Use --ld-path= for the autoconfigured Clang linker (#935)

When Clang is the compiler, the autoconfigured toolchain passes the linker's absolute path through `-fuse-ld=`, e.g.
`-fuse-ld=/usr/bin/ld.lld`. Clang 12 deprecated `-fuse-ld=<path>` in favor of `--ld-path=` (https://reviews.llvm.org/D83015) because the `-fuse-ld=` value is the linker flavor, which a path loses. For example, on Darwin `-fuse-ld=/path/to/ld64.lld` makes the driver pass ld64's version-dependent options to lld.

Pass `-fuse-ld=lld --ld-path=/usr/bin/ld.lld` (or the gold equivalent) when Clang accepts `--ld-path=`, and fall back to `-fuse-ld=<path>` otherwise.

Fixes #934

Closes #935

COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_cc/pull/935 from MaskRay:ld-path 4245e780980665cd3aa2d699bad594ae3e3b6f50
PiperOrigin-RevId: 1012001045
Change-Id: I59ab45762d04dd9be202c2515135b60d21519ef4
1 file changed
tree: b448e496e5d794b2ff51b13e15cdb6796ee1aee0
  1. .bazelci/
  2. .bcr/
  3. .github/
  4. cc/
  5. docs/
  6. examples/
  7. tests/
  8. .bazelignore
  9. .bazelrc
  10. .gitignore
  11. AUTHORS
  12. BUILD
  13. CONTRIBUTING.md
  14. googletest.patch
  15. ISSUE_TEMPLATE.md
  16. LICENSE
  17. local_bazel.bzl
  18. MODULE.bazel
  19. README.md
  20. WORKSPACE
  21. WORKSPACE.bzlmod
README.md

C++ rules for Bazel

  • Postsubmit Build status

This repository contains C, C++, and Objective-C language support for the Bazel build system.

For this module's main reference, see the Bazel documentation.

Get Started

Install Bazel

Follow the official instructions to Install Bazel.

Add rules_cc to your MODULE.bazel

Add the latest release to your MODULE.bazel project file.

Declare a build target

In a BUILD.bazel file, import and use the rules:

load("@rules_cc//cc:cc_binary.bzl", "cc_binary")

cc_binary(
    name = "hello_world",
    srcs = ["hello_world.cc"],
)

Build and run your project

Build and run your C/C++ binary with one command:

$ bazel run hello_world

To build the project without running the binary, use Bazel's build subcommand:

$ bazel build hello_world

Toolchains

Default autoconfigured toolchain

rules_cc includes an auto-configured toolchain that uses the local compiler installed on the host machine.

You can disable the autoconfigured C/C++ toolchain by adding the following Bazel flag to your project's .bazelrc file:

--repo_env=BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1

Hermetic toolchains

Configuring a hermetic toolchain makes your build more deterministic. rules_cc itself does not yet offer a hermetic toolchain distribution. Other community owned and maintained projects offer hermetic C/C++ toolchains:

Contributing

Bazel and rules_cc are the work of many contributors. We appreciate your help!

To contribute, please read the contribution guidelines: CONTRIBUTING.md.

Note that the rules_cc use the GitHub issue tracker for bug reports and feature requests only. For asking questions see: