Can I build LLVM using Basel for macOS+arm64

wangkuiyi · December 7, 2022, 4:04am

It seems that the closest configuration is generic_clang. So I tried it on my M1 MacBook Pro.

USE_BAZEL_VERSION=5.0.0 /opt/homebrew/bin/bazel build --config=generic_clang @llvm-project//...

Unfortunately, I got the following error.

FPUtil/FEnvImpl.h:16:10: fatal error: 'aarch64/fenv_darwin_impl.h' file not found

It seems that the aarch64/fenv_darwin_impl.h is not in the MacOSX.sdk.

$ cd
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/
$ du -a | grep fenv
8	./usr/include/c++/v1/fenv.h
8	./usr/include/c++/v1/cfenv
16	./usr/include/fenv.h
16	./usr/share/man/man3/fenv.3

Reading llvm-project/config.bzl at 70de0e014013b4d97febe6704881a9a8c893d078 · llvm/llvm-project · GitHub, it seems that there is “darwin_arm64”. How can I use it from the Bazel build command-line?

tschuett · December 7, 2022, 8:33am

This file was added during the initial commit of libc for Darwin arm64:
https://reviews.llvm.org/D120914

It is today in the mono repo:

github.com

llvm/llvm-project/blob/main/libc/src/__support/FPUtil/aarch64/fenv_darwin_impl.h

//===- darwin-aarch64 floating point env manipulation functions -*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIBC_SRC_SUPPORT_FPUTIL_AARCH64_FENV_DARWIN_IMPL_H
#define LLVM_LIBC_SRC_SUPPORT_FPUTIL_AARCH64_FENV_DARWIN_IMPL_H

#include "src/__support/architectures.h"

#if !defined(LLVM_LIBC_ARCH_AARCH64) || !defined(__APPLE__)
#error "Invalid include"
#endif

#include <arm_acle.h>
#include <fenv.h>
#include <stdint.h>

This file has been truncated. show original

tschuett · December 7, 2022, 12:36pm

My best guess is that someone forgot to add the header to bazel files:

github.com

llvm/llvm-project/blob/3abdd9b91bc17541e78de6251043e178efe0e3ee/utils/bazel/llvm-project-overlay/libc/BUILD.bazel#L273


      
              name = "__support_fputil_except_value_utils",
              hdrs = ["src/__support/FPUtil/except_value_utils.h"],
              deps = [
                  ":__support_cpp_optional",
                  ":__support_fputil_fenv_impl",
                  ":__support_fputil_fp_bits",
                  ":libc_root",
              ],
          )
          
          
cc_library(
              name = "__support_fputil_fenv_impl",
              hdrs = ["src/__support/FPUtil/FEnvImpl.h"],
              textual_hdrs = [
                  "src/__support/FPUtil/x86_64/FEnvImpl.h",
                  "src/__support/FPUtil/aarch64/FEnvImpl.h",
              ],
              deps = [
                  ":__support_common",
                  ":__support_fputil_fp_bits",
                  ":libc_root",

I would recommend to create an issue:

wangkuiyi · December 7, 2022, 7:00pm

Thank you, @tschuett ! I filed an issue Need to add header file fenv_darwin_impl.h into Bazel build rules · Issue #59378 · llvm/llvm-project · GitHub as recommended.