[libcxx-commits] [libcxx] 963495f - [libc++][format] Adds availability macros for std::format.

[Mark de Wever via libcxx-commits]

Author: Mark de Wever
Date: 2021-05-26T17:54:33+02:00
New Revision: 963495f0d4b5a0707f82b6c6454f42f3aa52da9b

URL: https://github.com/llvm/llvm-project/commit/963495f0d4b5a0707f82b6c6454f42f3aa52da9b
DIFF: https://github.com/llvm/llvm-project/commit/963495f0d4b5a0707f82b6c6454f42f3aa52da9b.diff

LOG: [libc++][format] Adds availability macros for std::format.

This prevents std::format to be available until there's an ABI stable
version. (This only impacts the Apple platform.)

Depends on D102703

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D102705

Added: 
    

Modified: 
    libcxx/include/__availability
    libcxx/include/__format/format_parse_context.h
    libcxx/include/version
    libcxx/utils/generate_feature_test_macro_components.py

Removed: 
    


################################################################################
diff  --git a/libcxx/include/__availability b/libcxx/include/__availability
index 59d92fffd2369..9d488f00ebb32 100644
--- a/libcxx/include/__availability
+++ b/libcxx/include/__availability
@@ -138,6 +138,13 @@
 // #   define _LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch
 // #   define _LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore
 
+    // This controls the availability of the C++20 format library.
+    // The library is in development and not ABI stable yet. Currently
+    // P2216 is aiming to be retroactively accepted in C++20. This paper
+    // contains ABI breaking changes.
+#   define _LIBCPP_AVAILABILITY_FORMAT
+// #   define _LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format
+
 #elif defined(__APPLE__)
 
 #   define _LIBCPP_AVAILABILITY_SHARED_MUTEX                                    \
@@ -223,6 +230,13 @@
 #   define _LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_latch
 #   define _LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_semaphore
 
+    // This controls the availability of the C++20 format library.
+    // The library is in development and not ABI stable yet. Currently
+    // P2216 is aiming to be retroactively accepted in C++20. This paper
+    // contains ABI breaking changes.
+#   define _LIBCPP_AVAILABILITY_FORMAT                                          \
+        __attribute__((unavailable))
+#   define _LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format
 #else
 
 // ...New vendors can add availability markup here...

diff  --git a/libcxx/include/__format/format_parse_context.h b/libcxx/include/__format/format_parse_context.h
index 43c756bf004df..abe580db2d041 100644
--- a/libcxx/include/__format/format_parse_context.h
+++ b/libcxx/include/__format/format_parse_context.h
@@ -33,7 +33,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
     !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
 
 template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS basic_format_parse_context {
+class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FORMAT basic_format_parse_context {
 public:
   using char_type = _CharT;
   using const_iterator = typename basic_string_view<_CharT>::const_iterator;

diff  --git a/libcxx/include/version b/libcxx/include/version
index fb5eb6ec2586b..3d1554b5c4d77 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -319,7 +319,9 @@ __cpp_lib_void_t                                        201411L <type_traits>
 # define __cpp_lib_erase_if                             202002L
 # undef  __cpp_lib_execution
 // # define __cpp_lib_execution                            201902L
-// # define __cpp_lib_format                               201907L
+# if !defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format)
+// #   define __cpp_lib_format                             201907L
+# endif
 # define __cpp_lib_generic_unordered_lookup             201811L
 # define __cpp_lib_int_pow2                             202002L
 # if !defined(_LIBCPP_HAS_NO_CONCEPTS)

diff  --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index 36fe3b35dfaf1..76ac93ec10237 100755
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -300,6 +300,8 @@ def add_version_header(tc):
     "name": "__cpp_lib_format",
     "values": { "c++20": 201907 },
     "headers": ["format"],
+    "test_suite_guard": "!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format)",
+    "libcxx_guard": "!defined(_LIBCPP_AVAILABILITY_DISABLE_FTM___cpp_lib_format)",
     "unimplemented": True,
   }, {
     "name": "__cpp_lib_gcd_lcm",