From 36278f48cbc08c78e4ed588e5a049bd45fd1c55a Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Thu, 17 Feb 2022 20:20:24 -0500 Subject: [PATCH] c++: implicit 'this' in noexcept-spec within class tmpl [PR94944] Here when instantiating the noexcept-spec we fail to resolve the implicit object for the member call A::f() ultimately because maybe_instantiate_noexcept sets current_class_ptr/ref to the dependent 'this' (of type B) rather than the specialized 'this' (of type B). This patch fixes this by making maybe_instantiate_noexcept set current_class_ptr/ref to the specialized 'this' instead, consistent with what tsubst_function_type does when substituting into the trailing return type of a non-static member function. PR c++/94944 gcc/cp/ChangeLog: * pt.cc (maybe_instantiate_noexcept): For non-static member functions, set current_class_ptr/ref to the specialized 'this' instead. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/noexcept34.C: Adjusted expected diagnostics. * g++.dg/cpp0x/noexcept75.C: New test. --- gcc/cp/pt.cc | 19 +++++++------------ gcc/testsuite/g++.dg/cpp0x/noexcept34.C | 8 ++++---- gcc/testsuite/g++.dg/cpp0x/noexcept75.C | 17 +++++++++++++++++ 3 files changed, 28 insertions(+), 16 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept75.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 352cff9..16bedbc 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -26140,20 +26140,15 @@ maybe_instantiate_noexcept (tree fn, tsubst_flags_t complain) push_deferring_access_checks (dk_no_deferred); input_location = DECL_SOURCE_LOCATION (fn); - if (!DECL_LOCAL_DECL_P (fn)) + if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) + && !DECL_LOCAL_DECL_P (fn)) { /* If needed, set current_class_ptr for the benefit of - tsubst_copy/PARM_DECL. The exception pattern will - refer to the parm of the template, not the - instantiation. */ - tree tdecl = DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (fn)); - if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tdecl)) - { - tree this_parm = DECL_ARGUMENTS (tdecl); - current_class_ptr = NULL_TREE; - current_class_ref = cp_build_fold_indirect_ref (this_parm); - current_class_ptr = this_parm; - } + tsubst_copy/PARM_DECL. */ + tree this_parm = DECL_ARGUMENTS (fn); + current_class_ptr = NULL_TREE; + current_class_ref = cp_build_fold_indirect_ref (this_parm); + current_class_ptr = this_parm; } /* If this function is represented by a TEMPLATE_DECL, then diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept34.C b/gcc/testsuite/g++.dg/cpp0x/noexcept34.C index dce3565..86129e7 100644 --- a/gcc/testsuite/g++.dg/cpp0x/noexcept34.C +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept34.C @@ -7,13 +7,13 @@ template struct A { constexpr int f () { return 0; } bool b = true; - void g () noexcept (f()) { } // { dg-error "use of parameter" } - void g2 () noexcept (this->f()) { } // { dg-error "use of parameter" } + void g () noexcept (f()) { } // { dg-error ".this. is not a constant" } + void g2 () noexcept (this->f()) { } // { dg-error ".this. is not a constant" } void g3 () noexcept (b) { } // { dg-error "use of .this. in a constant expression|use of parameter" } void g4 (int i) noexcept (i) { } // { dg-error "use of parameter" } - void g5 () noexcept (A::f()) { } // { dg-error "use of parameter" } + void g5 () noexcept (A::f()) { } // { dg-error ".this. is not a constant" } void g6 () noexcept (foo(b)) { } // { dg-error "use of .this. in a constant expression|use of parameter" } - void g7 () noexcept (int{f()}) { } // { dg-error "use of parameter" } + void g7 () noexcept (int{f()}) { } // { dg-error ".this. is not a constant" } }; int main () diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept75.C b/gcc/testsuite/g++.dg/cpp0x/noexcept75.C new file mode 100644 index 0000000..d746f47 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept75.C @@ -0,0 +1,17 @@ +// PR c++/94944 +// { dg-do compile { target c++11 } } + +template +struct A { + void f(); +}; + +template +struct B : A { + void g() noexcept(noexcept(A::f())); +}; + +int main() { + B b; + b.g(); +} -- 2.7.4