On Wed, 14 Feb 2024, Ken Matsui wrote: > This patch implements built-in trait for std::add_pointer. > > gcc/cp/ChangeLog: > > * cp-trait.def: Define __add_pointer. > * semantics.cc (finish_trait_type): Handle CPTK_ADD_POINTER. > > gcc/testsuite/ChangeLog: > > * g++.dg/ext/has-builtin-1.C: Test existence of __add_pointer. > * g++.dg/ext/add_pointer.C: New test. > > Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org> > --- > gcc/cp/cp-trait.def | 1 + > gcc/cp/semantics.cc | 9 ++++++ > gcc/testsuite/g++.dg/ext/add_pointer.C | 37 ++++++++++++++++++++++++ > gcc/testsuite/g++.dg/ext/has-builtin-1.C | 3 ++ > 4 files changed, 50 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/ext/add_pointer.C > > diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def > index 394f006f20f..cec385ee501 100644 > --- a/gcc/cp/cp-trait.def > +++ b/gcc/cp/cp-trait.def > @@ -48,6 +48,7 @@ > #define DEFTRAIT_TYPE_DEFAULTED > #endif > > +DEFTRAIT_TYPE (ADD_POINTER, "__add_pointer", 1) > DEFTRAIT_EXPR (HAS_NOTHROW_ASSIGN, "__has_nothrow_assign", 1) > DEFTRAIT_EXPR (HAS_NOTHROW_CONSTRUCTOR, "__has_nothrow_constructor", 1) > DEFTRAIT_EXPR (HAS_NOTHROW_COPY, "__has_nothrow_copy", 1) > diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc > index 57840176863..e23693ab57f 100644 > --- a/gcc/cp/semantics.cc > +++ b/gcc/cp/semantics.cc > @@ -12760,6 +12760,15 @@ finish_trait_type (cp_trait_kind kind, tree type1, > tree type2, > > switch (kind) > { > + case CPTK_ADD_POINTER: > + if (TREE_CODE (type1) == FUNCTION_TYPE > + && ((TYPE_QUALS (type1) & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)) > + || FUNCTION_REF_QUALIFIED (type1)))
In other parts of the front end, e.g. the POINTER_TYPE case of tsubst, in build_trait_object, grokdeclarator and get_typeid, it seems we check for an unqualified function type with (type_memfn_quals (type) != TYPE_UNQUALIFIED && type_mem_rqual (type) != REF_QUAL_NONE) which should be equivalent to your formulation except it also checks for non-standard qualifiers such as __restrict. I'm not sure what a __restrict-qualified function type means or if we care about the semantics of __add_pointer(void () __restrict), but I reckon we might as well be consistent and use the type_mem_quals/rqual formulation in new code too? > + return type1; > + if (TYPE_REF_P (type1)) > + type1 = TREE_TYPE (type1); > + return build_pointer_type (type1); > + > case CPTK_REMOVE_CV: > return cv_unqualified (type1); > > diff --git a/gcc/testsuite/g++.dg/ext/add_pointer.C > b/gcc/testsuite/g++.dg/ext/add_pointer.C > new file mode 100644 > index 00000000000..3091510f3b5 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/ext/add_pointer.C > @@ -0,0 +1,37 @@ > +// { dg-do compile { target c++11 } } > + > +#define SA(X) static_assert((X),#X) > + > +class ClassType { }; > + > +SA(__is_same(__add_pointer(int), int*)); > +SA(__is_same(__add_pointer(int*), int**)); > +SA(__is_same(__add_pointer(const int), const int*)); > +SA(__is_same(__add_pointer(int&), int*)); > +SA(__is_same(__add_pointer(ClassType*), ClassType**)); > +SA(__is_same(__add_pointer(ClassType), ClassType*)); > +SA(__is_same(__add_pointer(void), void*)); > +SA(__is_same(__add_pointer(const void), const void*)); > +SA(__is_same(__add_pointer(volatile void), volatile void*)); > +SA(__is_same(__add_pointer(const volatile void), const volatile void*)); > + > +void f1(); > +using f1_type = decltype(f1); > +using pf1_type = decltype(&f1); > +SA(__is_same(__add_pointer(f1_type), pf1_type)); > + > +void f2() noexcept; // PR libstdc++/78361 > +using f2_type = decltype(f2); > +using pf2_type = decltype(&f2); > +SA(__is_same(__add_pointer(f2_type), pf2_type)); > + > +using fn_type = void(); > +using pfn_type = void(*)(); > +SA(__is_same(__add_pointer(fn_type), pfn_type)); > + > +SA(__is_same(__add_pointer(void() &), void() &)); > +SA(__is_same(__add_pointer(void() & noexcept), void() & noexcept)); > +SA(__is_same(__add_pointer(void() const), void() const)); > +SA(__is_same(__add_pointer(void(...) &), void(...) &)); > +SA(__is_same(__add_pointer(void(...) & noexcept), void(...) & noexcept)); > +SA(__is_same(__add_pointer(void(...) const), void(...) const)); > diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C > b/gcc/testsuite/g++.dg/ext/has-builtin-1.C > index 02b4b4d745d..56e8db7ac32 100644 > --- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C > +++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C > @@ -2,6 +2,9 @@ > // { dg-do compile } > // Verify that __has_builtin gives the correct answer for C++ built-ins. > > +#if !__has_builtin (__add_pointer) > +# error "__has_builtin (__add_pointer) failed" > +#endif > #if !__has_builtin (__builtin_addressof) > # error "__has_builtin (__builtin_addressof) failed" > #endif > -- > 2.43.0 > >