Multilib

CMakeLists.txt

@@ -176,6 +176,8 @@ if(NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE Release CACHE BOOL "" FORCE)
 endif()
 
+find_package(Python3 REQUIRED COMPONENTS Interpreter)
+
 if(NOT CMAKE_C_COMPILER_LAUNCHER AND NOT CMAKE_CXX_COMPILER_LAUNCHER)
     # If ccache is available then use it by default.
     find_program(CCACHE_EXECUTABLE ccache)
@@ -457,7 +459,7 @@ function(add_picolibc directory variant target_triple flags qemu_params variant_
         INSTALL_DIR "${LLVM_BINARY_DIR}/${directory}"
         PREFIX picolibc/${variant}
         DEPENDS clang lld llvm-ar llvm-config llvm-nm llvm-ranlib llvm-strip
-        CONFIGURE_COMMAND ${MESON_EXECUTABLE} -Dincludedir=include -Dlibdir=lib -Dspecsdir=none --prefix <INSTALL_DIR> --cross-file <BINARY_DIR>/meson-cross-build.txt ${picolibc_SOURCE_DIR}
+        CONFIGURE_COMMAND ${MESON_EXECUTABLE} -Dincludedir=include -Dlibdir=lib -Dspecsdir=none -Dmultilib=false --prefix <INSTALL_DIR> --cross-file <BINARY_DIR>/meson-cross-build.txt ${picolibc_SOURCE_DIR}
         BUILD_COMMAND ninja
         INSTALL_COMMAND ${MESON_EXECUTABLE} install ${MESON_INSTALL_QUIET}
         USES_TERMINAL_CONFIGURE TRUE
@@ -831,7 +833,7 @@ function(make_config_cfg directory variant flags)
     )
 endfunction()
 
-function(get_compiler_rt_target_triple target_arch)
+function(get_compiler_rt_target_triple target_arch flags)
     if(target_arch STREQUAL "aarch64")
         set(target_triple "aarch64-none-elf")
     else()
@@ -861,7 +863,7 @@ endfunction()
 function(add_library_variants)
     set(variant_args "${ARGN}")
     while(variant_args)
-        list(POP_FRONT variant_args target_arch variant_suffix flags qemu_params)
+        list(POP_FRONT variant_args target_arch variant_suffix compile_flags multilib_flags qemu_params)
 
         if(variant_suffix)
             set(variant "${target_arch}_${variant_suffix}")
@@ -884,18 +886,18 @@ function(add_library_variants)
             set(parent_dir_name arm-none-eabi)
         endif()
 
-        get_compiler_rt_target_triple(${target_arch})
+        get_compiler_rt_target_triple("${target_arch}" "${compile_flags}")
 
         set(directory "${TARGET_LIBRARIES_DIR}/${parent_dir_name}/${variant}")
-        set(flags "--target=${target_triple} ${flags}")
-        make_config_cfg("${directory}" "${variant}" "${flags}")
+        set(compile_flags "--target=${target_triple} ${compile_flags}")
+        make_config_cfg("${directory}" "${variant}" "${compile_flags}")
         set(variant_options)
         if(NOT PREBUILT_TARGET_LIBRARIES)
-            add_picolibc("${directory}" "${variant}" "${target_triple}" "${flags}" "${qemu_params}" variant_options)
-            add_compiler_rt("${directory}" "${variant}" "${target_triple}" "${flags}" "${qemu_params}" "picolibc_${variant}")
+            add_picolibc("${directory}" "${variant}" "${target_triple}" "${compile_flags}" "${qemu_params}" variant_options)
+            add_compiler_rt("${directory}" "${variant}" "${target_triple}" "${compile_flags}" "${qemu_params}" "picolibc_${variant}")
             list(APPEND variant_options ${picolibc_specific_runtimes_options})
-            add_libcxx_libcxxabi_libunwind("${directory}" "${variant}" "${target_triple}" "${flags}" "picolibc_${variant}" "${variant_options}")
-            if(flags MATCHES "-march=armv8")
+            add_libcxx_libcxxabi_libunwind("${directory}" "${variant}" "${target_triple}" "${compile_flags}" "picolibc_${variant}" "${variant_options}")
+            if(compile_flags MATCHES "-march=armv8")
                 message("C++ runtime libraries tests disabled for ${variant}")
             else()
                 add_custom_target(check-llvm-toolchain-runtimes-${variant})
@@ -905,30 +907,52 @@ function(add_library_variants)
             endif()
         endif()
 
+        string(APPEND multilib_yaml_content "- Dir: ${parent_dir_name}/${variant}\n")
+
+        string(APPEND multilib_yaml_content "  Flags:\n")
+        string(REPLACE " " ";" multilib_flags_list ${multilib_flags})
+        foreach(flag ${multilib_flags_list})
+          string(APPEND multilib_yaml_content "  - ${flag}\n")
+        endforeach()
+
         install(
             DIRECTORY "${LLVM_BINARY_DIR}/${directory}/"
             DESTINATION "${directory}"
             COMPONENT llvm-toolchain-libs
         )
     endwhile()
+    set(multilib_yaml_content "${multilib_yaml_content}" PARENT_SCOPE)
 endfunction()
 
+set(multilib_yaml_content "")
+
 # Define which library variants to build and which flags to use.
-# The order is <parent dir> <arch> <name suffix> <flags> <qemu params>
+# The order is <arch> <name suffix> <compile flags> <multilib selection flags> <qemu params>
 add_library_variants(
-    aarch64         ""                  "-march=armv8-a"                                        "-M virt -cpu cortex-a57"
-    armv4t          ""                  "-march=armv4t"                                         "-M musicpal -cpu arm926"
-    armv5te         ""                  "-march=armv5te"                                        "-M musicpal -cpu arm926"
-    armv6m          soft_nofp           "-mfloat-abi=soft -march=armv6m"                        "-M mps2-an385"
-    armv7m          soft_nofp           "-mfloat-abi=soft -march=armv7m+nofp"                   "-M mps2-an385 -cpu cortex-m3"
-    armv7em         soft_nofp           "-mfloat-abi=soft -march=armv7em -mfpu=none"            "-M mps2-an386 -cpu cortex-m4"
-    armv7em         hard_fpv4_sp_d16    "-mfloat-abi=hard -march=armv7em -mfpu=fpv4-sp-d16"     "-M mps2-an386 -cpu cortex-m4"
-    armv7em         hard_fpv5_d16       "-mfloat-abi=hard -march=armv7em -mfpu=fpv5-d16"        "-M mps2-an500 -cpu cortex-m7"
-    armv8m.main     soft_nofp           "-mfloat-abi=soft -march=armv8m.main+nofp"              "-M mps2-an505 -cpu cortex-m33"
-    armv8m.main     hard_fp             "-mfloat-abi=hard -march=armv8m.main+fp"                "-M mps2-an505 -cpu cortex-m33"
-    armv8.1m.main   soft_nofp_nomve     "-mfloat-abi=soft -march=armv8.1m.main+nofp+nomve"      "-M mps3-an547 -cpu cortex-m55"
-    armv8.1m.main   hard_fp             "-mfloat-abi=hard -march=armv8.1m.main+fp"              "-M mps3-an547 -cpu cortex-m55"
-    armv8.1m.main   hard_nofp_mve       "-mfloat-abi=hard -march=armv8.1m.main+nofp+mve"        "-M mps3-an547 -cpu cortex-m55"
+    aarch64         ""                  "-march=armv8-a"                                        "--target=aarch64-none-unknown-elf"                                                         "-M virt -cpu cortex-a57"
+    armv4t          ""                  "-march=armv4t"                                         "--target=armv4t-none-unknown-eabi -mfpu=none"                                              "-M musicpal -cpu arm926"
+    armv5te         ""                  "-march=armv5te"                                        "--target=armv5e-none-unknown-eabi -mfpu=none"                                              "-M musicpal -cpu arm926"
+    armv6m          soft_nofp           "-mfloat-abi=soft -march=armv6m"                        "--target=thumbv6m-none-unknown-eabi -mfpu=none"                                            "-M mps2-an385"
+    armv7m          soft_nofp           "-mfloat-abi=soft -march=armv7m+nofp"                   "--target=thumbv7m-none-unknown-eabi -mfpu=none"                                            "-M mps2-an385 -cpu cortex-m3"
+    armv7em         soft_nofp           "-mfloat-abi=soft -march=armv7em -mfpu=none"            "--target=thumbv7em-none-unknown-eabi -mfpu=none"                                           "-M mps2-an386 -cpu cortex-m4"
+    armv7em         hard_fpv4_sp_d16    "-mfloat-abi=hard -march=armv7em -mfpu=fpv4-sp-d16"     "--target=thumbv7em-none-unknown-eabihf -mfpu=fpv4-sp-d16"                                  "-M mps2-an386 -cpu cortex-m4"
+    armv7em         hard_fpv5_d16       "-mfloat-abi=hard -march=armv7em -mfpu=fpv5-d16"        "--target=thumbv7em-none-unknown-eabihf -mfpu=fpv5-d16"                                     "-M mps2-an500 -cpu cortex-m7"
+    armv8m.main     soft_nofp           "-mfloat-abi=soft -march=armv8m.main+nofp"              "--target=thumbv8m.main-none-unknown-eabi -mfpu=none"                                       "-M mps2-an505 -cpu cortex-m33"
+    armv8m.main     hard_fp             "-mfloat-abi=hard -march=armv8m.main+fp"                "--target=thumbv8m.main-none-unknown-eabihf -mfpu=fpv5-d16"                                 "-M mps2-an505 -cpu cortex-m33"
+    armv8.1m.main   soft_nofp_nomve     "-mfloat-abi=soft -march=armv8.1m.main+nofp+nomve"      "--target=thumbv8.1m.main-none-unknown-eabi -mfpu=none"                                     "-M mps3-an547 -cpu cortex-m55"
+    armv8.1m.main   hard_fp             "-mfloat-abi=hard -march=armv8.1m.main+fp"              "--target=thumbv8.1m.main-none-unknown-eabihf -march=thumbv8.1m.main+fp16 -mfpu=fp-armv8-fullfp16-sp-d16"   "-M mps3-an547 -cpu cortex-m55"
+    armv8.1m.main   hard_nofp_mve       "-mfloat-abi=hard -march=armv8.1m.main+nofp+mve"        "--target=thumbv8.1m.main-none-unknown-eabihf -march=thumbv8.1m.main+dsp+mve -mfpu=none"    "-M mps3-an547 -cpu cortex-m55"
+)
+
+configure_file(
+    ${CMAKE_CURRENT_SOURCE_DIR}/cmake/multilib.yaml.in
+    ${CMAKE_CURRENT_BINARY_DIR}/llvm/${TARGET_LIBRARIES_DIR}/multilib.yaml
+    @ONLY
+)
+install(
+    FILES ${CMAKE_CURRENT_BINARY_DIR}/llvm/${TARGET_LIBRARIES_DIR}/multilib.yaml
+    DESTINATION ${TARGET_LIBRARIES_DIR}
+    COMPONENT llvm-toolchain-libs
 )
 
 install(
@@ -1075,12 +1099,15 @@ add_dependencies(
 
 
 
+# TODO move this into tests/CMakeLists.txt
 # Smoke tests
 
 # Run tests on the built toolchain.
 add_custom_target(check-llvm-toolchain)
 add_dependencies(check-llvm-toolchain check-picolibc)
 add_dependencies(check-llvm-toolchain check-compiler-rt)
+add_subdirectory(tests)
+add_dependencies(check-llvm-toolchain check-llvm-toolchain-lit)
 
 # Run tests on the packaged and unpacked toolchain.
 add_custom_target(check-package-llvm-toolchain)

cmake/multilib.yaml.in

@@ -0,0 +1,140 @@
+#
+# Copyright (c) 2023, 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.
+#
+
+# If you're reading this file under the name 'multilib.yaml.in' in the
+# LLVM-embedded-toolchain-for-Arm source tree, then it's not valid
+# YAML in its own right: it's a template that CMakeLists.txt will
+# expand into a real 'multilib.yaml' containing a list of library
+# variants and the flags that will select them.
+#
+# If you're reading it under the name 'multilib.yaml' in the build or
+# install directory, then that substitution has been done.
+#
+# Comments in this file mostly make more sense from the
+# multilib.yaml.in point of view.
+
+MultilibVersion: '1.0'
+
+# The list of library variants is substituted in by CMakeLists.txt, so
+# that it can respect the LLVM_TOOLCHAIN_LIBRARY_VARIANTS setting and
+# only include the set of libraries actually included in this build.
+
+Variants:
+@multilib_yaml_content@
+
+Mappings:
+
+# Map higher architecture versions to subsets of them, so that a
+# compatible library can be found even for architectures we don't have
+# specific variants for.
+
+# v8-M Baseline is a superset of v6-M
+- Match: --target=thumbv8m\.base-none-unknown-eabi
+  Flags:
+  - --target=thumbv6m-none-unknown-eabi
+
+# v8.2-M Mainline is a superset of v8.1-M Mainline, in both hard and
+# soft float variants.
+#
+# Also, v8.1-M Mainline is also a superset of v8-M Mainline, which in
+# turn is a superset of v7E-M, and then of plain v7-M. We have
+# libraries for all those architecture versions, but not for every
+# combination of them with FPUs, so in some cases it might be
+# necessary to fall back to a lower architecture in order to provide
+# the needed FPU support.
+- Match: --target=thumbv8\.[2-9]m\.main-none-unknown-eabi
+  Flags:
+  - --target=thumbv8.1m.main-none-unknown-eabi
+  - --target=thumbv8m.main-none-unknown-eabi
+  - --target=thumbv7em-none-unknown-eabi
+  - --target=thumbv7m-none-unknown-eabi
+- Match: --target=thumbv8\.[2-9]m\.main-none-unknown-eabihf
+  Flags:
+  - --target=thumbv8.1m.main-none-unknown-eabihf
+  - --target=thumbv8m.main-none-unknown-eabihf
+  - --target=thumbv7em-none-unknown-eabihf
+  - --target=thumbv7m-none-unknown-eabihf
+- Match: --target=thumbv8\.1m\.main-none-unknown-eabi
+  Flags:
+  - --target=thumbv8m.main-none-unknown-eabi
+  - --target=thumbv7em-none-unknown-eabi
+  - --target=thumbv7m-none-unknown-eabi
+- Match: --target=thumbv8\.1m\.main-none-unknown-eabihf
+  Flags:
+  - --target=thumbv8m.main-none-unknown-eabihf
+  - --target=thumbv7em-none-unknown-eabihf
+  - --target=thumbv7m-none-unknown-eabihf
+- Match: --target=thumbv8m\.main-none-unknown-eabi
+  Flags:
+  - --target=thumbv7em-none-unknown-eabi
+  - --target=thumbv7m-none-unknown-eabi
+- Match: --target=thumbv8m\.main-none-unknown-eabihf
+  Flags:
+  - --target=thumbv7em-none-unknown-eabihf
+  - --target=thumbv7m-none-unknown-eabihf
+- Match: --target=thumbv7em-none-unknown-eabi
+  Flags:
+  - --target=thumbv7m-none-unknown-eabi
+- Match: --target=thumbv7em-none-unknown-eabihf
+  Flags:
+  - --target=thumbv7m-none-unknown-eabihf
+
+# Higher versions of v8-A, and v9-A, are all supersets of v8-A. (And
+# of each other, in the obvious way, but we don't have any libraries
+# for those at present, so there's no need to generate all their
+# flags.)
+- Match: --target=armv(8\.[1-9]|9|9\.[1-9])a-none-unknown-eabi
+  Flags:
+  - --target=armv8a-none-unknown-eabi
+
+# -march extensions
+- Match: -march=thumbv8\.[1-9]m\.main.*\+fp16.*
+  Flags:
+  - -march=thumbv8.1m.main+fp16
+- Match: -march=thumbv8\.[1-9]m\.main.*\+dsp.*\+mve.*
+  Flags:
+  - -march=thumbv8.1m.main+dsp+mve
+- Match: -march=thumbv8\.[1-9]m\.main.*\+fp16.*\+lob.*\+mve\.fp.*
+  Flags:
+  - -march=thumbv8.1m.main+fp16+lob+mve.fp
+
+# Hierarchy among FPUs: fpvN-d16 is a superset of fpvN-sp-d16, and
+# fpvN-d16 is a superset of fpv[N-1]-d16, for all N.
+#
+# We don't consider any hardware FP configuration to be compatible
+# with -mfpu=none. It would work in most cases to cross-call between
+# code compiled for an FPU or no FPU, if you were using the soft float
+# ABI. But it wouldn't work in all cases: setjmp needs to know whether
+# to save FP registers in the jmp_buf, so a non-FPU-aware setjmp would
+# not behave correctly if linked into an otherwise FPU-using
+# application. Similarly for exception unwinding. So we don't permit
+# selecting an -mfpu=none library as a fallback for any hard-FP
+# library.
+- Match: -mfpu=fpv5-d16
+  Flags:
+  - -mfpu=fpv4-d16
+  - -mfpu=fpv5-sp-d16
+  - -mfpu=fpv4-sp-d16
+- Match: -mfpu=fpv5-sp-d16
+  Flags:
+  - -mfpu=fpv4-sp-d16
+- Match: -mfpu=fpv4-d16
+  Flags:
+  - -mfpu=fpv4-sp-d16
+- Match: -mfpu=fp-armv8-fullfp16-d16
+  Flags:
+  - -mfpu=fp-armv8-fullfp16-sp-d16

tests/CMakeLists.txt

@@ -0,0 +1,30 @@
+if(LLVM_ENABLE_BACKTRACES)
+  set(ENABLE_BACKTRACES 1)
+endif()
+llvm_canonicalize_cmake_booleans(
+  ENABLE_BACKTRACES
+)
+
+configure_lit_site_cfg(
+  ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
+  ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
+  MAIN_CONFIG
+  ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
+)
+
+list(APPEND LLVM_TOOLCHAIN_TEST_DEPS
+  llvm-toolchain
+  FileCheck
+  count
+  not
+)
+
+add_lit_testsuite(check-llvm-toolchain-lit
+  "Running LLVM Embedded Toolchain for Arm regression tests"
+  ${CMAKE_CURRENT_BINARY_DIR}
+  DEPENDS ${LLVM_TOOLCHAIN_TEST_DEPS}
+)
+
+add_lit_testsuites(llvm-toolchain-lit ${CMAKE_CURRENT_SOURCE_DIR}
+  DEPENDS ${LLVM_TOOLCHAIN_TEST_DEPS}
+)

tests/lit.cfg.py

@@ -0,0 +1,20 @@
+# -*- Python -*-
+
+import os
+
+import lit.formats
+
+from lit.llvm import llvm_config
+
+# Configuration file for the 'lit' test runner.
+
+config.name = 'LLVM Embedded Toolchain for Arm'
+config.test_format = lit.formats.ShTest(not llvm_config.use_lit_shell)
+config.suffixes = ['.test']
+config.excludes = ['CMakeLists.txt', 'Makefile.conf', 'ldscripts', 'smoketests']
+config.test_source_root = os.path.dirname(__file__)
+
+llvm_config.use_default_substitutions()
+llvm_config.use_clang()
+
+config.environment["CLANG_NO_DEFAULT_CONFIG"] = "1"

tests/lit.site.cfg.py.in

@@ -0,0 +1,19 @@
+@LIT_SITE_CFG_IN_HEADER@
+
+config.llvm_src_root = "@LLVM_SOURCE_DIR@"
+config.llvm_obj_root = "@LLVM_BINARY_DIR@"
+config.llvm_tools_dir = lit_config.substitute("@LLVM_BINARY_DIR@/bin")
+config.llvm_libs_dir = lit_config.substitute("@LLVM_BINARY_DIR@/lib")
+config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
+config.enable_backtrace = @ENABLE_BACKTRACES@
+config.errc_messages = "@LLVM_LIT_ERRC_MESSAGES@"
+config.host_triple = "@LLVM_HOST_TRIPLE@"
+config.target_triple = "@LLVM_DEFAULT_TARGET_TRIPLE@"
+config.python_executable = "@Python3_EXECUTABLE@"
+config.test_exec_root = "@CMAKE_CURRENT_BINARY_DIR@"
+
+import lit.llvm
+lit.llvm.initialize(lit_config, config)
+
+# Let the main config do the real work.
+lit_config.load_config(config, "@CMAKE_CURRENT_SOURCE_DIR@/lit.cfg.py")

tests/multilib/aarch64.test

@@ -0,0 +1,2 @@
+# RUN: %clang -print-multi-directory --target=aarch64-none-elf | FileCheck %s
+# CHECK: aarch64-none-elf/aarch64

tests/multilib/armv4t.test

@@ -0,0 +1,2 @@
+# RUN: %clang -print-multi-directory --target=arm-none-eabi | FileCheck %s
+# CHECK: arm-none-eabi/armv4t

tests/multilib/armv5e.test

@@ -0,0 +1,2 @@
+# RUN: %clang -print-multi-directory --target=armv5e-none-eabi | FileCheck %s
+# CHECK: arm-none-eabi/armv5te

tests/multilib/armv6m.test

@@ -0,0 +1,2 @@
+# RUN: %clang -print-multi-directory --target=armv6m-none-eabi | FileCheck %s
+# CHECK: arm-none-eabi/armv6m_soft_nofp

tests/multilib/armv7em.test

@@ -0,0 +1,8 @@
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabi -mfpu=none | FileCheck %s
+# CHECK: arm-none-eabi/armv7em_soft_nofp
+
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabihf -mfpu=fpv4-sp-d16 | FileCheck --check-prefix=FPV4 %s
+# FPV4: arm-none-eabi/armv7em_hard_fpv4_sp_d16
+
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabihf -mfpu=fpv5-d16 | FileCheck --check-prefix=FPV5 %s
+# FPV5: arm-none-eabi/armv7em_hard_fpv5_d16

tests/multilib/armv7m.test

@@ -0,0 +1,2 @@
+# RUN: %clang -print-multi-directory --target=armv7m-none-eabi | FileCheck %s
+# CHECK: arm-none-eabi/armv7m_soft_nofp

tests/multilib/armv8.1m.main.test

@@ -0,0 +1,11 @@
+# RUN: %clang -print-multi-directory --target=armv8.1m.main-none-eabi -mfpu=none | FileCheck %s
+# CHECK: arm-none-eabi/armv8.1m.main_soft_nofp
+
+# RUN: %clang -print-multi-directory --target=armv8.1m.main-none-eabihf -march=armv8.1m.main+fp | FileCheck --check-prefix=HARD %s
+# HARD: arm-none-eabi/armv8.1m.main_hard_fp
+
+# RUN: %clang -print-multi-directory --target=armv8.1m.main-none-eabihf -march=armv8.1m.main+nofp+mve | FileCheck --check-prefix=MVE %s
+# MVE: arm-none-eabi/armv8.1m.main_hard_nofp_mve
+
+# RUN: %clang -print-multi-flags-experimental --target=arm-none-eabihf -mcpu=cortex-m55 | FileCheck --check-prefix=CORTEXM55 %s
+# CORTEXM55: -march=thumbv8.1m.main+fp16+lob+mve.fp

tests/multilib/armv8m.main.test

@@ -0,0 +1,5 @@
+# RUN: %clang -print-multi-directory --target=armv8m.main-none-eabi -mfpu=none | FileCheck %s
+# CHECK: arm-none-eabi/armv8m.main_soft_nofp
+
+# RUN: %clang -print-multi-directory --target=armv8m.main-none-eabihf | FileCheck --check-prefix=HARD %s
+# HARD: arm-none-eabi/armv8m.main_hard_fp