Add install targets for gtest

[tstellar]

Summary

Stand-alone builds need an installed version of gtest in order to run
the unittests.

[mgorny]

I'll try to test this today. I suppose the main idea would be to enable LLVM_INSTALL_GTEST, then stop unpacking third-party directory when building other packages, correct? Perhaps it would make sense to update the checks like the one in clang while doing that:

if( CLANG_INCLUDE_TESTS )
  if(EXISTS ${LLVM_THIRD_PARTY_DIR}/unittest/googletest/include/gtest/gtest.h)
    add_subdirectory(unittests)
    ...

[mgorny]

Plus there's the matter of LLVMTestingSupport library.

[tstellar]

In D137890#3942748, @mgorny wrote:

I'll try to test this today. I suppose the main idea would be to enable LLVM_INSTALL_GTEST, then stop unpacking third-party directory when building other packages, correct? Perhaps it would make sense to update the checks like the one in clang while doing that:

if( CLANG_INCLUDE_TESTS )
  if(EXISTS ${LLVM_THIRD_PARTY_DIR}/unittest/googletest/include/gtest/gtest.h)
    add_subdirectory(unittests)
    ...

I submitted the clang patch here: D138472

[mgorny]

third-party/unittest/CMakeLists.txt

91

Any reason you think this should be installed separately rather than included in the usual LLVM export list? I think the latter would make it more consistent to use in in-tree vs standalone builds (as you wouldn't have to find_package it).

[tstellar]

third-party/unittest/CMakeLists.txt

91

The problem with having it in the main export list is that it then it would have to be present on disk for users to be able to load LLVMConfig.cmake.

91

I was just trying to make the patch more self-contained, so it wouldn't risk breaking other build configurations, but I can add it into the main export list if you think that's better.

[mgorny]

third-party/unittest/CMakeLists.txt

91

I suppose you're thinking of packaging it separate from llvm-devel then? If not, then I think it'd be better to keep it simple and include it in main exports. After all, most users simply won't enable the option to install it, so shouldn't be affected.

[kwk]

Works for me.

[tstellar]

Add exports to LLVMExports.cmake instead of a separate file.

[tstellar]

third-party/unittest/CMakeLists.txt

91

v

[mgorny]

I think it's good.

llvm/lib/Testing/Annotations/CMakeLists.txt

4

Missing indent?

[mgorny]

First observation: third-party/unittest/UnitTestMain/CMakeLists.txt still has BUILDTREE_ONLY which makes it impossible to use this with LLVM_DISTRIBUTION_COMPONENTS. Could you adjust that as well?

llvm/CMakeLists.txt

 if(LLVM_BUILD_EXAMPLES)
   add_compile_definitions(BUILD_EXAMPLES)
 endif(LLVM_BUILD_EXAMPLES)
 
 option(LLVM_BUILD_TESTS
   "Build LLVM unit tests. If OFF, just generate build targets." OFF)
 option(LLVM_INCLUDE_TESTS "Generate build targets for the LLVM unit tests." ON)
 
+option(LLVM_INSTALL_GTEST
+  "Install the llvm gtest library.  This should be on if you want to do
+   stand-alone builds of the other projects and run their unit tests." OFF)
+
 option(LLVM_BUILD_BENCHMARKS "Add LLVM benchmark targets to the list of default
 targets. If OFF, benchmarks still could be built using Benchmarks target." OFF)
 option(LLVM_INCLUDE_BENCHMARKS "Generate benchmark targets. If OFF, benchmarks can't be built." ON)
 
 option (LLVM_BUILD_DOCS "Build the llvm documentation." OFF)
 option (LLVM_INCLUDE_DOCS "Generate build targets for llvm documentation." ON)
 option (LLVM_ENABLE_DOXYGEN "Use doxygen to generate llvm API documentation." OFF)
 option (LLVM_ENABLE_SPHINX "Use Sphinx to generate llvm documentation." OFF)

llvm/lib/Testing/Annotations/CMakeLists.txt

 # Do not build unittest libraries automatically, they will be pulled in
 # by unittests if these are built.
+if (NOT ${LLVM_INSTALL_GTEST})
+set (BUILDTREE_ONLY BUILDTREE_ONLY)
   set(EXCLUDE_FROM_ALL ON)
+endif()
 
 add_llvm_library(LLVMTestingAnnotations
   Annotations.cpp
 
-  BUILDTREE_ONLY
+  ${BUILDTREE_ONLY}
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Testing/Support
 
   LINK_COMPONENTS
   Support
   )

llvm/lib/Testing/Support/CMakeLists.txt

 # Do not build unittest libraries automatically, they will be pulled in
 # by unittests if these are built.
+if (NOT ${LLVM_INSTALL_GTEST})
+  set (BUILDTREE_ONLY BUILDTREE_ONLY)
   set(EXCLUDE_FROM_ALL ON)
+endif()
 
 add_llvm_library(LLVMTestingSupport
   Error.cpp
   SupportHelpers.cpp
 
-  BUILDTREE_ONLY
+  ${BUILDTREE_ONLY}
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Testing/Support
 
   LINK_COMPONENTS
   Support
   )
 

third-party/unittest/CMakeLists.txt

 add_definitions( -DGTEST_HAS_RTTI=0 )
 
 if (HAVE_LIBPTHREAD)
   list(APPEND LIBS pthread)
 endif()
 
 # Do not build unittest libraries automatically, they will be pulled in
 # by unittests if these are built.
+
+set(BUILDTREE_ONLY BUILDTREE_ONLY)
 set(EXCLUDE_FROM_ALL ON)
+if (LLVM_INSTALL_GTEST)
+  set(EXCLUDE_FROM_ALL OFF)
+  set(BUILDTREE_ONLY "")
+endif ()
 
 add_llvm_library(llvm_gtest
   googletest/src/gtest-all.cc
   googlemock/src/gmock-all.cc
 
   LINK_LIBS
   ${LIBS}
 
   LINK_COMPONENTS
   Support # Depends on llvm::raw_ostream
 
   # This is a library meant only for the build tree.
-  BUILDTREE_ONLY
+  ${BUILDTREE_ONLY}
 )
 
 # The googletest and googlemock sources don't presently use the 'override'
 # keyword, which leads to lots of warnings from -Wsuggest-override. Disable
 # that warning here for any targets that link to gtest.
 if(CXX_SUPPORTS_SUGGEST_OVERRIDE_FLAG)
   add_definitions("-Wno-suggest-override")
   set_target_properties(llvm_gtest PROPERTIES INTERFACE_COMPILE_OPTIONS "-Wno-suggest-override")
 endif()
 
 if (NOT LLVM_ENABLE_THREADS)
   target_compile_definitions(llvm_gtest PUBLIC GTEST_HAS_PTHREAD=0)
 endif ()
 
 target_include_directories(llvm_gtest
-  PUBLIC googletest/include googlemock/include
+  PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/googletest/include>
+         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/googlemock/include>
+         $<INSTALL_INTERFACE:include/llvm-gtest/>
+         $<INSTALL_INTERFACE:include/llvm-gmock/>
   PRIVATE googletest googlemock
   )
 
 add_subdirectory(UnitTestMain)
 
+if (LLVM_INSTALL_GTEST)
+  install(TARGETS llvm_gtest llvm_gtest_main LLVMTestingSupport LLVMTestingAnnotations
+    ARCHIVE DESTINATION "lib${LLVM_LIBDIR_SUFFIX}" COMPONENT llvm_gtest)
+  install(DIRECTORY googletest/include/gtest/ DESTINATION include/llvm-gtest/gtest/ COMPONENT llvm_gtest)
+  install(DIRECTORY googlemock/include/gmock/ DESTINATION include/llvm-gmock/gmock/ COMPONENT llvm_gtest)
+endif()
+
 # When LLVM_LINK_LLVM_DYLIB is enabled, libLLVM.so is added to the interface
 # link libraries for gtest and gtest_main.  This means that any target, like
 # unittests for example, that links against gtest will be forced to link
 # against libLLVM.so.  In some cases we may want to statically unittests if they
 # need access to symbols that are marked private in libLLVM.so.  The only
 # way we can make this work is to remove libLLVM.so from the list of interface
 # link libraries for gtest and then make gtest users responsible for explicitly
 # adding libLLVM.so to their targets link libraries if they need it.