Move googletest to the third-party directory

[tstellar]

Summary

This will help improve the project's layering, so that sub-projects
that don't actually need any llvm code can still use googletest
without having to reference code in the llvm directory.

This will also make it easier to consolidate and simplify the standalone
build configurations.

[lattner]

I didn't review the patch in detail, but +1 this is a great step forward to reorganize the repo!

[phosek]

LGTM

[stellaraccident]

llvm/cmake/modules/HandleLLVMOptions.cmake

1264

Is the implication that this file should only ever be included by top-level sub-projects (i.e. clang, mlir, llvm, etc)? If included from elsewhere, it seems like it won't do the right thing.

Also, having this as a cache entry is going to make it harder for out of tree projects to define it reliably (requiring various FORCE heroics) -- but I know why you are doing it if trying to define it here.

As is, this file is included from most of the top-levels and making it a cache variable will have them racing to set it. Why not make it a regular variable? And why not derive it from LLVM_MAIN_SRC_DIR?

[tstellar]

llvm/cmake/modules/HandleLLVMOptions.cmake

1264

I put it in this file so that this variable would be available for stand-alone builds and made it a cache variable so it could be overridden by standalone builds too.

The alternative would be to define this variable in llvm/CMakeLists.txt and then in the stand-alone build handling for each sub-project. It's a lot of code duplication that way, but we already have a lot of similar duplication in the CMakeLists.txt today (this is something I would like to clean up in the future).

Using LLVM_MAIN_SRC_DIR here breaks stand-alone builds, because LLVM_MAIN_SRC_DIR expands to ../llvm/../, so if I try to build lld, with a directory layout of:

lld/ cmake/ third-party/

Then CMake won't be able to find the third-party/ directory even though it is in the right place (because llvm/ is missing). I also think in general, it's cleaner to only use LLVM_MAIN_SRC_DIR when we want to use files in llvm/ and not for finding the root of the monorepo.

[stellaraccident]

llvm/cmake/modules/HandleLLVMOptions.cmake

1264

Thanks - I think I understand why you are doing it this way. I'm just trying to think of a way that has fewer thorns... And not being successful (without major surgery on the way this cmake setup is layered). I'm fine with how you have it.

[tstellar]

Rebase.

[probinson]

clang/CMakeLists.txt

118

Should this be third-party/unittest ? Looking at how the lldb cmake files were modified.

lld/CMakeLists.txt

75

See comment for clang/CMakeLists.txt

mlir/CMakeLists.txt

30

See comment for clang/CMakeLists.txt

polly/CMakeLists.txt

34

See comment for clang/CMakeLists.txt

[Meinersbur]

Semi-OT: polly\lib\External has 3 more third-party libraries. Two of them have been heavily modified in-tree, the third has just a custom CMakeLists.txt.
Should these eventually also be moved?

[probinson]

In D131919#3749850, @Meinersbur wrote:

Semi-OT: polly\lib\External has 3 more third-party libraries. Two of them have been heavily modified in-tree, the third has just a custom CMakeLists.txt.
Should these eventually also be moved?

I don't know that there's a formal policy. Our copy of googletest is used by several projects, so unhooking it from the llvm tree has value in that regard.
Heavy modification might not be a blocker; googletest is somewhat stripped-down, although otherwise I think only lightly modified.

[tstellar]

Rebase and fix some missed path updates.

[tstellar]

@probinson Does this latest update look better?

[probinson]

Yes, LGTM

clang/CMakeLists.txt

if(EXISTS ${LLVM_MAIN_SRC_DIR}/utils/lit/lit.py)
       endif()
       if(NOT LLVM_UTILS_PROVIDED)
         add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/FileCheck utils/FileCheck)
         add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/count utils/count)
         add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/not utils/not)
         set(LLVM_UTILS_PROVIDED ON)
         set(CLANG_TEST_DEPS FileCheck count not)
       endif()
-      set(UNITTEST_DIR ${LLVM_MAIN_SRC_DIR}/utils/unittest)
+      set(UNITTEST_DIR ${LLVM_THIRD_PARTY_DIR}/unittest)
       if(EXISTS ${UNITTEST_DIR}/googletest/include/gtest/gtest.h
           AND NOT EXISTS ${LLVM_LIBRARY_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}gtest${CMAKE_STATIC_LIBRARY_SUFFIX}
           AND EXISTS ${UNITTEST_DIR}/CMakeLists.txt)
-        add_subdirectory(${UNITTEST_DIR} utils/unittest)
+        add_subdirectory(${UNITTEST_DIR} third-party/unittest)
       endif()
     endif()
 
     if(LLVM_LIT)
       # Define the default arguments to use with 'lit', and an option for the user
       # to override.
       set(LIT_ARGS_DEFAULT "-sv")
       if (MSVC OR XCODE)
if(NOT EXISTS ${CLANG_ORDER_FILE})
     else()
       message(FATAL_ERROR "Specified order file '${CLANG_ORDER_FILE}' does not exist.")
     endif()
   endif()
 endif()
 
 
 if( CLANG_INCLUDE_TESTS )
-  if(EXISTS ${LLVM_MAIN_SRC_DIR}/utils/unittest/googletest/include/gtest/gtest.h)
+  if(EXISTS ${LLVM_THIRD_PARTY_DIR}/unittest/googletest/include/gtest/gtest.h)
     add_subdirectory(unittests)
     list(APPEND CLANG_TEST_DEPS ClangUnitTests)
     list(APPEND CLANG_TEST_PARAMS
       clang_unit_site_config=${CMAKE_CURRENT_BINARY_DIR}/test/Unit/lit.site.cfg
       )
   endif()
   add_subdirectory(test)
   add_subdirectory(bindings/python/tests)

compiler-rt/CMakeLists.txt

if (SANITIZER_TEST_CXX_LIBNAME STREQUAL "libc++")
   else()
     append_list_if(COMPILER_RT_HAS_LIBCXX -lc++ SANITIZER_TEST_CXX_LIBRARIES)
   endif()
 elseif (SANITIZER_TEST_CXX_LIBNAME STREQUAL "libstdc++")
   append_list_if(COMPILER_RT_HAS_LIBSTDCXX -lstdc++ SANITIZER_TEST_CXX_LIBRARIES)
 endif()
 
 # Unittests support.
-set(COMPILER_RT_GTEST_PATH ${LLVM_MAIN_SRC_DIR}/utils/unittest/googletest)
+set(COMPILER_RT_GTEST_PATH ${LLVM_THIRD_PARTY_DIR}/unittest/googletest)
 set(COMPILER_RT_GTEST_SOURCE ${COMPILER_RT_GTEST_PATH}/src/gtest-all.cc)
 set(COMPILER_RT_GTEST_CFLAGS
   -DGTEST_NO_LLVM_SUPPORT=1
   -DGTEST_HAS_RTTI=0
   -I${COMPILER_RT_GTEST_PATH}/include
   -I${COMPILER_RT_GTEST_PATH}
 )
 
 # Mocking support.
-set(COMPILER_RT_GMOCK_PATH ${LLVM_MAIN_SRC_DIR}/utils/unittest/googlemock)
+set(COMPILER_RT_GMOCK_PATH ${LLVM_THIRD_PATY_DIR}/unittest/googlemock)
 set(COMPILER_RT_GMOCK_SOURCE ${COMPILER_RT_GMOCK_PATH}/src/gmock-all.cc)
 set(COMPILER_RT_GMOCK_CFLAGS
   -DGTEST_NO_LLVM_SUPPORT=1
   -DGTEST_HAS_RTTI=0
   -I${COMPILER_RT_GMOCK_PATH}/include
   -I${COMPILER_RT_GMOCK_PATH}
 )
 

lld/CMakeLists.txt

if(EXISTS ${LLVM_MAIN_SRC_DIR}/utils/lit/lit.py)
       # Note: path not really used, except for checking if lit was found
       set(LLVM_LIT ${LLVM_MAIN_SRC_DIR}/utils/lit/lit.py)
       if(NOT LLVM_UTILS_PROVIDED)
         add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/FileCheck utils/FileCheck)
         add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/not utils/not)
         set(LLVM_UTILS_PROVIDED ON)
         set(LLD_TEST_DEPS FileCheck not)
       endif()
-      set(UNITTEST_DIR ${LLVM_MAIN_SRC_DIR}/utils/unittest)
+      set(UNITTEST_DIR ${LLVM_THIRD_PARTY_DIR}/unittest)
       if(EXISTS ${UNITTEST_DIR}/googletest/include/gtest/gtest.h
           AND NOT EXISTS ${LLVM_LIBRARY_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}gtest${CMAKE_STATIC_LIBRARY_SUFFIX}
           AND EXISTS ${UNITTEST_DIR}/CMakeLists.txt)
-        add_subdirectory(${UNITTEST_DIR} utils/unittest)
+        add_subdirectory(${UNITTEST_DIR} third-party/unittest)
       endif()
     else()
       # Seek installed Lit.
       find_program(LLVM_LIT
                    NAMES llvm-lit lit.py lit
                    PATHS "${LLVM_MAIN_SRC_DIR}/utils/lit"
                    DOC "Path to lit.py")
     endif()

lldb/cmake/modules/LLDBStandalone.cmake

 include_directories(
   "${CMAKE_BINARY_DIR}/include"
   "${LLVM_INCLUDE_DIRS}"
   "${CLANG_INCLUDE_DIRS}")
 
 if(LLDB_INCLUDE_TESTS)
   # Build the gtest library needed for unittests, if we have LLVM sources
   # handy.
-  if (EXISTS ${LLVM_MAIN_SRC_DIR}/utils/unittest AND NOT TARGET llvm_gtest)
-    add_subdirectory(${LLVM_MAIN_SRC_DIR}/utils/unittest utils/unittest)
+  if (EXISTS ${LLVM_THIRD_PARTY_DIR}/unittest AND NOT TARGET llvm_gtest)
+    add_subdirectory(${LLVM_THIRD_PARTY_DIR}}/utils/unittest third-party/unittest)
   endif()
   # LLVMTestingSupport library is needed for Process/gdb-remote.
   if (EXISTS ${LLVM_MAIN_SRC_DIR}/lib/Testing/Support
       AND NOT TARGET LLVMTestingSupport)
     add_subdirectory(${LLVM_MAIN_SRC_DIR}/lib/Testing/Support
       lib/Testing/Support)
   endif()
 endif()

llvm/CMakeLists.txt

 
 # Each of them corresponds to llvm-config's.
 set(LLVM_TOOLS_BINARY_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR}) # --bindir
 set(LLVM_LIBRARY_DIR      ${LLVM_LIBRARY_OUTPUT_INTDIR}) # --libdir
 set(LLVM_MAIN_SRC_DIR     ${CMAKE_CURRENT_SOURCE_DIR}  ) # --src-root
 set(LLVM_MAIN_INCLUDE_DIR ${LLVM_MAIN_SRC_DIR}/include ) # --includedir
 set(LLVM_BINARY_DIR       ${CMAKE_CURRENT_BINARY_DIR}  ) # --prefix
 
-set(LLVM_THIRD_PARTY_DIR  ${CMAKE_CURRENT_SOURCE_DIR}/../third-party)
 
 # Note: LLVM_CMAKE_DIR does not include generated files
 set(LLVM_CMAKE_DIR ${LLVM_MAIN_SRC_DIR}/cmake/modules)
 set(LLVM_EXAMPLES_BINARY_DIR ${LLVM_BINARY_DIR}/examples)
 set(LLVM_INCLUDE_DIR ${CMAKE_CURRENT_BINARY_DIR}/include)
 
 # List of all targets to be built by default:
 set(LLVM_ALL_TARGETS
if( LLVM_INCLUDE_UTILS )
   add_subdirectory(utils/FileCheck)
   add_subdirectory(utils/PerfectShuffle)
   add_subdirectory(utils/count)
   add_subdirectory(utils/not)
   add_subdirectory(utils/UnicodeData)
   add_subdirectory(utils/yaml-bench)
   add_subdirectory(utils/split-file)
   if( LLVM_INCLUDE_TESTS )
-    add_subdirectory(utils/unittest)
+    add_subdirectory(${LLVM_THIRD_PARTY_DIR}/unittest ${CMAKE_CURRENT_BINARY_DIR}/third-party/unittest)
   endif()
 else()
   if ( LLVM_INCLUDE_TESTS )
     message(FATAL_ERROR "Including tests when not building utils will not work.
     Either set LLVM_INCLUDE_UTILS to On, or set LLVM_INCLUDE_TESTS to Off.")
   endif()
 endif()
 

llvm/cmake/modules/HandleLLVMOptions.cmake

if(LLVM_USE_RELATIVE_PATHS_IN_FILES)
   else()
     set(source_root "${LLVM_MAIN_SRC_DIR}")
   endif()
   file(RELATIVE_PATH relative_root "${source_root}" "${CMAKE_BINARY_DIR}")
   append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${CMAKE_BINARY_DIR}=${relative_root}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   append_if(SUPPORTS_FFILE_PREFIX_MAP "-ffile-prefix-map=${source_root}/=${LLVM_SOURCE_PREFIX}" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   add_flag_if_supported("-no-canonical-prefixes" NO_CANONICAL_PREFIXES)
 endif()
+
+set(LLVM_THIRD_PARTY_DIR  ${CMAKE_CURRENT_SOURCE_DIR}/../third-party CACHE STRING
+    "Directory containing third party software used by LLVM (e.g. googletest)")

mlir/CMakeLists.txt

if(MLIR_STANDALONE_BUILD)
   find_package(LLVM CONFIG REQUIRED)
   set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${LLVM_CMAKE_DIR})
   include(HandleLLVMOptions)
   include(AddLLVM)
   include(TableGen)
 
   include_directories(${LLVM_INCLUDE_DIRS})
 
-  set(LLVM_MAIN_SRC_DIR ${CMAKE_SOURCE_DIR}/../llvm CACHE PATH
-      "Path to LLVM source tree")
-  set(UNITTEST_DIR ${LLVM_MAIN_SRC_DIR}/utils/unittest)
+  set(UNITTEST_DIR ${LLVM_THIRD_PARTY_DIR}/unittest)
   if(EXISTS ${UNITTEST_DIR}/googletest/include/gtest/gtest.h)
-    add_subdirectory(${UNITTEST_DIR} utils/unittest)
+    add_subdirectory(${UNITTEST_DIR} third-party/unittest)
   endif()
 
   set(CMAKE_LIBRARY_OUTPUT_DIRECTORY
     "${CMAKE_CURRENT_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}")
   set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin")
 
   set(LLVM_LIT_ARGS "-sv" CACHE STRING "Default options for lit")
 endif()

 add_subdirectory(include/mlir)
 add_subdirectory(lib)
 # C API needs all dialects for registration, but should be built before tests.
 add_subdirectory(lib/CAPI)
 
 if (MLIR_INCLUDE_TESTS)
   add_definitions(-DMLIR_INCLUDE_TESTS)
   add_custom_target(MLIRUnitTests)
-  if (EXISTS ${LLVM_MAIN_SRC_DIR}/utils/unittest/googletest/include/gtest/gtest.h)
+  if (EXISTS ${LLVM_THIRD_PARTY_DIR}/unittest/googletest/include/gtest/gtest.h)
     add_subdirectory(unittests)
   else()
     message(WARNING "gtest not found, unittests will not be available")
   endif()
   add_subdirectory(test)
 endif()
 # Tools needs to come late to ensure that MLIR_ALL_LIBS is populated.
 # Generally things after this point may depend on MLIR_ALL_LIBS or libMLIR.so.

polly/CMakeLists.txt

if (LLVM_BUILD_MAIN_SRC_DIR)
     set(default_llvm_src "${LLVM_BUILD_MAIN_SRC_DIR}")
   else()
     set(default_llvm_src "${CMAKE_CURRENT_SOURCE_DIR}/../llvm")
   endif()
   set(LLVM_SOURCE_ROOT ${default_llvm_src} CACHE PATH "Path to LLVM source tree")
 
   # Enable unit tests if available.
   set(POLLY_GTEST_AVAIL 0)
-  set(UNITTEST_DIR ${LLVM_SOURCE_ROOT}/utils/unittest)
+  set(UNITTEST_DIR ${LLVM_THIRD_PARTY_DIR}/unittest)
   if(EXISTS ${UNITTEST_DIR}/googletest/include/gtest/gtest.h)
     if (NOT TARGET gtest)
-      add_subdirectory(${UNITTEST_DIR} utils/unittest)
+      add_subdirectory(${UNITTEST_DIR} third-party/unittest)
     endif()
     set(POLLY_GTEST_AVAIL 1)
   endif()
 
   if (LLVM_ENABLE_PIC)
     # Make sure the isl c files are built as fPIC if possible
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
   endif ()