On 4/25/25 8:56 AM, Nathaniel Shead wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk/15?
OK.
-- >8 -- When importing a CNTTP object, since r15-3031-g0b7904e274fbd6 we shortcut the processing of the generated NTTP so that we don't attempt to recursively load pendings. However, due to an oversight we do not properly set TREE_CONSTANT or DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P on the decl, which confuses later processing. This patch ensures that this happens correctly. PR c++/119938 gcc/cp/ChangeLog: * pt.cc (get_template_parm_object): When !check_init, add assert that expr really is constant and mark decl as such. gcc/testsuite/ChangeLog: * g++.dg/modules/tpl-nttp-2_a.H: New test. * g++.dg/modules/tpl-nttp-2_b.C: New test. Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com> --- gcc/cp/pt.cc | 7 ++++++- gcc/testsuite/g++.dg/modules/tpl-nttp-2_a.H | 14 ++++++++++++++ gcc/testsuite/g++.dg/modules/tpl-nttp-2_b.C | 10 ++++++++++ 3 files changed, 30 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/modules/tpl-nttp-2_a.H create mode 100644 gcc/testsuite/g++.dg/modules/tpl-nttp-2_b.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index a71705fd085..75d34532426 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -7492,8 +7492,13 @@ get_template_parm_object (tree expr, tree name, bool check_init/*=true*/) { /* The EXPR is the already processed initializer, set it on the NTTP object now so that cp_finish_decl doesn't do it again later. */ + gcc_checking_assert (reduced_constant_expression_p (expr)); DECL_INITIAL (decl) = expr; - DECL_INITIALIZED_P (decl) = 1; + DECL_INITIALIZED_P (decl) = true; + DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true; + /* FIXME setting TREE_CONSTANT on refs breaks the back end. */ + if (!TYPE_REF_P (type)) + TREE_CONSTANT (decl) = true; }pushdecl_top_level_and_finish (decl, expr);diff --git a/gcc/testsuite/g++.dg/modules/tpl-nttp-2_a.H b/gcc/testsuite/g++.dg/modules/tpl-nttp-2_a.H new file mode 100644 index 00000000000..bfae11cd185 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-nttp-2_a.H @@ -0,0 +1,14 @@ +// PR c++/119938 +// { dg-additional-options "-fmodules -std=c++20" } +// { dg-module-cmi {} } + +struct A { int x; }; + +template <A a> struct B { static_assert(a.x == 1); }; +using C = B<A{1}>; + +template <A a> void D() { static_assert(a.x == 2); }; +inline void E() { D<A{2}>(); } + +template <A a> struct F { static constexpr int result = a.x; }; +template <int=0> constexpr int G() { return F<A{3}>::result; }; diff --git a/gcc/testsuite/g++.dg/modules/tpl-nttp-2_b.C b/gcc/testsuite/g++.dg/modules/tpl-nttp-2_b.C new file mode 100644 index 00000000000..7e661cbdef0 --- /dev/null +++ b/gcc/testsuite/g++.dg/modules/tpl-nttp-2_b.C @@ -0,0 +1,10 @@ +// PR c++/119938 +// { dg-additional-options "-fmodules -std=c++20" } + +import "tpl-nttp-2_a.H"; + +int main() { + C c; + E(); + static_assert(G() == 3); +}
