cmake: delete SYSTEM_CLANG and auto-download mechanism

.appveyor.yml

@@ -15,7 +15,7 @@ install:
   - 7z x llvm.tar
   - git submodule update --init --recursive
 build_script:
-  - cmake -G"Visual Studio 15 2017 Win64" -H. -Bbuild -DCMAKE_BUILD_TYPE=Release -DSYSTEM_CLANG=ON -DCLANG_ROOT=C:\projects\ccls\llvm+clang-7.0.0-win64-msvc-release
+  - cmake -G"Visual Studio 15 2017 Win64" -H. -Bbuild -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH=C:\projects\ccls\llvm+clang-7.0.0-win64-msvc-release
   - cmake --build build --target ccls --config Release
 
 artifacts:

CMakeLists.txt

@@ -5,13 +5,7 @@ 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
@@ -30,10 +24,7 @@ add_executable(ccls "")
 # 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
+set_property(TARGET ccls PROPERTY CXX_EXTENSIONS OFF)
-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
@@ -76,37 +67,6 @@ else()
     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
@@ -143,31 +103,6 @@ target_include_directories(ccls SYSTEM PRIVATE
 
 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

clang_archive_hashes/LLVM-7.0.0-win64.exe.SHA256

@@ -1 +0,0 @@
-74b197a3959b0408adf0824be01db8dddfa2f9a967f4085af3fad900ed5fdbf6

clang_archive_hashes/clang+llvm-7.0.0-amd64-unknown-freebsd11.tar.xz.SHA256

@@ -1 +0,0 @@
-95ceb933ccf76e3ddaa536f41ab82c442bbac07cdea6f9fbf6e3b13cc1711255

clang_archive_hashes/clang+llvm-7.0.0-x86_64-apple-darwin.tar.xz.SHA256

@@ -1 +0,0 @@
-b3ad93c3d69dfd528df9c5bb1a434367babb8f3baea47fbb99bf49f1b03c94ca

clang_archive_hashes/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-14.04.tar.xz.SHA256

@@ -1 +0,0 @@
-5c90e61b06d37270bc26edb305d7e498e2c7be22d99e0afd9f2274ef5458575a

clang_archive_hashes/clang+llvm-7.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz.SHA256

@@ -1 +0,0 @@
-69b85c833cd28ea04ce34002464f10a6ad9656dd2bba0f7133536a9927c660d2

cmake/DownloadAndExtract7zip.cmake

@@ -1,52 +0,0 @@
-# Downloads and extracts the 7-Zip MSI installer from https://www.7-zip.org/. 
-# 
-# Returns the extracted 7-Zip directory in DOWNLOADED_7ZIP_DIR
-function(download_and_extract_7zip 7ZIP_DOWNLOAD_LOCATION)
-
-set(7ZIP_VERSION 1801)
-set(7ZIP_EXT .msi)
-set(7ZIP_NAME 7z${7ZIP_VERSION}-x64)
-set(7ZIP_FULL_NAME ${7ZIP_NAME}${7ZIP_EXT})
-
-set(7ZIP_FILE ${7ZIP_DOWNLOAD_LOCATION}/${7ZIP_FULL_NAME})
-set(7ZIP_EXTRACT_DIR ${7ZIP_DOWNLOAD_LOCATION}/${7ZIP_NAME})
-set(7ZIP_URL https://www.7-zip.org/a/${7ZIP_FULL_NAME})
-
-# Exit if 7-Zip is already downloaded and extracted
-find_program(7ZIP_EXECUTABLE 7z NO_DEFAULT_PATH
-             PATHS ${7ZIP_EXTRACT_DIR}/Files/7-Zip)
-if(7ZIP_EXECUTABLE)
-  message(STATUS "7-Zip already downloaded")
-  return()
-endif()
-
-message(STATUS "Downloading 7-Zip ${7ZIP_VERSION} (${7ZIP_URL}) ...")
-file(DOWNLOAD ${7ZIP_URL} ${7ZIP_FILE})
-
-find_program(MSIEXEC_EXECUTABLE msiexec)
-if(NOT MSIEXEC_EXECUTABLE)
-  message(FATAL_ERROR "Unable to find msiexec (required to extract 7-Zip msi \
-installer). Install 7-Zip yourself and make sure it is available in the path")    
-endif()
-
-message(STATUS "Extracting downloaded 7-Zip ...")
-
-# msiexec requires Windows path separators (\)
-file(TO_NATIVE_PATH ${7ZIP_FILE} 7ZIP_FILE)
-file(TO_NATIVE_PATH ${7ZIP_EXTRACT_DIR} 7ZIP_EXTRACT_DIR) 
-
-# msiexec with /a option allows extraction of msi installers without requiring
-# admin privileges. We use this to extract the 7-Zip installer without
-# requiring any actions from the user
-execute_process(COMMAND ${MSIEXEC_EXECUTABLE} /a ${7ZIP_FILE} /qn
-                        TARGETDIR=${7ZIP_EXTRACT_DIR}
-                WORKING_DIRECTORY ${7ZIP_DOWNLOAD_LOCATION}
-                OUTPUT_QUIET)     
-
-# Convert back to CMake separators (/) before returning
-file(TO_CMAKE_PATH ${7ZIP_EXTRACT_DIR} 7ZIP_EXTRACT_DIR)
-
-# Actual 7-Zip directory is nested inside the extract directory.
-set(DOWNLOADED_7ZIP_DIR ${7ZIP_EXTRACT_DIR}/Files/7-Zip PARENT_SCOPE)
-
-endfunction()

cmake/DownloadAndExtractClang.cmake

@@ -1,129 +0,0 @@
-# Downloads and extracts the Clang archive for the current system from
-# https://releases.llvm.org
-#
-# Returns the extracted Clang archive directory in DOWNLOADED_CLANG_DIR
-#
-# Downloads 7-Zip to extract Clang if it isn't available in the PATH
-function(download_and_extract_clang CLANG_DOWNLOAD_LOCATION)
-
-set(CLANG_VERSION 7.0.0)
-set(CLANG_ARCHIVE_EXT .tar.xz)
-
-if(${CMAKE_SYSTEM_NAME} STREQUAL Linux)
-
-  # Default to Ubuntu 16.04
-  set(CLANG_ARCHIVE_NAME
-      clang+llvm-${CLANG_VERSION}-x86_64-linux-gnu-ubuntu-16.04)
-
-elseif(${CMAKE_SYSTEM_NAME} STREQUAL Darwin)
-
-  set(CLANG_ARCHIVE_NAME clang+llvm-${CLANG_VERSION}-x86_64-apple-darwin)
-
-elseif(${CMAKE_SYSTEM_NAME} STREQUAL Windows)
-
-  set(CLANG_ARCHIVE_NAME LLVM-${CLANG_VERSION}-win64)
-  set(CLANG_ARCHIVE_EXT .exe)
-
-elseif(${CMAKE_SYSTEM_NAME} STREQUAL FreeBSD)
-
-  set(CLANG_ARCHIVE_NAME clang+llvm-${CLANG_VERSION}-amd64-unknown-freebsd11)
-
-endif()
-
-set(CLANG_ARCHIVE_FULL_NAME ${CLANG_ARCHIVE_NAME}${CLANG_ARCHIVE_EXT})
-set(CLANG_ARCHIVE_FILE ${CLANG_DOWNLOAD_LOCATION}/${CLANG_ARCHIVE_FULL_NAME})
-set(CLANG_ARCHIVE_EXTRACT_DIR ${CLANG_DOWNLOAD_LOCATION}/${CLANG_ARCHIVE_NAME})
-set(CLANG_ARCHIVE_URL
-    https://releases.llvm.org/${CLANG_VERSION}/${CLANG_ARCHIVE_FULL_NAME})
-set(CLANG_ARCHIVE_HASH_FILE
-    ${CMAKE_SOURCE_DIR}/clang_archive_hashes/${CLANG_ARCHIVE_FULL_NAME}.SHA256)
-
-# Exit if Clang is already downloaded and extracted
-set(CLANG_ROOT ${CLANG_ARCHIVE_EXTRACT_DIR})
-find_package(Clang ${CLANG_VERSION} QUIET)
-if(Clang_FOUND)
-  message(STATUS "Clang already downloaded")
-  set(DOWNLOADED_CLANG_DIR ${CLANG_ARCHIVE_EXTRACT_DIR} PARENT_SCOPE)
-  return()
-endif()
-
-if(NOT CLANG_ARCHIVE_NAME)
-  message(FATAL_ERROR "No Clang archive url specified for current platform \
-(${CMAKE_SYSTEM_NAME}). Please file an issue to get it added.")
-endif()
-
-if(NOT EXISTS ${CLANG_ARCHIVE_HASH_FILE})
-  message(FATAL_ERROR "No SHA256 hash available for the current platform \
-(${CMAKE_SYSTEM_NAME}) + clang version (${CLANG_VERSION}) combination. Please \
-file an issue to get it added.")
-endif()
-
-# Download Clang archive
-message(STATUS "Downloading Clang ${CLANG_VERSION} (${CLANG_ARCHIVE_URL}) ...")
-file(DOWNLOAD ${CLANG_ARCHIVE_URL} ${CLANG_ARCHIVE_FILE}
-     STATUS CLANG_ARCHIVE_DOWNLOAD_RESULT)
-
-# Abort if download failed
-list(GET ${CLANG_ARCHIVE_DOWNLOAD_RESULT} 0 ERROR_CODE)
-if(${ERROR_CODE})
-  list(GET ${CLANG_ARCHIVE_DOWNLOAD_RESULT} 1 ERROR_STRING)
-  message(FATAL_ERROR ${ERROR_STRING})
-endif()
-
-# Retrieve expected hash from file and strip newline
-file(READ ${CLANG_ARCHIVE_HASH_FILE} CLANG_ARCHIVE_EXPECTED_HASH)
-string(STRIP ${CLANG_ARCHIVE_EXPECTED_HASH} CLANG_ARCHIVE_EXPECTED_HASH)
-# Calculate actual hash
-file(SHA256 ${CLANG_ARCHIVE_FILE} CLANG_ARCHIVE_HASH)
-# Abort if hashes do not match
-if(NOT ${CLANG_ARCHIVE_EXPECTED_HASH} STREQUAL ${CLANG_ARCHIVE_HASH})
-  message(FATAL_ERROR "SHA256 hash of downloaded Clang does not match \
-expected hash. Remove the build directory and try running CMake again. If this \
-keeps happening, file an issue to report the problem.")
-endif()
-
-if(${CLANG_ARCHIVE_EXT} STREQUAL .exe)
-  # Download and extract 7-zip if not found in PATH
-  find_program(7ZIP_EXECUTABLE 7z)
-  if(NOT 7ZIP_EXECUTABLE)
-    message(STATUS "7-Zip not found in PATH")
-
-    include(DownloadAndExtract7zip)
-    download_and_extract_7zip(${CLANG_DOWNLOAD_LOCATION})
-    find_program(7ZIP_EXECUTABLE
-      NAMES 7z
-      NO_DEFAULT_PATH
-      PATHS ${DOWNLOADED_7ZIP_DIR}
-    )
-  else()
-    message(STATUS "7-Zip found in PATH")
-  endif()
-
-  message(STATUS "Extracting downloaded Clang with 7-Zip ...")
-
-  # Avoid running the Clang installer by extracting the exe with 7-Zip
-  execute_process(
-    COMMAND ${7ZIP_EXECUTABLE} x 
-            -o${CLANG_ARCHIVE_EXTRACT_DIR} 
-            -xr!$PLUGINSDIR ${CLANG_ARCHIVE_FILE}
-    WORKING_DIRECTORY ${CLANG_DOWNLOAD_LOCATION}
-    OUTPUT_QUIET
-  )
-
-elseif(${CLANG_ARCHIVE_EXT} STREQUAL .tar.xz)
-  message(STATUS "Extracting downloaded Clang with CMake built-in tar ...")
-
-  # CMake has builtin support for tar via the -E flag
-  execute_process(
-    COMMAND ${CMAKE_COMMAND} -E tar -xf ${CLANG_ARCHIVE_FILE}
-    # Specify working directory to allow running cmake from 
-    # everywhere
-    # (example: cmake -H"$HOME/cquery" -B"$home/cquery/build")
-    WORKING_DIRECTORY ${CLANG_DOWNLOAD_LOCATION}
-    OUTPUT_QUIET
-  )
-endif()
-
-set(DOWNLOADED_CLANG_DIR ${CLANG_ARCHIVE_EXTRACT_DIR} PARENT_SCOPE)
-
-endfunction()