[libunwind] Refactor CMake flag checks to match libc++ and libc++abi

libunwind was using its own set of macros/functions for flag checking
which was similar but different from libc++ and libc++abi. This made
it difficult to replicate the same checks across projects, in fact
there were some checks that appear to have been copy & pasted from
another project and that were broken in the standalone libunwind build.
This change refactors flag checks to match libc++ and libc++abi using
a copy of HandleLibunwindFlags.cmake which is derived from the versions
used by the other projects. This also paves a road to deduplicating and
unifying HandleLibunwindFlags.cmake, HandleLibcxxabiFlags.cmake and
HandleLibcxxFlags.cmake post monorepo switch.

Differential Revision: https://reviews.llvm.org/D68855

llvm-svn: 374606

1 files changed, 49 insertions, 36 deletions

diff --git a/libunwind/src/CMakeLists.txt b/libunwind/src/CMakeLists.txt
index 572c82396bf..0b2a830b2ca 100644
--- a/libunwind/src/CMakeLists.txt
+++ b/libunwind/src/CMakeLists.txt
@@ -5,7 +5,11 @@ set(LIBUNWIND_CXX_SOURCES
     Unwind-EHABI.cpp
     Unwind-seh.cpp
     )
-unwind_append_if(LIBUNWIND_CXX_SOURCES APPLE Unwind_AppleExtras.cpp)
+if(APPLE)
+  list(APPEND LIBUNWIND_CXX_SOURCES
+    Unwind_AppleExtras.cpp
+    )
+endif()
 
 set(LIBUNWIND_C_SOURCES
     UnwindLevel1.c
@@ -39,10 +43,11 @@ set(LIBUNWIND_HEADERS
     ../include/libunwind.h
     ../include/unwind.h
     )
-
-unwind_append_if(LIBUNWIND_HEADERS APPLE
+if(APPLE)
+  list(APPEND LIBUNWIND_HEADERS
     ../include/mach-o/compact_unwind_encoding.h
     )
+endif()
 
 if (MSVC_IDE)
   # Force them all into the headers dir on MSVC, otherwise they end up at
@@ -56,32 +61,28 @@ set(LIBUNWIND_SOURCES
     ${LIBUNWIND_ASM_SOURCES})
 
 # Generate library list.
-set(libraries)
-unwind_append_if(libraries LIBUNWIND_HAS_C_LIB c)
+add_library_flags_if(LIBUNWIND_HAS_C_LIB c)
 if (LIBUNWIND_USE_COMPILER_RT)
-  list(APPEND libraries "${LIBUNWIND_BUILTINS_LIBRARY}")
+  add_library_flags("${LIBUNWIND_BUILTINS_LIBRARY}")
 else()
-  unwind_append_if(libraries LIBUNWIND_HAS_GCC_S_LIB gcc_s)
-  unwind_append_if(libraries LIBUNWIND_HAS_GCC_LIB gcc)
+  add_library_flags_if(LIBUNWIND_HAS_GCC_S_LIB gcc_s)
+  add_library_flags_if(LIBUNWIND_HAS_GCC_LIB gcc)
 endif()
-unwind_append_if(libraries LIBUNWIND_HAS_DL_LIB dl)
+add_library_flags_if(LIBUNWIND_HAS_DL_LIB dl)
 if (LIBUNWIND_ENABLE_THREADS)
-  unwind_append_if(libraries LIBUNWIND_HAS_PTHREAD_LIB pthread)
-  unwind_append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_WEAK_PTHREAD_LIB -DLIBUNWIND_USE_WEAK_PTHREAD=1)
+  add_library_flags_if(LIBUNWIND_HAS_PTHREAD_LIB pthread)
+  add_compile_flags_if(LIBUNWIND_WEAK_PTHREAD_LIB -DLIBUNWIND_USE_WEAK_PTHREAD=1)
 endif()
 
 # Setup flags.
-unwind_append_if(LIBUNWIND_CXX_FLAGS LIBUNWIND_HAS_NO_RTTI_FLAG -fno-rtti)
-
-unwind_append_if(LIBUNWIND_LINK_FLAGS LIBUNWIND_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
+add_link_flags_if_supported(-nodefaultlibs)
 
 # MINGW_LIBRARIES is defined in config-ix.cmake
-unwind_append_if(libraries MINGW "${MINGW_LIBRARIES}")
+add_library_flags_if(MINGW "${MINGW_LIBRARIES}")
 
-if (LIBUNWIND_HAS_NO_EXCEPTIONS_FLAG AND LIBUNWIND_HAS_FUNWIND_TABLES)
-  list(APPEND LIBUNWIND_COMPILE_FLAGS -fno-exceptions)
-  list(APPEND LIBUNWIND_COMPILE_FLAGS -funwind-tables)
-elseif (LIBUNWIND_ENABLE_SHARED)
+if (LIBUNWIND_ENABLE_SHARED AND
+    NOT (LIBUNWIND_SUPPORTS_FNO_EXCEPTIONS_FLAG AND
+         LIBUNWIND_SUPPORTS_FUNWIND_TABLES_FLAG))
   message(FATAL_ERROR
           "Compiler doesn't support generation of unwind tables if exception "
           "support is disabled.  Building libunwind DSO with runtime dependency "
@@ -89,15 +90,11 @@ elseif (LIBUNWIND_ENABLE_SHARED)
 endif()
 
 if (APPLE)
-  list(APPEND LIBUNWIND_COMPILE_FLAGS "-U__STRICT_ANSI__")
-  list(APPEND LIBUNWIND_LINK_FLAGS
-       "-compatibility_version 1"
-       "-install_name /usr/lib/libunwind.1.dylib")
+  add_compile_flags("-U__STRICT_ANSI__")
+  add_link_flags("-compatibility_version 1" "-install_name /usr/lib/libunwind.1.dylib")
 
   if (CMAKE_OSX_DEPLOYMENT_TARGET STREQUAL "10.6")
-    list(APPEND LIBUNWIND_LINK_FLAGS
-         "-current_version ${LIBUNWIND_VERSION}"
-         "/usr/lib/libSystem.B.dylib")
+    add_link_flags("-current_version ${LIBUNWIND_VERSION}" "/usr/lib/libSystem.B.dylib")
   endif ()
 endif ()
 
@@ -117,14 +114,23 @@ if (LIBUNWIND_ENABLE_SHARED)
   if(COMMAND llvm_setup_rpath)
     llvm_setup_rpath(unwind_shared)
   endif()
-  target_link_libraries(unwind_shared PRIVATE ${libraries})
+  target_link_libraries(unwind_shared PRIVATE ${LIBUNWIND_LIBRARIES})
   set_target_properties(unwind_shared
                         PROPERTIES
-                          COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}"
-                          LINK_FLAGS    "${LIBUNWIND_LINK_FLAGS}"
-                          OUTPUT_NAME   "unwind"
-                          VERSION       "1.0"
-                          SOVERSION     "1")
+                          CXX_STANDARD
+                            11
+                          CXX_STANDARD_REQUIRED
+                            ON
+                          COMPILE_FLAGS
+                            "${LIBUNWIND_COMPILE_FLAGS}"
+                          LINK_FLAGS
+                            "${LIBUNWIND_LINK_FLAGS}"
+                          OUTPUT_NAME
+                            "unwind"
+                          VERSION
+                            "1.0"
+                          SOVERSION
+                            "1")
   list(APPEND LIBUNWIND_BUILD_TARGETS "unwind_shared")
   if (LIBUNWIND_INSTALL_SHARED_LIBRARY)
     list(APPEND LIBUNWIND_INSTALL_TARGETS "unwind_shared")
@@ -134,12 +140,19 @@ endif()
 # Build the static library.
 if (LIBUNWIND_ENABLE_STATIC)
   add_library(unwind_static STATIC ${LIBUNWIND_SOURCES} ${LIBUNWIND_HEADERS})
-  target_link_libraries(unwind_static PRIVATE ${libraries})
+  target_link_libraries(unwind_static PRIVATE ${LIBUNWIND_LIBRARIES})
   set_target_properties(unwind_static
                         PROPERTIES
-                          COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}"
-                          LINK_FLAGS    "${LIBUNWIND_LINK_FLAGS}"
-                          OUTPUT_NAME   "unwind")
+                          CXX_STANDARD
+                            11
+                          CXX_STANDARD_REQUIRED
+                            ON
+                          COMPILE_FLAGS
+                            "${LIBUNWIND_COMPILE_FLAGS}"
+                          LINK_FLAGS
+                            "${LIBUNWIND_LINK_FLAGS}"
+                          OUTPUT_NAME
+                            "unwind")
 
   if(LIBUNWIND_HERMETIC_STATIC_LIBRARY)
     append_flags_if_supported(UNWIND_STATIC_LIBRARY_FLAGS -fvisibility=hidden)