Move CMake code for building multilib and variants to subprojects

arm-multilib/CMakeLists.txt

@@ -0,0 +1,282 @@
+#
+# Copyright (c) 2024, Arm Limited and affiliates.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# CMake build for a multilib layout of library variants, with each
+# variant in a subdirectory and a multilib.yaml file to map flags to
+# a variant.
+
+cmake_minimum_required(VERSION 3.20)
+
+project(arm-multilib)
+
+# Root directory of the repo.
+set(TOOLCHAIN_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/..)
+
+# Cache variables to be set by user
+set(MULTILIB_JSON "" CACHE STRING "JSON file to load library definitions from.")
+set(ENABLE_VARIANTS "all" CACHE STRING "Semicolon separated list of variants to build, or \"all\". Must match entries in the json.")
+set(C_LIBRARY "picolibc" CACHE STRING "Which C library to use.")
+set_property(CACHE C_LIBRARY PROPERTY STRINGS picolibc newlib llvmlibc)
+set(LLVM_BINARY_DIR "" CACHE PATH "Path to LLVM toolchain build or install root.")
+set(LIBC_HDRGEN "" CACHE PATH "Path to prebuilt lbc-hdrgen if not included in LLVM binaries set by LLVM_BINARY_DIR")
+set(
+    FVP_INSTALL_DIR
+    "" CACHE STRING
+    "The directory in which the FVP models are installed. These are not
+    included in this repository, but can be downloaded by the script
+    fvp/get_fvps.sh"
+)
+set(FVP_CONFIG_DIR "${TOOLCHAIN_SOURCE_DIR}/fvp/config" CACHE STRING "The directory in which the FVP models are installed.")
+
+# If a compiler launcher such as ccache has been set, it should be
+# passed down to each subproject build.
+set(compiler_launcher_cmake_args "")
+if(CMAKE_C_COMPILER_LAUNCHER)
+    list(APPEND compiler_launcher_cmake_args "-DCMAKE_C_COMPILER_LAUNCHER=${CMAKE_C_COMPILER_LAUNCHER}")
+endif()
+if(CMAKE_CXX_COMPILER_LAUNCHER)
+    list(APPEND compiler_launcher_cmake_args "-DCMAKE_CXX_COMPILER_LAUNCHER=${CMAKE_CXX_COMPILER_LAUNCHER}")
+endif()
+
+# Arguments to pass down to the library projects.
+foreach(arg
+    LLVM_BINARY_DIR
+    LIBC_HDRGEN
+    FVP_INSTALL_DIR
+    FVP_CONFIG_DIR
+)
+    if(${arg})
+        list(APPEND passthrough_dirs "-D${arg}=${${arg}}")
+    endif()
+endforeach()
+
+include(ExternalProject)
+include(${TOOLCHAIN_SOURCE_DIR}/cmake/fetch_llvm.cmake)
+list(APPEND passthrough_dirs "-DFETCHCONTENT_SOURCE_DIR_LLVMPROJECT=${FETCHCONTENT_SOURCE_DIR_LLVMPROJECT}")
+if(C_LIBRARY STREQUAL picolibc)
+    include(${TOOLCHAIN_SOURCE_DIR}/cmake/fetch_picolibc.cmake)
+    list(APPEND passthrough_dirs "-DFETCHCONTENT_SOURCE_DIR_PICOLIBC=${FETCHCONTENT_SOURCE_DIR_PICOLIBC}")
+elseif(C_LIBRARY STREQUAL newlib)
+    include(${TOOLCHAIN_SOURCE_DIR}/cmake/fetch_newlib.cmake)
+    list(APPEND passthrough_dirs "-DFETCHCONTENT_SOURCE_DIR_NEWLIB=${FETCHCONTENT_SOURCE_DIR_NEWLIB}")
+endif()
+
+# Target for any dependencies to build the runtimes project.
+add_custom_target(runtimes-depends)
+
+# If building llvm-libc, ensure libc-hdrgen is available.
+if(C_LIBRARY STREQUAL llvmlibc)
+    if(NOT LIBC_HDRGEN)
+        if(EXISTS ${LLVM_BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
+            set(LIBC_HDRGEN ${LLVM_BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
+        else()
+            ExternalProject_Add(
+                libc_hdrgen
+                SOURCE_DIR ${llvmproject_SOURCE_DIR}/llvm
+                CMAKE_ARGS
+                    -DLLVM_ENABLE_RUNTIMES=libc
+                    -DLLVM_LIBC_FULL_BUILD=ON
+                    -DCMAKE_BUILD_TYPE=Debug
+                BUILD_COMMAND ${CMAKE_COMMAND} --build . --target libc-hdrgen
+                INSTALL_COMMAND ${CMAKE_COMMAND} -E true
+                CONFIGURE_HANDLED_BY_BUILD TRUE
+            )
+            ExternalProject_Get_property(libc_hdrgen BINARY_DIR)
+            set(LIBC_HDRGEN ${BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
+            add_dependencies(runtimes-depends libc_hdrgen)
+        endif()
+    endif()
+    list(APPEND passthrough_dirs "-DLIBC_HDRGEN=${LIBC_HDRGEN}")
+endif()
+
+# Create one target to run all the tests.
+add_custom_target(check-${C_LIBRARY})
+add_custom_target(check-compiler-rt)
+add_custom_target(check-cxx)
+add_custom_target(check-cxxabi)
+add_custom_target(check-unwind)
+
+add_custom_target(check-all)
+add_dependencies(
+    check-all
+    check-${C_LIBRARY}
+    check-compiler-rt
+    check-cxx
+    check-cxxabi
+    check-unwind
+)
+
+# Read the JSON file to load a multilib configuration.
+file(READ ${MULTILIB_JSON} multilib_json_str)
+string(JSON multilib_defs GET ${multilib_json_str} "libs")
+
+string(JSON lib_count LENGTH ${multilib_defs})
+math(EXPR lib_count_dec "${lib_count} - 1")
+
+foreach(lib_idx RANGE ${lib_count_dec})
+    string(JSON lib_def GET ${multilib_defs} ${lib_idx})
+    string(JSON variant GET ${lib_def} "variant")
+
+    if(variant IN_LIST ENABLE_VARIANTS OR ENABLE_VARIANTS STREQUAL "all")
+        string(JSON variant_multilib_flags GET ${lib_def} "flags")
+        # Placeholder libraries won't have a json, so store the error in
+        # a variable so a fatal error isn't generated.
+        string(JSON variant_json ERROR_VARIABLE json_error GET ${lib_def} "json")
+
+        if(NOT variant_json STREQUAL "json-NOTFOUND")
+            # Sort by target triple
+            if(variant MATCHES "^aarch64")
+                set(parent_dir_name aarch64-none-elf)
+            else()
+                set(parent_dir_name arm-none-eabi)
+            endif()
+            set(destination_directory "${CMAKE_CURRENT_BINARY_DIR}/multilib/${parent_dir_name}/${variant}")
+            install(
+                DIRECTORY ${destination_directory}
+                DESTINATION ${parent_dir_name}
+            )
+            set(variant_json_file ${CMAKE_CURRENT_SOURCE_DIR}/json/variants/${variant_json})
+
+            ExternalProject_Add(
+                runtimes-${variant}
+                PREFIX ${CMAKE_BINARY_DIR}/lib-builds
+                SOURCE_DIR ${TOOLCHAIN_SOURCE_DIR}/arm-runtimes
+                INSTALL_DIR ${destination_directory}
+                DEPENDS runtimes-depends
+                CMAKE_ARGS
+                ${compiler_launcher_cmake_args}
+                ${passthrough_dirs}
+                -DVARIANT_JSON=${variant_json_file}
+                -DC_LIBRARY=${C_LIBRARY}
+                -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
+                STEP_TARGETS build install
+                USES_TERMINAL_CONFIGURE FALSE
+                USES_TERMINAL_BUILD TRUE
+                USES_TERMINAL_TEST TRUE
+                LIST_SEPARATOR ,
+                CONFIGURE_HANDLED_BY_BUILD TRUE
+                TEST_EXCLUDE_FROM_MAIN TRUE
+            )
+
+            # Read info from the variant specific json.
+            # From the json, check which tests are enabled.
+            file(READ ${variant_json_file} variant_json_str)
+            foreach(test_enable_var
+                ENABLE_LIBC_TESTS
+                ENABLE_COMPILER_RT_TESTS
+                ENABLE_LIBCXX_TESTS
+            )
+                string(JSON read_${test_enable_var} ERROR_VARIABLE json_error GET ${variant_json_str} "args" ${C_LIBRARY} ${test_enable_var})
+                if(read_${test_enable_var} STREQUAL "json-NOTFOUND")
+                    string(JSON read_${test_enable_var} ERROR_VARIABLE json_error GET ${variant_json_str} "args" "common" ${test_enable_var})
+                    if(read_${test_enable_var} STREQUAL "json-NOTFOUND")
+                        set(read_${test_enable_var} "OFF")
+                    endif()
+                endif()
+            endforeach()
+            set(check_targets "")
+            if(read_ENABLE_LIBC_TESTS)
+                list(APPEND check_targets check-${C_LIBRARY})
+            endif()
+            if(read_ENABLE_COMPILER_RT_TESTS)
+                list(APPEND check_targets check-compiler-rt)
+            endif()
+            if(read_ENABLE_LIBCXX_TESTS)
+                list(APPEND check_targets check-cxx)
+                list(APPEND check_targets check-cxxabi)
+                list(APPEND check_targets check-unwind)
+            endif()
+            foreach(check_target ${check_targets})
+                ExternalProject_Add_Step(
+                    runtimes-${variant}
+                    ${check_target}
+                    COMMAND "${CMAKE_COMMAND}" --build <BINARY_DIR> --target ${check_target}
+                    USES_TERMINAL TRUE
+                    EXCLUDE_FROM_MAIN TRUE
+                    ALWAYS TRUE
+                )
+                ExternalProject_Add_StepTargets(runtimes-${variant} ${check_target})
+                ExternalProject_Add_StepDependencies(
+                    runtimes-${variant}
+                    ${check_target}
+                    runtimes-${variant}-build
+                )
+                add_custom_target(${check_target}-${variant})
+                add_dependencies(${check_target} runtimes-${variant}-${check_target})
+                add_dependencies(${check_target}-${variant} runtimes-${variant}-${check_target})
+            endforeach()
+
+            # Add the variant to the multilib yaml
+            string(APPEND multilib_yaml_content "- Dir: ${parent_dir_name}/${variant}\n")
+            string(APPEND multilib_yaml_content "  Flags:\n")
+            string(REPLACE " " ";" multilib_flags_list ${variant_multilib_flags})
+            foreach(flag ${multilib_flags_list})
+                string(APPEND multilib_yaml_content "  - ${flag}\n")
+            endforeach()
+            string(APPEND multilib_yaml_content "  Group: stdlibs\n")
+        else()
+            # In place of a json, an error message is expected.
+            string(JSON variant_error_msg GET ${lib_def} "error")
+
+            string(APPEND multilib_yaml_content "- Error: \"${variant_error_msg}\"\n")
+            string(APPEND multilib_yaml_content "  Flags:\n")
+            string(REPLACE " " ";" multilib_flags_list ${variant_multilib_flags})
+            foreach(flag ${multilib_flags_list})
+                string(APPEND multilib_yaml_content "  - ${flag}\n")
+            endforeach()
+            string(APPEND multilib_yaml_content "  Group: stdlibs\n")
+        endif()
+    endif()
+
+endforeach()
+
+# Multilib file is generated in two parts.
+# 1. Template is filled with multilib flags from json
+configure_file(
+    ${CMAKE_CURRENT_SOURCE_DIR}/multilib.yaml.in
+    ${CMAKE_CURRENT_BINARY_DIR}/multilib-without-fpus.yaml
+    @ONLY
+)
+
+# 2. multilib-generate.py maps compiler command line options to flags
+add_custom_command(
+    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/multilib-fpus.yaml
+    COMMAND ${Python3_EXECUTABLE} "${CMAKE_CURRENT_SOURCE_DIR}/multilib-generate.py"
+        "--clang=${LLVM_BINARY_DIR}/bin/clang${CMAKE_EXECUTABLE_SUFFIX}"
+        "--llvm-source=${FETCHCONTENT_SOURCE_DIR_LLVMPROJECT}"
+    >> ${CMAKE_CURRENT_BINARY_DIR}/multilib-fpus.yaml
+)
+
+# Combine the two parts.
+add_custom_command(
+    OUTPUT
+        ${CMAKE_CURRENT_BINARY_DIR}/multilib/multilib.yaml
+    COMMAND
+        ${CMAKE_COMMAND} -E cat
+        ${CMAKE_CURRENT_BINARY_DIR}/multilib-without-fpus.yaml
+        ${CMAKE_CURRENT_BINARY_DIR}/multilib-fpus.yaml
+        > ${CMAKE_CURRENT_BINARY_DIR}/multilib/multilib.yaml
+    DEPENDS
+        ${CMAKE_CURRENT_BINARY_DIR}/multilib-without-fpus.yaml
+        ${CMAKE_CURRENT_BINARY_DIR}/multilib-fpus.yaml
+)
+
+add_custom_target(multilib-yaml ALL DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/multilib/multilib.yaml)
+install(
+    FILES ${CMAKE_CURRENT_BINARY_DIR}/multilib/multilib.yaml
+    DESTINATION .
+)