[cmake] Support running tests in stand-alone builds

Add the CMake bits necessary to run lld tests (and unittests) when
building stand-alone. The code is based on the equivalent code in clang,
and includes:

1. checking for Python, searching for lit and necessary LLVM test tools
(FileCount and not),

2. building LLVM test tools (FileCount and not) from LLVM sources if
they are not installed,

3. building gtest libraries from LLVM sources,

4. adjusting dependencies so that test targets depend only on those LLVM
targets that are available for a particular variant of stand-alone
build.

With this patch, I am able to successfully run 1002 (+10 unsupported)
lit tests on Gentoo using installed LLVM.

Differential Revision: https://reviews.llvm.org/D28750

llvm-svn: 293630

lld/CMakeLists.txt

@@ -11,8 +11,11 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     message(FATAL_ERROR "llvm-config not found: specify LLVM_CONFIG_PATH")
   endif()
 
-  execute_process(COMMAND "${LLVM_CONFIG_PATH}" "--obj-root" "--includedir"
+  execute_process(COMMAND "${LLVM_CONFIG_PATH}"
+                          "--obj-root"
+                          "--includedir"
                           "--cmakedir"
+                          "--src-root"
                   RESULT_VARIABLE HAD_ERROR
                   OUTPUT_VARIABLE LLVM_CONFIG_OUTPUT
                   OUTPUT_STRIP_TRAILING_WHITESPACE)
@@ -25,9 +28,11 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   list(GET LLVM_CONFIG_OUTPUT 0 OBJ_ROOT)
   list(GET LLVM_CONFIG_OUTPUT 1 MAIN_INCLUDE_DIR)
   list(GET LLVM_CONFIG_OUTPUT 2 LLVM_CMAKE_PATH)
+  list(GET LLVM_CONFIG_OUTPUT 3 MAIN_SRC_DIR)
 
   set(LLVM_OBJ_ROOT ${OBJ_ROOT} CACHE PATH "path to LLVM build tree")
   set(LLVM_MAIN_INCLUDE_DIR ${MAIN_INCLUDE_DIR} CACHE PATH "path to llvm/include")
+  set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
 
   file(TO_CMAKE_PATH ${LLVM_OBJ_ROOT} LLVM_BINARY_DIR)
 
@@ -49,6 +54,67 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   include(AddLLVM)
   include(TableGen)
   include(HandleLLVMOptions)
+
+  if(LLVM_INCLUDE_TESTS)
+    set(Python_ADDITIONAL_VERSIONS 2.7)
+    include(FindPythonInterp)
+    if(NOT PYTHONINTERP_FOUND)
+      message(FATAL_ERROR
+"Unable to find Python interpreter, required for testing.
+
+Please install Python or specify the PYTHON_EXECUTABLE CMake variable.")
+    endif()
+
+    if(${PYTHON_VERSION_STRING} VERSION_LESS 2.7)
+      message(FATAL_ERROR "Python 2.7 or newer is required")
+    endif()
+
+    # Check prebuilt llvm/utils.
+    if(EXISTS ${LLVM_TOOLS_BINARY_DIR}/FileCheck${CMAKE_EXECUTABLE_SUFFIX}
+        AND EXISTS ${LLVM_TOOLS_BINARY_DIR}/not${CMAKE_EXECUTABLE_SUFFIX})
+      set(LLVM_UTILS_PROVIDED ON)
+    endif()
+
+    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)
+      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)
+      endif()
+    else()
+      # Seek installed Lit.
+      find_program(LLVM_LIT
+                   NAMES llvm-lit lit.py lit
+                   PATHS "${LLVM_MAIN_SRC_DIR}/utils/lit"
+                   DOC "Path to lit.py")
+    endif()
+
+    if(LLVM_LIT)
+      # Define the default arguments to use with 'lit', and an option for the user
+      # to override.
+      set(LIT_ARGS_DEFAULT "-sv")
+      if (MSVC OR XCODE)
+        set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
+      endif()
+      set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
+
+      # On Win32 hosts, provide an option to specify the path to the GnuWin32 tools.
+      if(WIN32 AND NOT CYGWIN)
+        set(LLVM_LIT_TOOLS_DIR "" CACHE PATH "Path to GnuWin32 tools")
+      endif()
+    else()
+      set(LLVM_INCLUDE_TESTS OFF)
+    endif()
+  endif()
 endif()
 
 set(LLD_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})

lld/test/CMakeLists.txt

@@ -19,13 +19,17 @@ configure_lit_site_cfg(
   ${CMAKE_CURRENT_BINARY_DIR}/Unit/lit.site.cfg
   )
 
-set(LLD_TEST_DEPS
-  FileCheck not llvm-ar llvm-as llvm-dis llvm-dwarfdump llvm-nm
-  llc lld llvm-config llvm-objdump llvm-readobj yaml2obj obj2yaml
-  llvm-mc llvm-lib llvm-pdbdump opt
-  )
+set(LLD_TEST_DEPS lld)
+if (NOT LLD_BUILT_STANDALONE)
+  list(APPEND LLD_TEST_DEPS
+    FileCheck not llvm-ar llvm-as llvm-dis llvm-dwarfdump llvm-nm
+    llc llvm-config llvm-objdump llvm-readobj yaml2obj obj2yaml
+    llvm-mc llvm-lib llvm-pdbdump opt
+    )
+endif()
+
 if (LLVM_INCLUDE_TESTS)
-  set(LLD_TEST_DEPS ${LLD_TEST_DEPS} LLDUnitTests)
+  list(APPEND LLD_TEST_DEPS LLDUnitTests)
 endif()
 
 set(LLD_TEST_PARAMS