[CMake][compiler-rt] Enable statically linking unwinder and c++abi

[phosek]

Summary

Rather than guessing whether to use static or shared version of
unwinder and c++abi when using linking against the in-tree versions,
provide a CMake option to control this.

[mcgrathr]

lgtm

CMakeLists.txt

else()
     set(SANITIZER_CXX_ABI_LIBNAME "libstdc++")
     set(SANITIZER_CXX_ABI_SYSTEM 1)
   endif()
 else()
   set(SANITIZER_CXX_ABI_LIBNAME "${SANITIZER_CXX_ABI}")
   set(SANITIZER_CXX_ABI_SYSTEM 1)
 endif()
 
+set(DEFAULT_SANITIZER_USE_STATIC_LLVM_UNWINDER OFF)
+if (FUCHSIA)
+  set(DEFAULT_SANITIZER_USE_STATIC_LLVM_UNWINDER ON)
+elseif (DEFINED LIBUNWIND_ENABLE_SHARED AND NOT LIBUNWIND_ENABLE_SHARED)
+  set(DEFAULT_SANITIZER_USE_STATIC_LLVM_UNWINDER ON)
+endif()
+
+option(SANITIZER_USE_STATIC_LLVM_UNWINDER
+  "Use static LLVM unwinder." ${DEFAULT_SANITIZER_USE_STATIC_LLVM_UNWINDER})
+
+set(DEFAULT_SANITIZER_USE_STATIC_CXX_ABI OFF)
+if (DEFINED LIBCXXABI_ENABLE_SHARED AND NOT LIBCXXABI_ENABLE_SHARED)
+  set(DEFAULT_SANITIZER_USE_STATIC_CXX_ABI ON)
+endif()
+
+option(SANITIZER_USE_STATIC_CXX_ABI
+  "Use static libc++abi." ${DEFAULT_SANITIZER_USE_STATIC_CXX_ABI})
+
 set(DEFAULT_COMPILER_RT_USE_BUILTINS_LIBRARY OFF)
 if (FUCHSIA)
   set(DEFAULT_COMPILER_RT_USE_BUILTINS_LIBRARY ON)
 endif()
 
 option(COMPILER_RT_USE_BUILTINS_LIBRARY
   "Use compiler-rt builtins instead of libgcc" ${DEFAULT_COMPILER_RT_USE_BUILTINS_LIBRARY})
 

 
 if("${CMAKE_SYSTEM_NAME}" STREQUAL "Fuchsia")
   list(APPEND SANITIZER_COMMON_LINK_FLAGS -Wl,-z,defs,-z,now,-z,relro)
   list(APPEND SANITIZER_COMMON_LINK_LIBS zircon)
 endif()
 
 if (SANITIZER_CXX_ABI_LIBNAME STREQUAL "libc++")
   if (SANITIZER_CXX_ABI_INTREE)
-    if (NOT LIBCXXABI_ENABLE_STATIC_UNWINDER AND (TARGET unwind_shared OR HAVE_LIBUNWIND))
-      list(APPEND SANITIZER_CXX_ABI_LIBRARY unwind_shared)
-    elseif (LIBCXXABI_ENABLE_STATIC_UNWINDER AND (TARGET unwind_static OR HAVE_LIBUNWIND))
+    if (SANITIZER_USE_STATIC_LLVM_UNWINDER AND (TARGET unwind_static OR HAVE_LIBUNWIND))
       list(APPEND SANITIZER_CXX_ABI_LIBRARY unwind_static)
+    elseif (TARGET unwind_shared OR HAVE_LIBUNWIND)
+      list(APPEND SANITIZER_CXX_ABI_LIBRARY unwind_shared)
     endif()
-    if (NOT LIBCXX_ENABLE_STATIC_ABI_LIBRARY AND (TARGET cxxabi_shared OR HAVE_LIBCXXABI))
-      list(APPEND SANITIZER_CXX_ABI_LIBRARY cxxabi_shared)
-    elseif (LIBCXX_ENABLE_STATIC_ABI_LIBRARY AND (TARGET cxxabi_static OR HAVE_LIBCXXABI))
+
+    if (SANITIZER_USE_STATIC_CXX_ABI AND (TARGET cxxabi_static OR HAVE_LIBCXXABI))
       list(APPEND SANITIZER_CXX_ABI_LIBRARY cxxabi_static)
+    elseif (TARGET cxxabi_shared OR HAVE_LIBCXXABI)
+      list(APPEND SANITIZER_CXX_ABI_LIBRARY cxxabi_shared)
     endif()
   else()
     append_list_if(COMPILER_RT_HAS_LIBCXX c++ SANITIZER_CXX_ABI_LIBRARY)
   endif()
 elseif (SANITIZER_CXX_ABI_LIBNAME STREQUAL "libcxxabi")
   list(APPEND SANITIZER_CXX_ABI_LIBRARY "c++abi")
 elseif (SANITIZER_CXX_ABI_LIBNAME STREQUAL "libstdc++")
   append_list_if(COMPILER_RT_HAS_LIBSTDCXX stdc++ SANITIZER_CXX_ABI_LIBRARY)