On 9/13/22 07:45, Patrick Palka wrote:
It looks like we aren't respecting SFINAE for:* an invalid/non-constant conditional explicit-specifier * a non-constant conditional noexcept-specifier * a non-constant argument to __integer_pack This patch fixes these issues in the usual way, by passing complain and propagating error_mark_node appropriately. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? gcc/cp/ChangeLog: * decl.cc (build_explicit_specifier): Pass complain to cxx_constant_value. * except.cc (build_noexcept_spec): Likewise. * pt.cc (expand_integer_pack): Likewise. (tsubst_function_decl): Propagate error_mark_node returned from build_explicit_specifier. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/noexcept-type26.C: New test. * g++.dg/cpp2a/explicit19.C: New test. * g++.dg/ext/integer-pack6.C: New test. --- gcc/cp/decl.cc | 2 +- gcc/cp/except.cc | 2 +- gcc/cp/pt.cc | 6 ++++-- gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C | 12 ++++++++++++ gcc/testsuite/g++.dg/cpp2a/explicit19.C | 12 ++++++++++++ gcc/testsuite/g++.dg/ext/integer-pack6.C | 13 +++++++++++++ 6 files changed, 43 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit19.C create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack6.C diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 936f1cf0197..5404d7e084c 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -18557,7 +18557,7 @@ build_explicit_specifier (tree expr, tsubst_flags_t complain)expr = build_converted_constant_bool_expr (expr, complain);expr = instantiate_non_dependent_expr (expr, complain); - expr = cxx_constant_value (expr); + expr = cxx_constant_value (expr, NULL_TREE, complain);
The patch is OK, but perhaps we want another overload that omits the object parameter?
return expr; }diff --git a/gcc/cp/except.cc b/gcc/cp/except.ccindex 7fdbc747c22..4d7f0ce102d 100644 --- a/gcc/cp/except.cc +++ b/gcc/cp/except.cc @@ -1257,7 +1257,7 @@ build_noexcept_spec (tree expr, tsubst_flags_t complain) { expr = build_converted_constant_bool_expr (expr, complain); expr = instantiate_non_dependent_expr (expr, complain); - expr = cxx_constant_value (expr); + expr = cxx_constant_value (expr, NULL_TREE, complain); } if (TREE_CODE (expr) == INTEGER_CST) { diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 1c6f4b84612..f16f5ffca20 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -3869,7 +3869,7 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain, else { hi = instantiate_non_dependent_expr (hi, complain); - hi = cxx_constant_value (hi); + hi = cxx_constant_value (hi, NULL_TREE, complain); int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;/* Calculate the largest value of len that won't make the size of the vec@@ -14312,7 +14312,9 @@ tsubst_function_decl (tree t, tree args, tsubst_flags_t complain, /*function_p=*/false, /*i_c_e_p=*/true); spec = build_explicit_specifier (spec, complain); - if (instantiation_dependent_expression_p (spec)) + if (spec == error_mark_node) + return error_mark_node; + else if (instantiation_dependent_expression_p (spec)) store_explicit_specifier (r, spec); else { diff --git a/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C new file mode 100644 index 00000000000..73058395f0a --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/noexcept-type26.C @@ -0,0 +1,12 @@ +// Verify a non-constant conditional noexcept-specifier of a function type +// is a SFINAE error. +// { dg-do compile { target c++17 } } + +template<class T> void f(void() noexcept(T::value)) = delete; +template<class T> void f(...); + +struct B { static bool value; }; + +int main() { + f<B>(nullptr); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit19.C b/gcc/testsuite/g++.dg/cpp2a/explicit19.C new file mode 100644 index 00000000000..47903813680 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/explicit19.C @@ -0,0 +1,12 @@ +// Verify a conditional explicit-specifier is a SFINAE context. +// { dg-do compile { target c++20 } } + +struct A { + template<class T> explicit(T::value) A(T) = delete; + A(...); +}; + +struct B { static bool value; }; + +A x(0); +A y(B{}); diff --git a/gcc/testsuite/g++.dg/ext/integer-pack6.C b/gcc/testsuite/g++.dg/ext/integer-pack6.C new file mode 100644 index 00000000000..7e16bc44b40 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/integer-pack6.C @@ -0,0 +1,13 @@ +// Verify a non-constant argument to __integer_pack is a SFINAE error. +// { dg-do compile { target c++11 } } + +template<int...> struct A { }; + +template<class T> auto f(int) -> A<__integer_pack(T::value)...> = delete; +template<class T> void f(...); + +struct B { static int value; }; + +int main() { + f<B>(0); +}
