[CMake] Use `LLVM_COMMON_CMAKE_UTILS` in runtimes just for clarity

[Ericson2314]

Summary

In D116472 we created conditionally defined variables for the tools to
unbreak the legacy build where they are in llvm/tools.

The runtimes are not tools, so that flexibility doesn't matter. Still,
it might be nice to define (unconditionally) and use the variable for
the runtimes simply to make the code a bit clearer and document what is
going on.

Also, consistently put project dirs at the beginning, not end of CMAKE_MODULE_PATH. This ensures they will properly shadow similarly named stuff that happens to be later on the path.

[mstorsjo]

Looks sensible overall, modulo the typo.

compiler-rt/lib/builtins/CMakeLists.txt

13

Stray }, missing a space?

libcxx/CMakeLists.txt

16

I presume this is fine (even if slightly unrelated) - I see that this aspect is inconsistent between runtimes today. It could be good to mention this in the commit message in any case.

[Ericson2314]

1. Updating D116477: Use LLVM_COMMON_CMAKE_UTILS in runtimes just for clarity #
2. Enter a brief description of the changes included in this update.
3. The first line is used as subject, next lines as comment. #
4. If you intended to create a new revision, use:
5. $ arc diff --create

Fix typo

[Ericson2314]

compiler-rt/lib/builtins/CMakeLists.txt

13

Oops! Sorry that got through

libcxx/CMakeLists.txt

16

Included now, with motivation.

[mstorsjo]

libcxxabi/CMakeLists.txt

20

This has a duplicate /cmake (not present in the other ones). I presume the libcxx precommit CI will tell you that in an hour too...

Other than that, it does seem to build fine in my setup.

[mstorsjo]

compiler-rt/CMakeLists.txt

15

This one has CACHE PATH in here while the other ones don't. (And this seems to break the build.)

[Ericson2314]

Fix issues

[mstorsjo]

Seems to work fine for me now, but I guess it still requires approval from some of the libcxx approvers.

(It might be nice to add a [CMake] prefix on the commit subject line though.)

[ldionne]

LGTM with a suggestion.

libcxx/CMakeLists.txt

13–16

If you agree, you should also make the change in the other projects.

[Ericson2314]

libcxx/CMakeLists.txt

13–16

If I did that, I would want to also get the tools which do the similar thing but with the current syle, so I think I will save that for D116524.

compiler-rt/CMakeLists.txt

 # CMake build for CompilerRT.
 #
 # An important constraint of the build is that it only produces libraries
 # based on the ability of the host toolchain to target various platforms.
 
 cmake_minimum_required(VERSION 3.13.4)
 
 # Check if compiler-rt is built as a standalone project.
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR COMPILER_RT_STANDALONE_BUILD)
   project(CompilerRT C CXX ASM)
   set(COMPILER_RT_STANDALONE_BUILD TRUE)
   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 endif()
 
+set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
+
 # Add path for custom compiler-rt modules.
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
+  "${LLVM_COMMON_CMAKE_UTILS}"
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 if(CMAKE_CONFIGURATION_TYPES)
   set(CMAKE_CFG_RESOLVED_INTDIR "${CMAKE_CFG_INTDIR}/")
 else()
   set(CMAKE_CFG_RESOLVED_INTDIR "")
 endif()
 

compiler-rt/lib/builtins/CMakeLists.txt

 # This directory contains a large amount of C code which provides
 # generic implementations of the core runtime library along with optimized
 # architecture-specific code in various subdirectories.
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   cmake_minimum_required(VERSION 3.13.4)
 
   set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
   project(CompilerRTBuiltins C ASM)
   set(COMPILER_RT_STANDALONE_BUILD TRUE)
   set(COMPILER_RT_BUILTINS_STANDALONE_BUILD TRUE)
+
+  set(COMPILER_RT_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../..")
+
+  set(LLVM_COMMON_CMAKE_UTILS "${COMPILER_RT_SOURCE_DIR}/../cmake")
+
+  # Add path for custom modules
   list(INSERT CMAKE_MODULE_PATH 0
-    "${CMAKE_SOURCE_DIR}/../../cmake"
-    "${CMAKE_SOURCE_DIR}/../../cmake/Modules"
-    "${CMAKE_SOURCE_DIR}/../../../cmake"
-    "${CMAKE_SOURCE_DIR}/../../../cmake/Modules")
+    "${COMPILER_RT_SOURCE_DIR}/cmake"
+    "${COMPILER_RT_SOURCE_DIR}/cmake/Modules"
+    "${LLVM_COMMON_CMAKE_UTILS}"
+    "${LLVM_COMMON_CMAKE_UTILS}/Modules"
+    )
+
   include(base-config-ix)
   include(CompilerRTUtils)
 
   load_llvm_config()
   construct_compiler_rt_default_triple()
 
   if(APPLE)
     include(CompilerRTDarwinUtils)

libcxx/CMakeLists.txt

 # See https://libcxx.llvm.org/docs/BuildingLibcxx.html for instructions on how
 # to build libcxx with CMake.
 
 if (NOT IS_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}/../libcxxabi")
   message(FATAL_ERROR "libc++ now requires being built in a monorepo layout with libcxxabi available")
 endif()
 
 #===============================================================================
 # Setup Project
 #===============================================================================
 cmake_minimum_required(VERSION 3.13.4)
 
+set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
+
 # Add path for custom modules
-set(CMAKE_MODULE_PATH
+list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
-  ${CMAKE_MODULE_PATH}
+  "${LLVM_COMMON_CMAKE_UTILS}"
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 set(CMAKE_FOLDER "libc++")
 
 set(LIBCXX_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
 set(LIBCXX_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
 set(LIBCXX_BINARY_INCLUDE_DIR "${LIBCXX_BINARY_DIR}/include/c++build")
 

libcxxabi/CMakeLists.txt

 # See www/CMake.html for instructions on how to build libcxxabi with CMake.
 
 if (NOT IS_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}/../libcxx")
   message(FATAL_ERROR "libc++abi now requires being built in a monorepo layout with libcxx available")
 endif()
 
 #===============================================================================
 # Setup Project
 #===============================================================================
 
 cmake_minimum_required(VERSION 3.13.4)
 
+set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
+
 # Add path for custom modules
-set(CMAKE_MODULE_PATH
+list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
-  ${CMAKE_MODULE_PATH}
+  "${LLVM_COMMON_CMAKE_UTILS}"
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 set(CMAKE_FOLDER "libc++")
 
 set(LIBCXXABI_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
 set(LIBCXXABI_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
 set(LIBCXXABI_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
         "Specify path to libc++ source.")

libunwind/CMakeLists.txt

 if (NOT IS_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}/../libcxx")
   message(FATAL_ERROR "libunwind requires being built in a monorepo layout with libcxx available")
 endif()
 
 #===============================================================================
 # Setup Project
 #===============================================================================
 
 cmake_minimum_required(VERSION 3.13.4)
 
+set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
+
 # Add path for custom modules
-set(CMAKE_MODULE_PATH
+list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
-  ${CMAKE_MODULE_PATH}
+  "${LLVM_COMMON_CMAKE_UTILS}"
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   )
 
 set(LIBUNWIND_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
 set(LIBUNWIND_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
 set(LIBUNWIND_LIBCXX_PATH "${CMAKE_CURRENT_LIST_DIR}/../libcxx" CACHE PATH
         "Specify path to libc++ source.")
 
 if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR OR LIBUNWIND_STANDALONE_BUILD)

runtimes/CMakeLists.txt

 
 function(runtime_register_component name)
   set_property(GLOBAL APPEND PROPERTY SUB_COMPONENTS ${name})
 endfunction()
 
 find_package(LLVM PATHS "${LLVM_BINARY_DIR}" NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
 find_package(Clang PATHS "${LLVM_BINARY_DIR}" NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
 
+set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
+
 # Add path for custom and the LLVM build's modules to the CMake module path.
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
+  "${LLVM_COMMON_CMAKE_UTILS}"
+  "${LLVM_COMMON_CMAKE_UTILS}/Modules"
   "${CMAKE_CURRENT_SOURCE_DIR}/../llvm/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/../llvm/cmake/modules"
 )
 
 set(LLVM_THIRD_PARTY_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../third-party")
 
 function(get_compiler_rt_path path)
   foreach(entry ${runtimes})