[libcxx-commits] [libcxx] Revert "[libc++] Allow the use of extensions in the implementation (#79532)" (PR #85792)
Sam McCall via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Mar 19 12:34:49 PDT 2024
https://github.com/sam-mccall updated https://github.com/llvm/llvm-project/pull/85792
>From 233bda0d2d5a4422e7cc296ed0e62730953024b3 Mon Sep 17 00:00:00 2001
From: Sam McCall <sam.mccall at gmail.com>
Date: Tue, 19 Mar 2024 14:59:43 +0100
Subject: [PATCH 1/4] Revert "[libc++] Allow the use of extensions in the
implementation (#79532)"
This reverts commit 4d323e404d43526ad8263769f00aace9db2e57c5.
The heavy use of push/pop directives causes a severe compile-time
regression (>50%) when building code that uses libc++ via modules.
See discussion on https://github.com/llvm/llvm-project/pull/79532
---
libcxx/include/__config | 61 ++++++++++++++---------------------------
libcxx/include/tuple | 6 ++++
2 files changed, 26 insertions(+), 41 deletions(-)
diff --git a/libcxx/include/__config b/libcxx/include/__config
index 11e13e0c24986a..3a438e85a7b819 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -406,10 +406,6 @@ _LIBCPP_HARDENING_MODE_DEBUG
# define __has_include(...) 0
# endif
-# ifndef __has_warning
-# define __has_warning(...) 0
-# endif
-
# if !defined(_LIBCPP_COMPILER_CLANG_BASED) && __cplusplus < 201103L
# error "libc++ only supports C++03 with Clang-based compilers. Please enable C++11"
# endif
@@ -727,23 +723,6 @@ typedef __char32_t char32_t;
# define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
# endif
-# ifdef _LIBCPP_COMPILER_CLANG_BASED
-# define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("clang diagnostic push")
-# define _LIBCPP_DIAGNOSTIC_POP _Pragma("clang diagnostic pop")
-# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(clang diagnostic ignored str))
-# define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
-# elif defined(_LIBCPP_COMPILER_GCC)
-# define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
-# define _LIBCPP_DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
-# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
-# define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(GCC diagnostic ignored str))
-# else
-# define _LIBCPP_DIAGNOSTIC_PUSH
-# define _LIBCPP_DIAGNOSTIC_POP
-# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
-# define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
-# endif
-
# if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_FAST
# define _LIBCPP_HARDENING_SIG f
# elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_EXTENSIVE
@@ -831,33 +810,16 @@ typedef __char32_t char32_t;
# define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
# endif
-// TODO: Remove this workaround once we drop support for Clang 16
-#if __has_warning("-Wc++23-extensions")
-# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
-#else
-# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++2b-extensions")
-#endif
-
// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
// clang-format off
-# define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_DIAGNOSTIC_PUSH \
- _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++11-extensions") \
- _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++14-extensions") \
- _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++17-extensions") \
- _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions") \
- _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION \
- _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++14-extensions") \
- _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++17-extensions") \
- _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions") \
- _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++23-extensions") \
- namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std { \
+# define _LIBCPP_BEGIN_NAMESPACE_STD namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std { \
inline namespace _LIBCPP_ABI_NAMESPACE {
-# define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_DIAGNOSTIC_POP
+# define _LIBCPP_END_NAMESPACE_STD }}
# define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD \
inline namespace __fs { namespace filesystem {
-# define _LIBCPP_END_NAMESPACE_FILESYSTEM }} _LIBCPP_END_NAMESPACE_STD
+# define _LIBCPP_END_NAMESPACE_FILESYSTEM _LIBCPP_END_NAMESPACE_STD }}
// clang-format on
# if __has_attribute(__enable_if__)
@@ -1294,6 +1256,23 @@ __sanitizer_verify_double_ended_contiguous_container(const void*, const void*, c
// the ABI inconsistent.
# endif
+# ifdef _LIBCPP_COMPILER_CLANG_BASED
+# define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("clang diagnostic push")
+# define _LIBCPP_DIAGNOSTIC_POP _Pragma("clang diagnostic pop")
+# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(clang diagnostic ignored str))
+# define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
+# elif defined(_LIBCPP_COMPILER_GCC)
+# define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
+# define _LIBCPP_DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
+# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
+# define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(GCC diagnostic ignored str))
+# else
+# define _LIBCPP_DIAGNOSTIC_PUSH
+# define _LIBCPP_DIAGNOSTIC_POP
+# define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
+# define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
+# endif
+
// c8rtomb() and mbrtoc8() were added in C++20 and C23. Support for these
// functions is gradually being added to existing C libraries. The conditions
// below check for known C library versions and conditions under which these
diff --git a/libcxx/include/tuple b/libcxx/include/tuple
index f78db061b844b0..8e38dfe4d0eaa8 100644
--- a/libcxx/include/tuple
+++ b/libcxx/include/tuple
@@ -540,6 +540,10 @@ class _LIBCPP_TEMPLATE_VIS tuple {
public:
// [tuple.cnstr]
+ _LIBCPP_DIAGNOSTIC_PUSH
+ _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions")
+ _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")
+
// tuple() constructors (including allocator_arg_t variants)
template <template <class...> class _IsImpDefault = __is_implicitly_default_constructible,
template <class...> class _IsDefault = is_default_constructible,
@@ -821,6 +825,8 @@ public:
: __base_(allocator_arg_t(), __alloc, std::move(__p)) {}
# endif // _LIBCPP_STD_VER >= 23
+ _LIBCPP_DIAGNOSTIC_POP
+
// [tuple.assign]
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 tuple&
operator=(_If<_And<is_copy_assignable<_Tp>...>::value, tuple, __nat> const& __tuple)
>From d9a2a06956778848096a0befa08aee0efac683cc Mon Sep 17 00:00:00 2001
From: Sam McCall <sam.mccall at gmail.com>
Date: Tue, 19 Mar 2024 18:35:06 +0100
Subject: [PATCH 2/4] Add suppression to new extension use in pair
---
libcxx/include/__utility/pair.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/libcxx/include/__utility/pair.h b/libcxx/include/__utility/pair.h
index 0056806877e13c..7841b95b687066 100644
--- a/libcxx/include/__utility/pair.h
+++ b/libcxx/include/__utility/pair.h
@@ -68,6 +68,11 @@ template <class _Iter, class _Sent, ranges::subrange_kind _Kind>
struct __is_specialization_of_subrange<ranges::subrange<_Iter, _Sent, _Kind>> : true_type {};
#endif
+_LIBCPP_DIAGNOSTIC_PUSH
+// Allow use of explicit(bool) extension.
+_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions")
+_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")_LIBCPP_DIAGNOSTIC_POP
+
template <class _T1, class _T2>
struct _LIBCPP_TEMPLATE_VIS pair
#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
@@ -444,6 +449,8 @@ struct _LIBCPP_TEMPLATE_VIS pair
#endif
};
+_LIBCPP_DIAGNOSTIC_POP
+
#if _LIBCPP_STD_VER >= 17
template <class _T1, class _T2>
pair(_T1, _T2) -> pair<_T1, _T2>;
>From c2c800b9a241c69e8cd0c2a3c385f416d2c2db77 Mon Sep 17 00:00:00 2001
From: Sam McCall <sam.mccall at gmail.com>
Date: Tue, 19 Mar 2024 19:52:29 +0100
Subject: [PATCH 3/4] Fix typo between test and commit :-(
---
libcxx/include/__utility/pair.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libcxx/include/__utility/pair.h b/libcxx/include/__utility/pair.h
index 7841b95b687066..840e81d514210a 100644
--- a/libcxx/include/__utility/pair.h
+++ b/libcxx/include/__utility/pair.h
@@ -71,7 +71,7 @@ struct __is_specialization_of_subrange<ranges::subrange<_Iter, _Sent, _Kind>> :
_LIBCPP_DIAGNOSTIC_PUSH
// Allow use of explicit(bool) extension.
_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions")
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")_LIBCPP_DIAGNOSTIC_POP
+_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")
template <class _T1, class _T2>
struct _LIBCPP_TEMPLATE_VIS pair
>From c4abb87673da783e74d1264f60fe341d748c58cc Mon Sep 17 00:00:00 2001
From: Sam McCall <sam.mccall at gmail.com>
Date: Tue, 19 Mar 2024 20:34:37 +0100
Subject: [PATCH 4/4] Suppress one more if constexpr warning found by bots
---
libcxx/include/__algorithm/equal.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/libcxx/include/__algorithm/equal.h b/libcxx/include/__algorithm/equal.h
index c76a16b47f5da4..5ee5be85c8250b 100644
--- a/libcxx/include/__algorithm/equal.h
+++ b/libcxx/include/__algorithm/equal.h
@@ -96,6 +96,11 @@ __equal_impl(_Tp* __first1, _Tp* __last1, _Up* __first2, _Up*, _Pred&, _Proj1&,
return std::__constexpr_memcmp_equal(__first1, __first2, __element_count(__last1 - __first1));
}
+_LIBCPP_DIAGNOSTIC_PUSH
+// Allow use of if constexpr extension.
+_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++17-extensions")
+_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++17-extensions")
+
template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
equal(_InputIterator1 __first1,
@@ -119,6 +124,8 @@ equal(_InputIterator1 __first1,
__proj);
}
+_LIBCPP_DIAGNOSTIC_POP
+
template <class _InputIterator1, class _InputIterator2>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
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