[libcxx-commits] [libcxx] e044362 - [libc++] Deprecate removed features macros. (#77879)
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Tue Jan 16 10:13:03 PST 2024
Author: Mark de Wever
Date: 2024-01-16T19:12:59+01:00
New Revision: e0443624b9b418cd2a1b26cac662885aedfb4977
URL: https://github.com/llvm/llvm-project/commit/e0443624b9b418cd2a1b26cac662885aedfb4977
DIFF: https://github.com/llvm/llvm-project/commit/e0443624b9b418cd2a1b26cac662885aedfb4977.diff
LOG: [libc++] Deprecate removed features macros. (#77879)
We discussed the removal of these enable-all macros in the libc++
monthly meeting and we agreed that we should deprecate these macros in
LLVM 18, and then remove them in LLVM 19 since they can silently enable
deprecated features that are implemented after the first release of the
macro.
This patch does the first part of this -- it deprecates the macro.
Note that the file
test/libcxx/depr/enable_removed_cpp20_features.compile.pass.cpp
does not exist so this file is not adapted. Since the feature is
deprecated and slated for removal soon the missing test is not
implemented.
Partly addresses: https://github.com/llvm/llvm-project/issues/75976
---------
Co-authored-by: Louis Dionne <ldionne.2 at gmail.com>
Added:
libcxx/test/libcxx/depr/enable_removed_cpp17_features.deprecated.verify.cpp
libcxx/test/libcxx/depr/enable_removed_cpp20_features.deprecated.verify.cpp
Modified:
libcxx/docs/ReleaseNotes/18.rst
libcxx/docs/UsingLibcxx.rst
libcxx/include/__config
libcxx/test/libcxx/depr/enable_removed_cpp17_features.compile.pass.cpp
Removed:
################################################################################
diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index 62a1fec627d0ca..6a68514723bf2c 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -123,6 +123,12 @@ Deprecations and Removals
overload of ``allocate``. However, this led to the library being non-conforming due to incorrect
constexpr-ness.
+- The macros ``_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES`` and
+ ``_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES`` have been deprecated and
+ will be removed in LLVM 19. These macros used to re-enable all features
+ that were removed in the C++17 and C++20 standards. Instead of using these
+ macros, please use the macros to re-enable individual features.
+
Upcoming Deprecations and Removals
----------------------------------
@@ -149,6 +155,10 @@ LLVM 19
- The ``_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS`` macro has been deprecated in LLVM 18 and will be removed
entirely in LLVM 19.
+- The ``_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES`` and
+ ``_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES`` macros have been deprecated
+ in LLVM 18 and will be removed entirely in LLVM 19.
+
LLVM 20
~~~~~~~
diff --git a/libcxx/docs/UsingLibcxx.rst b/libcxx/docs/UsingLibcxx.rst
index e1bbf39b9634a3..85e4fc33a27db9 100644
--- a/libcxx/docs/UsingLibcxx.rst
+++ b/libcxx/docs/UsingLibcxx.rst
@@ -275,6 +275,8 @@ C++17 Specific Configuration Macros
**_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES**:
This macro is used to re-enable all the features removed in C++17. The effect
is equivalent to manually defining each macro listed below.
+ This macro is deprecated and will be removed in LLVM-19. Use the
+ individual macros listed below.
**_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR**:
This macro is used to re-enable `auto_ptr`.
@@ -303,6 +305,8 @@ C++20 Specific Configuration Macros
**_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES**:
This macro is used to re-enable all the features removed in C++20. The effect
is equivalent to manually defining each macro listed below.
+ This macro is deprecated and will be removed in LLVM-19. Use the
+ individual macros listed below.
**_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS**:
This macro is used to re-enable redundant members of `allocator<T>`,
diff --git a/libcxx/include/__config b/libcxx/include/__config
index 1958d5c50ca911..ee272a62711af5 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -16,6 +16,17 @@
# pragma GCC system_header
#endif
+#if defined(_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES) && !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
+# pragma clang deprecated( \
+ _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES, \
+ "_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES is deprecated in LLVM 18 and will be removed in LLVM 19")
+#endif
+#if defined(_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES) && !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
+# pragma clang deprecated( \
+ _LIBCPP_ENABLE_CXX20_REMOVED_FEATURES, \
+ "_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES is deprecated in LLVM 18 and will be removed in LLVM 19")
+#endif
+
#if defined(__apple_build_version__)
// Given AppleClang XX.Y.Z, _LIBCPP_APPLE_CLANG_VER is XXYZ (e.g. AppleClang 14.0.3 => 1403)
# define _LIBCPP_COMPILER_CLANG_BASED
diff --git a/libcxx/test/libcxx/depr/enable_removed_cpp17_features.compile.pass.cpp b/libcxx/test/libcxx/depr/enable_removed_cpp17_features.compile.pass.cpp
index 2ee6010b3fc218..1b7acad3cfa464 100644
--- a/libcxx/test/libcxx/depr/enable_removed_cpp17_features.compile.pass.cpp
+++ b/libcxx/test/libcxx/depr/enable_removed_cpp17_features.compile.pass.cpp
@@ -9,7 +9,7 @@
// Test that defining _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES correctly defines
// _LIBCPP_ENABLE_CXX17_REMOVED_FOO for each individual component macro.
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES -Wno-deprecated-pragma
#include <__config>
diff --git a/libcxx/test/libcxx/depr/enable_removed_cpp17_features.deprecated.verify.cpp b/libcxx/test/libcxx/depr/enable_removed_cpp17_features.deprecated.verify.cpp
new file mode 100644
index 00000000000000..059c1b3ead4f15
--- /dev/null
+++ b/libcxx/test/libcxx/depr/enable_removed_cpp17_features.deprecated.verify.cpp
@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <__config>
+
+// Ensure that defining _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES yields a
+// deprecation warning. We intend to issue a deprecation warning in LLVM 18
+// and remove the macro entirely in LLVM 19. As such, this test will be quite
+// short lived.
+
+// UNSUPPORTED: clang-modules-build
+
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES
+
+#include <__config> // expected-warning@* 1+ {{macro '_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES' has been marked as deprecated}}
diff --git a/libcxx/test/libcxx/depr/enable_removed_cpp20_features.deprecated.verify.cpp b/libcxx/test/libcxx/depr/enable_removed_cpp20_features.deprecated.verify.cpp
new file mode 100644
index 00000000000000..163ff7d8fbda03
--- /dev/null
+++ b/libcxx/test/libcxx/depr/enable_removed_cpp20_features.deprecated.verify.cpp
@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <__config>
+
+// Ensure that defining _LIBCPP_ENABLE_CXX20_REMOVED_FEATURES yields a
+// deprecation warning. We intend to issue a deprecation warning in LLVM 18
+// and remove the macro entirely in LLVM 19. As such, this test will be quite
+// short lived.
+
+// UNSUPPORTED: clang-modules-build
+
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES
+
+#include <version> // expected-warning@* 1+ {{macro '_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES' has been marked as deprecated}}
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