[libc++][libc++abi][libunwind] Dedup install path var definitions

[Ericson2314]

Summary

In D116873 I did this for libunwind prior to defining a new install path
variable. But I think the change is good on its own, and libc++{,abi}
could also use it.

libc++ needed the base header var defined above the conditional part to
use it for the prefi+ed headers in the non-target-specific case. For
consistency, I therefore put the unconditional ones above for all 3
libs, which is why I touched the libunwind code (seeing that it had the
core change already)

[phosek]

LGTM

libcxx/CMakeLists.txt

 endif ()
 
 #===============================================================================
 # Configure System
 #===============================================================================
 
 # TODO: Projects that depend on libc++ should use LIBCXX_GENERATED_INCLUDE_DIR
 # instead of hard-coding include/c++/v1.
+
+set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
+    "Path where target-agnostic libc++ headers should be installed.")
+set(LIBCXX_INSTALL_RUNTIME_DIR bin CACHE PATH
+    "Path where built libc++ runtime libraries should be installed.")
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
   set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LLVM_BINARY_DIR}/include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1")
   set(LIBCXX_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
       "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_RUNTIME_DIR bin CACHE PATH
-      "Path where built libc++ runtime libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
-      "Path where target-agnostic libc++ headers should be installed.")
   set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "include/${LLVM_DEFAULT_TARGET_TRIPLE}/c++/v1" CACHE PATH
       "Path where target-specific libc++ headers should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXX_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
     string(APPEND LIBCXX_INSTALL_LIBRARY_DIR /${LIBCXX_LIBDIR_SUBDIR})
   endif()
-elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+else()
+  if(LLVM_LIBRARY_OUTPUT_INTDIR)
     set(LIBCXX_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
     set(LIBCXX_GENERATED_INCLUDE_DIR "${LLVM_BINARY_DIR}/include/c++/v1")
-  set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LIBCXX_GENERATED_INCLUDE_DIR}")
-  set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
-      "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_RUNTIME_DIR bin CACHE PATH
-      "Path where built libc++ runtime libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
-      "Path where target-agnostic libc++ headers should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${LIBCXX_INSTALL_INCLUDE_DIR}" CACHE PATH
-      "Path where target-specific libc++ headers should be installed.")
   else()
     set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
     set(LIBCXX_GENERATED_INCLUDE_DIR "${CMAKE_BINARY_DIR}/include/c++/v1")
+  endif()
   set(LIBCXX_GENERATED_INCLUDE_TARGET_DIR "${LIBCXX_GENERATED_INCLUDE_DIR}")
   set(LIBCXX_INSTALL_LIBRARY_DIR lib${LIBCXX_LIBDIR_SUFFIX} CACHE PATH
       "Path where built libc++ libraries should be installed.")
-  set(LIBCXX_INSTALL_RUNTIME_DIR bin CACHE PATH
-      "Path where built libc++ runtime libraries should be installed.")
-  set(LIBCXX_INSTALL_INCLUDE_DIR "include/c++/v1" CACHE PATH
-      "Path where target-agnostic libc++ headers should be installed.")
   set(LIBCXX_INSTALL_INCLUDE_TARGET_DIR "${LIBCXX_INSTALL_INCLUDE_DIR}" CACHE PATH
       "Path where target-specific libc++ headers should be installed.")
 endif()
 
 file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})

libcxxabi/CMakeLists.txt

 
 # Add path for custom modules
 set(CMAKE_MODULE_PATH
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
   ${CMAKE_MODULE_PATH}
   )
 
+set(LIBCXXABI_INSTALL_RUNTIME_DIR bin CACHE PATH
+    "Path where built libc++abi runtime libraries should be installed.")
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
   set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
   set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
       "Path where built libc++abi libraries should be installed.")
-  set(LIBCXXABI_INSTALL_RUNTIME_DIR bin CACHE PATH
-      "Path where built libc++abi runtime libraries should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBCXXABI_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
     string(APPEND LIBCXXABI_INSTALL_LIBRARY_DIR /${LIBCXXABI_LIBDIR_SUBDIR})
   endif()
-elseif(LLVM_LIBRARY_OUTPUT_INTDIR)
+else()
+  if(LLVM_LIBRARY_OUTPUT_INTDIR)
     set(LIBCXXABI_HEADER_DIR ${LLVM_BINARY_DIR})
     set(LIBCXXABI_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
-  set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
-      "Path where built libc++abi libraries should be installed.")
-  set(LIBCXXABI_INSTALL_RUNTIME_DIR bin CACHE PATH
-      "Path where built libc++abi runtime libraries should be installed.")
   else()
     set(LIBCXXABI_HEADER_DIR ${CMAKE_BINARY_DIR})
     set(LIBCXXABI_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXXABI_LIBDIR_SUFFIX})
+  endif()
   set(LIBCXXABI_INSTALL_LIBRARY_DIR lib${LIBCXXABI_LIBDIR_SUFFIX} CACHE PATH
       "Path where built libc++abi libraries should be installed.")
-  set(LIBCXXABI_INSTALL_RUNTIME_DIR bin CACHE PATH
-      "Path where built libc++abi runtime libraries should be installed.")
 endif()
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBCXXABI_LIBRARY_DIR})
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBCXXABI_LIBRARY_DIR})
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${LIBCXXABI_LIBRARY_DIR})
 
 # By default, for non-standalone builds, libcxx and libcxxabi share a library
 # directory.

libunwind/CMakeLists.txt

 # Configure System
 #===============================================================================
 
 # Add path for custom modules
 set(CMAKE_MODULE_PATH
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
     ${CMAKE_MODULE_PATH})
 
+set(LIBUNWIND_INSTALL_INCLUDE_DIR include CACHE PATH
+    "Path where built libunwind headers should be installed.")
+set(LIBUNWIND_INSTALL_RUNTIME_DIR bin CACHE PATH
+    "Path where built libunwind runtime libraries should be installed.")
+
 if(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR AND NOT APPLE)
   set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/${LLVM_DEFAULT_TARGET_TRIPLE})
   set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LLVM_LIBDIR_SUFFIX}/${LLVM_DEFAULT_TARGET_TRIPLE} CACHE PATH
       "Path where built libunwind libraries should be installed.")
   if(LIBCXX_LIBDIR_SUBDIR)
     string(APPEND LIBUNWIND_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
     string(APPEND LIBUNWIND_INSTALL_LIBRARY_DIR /${LIBUNWIND_LIBDIR_SUBDIR})
   endif()
 else()
   if(LLVM_LIBRARY_OUTPUT_INTDIR)
     set(LIBUNWIND_LIBRARY_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR})
   else()
     set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBUNWIND_LIBDIR_SUFFIX})
   endif()
   set(LIBUNWIND_INSTALL_LIBRARY_DIR lib${LIBUNWIND_LIBDIR_SUFFIX} CACHE PATH
       "Path where built libunwind libraries should be installed.")
 endif()
 
-set(LIBUNWIND_INSTALL_INCLUDE_DIR include CACHE PATH
-    "Path where built libunwind headers should be installed.")
-set(LIBUNWIND_INSTALL_RUNTIME_DIR bin CACHE PATH
-    "Path where built libunwind runtime libraries should be installed.")
-
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${LIBUNWIND_LIBRARY_DIR})
 
 set(LIBUNWIND_C_FLAGS "")
 set(LIBUNWIND_CXX_FLAGS "")
 set(LIBUNWIND_COMPILE_FLAGS "")
 set(LIBUNWIND_LINK_FLAGS "")