From 989eca62c6b23f15fcc9da5de5f17b628fbde1db Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne@apple.com>
Date: Thu, 14 Mar 2019 14:19:08 +0000
Subject: [PATCH] [libc++] Do not share an object library to create the
 static/shared libraries

Summary:
The problem with using an object library for doing this is that it prevents
the shared library and the static library from being built with the right
default flags. For example, CMake will build shared libraries with -fPIC
by default, but not static libraries. Using an object library to create
the shared library will prevent the right default flags for shared
libraries from being used.

As a side effect, this patch also localizes the logic related to building
a hermetic static library to the static library case, making clear that
this has no effect on the shared library.

Reviewers: phosek, EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59248

llvm-svn: 356150
---
 libcxx/lib/CMakeLists.txt | 57 ++++++++++++++++-------------------------------
 1 file changed, 19 insertions(+), 38 deletions(-)

diff --git a/libcxx/lib/CMakeLists.txt b/libcxx/lib/CMakeLists.txt
index 22a9bf3..b8cb14a 100644
--- a/libcxx/lib/CMakeLists.txt
+++ b/libcxx/lib/CMakeLists.txt
@@ -166,14 +166,7 @@ if (LIBCXX_OSX_REEXPORT_LIBCXXABI_SYMBOLS)
   endif()
 endif()
 
-split_list(LIBCXX_COMPILE_FLAGS)
-split_list(LIBCXX_LINK_FLAGS)
-
-macro(cxx_object_library name)
-  cmake_parse_arguments(ARGS "" "" "DEFINES;FLAGS" ${ARGN})
-
-  # Add an object library that contains the compiled source files.
-  add_library(${name} OBJECT ${exclude_from_all} ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
+function(cxx_set_common_defines name)
   if(LIBCXX_CXX_ABI_HEADER_TARGET)
     add_dependencies(${name} ${LIBCXX_CXX_ABI_HEADER_TARGET})
   endif()
@@ -199,50 +192,28 @@ macro(cxx_object_library name)
                                  # in printf, scanf.
                                  _CRT_STDIO_ISO_WIDE_SPECIFIERS)
   endif()
+endfunction()
 
-  if(ARGS_DEFINES)
-    target_compile_definitions(${name} PRIVATE ${ARGS_DEFINES})
-  endif()
-
-  set_target_properties(${name}
-    PROPERTIES
-      COMPILE_FLAGS ${LIBCXX_COMPILE_FLAGS}
-  )
-
-  if(ARGS_FLAGS)
-    target_compile_options(${name} PRIVATE ${ARGS_FLAGS})
-  endif()
-endmacro()
-
-if(LIBCXX_HERMETIC_STATIC_LIBRARY)
-  append_flags_if_supported(CXX_STATIC_OBJECTS_FLAGS -fvisibility=hidden)
-  append_flags_if_supported(CXX_STATIC_OBJECTS_FLAGS -fvisibility-global-new-delete-hidden)
-  cxx_object_library(cxx_static_objects
-    DEFINES _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
-    FLAGS ${CXX_STATIC_OBJECTS_FLAGS})
-  cxx_object_library(cxx_shared_objects)
-  set(cxx_static_sources $<TARGET_OBJECTS:cxx_static_objects>)
-  set(cxx_shared_sources $<TARGET_OBJECTS:cxx_shared_objects>)
-else()
-  cxx_object_library(cxx_objects)
-  set(cxx_static_sources $<TARGET_OBJECTS:cxx_objects>)
-  set(cxx_shared_sources $<TARGET_OBJECTS:cxx_objects>)
-endif()
+split_list(LIBCXX_COMPILE_FLAGS)
+split_list(LIBCXX_LINK_FLAGS)
 
 # Build the shared library.
 if (LIBCXX_ENABLE_SHARED)
-  add_library(cxx_shared SHARED ${cxx_shared_sources})
+  add_library(cxx_shared SHARED ${exclude_from_all} ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
   if(COMMAND llvm_setup_rpath)
     llvm_setup_rpath(cxx_shared)
   endif()
   target_link_libraries(cxx_shared PRIVATE ${LIBCXX_LIBRARIES})
   set_target_properties(cxx_shared
     PROPERTIES
+      COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"
       LINK_FLAGS    "${LIBCXX_LINK_FLAGS}"
       OUTPUT_NAME   "c++"
       VERSION       "${LIBCXX_ABI_VERSION}.0"
       SOVERSION     "${LIBCXX_ABI_VERSION}"
   )
+  cxx_set_common_defines(cxx_shared)
+
   list(APPEND LIBCXX_BUILD_TARGETS "cxx_shared")
   if (LIBCXX_INSTALL_SHARED_LIBRARY)
     list(APPEND LIBCXX_INSTALL_TARGETS "cxx_shared")
@@ -258,14 +229,24 @@ endif()
 
 # Build the static library.
 if (LIBCXX_ENABLE_STATIC)
-  add_library(cxx_static STATIC ${cxx_static_sources})
+  add_library(cxx_static STATIC ${exclude_from_all} ${LIBCXX_SOURCES} ${LIBCXX_HEADERS})
   target_link_libraries(cxx_static PRIVATE ${LIBCXX_LIBRARIES})
   set(CMAKE_STATIC_LIBRARY_PREFIX "lib")
   set_target_properties(cxx_static
     PROPERTIES
+      COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"
       LINK_FLAGS    "${LIBCXX_LINK_FLAGS}"
       OUTPUT_NAME   "c++"
   )
+  cxx_set_common_defines(cxx_shared)
+
+  if (LIBCXX_HERMETIC_STATIC_LIBRARY)
+    append_flags_if_supported(CXX_STATIC_LIBRARY_FLAGS -fvisibility=hidden)
+    append_flags_if_supported(CXX_STATIC_LIBRARY_FLAGS -fvisibility-global-new-delete-hidden)
+    target_compile_options(cxx_static PRIVATE ${CXX_STATIC_LIBRARY_FLAGS})
+    target_compile_definitions(cxx_static PRIVATE _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
+  endif()
+
   list(APPEND LIBCXX_BUILD_TARGETS "cxx_static")
   if (LIBCXX_INSTALL_STATIC_LIBRARY)
     list(APPEND LIBCXX_INSTALL_TARGETS "cxx_static")
-- 
2.7.4