Re: [PATCH 1/4] libstdc++: Harmonize <version> and other headers

[Jonathan Wakely <jwakely@redhat.com>]

On 05/04/23 01:09 +0200, Arsen Arsenović wrote:
>Due to recent, large changes in libstdc++, the feature test macros
>declared in <version> got out of sync with the other headers that
>possibly declare them.
>
>libstdc++-v3/ChangeLog:
>
>	* include/bits/unique_ptr.h (__cpp_lib_constexpr_memory):
>	Synchronize the definition block with...
>	* include/bits/ptr_traits.h (__cpp_lib_constexpr_memory):
>	... this one here.  Also define the 202202L value, rather than
>	leaving it up to purely unique_ptr.h, so that the value is
>	synchronized across all headers.
>	(__gnu_debug::_Safe_iterator_base): Move into new conditional
>	block.
>	* include/std/memory (__cpp_lib_atomic_value_initialization):
>	Define on freestanding under the same conditions as in
>	atomic_base.h.
>	* include/std/version (__cpp_lib_robust_nonmodifying_seq_ops):
>	Also define on freestanding.
>	(__cpp_lib_to_chars): Ditto.
>	(__cpp_lib_gcd): Ditto.
>	(__cpp_lib_gcd_lcm): Ditto.
>	(__cpp_lib_raw_memory_algorithms): Ditto.
>	(__cpp_lib_array_constexpr): Ditto.
>	(__cpp_lib_nonmember_container_access): Ditto.
>	(__cpp_lib_clamp): Ditto.
>	(__cpp_lib_constexpr_char_traits): Ditto.
>	(__cpp_lib_constexpr_string): Ditto.
>	(__cpp_lib_sample): Ditto.
>	(__cpp_lib_lcm): Ditto.
>	(__cpp_lib_constexpr_iterator): Ditto.
>	(__cpp_lib_constexpr_char_traits): Ditto.
>	(__cpp_lib_interpolate): Ditto.
>	(__cpp_lib_constexpr_utility): Ditto.
>	(__cpp_lib_shift): Ditto.
>	(__cpp_lib_ranges): Ditto.
>	(__cpp_lib_move_iterator_concept): Ditto.
>	(__cpp_lib_constexpr_numeric): Ditto.
>	(__cpp_lib_constexpr_functional): Ditto.
>	(__cpp_lib_constexpr_algorithms): Ditto.
>	(__cpp_lib_constexpr_tuple): Ditto.
>	(__cpp_lib_constexpr_memory): Ditto.
>---
>Evening,
>
>This patchset is a replacement to and extension of the one presented at
>https://inbox.sourceware.org/libstdc++/20230309222626.4008373-1-arsen@aarsen.me/
>... that has been rebased as to include newer additions, and extended to
>cover some regressions that seem to have occurred recently in
>freestanding mode.
>
>Tested on x86_64-pc-linux-gnu.
>
>OK for trunk?
>
>Thanks in advance, have a lovely night.
>
> libstdc++-v3/include/bits/ptr_traits.h | 13 ++--
> libstdc++-v3/include/bits/unique_ptr.h | 11 ++--
> libstdc++-v3/include/std/memory        |  6 ++
> libstdc++-v3/include/std/version       | 85 ++++++++++++++------------
> 4 files changed, 66 insertions(+), 49 deletions(-)
>
>diff --git a/libstdc++-v3/include/bits/ptr_traits.h b/libstdc++-v3/include/bits/ptr_traits.h
>index dc42a743c96..f6cc6b65f93 100644
>--- a/libstdc++-v3/include/bits/ptr_traits.h
>+++ b/libstdc++-v3/include/bits/ptr_traits.h
>@@ -34,12 +34,15 @@
>
> #include <bits/move.h>
>
>+/* Duplicate definition with unique_ptr.h.  */
>+#if __cplusplus > 202002L && defined(__cpp_constexpr_dynamic_alloc)
>+# define __cpp_lib_constexpr_memory 202202L
>+#elif __cplusplus > 201703L
>+# include <concepts>

Including <concepts> is unrelated to the FTM, and should always be
done for >= C++17, but this change means it's not included for the
first block.

Please leave the #include with the _Safe_iterator_base declaration.


>+# define __cpp_lib_constexpr_memory 201811L
>+#endif
>+
> #if __cplusplus > 201703L
>-#include <concepts>
>-# ifndef __cpp_lib_constexpr_memory
>-// Defined to a newer value in bits/unique_ptr.h for C++23
>-#  define __cpp_lib_constexpr_memory 201811L
>-# endif
> namespace __gnu_debug { struct _Safe_iterator_base; }
> #endif
>
>diff --git a/libstdc++-v3/include/bits/unique_ptr.h b/libstdc++-v3/include/bits/unique_ptr.h
>index c8daff41865..f0c6d2383b4 100644
>--- a/libstdc++-v3/include/bits/unique_ptr.h
>+++ b/libstdc++-v3/include/bits/unique_ptr.h
>@@ -43,12 +43,11 @@
> # endif
> #endif
>
>-#if __cplusplus > 202002L && __cpp_constexpr_dynamic_alloc
>-# if __cpp_lib_constexpr_memory < 202202L
>-// Defined with older value in bits/ptr_traits.h for C++20
>-#  undef __cpp_lib_constexpr_memory
>-#  define __cpp_lib_constexpr_memory 202202L
>-# endif
>+/* Duplicate definition with ptr_traits.h.  */
>+#if __cplusplus > 202002L && defined(__cpp_constexpr_dynamic_alloc)
>+# define __cpp_lib_constexpr_memory 202202L
>+#elif __cplusplus > 201703L
>+# define __cpp_lib_constexpr_memory 201811L
> #endif
>
> namespace std _GLIBCXX_VISIBILITY(default)
>diff --git a/libstdc++-v3/include/std/memory b/libstdc++-v3/include/std/memory
>index 341f9857730..85c36d67ee1 100644
>--- a/libstdc++-v3/include/std/memory
>+++ b/libstdc++-v3/include/std/memory
>@@ -91,6 +91,12 @@
> #  include <bits/uses_allocator_args.h>
> #endif
>
>+/* As a hack, we declare __cpp_lib_atomic_value_initialization here even though
>+   we don't include the bit that actually declares it, for consistency.  */
>+#if !defined(__cpp_lib_atomic_value_initialization) && __cplusplus >= 202002L
>+# define __cpp_lib_atomic_value_initialization 201911L
>+#endif
>+
> #if __cplusplus >= 201103L && __cplusplus <= 202002L && _GLIBCXX_HOSTED
> namespace std _GLIBCXX_VISIBILITY(default)
> {
>diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
>index a19c39c6cdd..0239fcea813 100644
>--- a/libstdc++-v3/include/std/version
>+++ b/libstdc++-v3/include/std/version
>@@ -85,6 +85,12 @@
> #define __cpp_lib_transparent_operators 201510L
> #define __cpp_lib_tuple_element_t 201402L
> #define __cpp_lib_tuples_by_type 201304L
>+#define __cpp_lib_robust_nonmodifying_seq_ops 201304L

Pleae keep them in alphabetical order (within their relevant
blocks/groups).


>+
>+#if _GLIBCXX_FLOAT_IS_IEEE_BINARY32 && _GLIBCXX_DOUBLE_IS_IEEE_BINARY64 \
>+    && __SIZE_WIDTH__ >= 32
>+# define __cpp_lib_to_chars 201611L
>+#endif
>
> #if _GLIBCXX_HOSTED
> # define __cpp_lib_chrono_udls 201304L
>@@ -92,7 +98,6 @@
> # define __cpp_lib_generic_associative_lookup 201304L
> # define __cpp_lib_make_unique 201304L
> # define __cpp_lib_quoted_string_io 201304L
>-# define __cpp_lib_robust_nonmodifying_seq_ops 201304L
> # ifdef _GLIBCXX_HAS_GTHREADS
> #  define __cpp_lib_shared_timed_mutex 201402L
> # endif
>@@ -136,13 +141,13 @@
> # define __cpp_lib_variant 202102L
> #endif
> #define __cpp_lib_void_t 201411L
>-
>-#if _GLIBCXX_HOSTED
>+#define __cpp_lib_gcd 201606L
>+#define __cpp_lib_gcd_lcm 201606L
>+#define __cpp_lib_raw_memory_algorithms 201606L
> #if __cplusplus == 201703L // N.B. updated value in C++20
> # define __cpp_lib_array_constexpr 201803L
> #endif
>-#define __cpp_lib_boyer_moore_searcher 201603L
>-#define __cpp_lib_chrono 201611L
>+#define __cpp_lib_nonmember_container_access 201411L
> #define __cpp_lib_clamp 201603L
> #if __cplusplus == 201703L // N.B. updated value in C++20
> # if _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED
>@@ -150,13 +155,16 @@
> #  define __cpp_lib_constexpr_string 201611L
> # endif
> #endif
>+#define __cpp_lib_sample 201603L
>+#define __cpp_lib_lcm 201606L
>+
>+#if _GLIBCXX_HOSTED
>+#define __cpp_lib_boyer_moore_searcher 201603L
>+#define __cpp_lib_chrono 201611L
> #define __cpp_lib_enable_shared_from_this 201603L
> #define __cpp_lib_execution 201902L // FIXME: should be 201603L
> #define __cpp_lib_filesystem 201703L
>-#define __cpp_lib_gcd 201606L
>-#define __cpp_lib_gcd_lcm 201606L
> #define __cpp_lib_hypot 201603L
>-#define __cpp_lib_lcm 201606L
> #define __cpp_lib_map_try_emplace 201411L
> #define __cpp_lib_math_special_functions 201603L
> #ifdef _GLIBCXX_HAS_GTHREADS
>@@ -165,20 +173,13 @@
> # define __cpp_lib_memory_resource 1
> #endif
> #define __cpp_lib_node_extract 201606L
>-#define __cpp_lib_nonmember_container_access 201411L
> #define __cpp_lib_parallel_algorithm 201603L
>-#define __cpp_lib_raw_memory_algorithms 201606L
>-#define __cpp_lib_sample 201603L
> #ifdef _GLIBCXX_HAS_GTHREADS
> # define __cpp_lib_scoped_lock 201703L
> # define __cpp_lib_shared_mutex 201505L
> #endif
> #define __cpp_lib_shared_ptr_weak_type 201606L
> #define __cpp_lib_string_view 201803L
>-#if _GLIBCXX_FLOAT_IS_IEEE_BINARY32 && _GLIBCXX_DOUBLE_IS_IEEE_BINARY64 \
>-    && __SIZE_WIDTH__ >= 32
>-# define __cpp_lib_to_chars 201611L
>-#endif
> #define __cpp_lib_unordered_map_try_emplace 201411L
> #endif
>
>@@ -224,7 +225,9 @@
> #if __cpp_lib_concepts
> # define __cpp_lib_make_obj_using_allocator 201811L
> #endif
>-#define __cpp_lib_optional 202106L
>+#if __cplusplus <= 202002L // N.B. updated value in C++23
>+# define __cpp_lib_optional 202106L
>+#endif
> #define __cpp_lib_remove_cvref 201711L
> #if __has_builtin(__builtin_source_location)
> # define __cpp_lib_source_location 201907L
>@@ -243,9 +246,27 @@
> #if __cpp_concepts >= 202002L && __cpp_constexpr >= 201811L
> # define __cpp_lib_variant 202106L
> #endif
>-
>-#if _GLIBCXX_HOSTED
> #define __cpp_lib_array_constexpr 201811L
>+#define __cpp_lib_constexpr_iterator 201811L
>+#ifdef __cpp_lib_is_constant_evaluated
>+# define __cpp_lib_constexpr_char_traits 201811L
>+#endif
>+#define __cpp_lib_interpolate 201902L
>+#define __cpp_lib_constexpr_utility 201811L
>+#define __cpp_lib_shift 201806L
>+#if __cpp_lib_concepts
>+# define __cpp_lib_move_iterator_concept 202207L
>+# define __cpp_lib_ranges 202110L
>+#endif
>+#define __cpp_lib_constexpr_numeric 201911L
>+#define __cpp_lib_constexpr_functional 201907L
>+#define __cpp_lib_constexpr_algorithms 201806L
>+#define __cpp_lib_constexpr_tuple 201811L
>+#if __cplusplus <= 202002L // N.B. updated value in C++23
>+# define __cpp_lib_constexpr_memory 201811L
>+#endif // C++20
>+
>+#if _GLIBCXX_HOSTED
> #define __cpp_lib_atomic_shared_ptr 201711L
> #if defined _GLIBCXX_HAS_GTHREADS || defined _GLIBCXX_HAVE_LINUX_FUTEX
> # define __cpp_lib_atomic_wait 201907L
>@@ -256,16 +277,9 @@
> // #undef __cpp_lib_chrono
> // #define __cpp_lib_chrono 201907L
> // FIXME: #define __cpp_lib_execution 201902L
>-#define __cpp_lib_constexpr_algorithms 201806L
>-#ifdef __cpp_lib_is_constant_evaluated
>-# define __cpp_lib_constexpr_char_traits 201811L
>-#endif
> #define __cpp_lib_constexpr_complex 201711L
> #define __cpp_lib_constexpr_dynamic_alloc 201907L
>-#define __cpp_lib_constexpr_functional 201907L
>-#define __cpp_lib_constexpr_iterator 201811L
>-#define __cpp_lib_constexpr_memory 201811L
>-#define __cpp_lib_constexpr_numeric 201911L
>+#define __cpp_lib_constexpr_tuple 201811L
> #ifdef __cpp_lib_is_constant_evaluated
> # if _GLIBCXX_USE_CXX11_ABI
> #  define __cpp_lib_constexpr_string 201907L
>@@ -273,13 +287,10 @@
> #  define __cpp_lib_constexpr_string 201811L
> # endif
> #endif
>-#define __cpp_lib_constexpr_tuple 201811L
>-#define __cpp_lib_constexpr_utility 201811L
> #define __cpp_lib_constexpr_vector 201907L
> #define __cpp_lib_erase_if 202002L
> #define __cpp_lib_format 202106L
> #define __cpp_lib_generic_unordered_lookup 201811L
>-#define __cpp_lib_interpolate 201902L
> #ifdef _GLIBCXX_HAS_GTHREADS
> # define __cpp_lib_jthread 201911L
> #endif
>@@ -288,15 +299,10 @@
> #endif
> #define __cpp_lib_list_remove_return_type 201806L
> #define __cpp_lib_polymorphic_allocator 201902L
>-#if __cpp_lib_concepts
>-# define __cpp_lib_ranges 202110L
>-# define __cpp_lib_move_iterator_concept 202207L
>-#endif
> #if __cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE
> # define __cpp_lib_semaphore 201907L
> #endif
> #define __cpp_lib_shared_ptr_arrays 201707L
>-#define __cpp_lib_shift 201806L
> #define __cpp_lib_smart_ptr_for_overwrite 202002L
> # if _GLIBCXX_USE_CXX11_ABI
> // Only supported with cxx11-abi
>@@ -330,14 +336,17 @@
> #define __cpp_lib_ranges_stride 202207L
> #define __cpp_lib_ranges_cartesian_product 202207L
> #define __cpp_lib_ranges_as_rvalue 202207L
>-
>-#if _GLIBCXX_HOSTED
>-#define __cpp_lib_adaptor_iterator_pair_constructor 202106L
> #if __cpp_constexpr_dynamic_alloc
>-# define __cpp_lib_constexpr_bitset 202202L
>+# if _GLIBCXX_HOSTED
>+#  define __cpp_lib_constexpr_bitset 202202L
>+# endif
> # undef __cpp_lib_constexpr_memory
> # define __cpp_lib_constexpr_memory 202202L
> #endif
>+#define __cpp_lib_stdatomic_h 202011L
>+
>+#if _GLIBCXX_HOSTED
>+#define __cpp_lib_adaptor_iterator_pair_constructor 202106L
> #define __cpp_lib_ios_noreplace 202207L
> #define __cpp_lib_move_only_function 202110L
> #if __cpp_lib_span