| Message ID | 20230912172744.1930180-1-jason@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [pushed] c++: __integer_pack with class argument [PR111357] | expand |
On Tue, Sep 12, 2023 at 01:27:44PM -0400, Jason Merrill via Gcc-patches wrote: > Tested x86_64-pc-linux-gnu, applying to trunk. > > -- 8< -- > > The argument might not already be an integer. > > PR c++/111357 > > gcc/cp/ChangeLog: > > * pt.cc (expand_integer_pack): Convert argument to int. > > gcc/testsuite/ChangeLog: > > * g++.dg/ext/integer-pack7.C: New test. > --- > gcc/cp/pt.cc | 2 ++ > gcc/testsuite/g++.dg/ext/integer-pack7.C | 38 ++++++++++++++++++++++++ > 2 files changed, 40 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack7.C > > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > index 838179d5fe3..b583c11eb99 100644 > --- a/gcc/cp/pt.cc > +++ b/gcc/cp/pt.cc > @@ -3793,6 +3793,8 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain, > } > else > { > + hi = perform_implicit_conversion_flags (integer_type_node, hi, complain, > + LOOKUP_IMPLICIT); FWIW, we have perform_implicit_conversion for this. Marek
On Tue, Sep 12, 2023 at 01:34:43PM -0400, Marek Polacek via Gcc-patches wrote: > On Tue, Sep 12, 2023 at 01:27:44PM -0400, Jason Merrill via Gcc-patches wrote: > > Tested x86_64-pc-linux-gnu, applying to trunk. > > > > -- 8< -- > > > > The argument might not already be an integer. > > > > PR c++/111357 > > > > gcc/cp/ChangeLog: > > > > * pt.cc (expand_integer_pack): Convert argument to int. > > > > gcc/testsuite/ChangeLog: > > > > * g++.dg/ext/integer-pack7.C: New test. > > --- > > gcc/cp/pt.cc | 2 ++ > > gcc/testsuite/g++.dg/ext/integer-pack7.C | 38 ++++++++++++++++++++++++ > > 2 files changed, 40 insertions(+) > > create mode 100644 gcc/testsuite/g++.dg/ext/integer-pack7.C > > > > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > > index 838179d5fe3..b583c11eb99 100644 > > --- a/gcc/cp/pt.cc > > +++ b/gcc/cp/pt.cc > > @@ -3793,6 +3793,8 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain, > > } > > else > > { > > + hi = perform_implicit_conversion_flags (integer_type_node, hi, complain, > > + LOOKUP_IMPLICIT); > > FWIW, we have perform_implicit_conversion for this. Is it correct to convert exactly to integer_type_node though? Consider #include <utility> using std::integer_sequence; using std::make_integer_sequence; template<long... V> void g(integer_sequence<long,V...>) {} template<typename ...T> struct c1 { static constexpr int value = 1; constexpr operator int() { return value; } constexpr operator long() { return value + 1; } }; template<typename T> struct R { using S = make_integer_sequence<long,c1<T>{}>; R() noexcept(noexcept(g(S()))) {} }; int main() { R<int>(); } Shouldn't that invoke c1<T>{}.operator long() rather than operator int()? I thought the conversion was supposed to be done a few lines earlier, instead of doing CALL_EXPR_ARG (call, 0) = hi; do CALL_EXPR_ARG (call, 0) = perform_implicit_conversion_flags (TREE_TYPE (ohi), hi, complain, LOOKUP_IMPLICIT); or tsubst that TREE_TYPE (ohi) as well? I.e. convert to type of the template parameter. Jakub
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 838179d5fe3..b583c11eb99 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -3793,6 +3793,8 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain, } else { + hi = perform_implicit_conversion_flags (integer_type_node, hi, complain, + LOOKUP_IMPLICIT); hi = instantiate_non_dependent_expr (hi, complain); hi = cxx_constant_value (hi, complain); int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1; diff --git a/gcc/testsuite/g++.dg/ext/integer-pack7.C b/gcc/testsuite/g++.dg/ext/integer-pack7.C new file mode 100644 index 00000000000..95b1195bef4 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/integer-pack7.C @@ -0,0 +1,38 @@ +// PR c++/111357 +// { dg-do compile { target c++11 } } + +namespace std { + template<typename _Tp, _Tp... _Idx> + struct integer_sequence + { }; + + template<typename _Tp, _Tp _Num> + using make_integer_sequence + = integer_sequence<_Tp, __integer_pack(_Num)...>; +} + +using std::integer_sequence; +using std::make_integer_sequence; + +template<int... V> +void g(integer_sequence<int,V...>) +{} + +template<typename ...T> +struct c1 +{ + static constexpr int value = 1; + constexpr operator int() { return value; } +}; +template<typename T> +struct R +{ + using S = make_integer_sequence<int,c1<T>{}>; + + R() noexcept(noexcept(g(S()))) + {} +}; +int main() +{ + R<int>(); +}