[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

llvm-svn: 337668

5 files changed, 38 insertions, 15 deletions

diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
index 6521ebbe4d3..df59b5610f6 100644
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/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/libcxx/cmake/Modules/HandleLibCXXABI.cmake b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
index 0eb70a739d5..d837c3c3758 100644
--- a/libcxx/cmake/Modules/HandleLibCXXABI.cmake
+++ b/libcxx/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/libcxx/lib/CMakeLists.txt b/libcxx/lib/CMakeLists.txt
index d32f8fb8e86..5ac691a75ed 100644
--- a/libcxx/lib/CMakeLists.txt
+++ b/libcxx/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}")
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
index caadb7972af..adfe8c6f762 100644
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -84,6 +84,13 @@ set(LIBCXXABI_LIBCXX_LIBRARY_PATH "" CACHE PATH "The path to libc++ library.")
 option(LIBCXXABI_ENABLE_SHARED "Build libc++abi as a shared library." ON)
 option(LIBCXXABI_ENABLE_STATIC "Build libc++abi as a static library." ON)
 
+cmake_dependent_option(LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY
+  "Statically link the LLVM unwinder to static library" ON
+  "LIBCXXABI_ENABLE_STATIC_UNWINDER;LIBCXXABI_ENABLE_STATIC" OFF)
+cmake_dependent_option(LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY
+  "Statically link the LLVM unwinder to shared library" ON
+  "LIBCXXABI_ENABLE_STATIC_UNWINDER;LIBCXXABI_ENABLE_SHARED" OFF)
+
 option(LIBCXXABI_BAREMETAL "Build libc++abi for baremetal targets." OFF)
 # The default terminate handler attempts to demangle uncaught exceptions, which
 # causes extra I/O and demangling code to be pulled in.
diff --git a/libcxxabi/src/CMakeLists.txt b/libcxxabi/src/CMakeLists.txt
index 5a929cff170..75c7e6d92ed 100644
--- a/libcxxabi/src/CMakeLists.txt
+++ b/libcxxabi/src/CMakeLists.txt
@@ -61,19 +61,27 @@ if (LIBCXXABI_USE_LLVM_UNWINDER)
   # Prefer using the in-tree version of libunwind, either shared or static. If
   # none are found fall back to using -lunwind.
   # FIXME: Is it correct to prefer the static version of libunwind?
-  if (NOT LIBCXXABI_ENABLE_STATIC_UNWINDER AND (TARGET unwind_shared OR HAVE_LIBUNWIND))
-    list(APPEND LIBCXXABI_LIBRARIES unwind_shared)
-  elseif (LIBCXXABI_ENABLE_STATIC_UNWINDER AND (TARGET unwind_static OR HAVE_LIBUNWIND))
-    list(APPEND LIBCXXABI_LIBRARIES unwind_static)
+  if (NOT LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY AND (TARGET unwind_shared OR HAVE_LIBUNWIND))
+    list(APPEND LIBCXXABI_SHARED_LIBRARIES unwind_shared)
+  elseif (LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY AND (TARGET unwind_static OR HAVE_LIBUNWIND))
+    list(APPEND LIBCXXABI_SHARED_LIBRARIES unwind_static)
   else()
-    list(APPEND LIBCXXABI_LIBRARIES unwind)
+    list(APPEND LIBCXXABI_SHARED_LIBRARIES unwind)
+  endif()
+  if (NOT LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY AND (TARGET unwind_shared OR HAVE_LIBUNWIND))
+    list(APPEND LIBCXXABI_STATIC_LIBRARIES unwind_shared)
+  elseif (LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY AND (TARGET unwind_static OR HAVE_LIBUNWIND))
+      # We handle this by directly merging libunwind objects into libc++abi.
+  else()
+    list(APPEND LIBCXXABI_STATIC_LIBRARIES unwind)
   endif()
 else()
   add_library_flags_if(LIBCXXABI_HAS_GCC_S_LIB gcc_s)
 endif()
 if (MINGW)
   # MINGW_LIBRARIES is defined in config-ix.cmake
-  list(APPEND LIBCXXABI_LIBRARIES ${MINGW_LIBRARIES})
+  list(APPEND LIBCXXABI_SHARED_LIBRARIES ${MINGW_LIBRARIES})
+  list(APPEND LIBCXXABI_STATIC_LIBRARIES ${MINGW_LIBRARIES})
 endif()
 
 # Setup flags.
@@ -130,7 +138,7 @@ if (LIBCXXABI_ENABLE_SHARED)
   if(COMMAND llvm_setup_rpath)
     llvm_setup_rpath(cxxabi_shared)
   endif()
-  target_link_libraries(cxxabi_shared ${LIBCXXABI_LIBRARIES})
+  target_link_libraries(cxxabi_shared ${LIBCXXABI_SHARED_LIBRARIES})
   set_target_properties(cxxabi_shared
                         PROPERTIES
                           CXX_EXTENSIONS
@@ -155,13 +163,13 @@ endif()
 # Build the static library.
 if (LIBCXXABI_ENABLE_STATIC)
   set(cxxabi_static_sources $<TARGET_OBJECTS:cxxabi_objects>)
-  if (LIBCXXABI_USE_LLVM_UNWINDER AND LIBCXXABI_ENABLE_STATIC_UNWINDER)
+  if (LIBCXXABI_USE_LLVM_UNWINDER AND LIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY)
     if (TARGET unwind_static OR HAVE_LIBUNWIND)
       list(APPEND cxxabi_static_sources $<TARGET_OBJECTS:unwind_objects>)
     endif()
   endif()
   add_library(cxxabi_static STATIC ${cxxabi_static_sources})
-  target_link_libraries(cxxabi_static ${LIBCXXABI_LIBRARIES})
+  target_link_libraries(cxxabi_static ${LIBCXXABI_STATIC_LIBRARIES})
   set_target_properties(cxxabi_static
                         PROPERTIES
                           CXX_EXTENSIONS