[libcxx] [libcxxabi] [libunwind] [libcxx, libcxxabi, libunwind] Prefer -fvisibility-global-new-delete=force-hidden (PR #84917)

[Martin Storsjö via cfe-commits]

https://github.com/mstorsjo created https://github.com/llvm/llvm-project/pull/84917

27ce26b06655cfece3d54b30e442ef93d3e78ac7 added the new option `-fvisibility-global-new-delete=`, where
`-fvisibility-global-new-delete=force-hidden` is equivalent to the old option `-fvisibility-global-new-delete-hidden`. At the same time, the old option was deprecated.

Test for and use the new option form first; if unsupported, try using the old form.

This avoids warnings in the MinGW builds, if built with Clang 18 or newer.

>From 4145880f327ed3ad76f7693193ba31ec2d2332ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin at martin.st>
Date: Tue, 12 Mar 2024 10:42:16 +0200
Subject: [PATCH] [libcxx, libcxxabi, libunwind] Prefer
 -fvisibility-global-new-delete=force-hidden

27ce26b06655cfece3d54b30e442ef93d3e78ac7 added the new option
`-fvisibility-global-new-delete=`, where
`-fvisibility-global-new-delete=force-hidden` is equivalent to the
old option `-fvisibility-global-new-delete-hidden`. At the same
time, the old option was deprecated.

Test for and use the new option form first; if unsupported, try
using the old form.

This avoids warnings in the MinGW builds, if built with Clang 18
or newer.
---
 libcxx/src/CMakeLists.txt    | 5 ++++-
 libcxxabi/src/CMakeLists.txt | 5 ++++-
 libunwind/src/CMakeLists.txt | 5 ++++-
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
index 07ffc8bfdaae3d..1110a79ddcacd5 100644
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -301,7 +301,10 @@ if (LIBCXX_ENABLE_STATIC)
     # then its code shouldn't declare them with hidden visibility.  They might
     # actually be provided by a shared library at link time.
     if (LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS)
-      append_flags_if_supported(CXX_STATIC_LIBRARY_FLAGS -fvisibility-global-new-delete-hidden)
+      append_flags_if_supported(CXX_STATIC_LIBRARY_FLAGS -fvisibility-global-new-delete=force-hidden)
+      if (NOT CXX_SUPPORTS_FVISIBILITY_GLOBAL_NEW_DELETE_EQ_FORCE_HIDDEN_FLAG)
+        append_flags_if_supported(CXX_STATIC_LIBRARY_FLAGS -fvisibility-global-new-delete-hidden)
+      endif()
     endif()
     target_compile_options(cxx_static PRIVATE ${CXX_STATIC_LIBRARY_FLAGS})
     # _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS can be defined in __config_site
diff --git a/libcxxabi/src/CMakeLists.txt b/libcxxabi/src/CMakeLists.txt
index 0af4dc1448e91a..c8cc93de50777b 100644
--- a/libcxxabi/src/CMakeLists.txt
+++ b/libcxxabi/src/CMakeLists.txt
@@ -268,7 +268,10 @@ if(LIBCXXABI_HERMETIC_STATIC_LIBRARY)
   # then its code shouldn't declare them with hidden visibility.  They might
   # actually be provided by a shared library at link time.
   if (LIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS)
-    target_add_compile_flags_if_supported(cxxabi_static_objects PRIVATE -fvisibility-global-new-delete-hidden)
+    target_add_compile_flags_if_supported(cxxabi_static_objects PRIVATE -fvisibility-global-new-delete=force-hidden)
+    if (NOT CXX_SUPPORTS_FVISIBILITY_GLOBAL_NEW_DELETE_EQ_FORCE_HIDDEN_FLAG)
+      target_add_compile_flags_if_supported(cxxabi_static_objects PRIVATE -fvisibility-global-new-delete-hidden)
+    endif()
   endif()
   # _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS can be defined in libcxx's
   # __config_site too. Define it in the same way here, to avoid redefinition
diff --git a/libunwind/src/CMakeLists.txt b/libunwind/src/CMakeLists.txt
index 9c6f5d908b0945..780430ba70ba60 100644
--- a/libunwind/src/CMakeLists.txt
+++ b/libunwind/src/CMakeLists.txt
@@ -201,7 +201,10 @@ set_target_properties(unwind_static_objects
 
 if(LIBUNWIND_HIDE_SYMBOLS)
   target_add_compile_flags_if_supported(unwind_static_objects PRIVATE -fvisibility=hidden)
-  target_add_compile_flags_if_supported(unwind_static_objects PRIVATE -fvisibility-global-new-delete-hidden)
+  target_add_compile_flags_if_supported(unwind_static_objects PRIVATE -fvisibility-global-new-delete=force-hidden)
+  if (NOT CXX_SUPPORTS_FVISIBILITY_GLOBAL_NEW_DELETE_EQ_FORCE_HIDDEN_FLAG)
+    target_add_compile_flags_if_supported(unwind_static_objects PRIVATE -fvisibility-global-new-delete-hidden)
+  endif()
   target_compile_definitions(unwind_static_objects PRIVATE _LIBUNWIND_HIDE_SYMBOLS)
 endif()