,16 @@ +// PR c++/119138 +// { dg-do compile } + +#include + +template +void +foo (va_list) +{ +} + +void +bar (va_list ap) +{ + foo (ap); +}