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make STDEXEC_ATTRIBUTE macro more maintainable #2067

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Merged
ericniebler merged 1 commit into from
May 5, 2026
+80 −93
Merged

make STDEXEC_ATTRIBUTE macro more maintainable #2067

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159 changes: 68 additions & 91 deletions include/stdexec/__detail/__config.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -273,121 +273,98 @@ namespace STDEXEC::__std
//
// STDEXEC_ATTRIBUTE(attr1, attr2, ...)
// void foo() { ... }
#define STDEXEC_ATTRIBUTE_I(_ATTR) \
STDEXEC_PP_CAT(STDEXEC_ATTR_WHICH_, STDEXEC_PP_CHECK(STDEXEC_PP_CAT(STDEXEC_ATTR_, _ATTR)))(_ATTR)
#define STDEXEC_ATTRIBUTE(...) STDEXEC_PP_FOR_EACH(STDEXEC_ATTRIBUTE_I, __VA_ARGS__)

// unknown attributes are treated like C++-style attributes
#define STDEXEC_ATTR_WHICH_0(_ATTR) [[_ATTR]]

// custom handling for specific attribute types
#if defined(__CUDACC__) && !STDEXEC_NVHPC()
# define STDEXEC_ATTR_WHICH_1(_ATTR) __host__
#else
# define STDEXEC_ATTR_WHICH_1(_ATTR)
#endif
#define STDEXEC_ATTR_host STDEXEC_PP_PROBE(~, 1)
#define STDEXEC_ATTR___host__ STDEXEC_PP_PROBE(~, 1)

#if defined(__CUDACC__) && !STDEXEC_NVHPC()
# define STDEXEC_ATTR_WHICH_2(_ATTR) __device__
#else
# define STDEXEC_ATTR_WHICH_2(_ATTR)
#endif
#define STDEXEC_ATTR_device STDEXEC_PP_PROBE(~, 2)
#define STDEXEC_ATTR___device__ STDEXEC_PP_PROBE(~, 2)

#if STDEXEC_NVHPC()
// NVBUG #4067067: NVHPC does not fully support [[no_unique_address]]
# if STDEXEC_NVHPC_VERSION < 2305
# define STDEXEC_ATTR_WHICH_3(_ATTR) /*nothing*/
# else
# define STDEXEC_ATTR_WHICH_3(_ATTR) [[no_unique_address]]
# endif
#elif STDEXEC_CLANG_CL()
// clang-cl does not support [[no_unique_address]]: https://reviews.llvm.org/D110485
// TODO: Find the version that started supporting [[msvc::no_unique_address]]
# if STDEXEC_CLANG_VERSION < 1801
# define STDEXEC_ATTR_WHICH_3(_ATTR) /*nothing*/
# else
# define STDEXEC_ATTR_WHICH_3(_ATTR) [[msvc::no_unique_address]]
# endif
#elif STDEXEC_MSVC()
// MSVCBUG https://developercommunity.visualstudio.com/t/Incorrect-codegen-when-using-msvc::no_/10452874
# if STDEXEC_MSVC_VERSION < 1943
# define STDEXEC_ATTR_WHICH_3(_ATTR) /*nothing*/
# else
# define STDEXEC_ATTR_WHICH_3(_ATTR) [[msvc::no_unique_address]]
# endif
#else
# define STDEXEC_ATTR_WHICH_3(_ATTR) [[no_unique_address]]
#endif
#define STDEXEC_ATTR_no_unique_address STDEXEC_PP_PROBE(~, 3)

#define STDEXEC_ATTRIBUTE_I(_ATTR) STDEXEC_PP_SWITCH(STDEXEC_ATTRIBUTE, _ATTR)
#define STDEXEC_ATTRIBUTE(...) STDEXEC_PP_FOR_EACH(STDEXEC_ATTRIBUTE_I, __VA_ARGS__)

#define STDEXEC_ATTRIBUTE_SWITCH_no_unique_address STDEXEC_PP_CASE(NO_UNIQUE_ADDRESS)
#define STDEXEC_ATTRIBUTE_SWITCH_always_inline STDEXEC_PP_CASE(ALWAYS_INLINE)
#define STDEXEC_ATTRIBUTE_SWITCH_empty_bases STDEXEC_PP_CASE(EMPTY_BASES)
#define STDEXEC_ATTRIBUTE_SWITCH_noinline STDEXEC_PP_CASE(NOINLINE)
#define STDEXEC_ATTRIBUTE_SWITCH_weak STDEXEC_PP_CASE(WEAK)
#define STDEXEC_ATTRIBUTE_SWITCH_preferred_name STDEXEC_PP_CASE(PREFERRED_NAME)
#define STDEXEC_ATTRIBUTE_SWITCH_musttail STDEXEC_PP_CASE(MUSTTAIL)
#define STDEXEC_ATTRIBUTE_SWITCH___musttail__ STDEXEC_PP_CASE(MUSTTAIL)
#define STDEXEC_ATTRIBUTE_SWITCH_host STDEXEC_PP_CASE(HOST)
#define STDEXEC_ATTRIBUTE_SWITCH___host__ STDEXEC_PP_CASE(HOST)
#define STDEXEC_ATTRIBUTE_SWITCH_device STDEXEC_PP_CASE(DEVICE)
#define STDEXEC_ATTRIBUTE_SWITCH___device__ STDEXEC_PP_CASE(DEVICE)
#define STDEXEC_ATTRIBUTE_SWITCH_launch_bounds(...) STDEXEC_PP_CASE(LAUNCH_BOUNDS(__VA_ARGS__))
#define STDEXEC_ATTRIBUTE_SWITCH___launch_bounds__(...) STDEXEC_PP_CASE(LAUNCH_BOUNDS(__VA_ARGS__))

// By default, assume the attribute is a C++11-style attribute that can be used as-is.
#define STDEXEC_ATTRIBUTE_CASE_DEFAULT(...) [[__VA_ARGS__]]

// [[no_unique_address]]
#if (STDEXEC_NVHPC() && STDEXEC_NVHPC_VERSION < 2305) \
|| (STDEXEC_MSVC() && STDEXEC_MSVC_VERSION < 1943) \
|| (STDEXEC_CLANG_CL() && STDEXEC_CLANG_VERSION < 1801)
# define STDEXEC_ATTRIBUTE_CASE_NO_UNIQUE_ADDRESS
#elif STDEXEC_CLANG_CL() || STDEXEC_MSVC()
# define STDEXEC_ATTRIBUTE_CASE_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
#else
# define STDEXEC_ATTRIBUTE_CASE_NO_UNIQUE_ADDRESS [[no_unique_address]]
#endif

// __attribute__((__always_inline__)) and __forceinline
#if STDEXEC_MSVC()
# define STDEXEC_ATTR_WHICH_4(_ATTR) __forceinline
# define STDEXEC_ATTRIBUTE_CASE_ALWAYS_INLINE __forceinline
#elif STDEXEC_CLANG()
# define STDEXEC_ATTR_WHICH_4(_ATTR) \
__attribute__((__always_inline__, __artificial__, __nodebug__)) inline
# define STDEXEC_ATTRIBUTE_CASE_ALWAYS_INLINE __attribute__((__always_inline__, __artificial__, __nodebug__)) inline
#elif STDEXEC_GCC()
# define STDEXEC_ATTR_WHICH_4(_ATTR) __attribute__((__always_inline__, __artificial__)) inline
# define STDEXEC_ATTRIBUTE_CASE_ALWAYS_INLINE __attribute__((__always_inline__, __artificial__)) inline
#else
# define STDEXEC_ATTR_WHICH_4(_ATTR) /*nothing*/
# define STDEXEC_ATTRIBUTE_CASE_ALWAYS_INLINE
#endif
#define STDEXEC_ATTR_always_inline STDEXEC_PP_PROBE(~, 4)

// __attribute__((__weak__))
#if STDEXEC_CLANG() || STDEXEC_GCC()
# define STDEXEC_ATTR_WHICH_5(_ATTR) __attribute__((__weak__))
# define STDEXEC_ATTRIBUTE_CASE_WEAK __attribute__((__weak__))
#else
# define STDEXEC_ATTR_WHICH_5(_ATTR) /*nothing*/
# define STDEXEC_ATTRIBUTE_CASE_WEAK
#endif
#define STDEXEC_ATTR_weak STDEXEC_PP_PROBE(~, 5)
#define STDEXEC_ATTR___weak__ STDEXEC_PP_PROBE(~, 5)

#if STDEXEC_HAS_ATTRIBUTE(__preferred_name__)
# define STDEXEC_ATTR_WHICH_6(_ATTR) __attribute__((_ATTR))
// __declspec(empty_bases) and __declspec(noinline)
#if STDEXEC_MSVC() && !STDEXEC_CLANG_CL()
# define STDEXEC_ATTRIBUTE_CASE_EMPTY_BASES __declspec(empty_bases)
# define STDEXEC_ATTRIBUTE_CASE_NOINLINE __declspec(noinline)
#else
# define STDEXEC_ATTR_WHICH_6(_ATTR) /*nothing*/
# define STDEXEC_ATTRIBUTE_CASE_EMPTY_BASES
# define STDEXEC_ATTRIBUTE_CASE_NOINLINE
#endif
#define STDEXEC_ATTR_preferred_name STDEXEC_PP_PROBE(~, 6)
#define STDEXEC_ATTR___preferred_name__ STDEXEC_PP_PROBE(~, 6)

#if defined(__launch_bounds__) && !STDEXEC_NVHPC()
# define STDEXEC_ATTR_WHICH_7(_ATTR) STDEXEC_PP_CAT(STDEXEC_ATTR_NORMALIZE_, _ATTR)
// __attribute__((__preferred_name__))
#if STDEXEC_HAS_ATTRIBUTE(__preferred_name__)
# define STDEXEC_ATTRIBUTE_CASE_PREFERRED_NAME __attribute__((__preferred_name__))
#else
# define STDEXEC_ATTR_WHICH_7(_ATTR)
# define STDEXEC_ATTRIBUTE_CASE_PREFERRED_NAME
#endif
#define STDEXEC_ATTR_NORMALIZE_launch_bounds(...) __launch_bounds__(__VA_ARGS__)
#define STDEXEC_ATTR_NORMALIZE___launch_bounds__(...) __launch_bounds__(__VA_ARGS__)
#define STDEXEC_ATTR_launch_bounds(...) STDEXEC_PP_PROBE(~, 7)
#define STDEXEC_ATTR___launch_bounds__(...) STDEXEC_PP_PROBE(~, 7)

#if STDEXEC_MSVC() && !STDEXEC_CLANG_CL()
# define STDEXEC_ATTR_WHICH_8(_ATTR) __declspec(_ATTR)
// [[musttail]]
#if STDEXEC_MSVC() && !STDEXEC_CLANG_CL() && STDEXEC_MSVC_VERSION >= 1950
# define STDEXEC_ATTRIBUTE_CASE_MUSTTAIL [[msvc::musttail]]
#elif STDEXEC_HAS_CPP_ATTRIBUTE(clang::musttail)
# define STDEXEC_ATTRIBUTE_CASE_MUSTTAIL [[clang::musttail]]
#elif STDEXEC_HAS_CPP_ATTRIBUTE(gnu::musttail)
# define STDEXEC_ATTRIBUTE_CASE_MUSTTAIL [[gnu::musttail]]
#else
# define STDEXEC_ATTR_WHICH_8(_ATTR) /*nothing*/
# define STDEXEC_ATTRIBUTE_CASE_MUSTTAIL
#endif
#define STDEXEC_ATTR_empty_bases STDEXEC_PP_PROBE(~, 8)

#if STDEXEC_MSVC() && !STDEXEC_CLANG_CL()
# define STDEXEC_ATTR_WHICH_9(_ATTR) __declspec(noinline)
// __host__ and __device__
#if STDEXEC_CUDA_COMPILATION() && !STDEXEC_NVHPC()
# define STDEXEC_ATTRIBUTE_CASE_HOST __host__
# define STDEXEC_ATTRIBUTE_CASE_DEVICE __device__
#else
# define STDEXEC_ATTR_WHICH_9(_ATTR) __attribute__((_ATTR))
# define STDEXEC_ATTRIBUTE_CASE_HOST
# define STDEXEC_ATTRIBUTE_CASE_DEVICE
#endif
#define STDEXEC_ATTR_noinline STDEXEC_PP_PROBE(~, 9)
#define STDEXEC_ATTR___noinline__ STDEXEC_PP_PROBE(~, 9)

#if STDEXEC_MSVC() && !STDEXEC_CLANG_CL() && STDEXEC_MSVC_VERSION >= 1950
# define STDEXEC_ATTR_WHICH_10(_ATTR) [[msvc::musttail]]
#elif STDEXEC_HAS_CPP_ATTRIBUTE(clang::musttail)
# define STDEXEC_ATTR_WHICH_10(_ATTR) [[clang::musttail]]
#elif STDEXEC_HAS_CPP_ATTRIBUTE(gnu::musttail)
# define STDEXEC_ATTR_WHICH_10(_ATTR) [[gnu::musttail]]
// __launch_bounds__(...)
#if defined(__launch_bounds__) && !STDEXEC_NVHPC()
# define STDEXEC_ATTRIBUTE_CASE_LAUNCH_BOUNDS(...) __launch_bounds__(__VA_ARGS__)
#else
# define STDEXEC_ATTR_WHICH_10(_ATTR) /*nothing*/
# define STDEXEC_ATTRIBUTE_CASE_LAUNCH_BOUNDS(...)
#endif
#define STDEXEC_ATTR_musttail STDEXEC_PP_PROBE(~, 10)
#define STDEXEC_ATTR___musttail__ STDEXEC_PP_PROBE(~, 10)

////////////////////////////////////////////////////////////////////////////////////////////////////
// warning push/pop portability macros
Expand Down
14 changes: 12 additions & 2 deletions include/stdexec/__detail/__preprocessor.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -49,13 +49,25 @@
STDEXEC_PP_EXPAND(STDEXEC_PP_COUNT_I(__VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1))
#define STDEXEC_PP_COUNT_I(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _NP, ...) _NP

#define STDEXEC_PP_FRONT_I(_A1, ...) _A1
#define STDEXEC_PP_FRONT(...) __VA_OPT__(STDEXEC_PP_FRONT_I(__VA_ARGS__))

// Used to check various properties of arguments
#define STDEXEC_PP_CHECK_EXPAND(...) __VA_ARGS__
#define STDEXEC_PP_CHECK_I(_XP, _NP, ...) _NP
#define STDEXEC_PP_CHECK(...) STDEXEC_PP_CHECK_EXPAND(STDEXEC_PP_CHECK_I(__VA_ARGS__, 0, ))
#define STDEXEC_PP_PROBE_I(_XP, _NP, ...) _XP, _NP,
#define STDEXEC_PP_PROBE(...) STDEXEC_PP_PROBE_I(__VA_ARGS__, 1)

// PP switch statement
#define STDEXEC_PP_CASE_LABEL_(_PREFIX, ...) \
STDEXEC_PP_EVAL(STDEXEC_PP_CHECK, \
STDEXEC_PP_CAT(_PREFIX##_SWITCH_, STDEXEC_PP_FRONT(__VA_ARGS__)), \
DEFAULT(STDEXEC_PP_FRONT(__VA_ARGS__)), )
#define STDEXEC_PP_CASE(_ARG) STDEXEC_PP_PROBE(~, _ARG)
#define STDEXEC_PP_SWITCH(_PREFIX, ...) \
STDEXEC_PP_CAT(_PREFIX##_CASE_, STDEXEC_PP_CASE_LABEL_(_PREFIX, __VA_ARGS__))

// Boolean logic
#define STDEXEC_PP_NOT(_XP) STDEXEC_PP_CHECK(STDEXEC_PP_CAT(STDEXEC_PP_NOT_, _XP))
#define STDEXEC_PP_NOT_0 STDEXEC_PP_PROBE(~, 1)
Expand Down Expand Up @@ -89,8 +101,6 @@

////////////////////////////////////////////////////////////////////////////////////////////////////

#define STDEXEC_PP_FRONT_I(_A1, ...) _A1
#define STDEXEC_PP_FRONT(...) __VA_OPT__(STDEXEC_PP_FRONT_I(__VA_ARGS__))
#define STDEXEC_PP_BACK_AGAIN() STDEXEC_PP_BACK_I
#define STDEXEC_PP_BACK_I(_A1, ...) \
STDEXEC_PP_FRONT(__VA_OPT__(, ) _A1, ) \
Expand Down
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