cmake_minimum_required(VERSION 3.1)
project(ccls LANGUAGES CXX)

list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/)
include(DefaultCMakeBuildType)

# Required Clang version
set(CLANG_DOWNLOAD_LOCATION ${CMAKE_BINARY_DIR}
    CACHE STRING "Downloaded Clang location")
option(SYSTEM_CLANG "Use system installation of Clang instead of \
       downloading Clang" OFF)
option(ASAN "Compile with address sanitizers" OFF)
option(LLVM_ENABLE_RTTI "-fno-rtti if OFF. This should match LLVM libraries" OFF)
option(CLANG_USE_BUNDLED_LIBC++ "Let Clang use bundled libc++" OFF)
option(USE_SHARED_LLVM "Link against libLLVM.so instead separate LLVM{Option,Support,...}" OFF)

# Sources for the executable are specified at end of CMakeLists.txt
add_executable(ccls "")

### Compile options

# CMake default compile flags:
# MSVC + Clang(Windows):
#   debug: /MDd /Zi /Ob0 /Od /RTC1
#   release: /MD /O2 /Ob2 /DNDEBUG
# GCC + Clang(Linux):
#   debug: -g
#   release: -O3 -DNDEBUG

# Enable C++17 (Required)
set_property(TARGET ccls PROPERTY CXX_STANDARD 17)
set_property(TARGET ccls PROPERTY CXX_STANDARD_REQUIRED ON)
# Disable gnu extensions except for Cygwin which needs them to build properly
if(NOT CYGWIN)
  set_property(TARGET ccls PROPERTY CXX_EXTENSIONS OFF)
endif()

if(NOT LLVM_ENABLE_RTTI)
  # releases.llvm.org libraries are compiled with -fno-rtti
  # The mismatch between lib{clang,LLVM}* and ccls can make libstdc++ std::make_shared return nullptr
  # _Sp_counted_ptr_inplace::_M_get_deleter
  target_compile_options(ccls PRIVATE -fno-rtti)
endif()

# CMake sets MSVC for both MSVC and Clang(Windows)
if(MSVC)
  # Common MSVC/Clang(Windows) options
  target_compile_options(ccls PRIVATE
    /nologo
    /EHsc
    /D_CRT_SECURE_NO_WARNINGS # don't try to use MSVC std replacements
    /W3 # roughly -Wall
    /wd4996 # disable loguru unsafe warnings
    /wd4722 # ignores warning C4722
            # (destructor never returns) in loguru
    /wd4267 # ignores warning C4267
            # (conversion from 'size_t' to 'type'),
            # roughly -Wno-sign-compare
    /wd4800
    /wd4068 # Disable unknown pragma warning
    $<$<CONFIG:Debug>:/FS>
  )
else()
  # Common GCC/Clang(Linux) options
  target_compile_options(ccls PRIVATE
                         -Wall
                         -Wno-sign-compare
                         )

  if(${CMAKE_CXX_COMPILER_ID} STREQUAL GNU)
    target_compile_options(ccls PRIVATE -Wno-return-type -Wno-unused-result)
  endif()

  if(${CMAKE_CXX_COMPILER_ID} STREQUAL Clang)
    target_compile_options(ccls PRIVATE
                           $<$<CONFIG:Debug>:-fno-limit-debug-info>)
  endif()

  if(ASAN)
    target_compile_options(ccls PRIVATE -fsanitize=address,undefined)
    # target_link_libraries also takes linker flags
    target_link_libraries(ccls PRIVATE -fsanitize=address,undefined)
  endif()
endif()

### Download Clang if required

if(NOT SYSTEM_CLANG)
  message(STATUS "Using downloaded Clang")

  include(DownloadAndExtractClang)
  download_and_extract_clang(${CLANG_DOWNLOAD_LOCATION})
  # Used by FindClang
  set(CLANG_ROOT ${DOWNLOADED_CLANG_DIR})

  if(${CMAKE_CXX_COMPILER_ID} STREQUAL Clang AND CLANG_USE_BUNDLED_LIBC++)
    message(STATUS "Using bundled libc++")
    target_compile_options(ccls PRIVATE -nostdinc++ -cxx-isystem ${CLANG_ROOT}/include/c++/v1)
    if(${CMAKE_SYSTEM_NAME} STREQUAL Linux)
      # Don't use -stdlib=libc++ because while ccls is linked with libc++, bundled clang+llvm require libstdc++
      target_link_libraries(ccls PRIVATE -L${CLANG_ROOT}/lib c++ c++abi)

      # FreeBSD defaults to -stdlib=libc++ and uses system libcxxrt.a
    endif()
  endif()

else()
  message(STATUS "Using system Clang")
endif()

### Libraries

# See cmake/FindClang.cmake
find_package(Clang 6.0.0)
target_link_libraries(ccls PRIVATE Clang::Clang)

# Enable threading support
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
target_link_libraries(ccls PRIVATE Threads::Threads)

if(${CMAKE_SYSTEM_NAME} STREQUAL FreeBSD)
  find_package(Backtrace REQUIRED)
  target_link_libraries(ccls PRIVATE ${Backtrace_LIBRARIES})
  # src/platform_posix.cc uses libthr
  target_link_libraries(ccls PRIVATE thr)
endif()

### Definitions

target_compile_definitions(ccls PRIVATE
                           DEFAULT_RESOURCE_DIRECTORY=R"\(${Clang_RESOURCE_DIR}\)")

### Includes

target_include_directories(ccls PRIVATE src)
target_include_directories(ccls SYSTEM PRIVATE
                           third_party
                           third_party/rapidjson/include)

### Install

install(TARGETS ccls RUNTIME DESTINATION bin)

if(NOT SYSTEM_CLANG AND NOT ${CMAKE_SYSTEM_NAME} STREQUAL Windows)

  if(${CMAKE_SYSTEM_NAME} MATCHES Linux|FreeBSD)
    set_property(TARGET ccls APPEND PROPERTY
                 INSTALL_RPATH $ORIGIN/../lib)
  elseif(${CMAKE_SYSTEM_NAME} STREQUAL Darwin)
    set_property(TARGET ccls APPEND PROPERTY
                 INSTALL_RPATH @loader_path/../lib)
  endif()

  file(GLOB LIBCLANG_PLUS_SYMLINKS
       ${DOWNLOADED_CLANG_DIR}/lib/libclang.[so,dylib]*)
  install(FILES ${LIBCLANG_PLUS_SYMLINKS} DESTINATION lib)
endif()

# Allow running from build Windows by copying libclang.dll to build directory
if(NOT SYSTEM_CLANG AND ${CMAKE_SYSTEM_NAME} STREQUAL Windows)
  add_custom_command(TARGET ccls
                     POST_BUILD
                     COMMAND ${CMAKE_COMMAND} -E copy
                     ${DOWNLOADED_CLANG_DIR}/bin/libclang.dll
                     $<TARGET_FILE_DIR:ccls>
                     COMMENT "Copying libclang.dll to build directory ...")
endif()

### Tools

# We use glob here since source files are already manually added with
# target_sources further down
file(GLOB SOURCES src/*.cc src/*.h src/serializers/*.cc src/serializers/*.h
                  src/messages/*.h src/messages/*.cc)

### Sources

target_sources(ccls PRIVATE third_party/siphash.cc)

target_sources(ccls PRIVATE
  src/clang_complete.cc
  src/clang_tu.cc
  src/config.cc
  src/filesystem.cc
  src/fuzzy_match.cc
  src/main.cc
  src/include_complete.cc
  src/indexer.cc
  src/method.cc
  src/log.cc
  src/lsp.cc
  src/match.cc
  src/message_handler.cc
  src/pipeline.cc
  src/platform_posix.cc
  src/platform_win.cc
  src/position.cc
  src/project.cc
  src/query_utils.cc
  src/query.cc
  src/serializer.cc
  src/test.cc
  src/utils.cc
  src/working_files.cc
)

target_sources(ccls PRIVATE
  src/messages/ccls_call.cc
  src/messages/ccls_info.cc
  src/messages/ccls_inheritance.cc
  src/messages/ccls_member.cc
  src/messages/ccls_navigate.cc
  src/messages/ccls_reload.cc
  src/messages/ccls_vars.cc
  src/messages/exit.cc
  src/messages/initialize.cc
  src/messages/shutdown.cc
  src/messages/textDocument_codeAction.cc
  src/messages/textDocument_codeLens.cc
  src/messages/textDocument_completion.cc
  src/messages/textDocument_definition.cc
  src/messages/textDocument_did.cc
  src/messages/textDocument_formatting.cc
  src/messages/textDocument_documentHighlight.cc
  src/messages/textDocument_documentSymbol.cc
  src/messages/textDocument_hover.cc
  src/messages/textDocument_implementation.cc
  src/messages/textDocument_references.cc
  src/messages/textDocument_rename.cc
  src/messages/textDocument_signatureHelp.cc
  src/messages/textDocument_typeDefinition.cc
  src/messages/workspace_did.cc
  src/messages/workspace_didChangeWatchedFiles.cc
  src/messages/workspace_symbol.cc
)