#===------------------------------------------------------------------------===#
#
#                     The KLEE Symbolic Virtual Machine
#
# This file is distributed under the University of Illinois Open Source
# License. See LICENSE.TXT for details.
#
#===------------------------------------------------------------------------===#

if (TARGET gtest AND TARGET gtest_main)
  # try to reuse LLVM's targets

  message(WARNING "LLVM exports 'gtest' and 'gtest_main' targets (for Google "
    "Test), so KLEE cannot create them. By default, KLEE will reuse "
    "LLVM's 'gtest' and 'gtest_main' targets if they are available. This is, "
    "however, only recommended if LLVM and KLEE were build with the same "
    "compiler and linker flags to prevent any compatibility issues.\n"
    "To prevent CMake from reusing the targets or to use a different version "
    "of Google Test, try either of the following:\n"
    "- Point LLVM_DIR to the directory containing the `LLVMConfig.cmake` file "
    "of an installed copy of LLVM instead of a build tree.\n"
    "- Pass -DLLVM_INCLUDE_TESTS=OFF to CMake when building LLVM. This "
    "prevents building unit tests in LLVM (but not in KLEE) and exporting the "
    "target to the build tree.")

  if (GTEST_SRC_DIR)
    message(FATAL_ERROR "Cannot use GTEST_SRC_DIR when targets 'gtest' and "
      "'gtest_main' are already defined.\n"
      "Either reuse LLVM's Google Test setup by not setting GTEST_SRC_DIR or "
      "choose one of the options to prevent LLVM from exporting these targets.")
  endif()

  # check if it's really LLVM that exports them
  list(FIND LLVM_EXPORTED_TARGETS "gtest" _GTEST_INDEX)
  list(FIND LLVM_EXPORTED_TARGETS "test_main" _GTEST_MAIN_INDEX)
  if (${_GTEST_INDEX} GREATER -1 AND ${_GTEST_MAIN_INDEX})
    message(STATUS "Google Test: Reusing LLVM's 'gtest' and 'gtest_main' targets.")
    # in this case, only include directory has to be set
    if (LLVM_BUILD_MAIN_SRC_DIR)
      set(GTEST_INCLUDE_DIR
        "${LLVM_BUILD_MAIN_SRC_DIR}/utils/unittest/googletest/include"
        CACHE
        PATH
        "Path to Google Test include directory"
      )
    endif()
  else()
    message(FATAL_ERROR "Reusing Google Test targets from LLVM failed:"
      "LLVM_EXPORTED_TARGETS does not contain 'gtest' or 'gtest_main'.")
  endif()
else()
  # LLVM's targets are not reused

  if (NOT GTEST_SRC_DIR)
    if (USE_CMAKE_FIND_PACKAGE_LLVM AND LLVM_BUILD_MAIN_SRC_DIR)
      # build from LLVM's utils directory
      # NOTE: This can only be done using USE_CMAKE_FIND_PACKAGE_LLVM as
      #       LLVM replaced Google Test's CMakeLists.txt with its own,
      #       requiring add_llvm_library() from AddLLVM.cmake.
      message(STATUS "Google Test: Building from LLVM's source tree.")

      set(GTEST_INCLUDE_DIR
        "${LLVM_BUILD_MAIN_SRC_DIR}/utils/unittest/googletest/include"
        CACHE
        PATH
        "Path to Google Test include directory"
      )

      add_subdirectory("${LLVM_BUILD_MAIN_SRC_DIR}/utils/unittest/"
        "${CMAKE_CURRENT_BINARY_DIR}/gtest_build")

      # add includes for LLVM's modifications
      target_include_directories(gtest BEFORE PRIVATE ${LLVM_INCLUDE_DIRS})
      target_include_directories(gtest_main BEFORE PRIVATE ${LLVM_INCLUDE_DIRS})
    else()
      # try to find Google Test, as GTEST_SRC_DIR is not manually specified
      find_path(GTEST_SRC_DIR
        "src/gtest.cc"

        HINTS
        "/usr/src/gtest"

        # prevent CMake from finding gtest.cc in LLVM's utils directory
        NO_DEFAULT_PATH

        DOC
        "Path to Google Test source directory"
      )
    endif()
  endif()

  if (NOT (TARGET gtest AND TARGET gtest_main))
    # building from GTEST_SRC_DIR, not from LLVM's utils directory
    find_path(GTEST_INCLUDE_DIR
      "gtest/gtest.h"

      HINTS
      "${GTEST_SRC_DIR}/include"

      NO_DEFAULT_PATH

      DOC
      "Path to Google Test include directory"
    )

    if (NOT EXISTS "${GTEST_SRC_DIR}")
      message(FATAL_ERROR "Google Test source directory \"${GTEST_SRC_DIR}\" "
      "cannot be found.\n"
      "Try passing -DGTEST_SRC_DIR=<path_to_gtest_source> to CMake where "
      "<path_to_gtest_source> is the path to the Google Test source tree.\n"
      "Alternatively, you can disable unit tests by passing "
      "-DENABLE_UNIT_TESTS=OFF to CMake.")
    endif()
    message(STATUS "Google Test: Building from source.")
    message(STATUS "GTEST_SRC_DIR: ${GTEST_SRC_DIR}")

    # Prevent Google Test from adding to our install target.
    # Required for >= 1.8.0, but can only be disabled starting with 1.8.1
    set(GTEST_INSTALL OFF CACHE BOOL "disable installing Google Test" FORCE)

    # Build Google Test as part of our project
    add_subdirectory(${GTEST_SRC_DIR} "${CMAKE_CURRENT_BINARY_DIR}/gtest_build")
  endif()

  # build Google Test with KLEE's defines and compile flags
  target_compile_definitions(gtest PRIVATE ${KLEE_COMPONENT_CXX_DEFINES})
  target_compile_definitions(gtest_main PRIVATE ${KLEE_COMPONENT_CXX_DEFINES})
  target_compile_options(gtest PRIVATE ${KLEE_COMPONENT_CXX_FLAGS})
  target_compile_options(gtest_main PRIVATE ${KLEE_COMPONENT_CXX_FLAGS})
endif()


# This keeps track of all the unit test
# targets so we can ensure they are built
# before trying to run them.
define_property(GLOBAL
  PROPERTY KLEE_UNIT_TEST_TARGETS
  BRIEF_DOCS "KLEE unit tests"
  FULL_DOCS "KLEE unit tests"
)

if (NOT IS_DIRECTORY "${GTEST_INCLUDE_DIR}")
  message(FATAL_ERROR
    "Cannot find Google Test include directory \"${GTEST_INCLUDE_DIR}\"")
endif()
message(STATUS "GTEST_INCLUDE_DIR: ${GTEST_INCLUDE_DIR}")

function(add_klee_unit_test target_name)
  add_executable(${target_name} ${ARGN})
  target_link_libraries(${target_name} PRIVATE gtest_main)
  target_include_directories(${target_name} BEFORE PRIVATE "${GTEST_INCLUDE_DIR}")
  target_include_directories(${target_name} BEFORE PRIVATE ${KLEE_COMPONENT_EXTRA_INCLUDE_DIRS})
  set_target_properties(${target_name}
    PROPERTIES
    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/unittests/"
  )
  set_property(GLOBAL
    APPEND
    PROPERTY KLEE_UNIT_TEST_TARGETS
    ${target_name}
  )
endfunction()

# Unit Tests
add_subdirectory(Assignment)
add_subdirectory(Expr)
add_subdirectory(Ref)
add_subdirectory(Solver)
add_subdirectory(TreeStream)
add_subdirectory(DiscretePDF)
add_subdirectory(Time)

# Set up lit configuration
set (UNIT_TEST_EXE_SUFFIX "Test")
configure_file(lit-unit-tests-common.site.cfg.in
  ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
  @ONLY)

# Add a target to run all the unit tests using lit
get_property(UNIT_TEST_DEPENDS
  GLOBAL
  PROPERTY KLEE_UNIT_TEST_TARGETS
)
add_custom_target(unittests
  COMMAND
    "${LIT_TOOL}" ${LIT_ARGS} "${CMAKE_CURRENT_BINARY_DIR}"
    DEPENDS ${UNIT_TEST_DEPENDS}
    COMMENT "Running unittests"
    ${ADD_CUSTOM_COMMAND_USES_TERMINAL_ARG}
)