set(LLVM_VERSION "11.0.0")

vcpkg_check_linkage(ONLY_STATIC_LIBRARY)

vcpkg_from_github(
    OUT_SOURCE_PATH SOURCE_PATH
    REPO llvm/llvm-project
    REF llvmorg-${LLVM_VERSION}
    SHA512 b6d38871ccce0e086e27d35e42887618d68e57d8274735c59e3eabc42dee352412489296293f8d5169fe0044936345915ee7da61ebdc64ec10f7737f6ecd90f2
    HEAD_REF master
    PATCHES
        0001-add-msvc-options.patch     # Fixed in LLVM 12.0.0
        0002-fix-install-paths.patch    # This patch fixes paths in ClangConfig.cmake, LLVMConfig.cmake, LLDConfig.cmake etc.
        0003-fix-openmp-debug.patch
        0004-fix-dr-1734.patch
        0005-fix-tools-path.patch
        0006-workaround-msvc-bug.patch  # Fixed in LLVM 12.0.0
)

vcpkg_check_features(OUT_FEATURE_OPTIONS FEATURE_OPTIONS
    tools LLVM_BUILD_TOOLS
    tools LLVM_INCLUDE_TOOLS
    utils LLVM_BUILD_UTILS
    utils LLVM_INCLUDE_UTILS
    enable-rtti LLVM_ENABLE_RTTI
)

# LLVM generates CMake error due to Visual Studio version 16.4 is known to miscompile part of LLVM.
# LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON disables this error.
# See https://developercommunity.visualstudio.com/content/problem/845933/miscompile-boolean-condition-deduced-to-be-always.html
# and thread "[llvm-dev] Longstanding failing tests - clang-tidy, MachO, Polly" on llvm-dev Jan 21-23 2020.
list(APPEND FEATURE_OPTIONS
    -DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON
)

# By default assertions are enabled for Debug configuration only.
if("enable-assertions" IN_LIST FEATURES)
    # Force enable assertions for all configurations.
    list(APPEND FEATURE_OPTIONS
        -DLLVM_ENABLE_ASSERTIONS=ON
    )
elseif("disable-assertions" IN_LIST FEATURES)
    # Force disable assertions for all configurations.
    list(APPEND FEATURE_OPTIONS
        -DLLVM_ENABLE_ASSERTIONS=OFF
    )
endif()

# LLVM_ABI_BREAKING_CHECKS can be WITH_ASSERTS (default), FORCE_ON or FORCE_OFF.
# By default abi-breaking checks are enabled if assertions are enabled.
if("enable-abi-breaking-checks" IN_LIST FEATURES)
    # Force enable abi-breaking checks.
    list(APPEND FEATURE_OPTIONS
        -DLLVM_ABI_BREAKING_CHECKS=FORCE_ON
    )
elseif("disable-abi-breaking-checks" IN_LIST FEATURES)
    # Force disable abi-breaking checks.
    list(APPEND FEATURE_OPTIONS
        -DLLVM_ABI_BREAKING_CHECKS=FORCE_OFF
    )
endif()

set(LLVM_ENABLE_PROJECTS)
if("clang" IN_LIST FEATURES OR "clang-tools-extra" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "clang")
    if("disable-clang-static-analyzer" IN_LIST FEATURES)
        list(APPEND FEATURE_OPTIONS
            # Disable ARCMT
            -DCLANG_ENABLE_ARCMT=OFF
            # Disable static analyzer
            -DCLANG_ENABLE_STATIC_ANALYZER=OFF
        )
    endif()
endif()
if("clang-tools-extra" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "clang-tools-extra")
endif()
if("compiler-rt" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "compiler-rt")
endif()
if("flang" IN_LIST FEATURES)
    # Disable Flang on Windows (see http://lists.llvm.org/pipermail/flang-dev/2020-July/000448.html).
    if(VCPKG_TARGET_IS_WINDOWS)
        message(FATAL_ERROR "Building Flang with MSVC is not supported.")
    endif()
    list(APPEND LLVM_ENABLE_PROJECTS "flang")
    list(APPEND FEATURE_OPTIONS
        # Flang requires C++17
        -DCMAKE_CXX_STANDARD=17
    )
endif()
if("lld" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "lld")
endif()
if("lldb" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "lldb")
endif()
if("mlir" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "mlir")
endif()
if("openmp" IN_LIST FEATURES)
    # Disable OpenMP on Windows (see https://bugs.llvm.org/show_bug.cgi?id=45074).
    if(VCPKG_TARGET_IS_WINDOWS)
        message(FATAL_ERROR "Building OpenMP with MSVC is not supported.")
    endif()
    list(APPEND LLVM_ENABLE_PROJECTS "openmp")
    # Perl is required for the OpenMP run-time
    vcpkg_find_acquire_program(PERL)
    list(APPEND FEATURE_OPTIONS
        "-DPERL_EXECUTABLE=${PERL}"
    )
    if(NOT DEFINED VCPKG_BUILD_TYPE OR VCPKG_BUILD_TYPE STREQUAL "debug")
        list(APPEND FEATURE_OPTIONS
            -DLIBOMP_DEFAULT_LIB_NAME=libompd
        )
    endif()
endif()
if("polly" IN_LIST FEATURES)
    list(APPEND LLVM_ENABLE_PROJECTS "polly")
endif()

set(known_llvm_targets
    AArch64
    AMDGPU
    ARM
    AVR
    BPF
    Hexagon
    Lanai
    Mips 
    MSP430
    NVPTX
    PowerPC
    RISCV
    Sparc
    SystemZ 
    WebAssembly
    X86
    XCore
)

set(LLVM_TARGETS_TO_BUILD "")
foreach(llvm_target IN LISTS known_llvm_targets)
    string(TOLOWER "target-${llvm_target}" feature_name)
    if(feature_name IN_LIST FEATURES)
        list(APPEND LLVM_TARGETS_TO_BUILD "${llvm_target}")
    endif()
endforeach()

vcpkg_find_acquire_program(PYTHON3)
get_filename_component(PYTHON3_DIR ${PYTHON3} DIRECTORY)
vcpkg_add_to_path(${PYTHON3_DIR})

vcpkg_configure_cmake(
    SOURCE_PATH ${SOURCE_PATH}/llvm
    PREFER_NINJA
    OPTIONS
        ${FEATURE_OPTIONS}
        -DLLVM_INCLUDE_EXAMPLES=OFF
        -DLLVM_BUILD_EXAMPLES=OFF
        -DLLVM_INCLUDE_TESTS=OFF
        -DLLVM_BUILD_TESTS=OFF
        # Disable optional dependencies to libxml2 and zlib.
        -DLLVM_ENABLE_LIBXML2=OFF
        -DLLVM_ENABLE_ZLIB=OFF
        # Force TableGen to be built with optimization. This will significantly improve build time.
        -DLLVM_OPTIMIZED_TABLEGEN=ON
        "-DLLVM_ENABLE_PROJECTS=${LLVM_ENABLE_PROJECTS}"
        "-DLLVM_TARGETS_TO_BUILD=${LLVM_TARGETS_TO_BUILD}"
        -DPACKAGE_VERSION=${LLVM_VERSION}
        # Limit the maximum number of concurrent link jobs to 1. This should fix low amount of memory issue for link.
        -DLLVM_PARALLEL_LINK_JOBS=1
        # Disable build LLVM-C.dll (Windows only) due to doesn't compile with CMAKE_DEBUG_POSTFIX
        -DLLVM_BUILD_LLVM_C_DYLIB=OFF
        # Path for binary subdirectory (defaults to 'bin')
        -DLLVM_TOOLS_INSTALL_DIR=tools/llvm
    OPTIONS_DEBUG
        -DCMAKE_DEBUG_POSTFIX=d
)

vcpkg_install_cmake()

if("clang" IN_LIST FEATURES)
    vcpkg_fixup_cmake_targets(CONFIG_PATH "share/clang" TARGET_PATH "share/clang" DO_NOT_DELETE_PARENT_CONFIG_PATH)
    file(INSTALL ${SOURCE_PATH}/clang/LICENSE.TXT DESTINATION ${CURRENT_PACKAGES_DIR}/share/clang RENAME copyright)
endif()

if("clang-tools-extra" IN_LIST FEATURES)
    # Remove empty include directory include/clang-tidy/plugin
    file(GLOB_RECURSE INCLUDE_CLANG_TIDY_PLUGIN_FILES "${CURRENT_PACKAGES_DIR}/include/clang-tidy/plugin/*")
    if(NOT INCLUDE_CLANG_TIDY_PLUGIN_FILES)
        file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/include/clang-tidy/plugin")
    endif()
endif()

if("flang" IN_LIST FEATURES)
    vcpkg_fixup_cmake_targets(CONFIG_PATH "share/flang" TARGET_PATH "share/flang" DO_NOT_DELETE_PARENT_CONFIG_PATH)
    file(INSTALL ${SOURCE_PATH}/flang/LICENSE.TXT DESTINATION ${CURRENT_PACKAGES_DIR}/share/flang RENAME copyright)
    # Remove empty include directory /include/flang/Config
    file(GLOB_RECURSE INCLUDE_FLANG_CONFIG_FILES "${CURRENT_PACKAGES_DIR}/include/flang/Config/*")
    if(NOT INCLUDE_FLANG_CONFIG_FILES)
        file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/include/flang/Config")
    endif()
endif()

if("lld" IN_LIST FEATURES)
    vcpkg_fixup_cmake_targets(CONFIG_PATH "share/lld" TARGET_PATH "share/lld" DO_NOT_DELETE_PARENT_CONFIG_PATH)
    file(INSTALL ${SOURCE_PATH}/lld/LICENSE.TXT DESTINATION ${CURRENT_PACKAGES_DIR}/share/lld RENAME copyright)
endif()

if("mlir" IN_LIST FEATURES)
    vcpkg_fixup_cmake_targets(CONFIG_PATH "share/mlir" TARGET_PATH "share/mlir" DO_NOT_DELETE_PARENT_CONFIG_PATH)
    file(INSTALL ${SOURCE_PATH}/mlir/LICENSE.TXT DESTINATION ${CURRENT_PACKAGES_DIR}/share/mlir RENAME copyright)
endif()

if("polly" IN_LIST FEATURES)
    vcpkg_fixup_cmake_targets(CONFIG_PATH "share/polly" TARGET_PATH "share/polly" DO_NOT_DELETE_PARENT_CONFIG_PATH)
    file(INSTALL ${SOURCE_PATH}/polly/LICENSE.TXT DESTINATION ${CURRENT_PACKAGES_DIR}/share/polly RENAME copyright)
endif()

vcpkg_fixup_cmake_targets(CONFIG_PATH "share/llvm" TARGET_PATH "share/llvm")
file(INSTALL ${SOURCE_PATH}/llvm/LICENSE.TXT DESTINATION ${CURRENT_PACKAGES_DIR}/share/llvm RENAME copyright)

if(VCPKG_TARGET_IS_WINDOWS)
    set(LLVM_EXECUTABLE_REGEX [[^([^.]*|[^.]*\.lld)\.exe$]])
else()
    set(LLVM_EXECUTABLE_REGEX [[^([^.]*|[^.]*\.lld)$]])
endif()

file(GLOB LLVM_TOOL_FILES "${CURRENT_PACKAGES_DIR}/bin/*")
set(LLVM_TOOLS)
foreach(tool_file IN LISTS LLVM_TOOL_FILES)
    get_filename_component(tool_file "${tool_file}" NAME)
    if(tool_file MATCHES "${LLVM_EXECUTABLE_REGEX}")
        list(APPEND LLVM_TOOLS "${CMAKE_MATCH_1}")
    endif()
endforeach()

vcpkg_copy_tools(TOOL_NAMES ${LLVM_TOOLS} AUTO_CLEAN)

if(NOT DEFINED VCPKG_BUILD_TYPE OR VCPKG_BUILD_TYPE STREQUAL "debug")
    file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)
    file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/share)
    file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/tools)
endif()

# LLVM still generates a few DLLs in the static build:
# * libclang.dll
# * LTO.dll
# * Remarks.dll
set(VCPKG_POLICY_DLLS_IN_STATIC_LIBRARY enabled)