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1# This macro mocks enough of the changes `LLVMConfig.cmake` makes so that2# compiler-rt can successfully configure itself when a LLVM toolchain is3# available but the corresponding CMake build files are not.4#5# The motivation for this is to be able to generate the compiler-rt6# lit tests suites and run them against an arbitrary LLVM toolchain7# which doesn't ship the LLVM CMake build files.8macro(compiler_rt_mock_llvm_cmake_config)9 message(STATUS "Attempting to mock the changes made by LLVMConfig.cmake")10 compiler_rt_mock_llvm_cmake_config_set_cmake_path()11 compiler_rt_mock_llvm_cmake_config_set_target_triple()12 compiler_rt_mock_llvm_cmake_config_include_cmake_files()13endmacro()14 15macro(compiler_rt_mock_llvm_cmake_config_set_cmake_path)16 # Point `LLVM_CMAKE_DIR` at the source tree in the monorepo.17 set(LLVM_CMAKE_DIR "${LLVM_MAIN_SRC_DIR}/cmake/modules")18 if (NOT EXISTS "${LLVM_CMAKE_DIR}")19 message(FATAL_ERROR "LLVM_CMAKE_DIR (${LLVM_CMAKE_DIR}) does not exist")20 endif()21 list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")22 message(STATUS "LLVM_CMAKE_DIR: \"${LLVM_CMAKE_DIR}\"")23endmacro()24 25function(compiler_rt_mock_llvm_cmake_config_set_target_triple)26 # Various bits of compiler-rt depend on the `LLVM_TARGET_TRIPLE` variable27 # being defined. This function tries to set a sensible value for the28 # variable. This is a function rather than a macro to avoid polluting the29 # variable namespace.30 set(COMPILER_OUTPUT "")31 32 # If the user provides `COMPILER_RT_DEFAULT_TARGET_ONLY` and `CMAKE_C_COMPILER_TARGET`33 # (see `construct_compiler_rt_default_triple`) then prefer that to examining the34 # compiler.35 if (COMPILER_RT_DEFAULT_TARGET_ONLY)36 if (NOT "${CMAKE_C_COMPILER_TARGET}" STREQUAL "")37 message(STATUS38 "Using CMAKE_C_COMPILER_TARGET (${CMAKE_C_COMPILER_TARGET}) as LLVM_TARGET_TRIPLE")39 endif()40 set(COMPILER_OUTPUT "${CMAKE_C_COMPILER_TARGET}")41 endif()42 43 # Try asking the compiler for its default target triple.44 set(HAD_ERROR FALSE)45 if ("${COMPILER_OUTPUT}" STREQUAL "")46 if ("${CMAKE_C_COMPILER_ID}" MATCHES "Clang|GNU")47 # Note: Clang also supports `-print-target-triple` but gcc doesn't48 # support this flag.49 set(DUMPMACHINE_ARG -dumpmachine)50 if(MSVC)51 # Use /clang:-dumpmachine for clang-cl.52 set(DUMPMACHINE_ARG /clang:-dumpmachine)53 endif()54 execute_process(55 COMMAND "${CMAKE_C_COMPILER}" ${DUMPMACHINE_ARG}56 RESULT_VARIABLE HAD_ERROR57 OUTPUT_VARIABLE COMPILER_OUTPUT58 OUTPUT_STRIP_TRAILING_WHITESPACE)59 else()60 message(FATAL_ERROR61 "Fetching target triple from compiler \"${CMAKE_C_COMPILER_ID}\" "62 "is not implemented.")63 endif()64 endif()65 66 if (HAD_ERROR)67 message(FATAL_ERROR "Fetching target triple from compiler failed")68 endif()69 set(LLVM_TARGET_TRIPLE "${COMPILER_OUTPUT}")70 message(STATUS "TARGET_TRIPLE: \"${LLVM_TARGET_TRIPLE}\"")71 if ("${LLVM_TARGET_TRIPLE}" STREQUAL "")72 message(FATAL_ERROR "TARGET_TRIPLE cannot be empty")73 endif()74 set(LLVM_TARGET_TRIPLE "${LLVM_TARGET_TRIPLE}" PARENT_SCOPE)75endfunction()76 77macro(compiler_rt_mock_llvm_cmake_config_include_cmake_files)78 # Some compiler-rt CMake code needs to call code in this file.79 include("${LLVM_CMAKE_DIR}/AddLLVM.cmake")80endmacro()81