[CMake] Support statically linking dependencies only to shared or static library

Currently it's possible to select whether to statically link unwinder
or the C++ ABI library, but this option applies to both the shared
and static library. However, in some scenarios it may be desirable to
only statically link unwinder and C++ ABI library into static C++
library since for shared C++ library we can rely on dynamic linking
and linker scripts. This change enables selectively enabling or
disabling statically linking only to shared or static library.

Differential Revision: https://reviews.llvm.org/D49502

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@337668 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 14 insertions, 6 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6521ebbe4..df59b5610 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -155,6 +155,14 @@ endif()
 # cannot be used with LIBCXX_ENABLE_ABI_LINKER_SCRIPT.
 option(LIBCXX_ENABLE_STATIC_ABI_LIBRARY "Statically link the ABI library" OFF)
 
+cmake_dependent_option(LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY
+  "Statically link the ABI library to static library" ON
+  "LIBCXX_ENABLE_STATIC_ABI_LIBRARY;LIBCXX_ENABLE_STATIC" OFF)
+
+cmake_dependent_option(LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY
+  "Statically link the ABI library to shared library" ON
+  "LIBCXX_ENABLE_STATIC_ABI_LIBRARY;LIBCXX_ENABLE_STATIC" OFF)
+
 # Generate and install a linker script inplace of libc++.so. The linker script
 # will link libc++ to the correct ABI library. This option is on by default
 # on UNIX platforms other than Apple unless 'LIBCXX_ENABLE_STATIC_ABI_LIBRARY'
diff --git a/cmake/Modules/HandleLibCXXABI.cmake b/cmake/Modules/HandleLibCXXABI.cmake
index 0eb70a739..d837c3c37 100644
--- a/cmake/Modules/HandleLibCXXABI.cmake
+++ b/cmake/Modules/HandleLibCXXABI.cmake
@@ -96,10 +96,10 @@ if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++" OR
 elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxabi")
   if (LIBCXX_CXX_ABI_INTREE)
     # Link against just-built "cxxabi" target.
-    if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
-        set(CXXABI_LIBNAME cxxabi_static)
+    if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
+      set(CXXABI_LIBNAME cxxabi_static)
     else()
-        set(CXXABI_LIBNAME cxxabi_shared)
+      set(CXXABI_LIBNAME cxxabi_shared)
     endif()
     set(LIBCXX_LIBCPPABI_VERSION "2" PARENT_SCOPE)
   else()
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index d32f8fb8e..5ac691a75 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -44,7 +44,7 @@ if (APPLE AND (LIBCXX_CXX_ABI_LIBNAME STREQUAL "libcxxabi" OR
   set(LIBCXX_OSX_REEXPORT_SYSTEM_ABI_LIBRARY ON)
 endif()
 
-if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
   add_library_flags("-Wl,--whole-archive" "-Wl,-Bstatic")
   add_library_flags("${LIBCXX_CXX_ABI_LIBRARY}")
   add_library_flags("-Wl,-Bdynamic" "-Wl,--no-whole-archive")
@@ -259,14 +259,14 @@ if (LIBCXX_ENABLE_STATIC)
 
   list(APPEND LIBCXX_TARGETS "cxx_static")
   # Attempt to merge the libc++.a archive and the ABI library archive into one.
-  if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+  if (LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY)
     set(MERGE_ARCHIVES_SEARCH_PATHS "")
     if (LIBCXX_CXX_ABI_LIBRARY_PATH)
       set(MERGE_ARCHIVES_SEARCH_PATHS "-L${LIBCXX_CXX_ABI_LIBRARY_PATH}")
     endif()
     if ((TARGET ${LIBCXX_CXX_ABI_LIBRARY}) OR
         (${LIBCXX_CXX_ABI_LIBRARY} MATCHES "cxxabi(_static|_shared)?" AND HAVE_LIBCXXABI))
-      set(MERGE_ARCHIVES_ABI_TARGET "$<TARGET_LINKER_FILE:${LIBCXX_CXX_ABI_LIBRARY}>")
+      set(MERGE_ARCHIVES_ABI_TARGET "$<TARGET_LINKER_FILE:cxxabi_static>")
     else()
       set(MERGE_ARCHIVES_ABI_TARGET
           "${CMAKE_STATIC_LIBRARY_PREFIX}${LIBCXX_CXX_ABI_LIBRARY}${CMAKE_STATIC_LIBRARY_SUFFIX}")