[libcxx-commits] [libcxx] 8a73aa8 - [libcxx] [libcxxabi] Set flags for visibility when statically linking libcxxabi into libcxx for windows

[Martin Storsjö via libcxx-commits]

Author: Martin Storsjö
Date: 2020-11-03T17:13:48+02:00
New Revision: 8a73aa8c4c3ee82e7d650c6a957937713a4a9ab4

URL: https://github.com/llvm/llvm-project/commit/8a73aa8c4c3ee82e7d650c6a957937713a4a9ab4
DIFF: https://github.com/llvm/llvm-project/commit/8a73aa8c4c3ee82e7d650c6a957937713a4a9ab4.diff

LOG: [libcxx] [libcxxabi] Set flags for visibility when statically linking libcxxabi into libcxx for windows

Previously, these had to be set manually when building each of the
projects standalone, in order to get proper symbol visibility when
combining the two libraries.

Differential Revision: https://reviews.llvm.org/D90021

Added: 
    

Modified: 
    libcxx/CMakeLists.txt
    libcxxabi/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
index ee8ba4543340..2353a4b5b9e9 100644
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -871,6 +871,12 @@ if (DEFINED WIN32 AND LIBCXX_ENABLE_STATIC AND NOT LIBCXX_ENABLE_SHARED)
   config_define(ON _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
 endif()
 
+if (WIN32 AND LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+  # If linking libcxxabi statically into libcxx, skip the dllimport attributes
+  # on symbols we refer to from libcxxabi.
+  add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
+endif()
+
 # Setup all common build flags =================================================
 function(cxx_add_common_build_flags target)
   cxx_add_basic_build_flags(${target})

diff  --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
index b8cdb188ebeb..146749f57b0a 100644
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -288,7 +288,14 @@ add_definitions(-D_LIBCPP_BUILDING_LIBRARY)
 
 # Disable DLL annotations on Windows for static builds.
 if (WIN32 AND LIBCXXABI_ENABLE_STATIC AND NOT LIBCXXABI_ENABLE_SHARED)
-  add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
+  if (LIBCXX_ENABLE_SHARED AND LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+    # Building libcxxabi statically, but intending for it to be statically
+    # linked into a shared libcxx; keep dllexport enabled within libcxxabi,
+    # as the symbols will need to be exported from libcxx.
+  else()
+    # Regular static build; disable dllexports.
+    add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
+  endif()
 endif()
 
 add_compile_flags_if_supported(-Werror=return-type)