Files
carbon-lang/MODULE.bazel
T
Chandler Carruth 217c7ba0b2 Begin building libc++ and libc++abi runtimes on demand (#6424)
This builds on the previous work to flesh out more on-demand runtimes
building. It adds building of the `libc++.a` archive runtime.

A number of changes are required for this to work:

- The runtimes build infrastructure needs to support building sources
  from multiple parts of LLVM rather than a single part. We do this by
  lifting the root of the runtimes source paths up a level to a common
  runtimes tree, and installing the runtimes sources below this
  directory.

- Both libc++ and libc++abi runtimes sources need to be installed, and
  we even need to install some interesting parts of llvm-libc that are
  used in the build of libc++.

- We need to generate the site configuration header file for libc++ from
  the CMake template. This includes both setting up a set of
  platform-independent defines and introducing some basic Bazel support
  for processing the CMake template itself.

Doing all of this also exposed some missing features and limitations of
the runtimes building infrastructure that are addressed here.

One note is that all of this just adds libc++ to the explicit
`build-runtimes` command for testing. It doesn't yet trigger
automatically building these prior to linking, or configuring any of the
other subcommands to automatically use these runtimes. All of that will
come in follow-up PRs.

Also, this makes the `clang_runtimes_test` ... _very_ slow in our
default build configuration. Compiling libc++, even with many threads on
a large Linux server requires up to 50 seconds. I'm open to any
suggestions on how to handle this, including disabling the test in
non-optimized builds. I have some ideas to speed this up, but
fundamentally building libc++ is... not cheap.

I did look at some of the existing Bazel tools to process the CMake
template, but they all seemed significantly more complex than what we
need and didn't have broad adoption. Given that, it seemed slightly
better to just roll our own given the simple format.

Two of the new LLVM patch are currently under review upstream and so
hopefully temporary:

- https://github.com/llvm/llvm-project/pull/169155
- https://github.com/llvm/llvm-project/pull/169292
2025-11-27 02:16:51 +00:00

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6.0 KiB
Python

# Part of the Carbon Language project, under the Apache License v2.0 with LLVM
# Exceptions. See /LICENSE for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
"""Bazel modules.
`MODULE.bazel.lock` may change locally when `bazel` is executed. This means one
of:
1. An input is changing, typically `MODULE.bazel` or `.bazelversion`.
- Running `bazel mod deps` provides a canonical update to
`MODULE.bazel.lock`; include the changes.
- GitHub test actions may also identify platform-specific lockfile
updates.
2. The host platform hasn't yet been added to the lock file.
- Platforms tested with GitHub actions are kept up-to-date. Other
platforms may fall out of sync due to `bazel` or dependency changes,
and should be updated with a PR the same way a platform is added.
- Running `bazel mod deps` provides a canonical update to
`MODULE.bazel.lock`; create a PR with those changes in order to include
the host platform.
"""
module(name = "carbon")
http_archive = use_repo_rule(
"@bazel_tools//tools/build_defs/repo:http.bzl",
"http_archive",
)
bazel_dep(name = "abseil-cpp", version = "20250512.1")
bazel_dep(name = "bazel_skylib", version = "1.8.1")
bazel_dep(name = "google_benchmark", version = "1.9.4")
bazel_dep(name = "googletest", version = "1.17.0")
bazel_dep(name = "re2", version = "2024-07-02.bcr.1")
bazel_dep(name = "rules_cc", version = "0.1.4")
bazel_dep(name = "rules_pkg", version = "1.1.0")
bazel_dep(name = "rules_shell", version = "0.5.0")
bazel_dep(name = "tcmalloc", version = "0.0.0-20250331-43fcf6e")
bazel_dep(name = "tree-sitter-bazel", version = "0.24.4")
# The registry only has an old version. We use that here to avoid a miss but
# override it with a newer version.
bazel_dep(name = "libpfm", version = "4.11.0")
libpfm_version = "4.13.0"
# The official site is https://perfmon2.sourceforge.net/, but SourceForge makes
# it difficult to download from bazel. On GitHub action runners,
# https://git.code.sf.net/p/perfmon2/libpfm4 seems to be blocked. As a
# consequence, use a mirror.
archive_override(
module_name = "libpfm",
integrity = "sha256-sGBx1+UoQCplBCc+pwA1Tr/PS2L/4jnLZHH82wSuPz0=",
patch_strip = 1,
patches = ["@//bazel/libpfm:0001-Introduce-a-simple-native-Bazel-build.patch"],
strip_prefix = "libpfm4-{0}".format(libpfm_version),
urls = ["https://github.com/wcohen/libpfm4/archive/v{0}.tar.gz".format(libpfm_version)],
)
bazel_dep(name = "bazel_clang_tidy", dev_dependency = True)
git_override(
module_name = "bazel_clang_tidy",
# HEAD as of 2025-01-09.
commit = "db677011c7363509a288a9fb3bf0a50830bbf791",
remote = "https://github.com/erenon/bazel_clang_tidy.git",
)
bazel_cc_toolchain = use_extension(
"//bazel/cc_toolchains:clang_configuration.bzl",
"clang_toolchain_extension",
)
use_repo(bazel_cc_toolchain, "bazel_cc_toolchain")
register_toolchains("@bazel_cc_toolchain//:all")
bazel_dep(name = "hedron_compile_commands", dev_dependency = True)
git_override(
module_name = "hedron_compile_commands",
# HEAD as of 2025-01-09.
commit = "4f28899228fb3ad0126897876f147ca15026151e",
remote = "https://github.com/hedronvision/bazel-compile-commands-extractor.git",
)
boost_unordered_version = "1.85.0"
http_archive(
name = "boost_unordered",
build_file = "@//:third_party/boost_unordered/BUILD.bazel",
integrity = "sha256-2dQ4IQH/xFiK1iWCkrMYLeR8zsSQqGchKOdTuf1u0zI=",
strip_prefix = "boost_unordered-{0}".format(boost_unordered_version),
urls = ["https://github.com/MikePopoloski/boost_unordered/archive/v{0}.tar.gz".format(boost_unordered_version)],
)
# Required for llvm-project.
bazel_dep(name = "platforms", version = "1.0.0")
bazel_dep(name = "protobuf", version = "33.1", repo_name = "com_google_protobuf")
bazel_dep(name = "zlib", version = "1.3.1.bcr.6", repo_name = "llvm_zlib")
bazel_dep(name = "zstd", version = "1.5.7", repo_name = "llvm_zstd")
###############################################################################
# llvm-project
###############################################################################
# We pin to specific upstream commits and try to track top-of-tree reasonably
# closely rather than pinning to a specific release.
# HEAD as of 2025-11-22.
llvm_project_version = "20ebc7ea8209cb8f1ff3916706b6e7d8232c9f3f"
# Load a repository for the raw llvm-project, pre-overlay.
http_archive(
name = "llvm-raw",
build_file_content = "# empty",
integrity = "sha256-/LVv96+cMl0CE3AxLZKzSE97CwbB1G2ic8h/Agqeafo=",
patch_args = ["-p1"],
patches = [
"@carbon//bazel/llvm_project:0001_Patch_for_mallinfo2_when_using_Bazel_build_system.patch",
"@carbon//bazel/llvm_project:0002_Added_Bazel_build_for_compiler_rt_fuzzer.patch",
"@carbon//bazel/llvm_project:0003_Comment_out_unloaded_proto_library_dependencies.patch",
"@carbon//bazel/llvm_project:0004_Introduce_basic_sources_exporting_for_libunwind.patch",
"@carbon//bazel/llvm_project:0005_Introduce_basic_sources_exporting_for_libcxx_and_libcxxabi.patch",
"@carbon//bazel/llvm_project:0006_Add_a_filegroup_containing__all__sources_to_the_libc_build_rules.patch",
"@carbon//bazel/llvm_project:0007_Remove_target_compatibility_restrictions_for_float128.patch",
],
strip_prefix = "llvm-project-{0}".format(llvm_project_version),
urls = ["https://github.com/llvm/llvm-project/archive/{0}.tar.gz".format(llvm_project_version)],
)
# Apply the overlay to produce llvm-project.
llvm_project = use_extension(
"//bazel/llvm_project:llvm_project.bzl",
"llvm_project",
)
use_repo(llvm_project, "llvm-project")
###############################################################################
# Python
###############################################################################
bazel_dep(name = "rules_python", version = "1.6.0")
python = use_extension("@rules_python//python/extensions:python.bzl", "python")
python.toolchain(
python_version = "3.11",
)
use_repo(python, "python_versions")