Fix exec transition handling in cc tool_map for multiplatform builds Copybara Import from https://github.com/bazelbuild/rules_cc/pull/548 BEGIN_PUBLIC Fix exec transition handling in cc tool_map for multiplatform builds (#548) These extra exec transitions are harmful because they allow Bazel to select a _different_ exec platform than the one the toolchain is being used on. This means when host != exec (say Windows host, Linux remote), the wrong compiler can be picked and the build fails. Without this patch, users who want to support multiplatform builds need to hack it by forcing the tools to transition to the correct exec platform, since the toolchain "forgets". See [example workaround being reverted](https://github.com/dzbarsky/toolchains_llvm_bootstrapped/pull/2/commits/ea3f261d933d702bdec98ddd8ecf081ae306568b) and CI works when [patch is applied](https://github.com/dzbarsky/toolchains_llvm_bootstrapped/pull/2/commits/970164f03f5802e30b2d9c3c9af2efc5bece2a54) While I was here I cleaned up the example a bit to be more like the canonical usage of `cc_tool`. Closes #548 END_PUBLIC COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_cc/pull/548 from dzbarsky:zbarsky/exec 5a34f390a06dcdb7a95a2b1c526232d2279d9d99 PiperOrigin-RevId: 845482957 Change-Id: Icbd6753cf131dac70a50e8a483a59096cd61c666
This repository contains a Starlark implementation of C++ rules in Bazel.
The rules are being incrementally converted from their native implementations in the Bazel source tree.
For the list of C++ rules, see the Bazel documentation.
Add the following to your WORKSPACE file:
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive") http_archive( name = "rules_cc", urls = ["https://github.com/bazelbuild/rules_cc/archive/refs/tags/<VERSION>.tar.gz"], sha256 = "...", )
Then, in your BUILD files, import and use the rules:
load("@rules_cc//cc:defs.bzl", "cc_library") cc_library( ... )
This repo contains an auto-detecting toolchain that expects to find tools installed on your host machine. This is non-hermetic, and may have varying behaviors depending on the versions of tools found.
There are third-party contributed hermetic toolchains you may want to investigate:
If you'd like to use the cc toolchain defined in this repo, add this to your WORKSPACE after you include rules_cc:
load("@rules_cc//cc:repositories.bzl", "rules_cc_dependencies", "rules_cc_toolchains") rules_cc_dependencies() rules_cc_toolchains()
This repository also contains migration tools that can be used to migrate your project for Bazel incompatible changes.
Script that migrates legacy crosstool fields into features (incompatible flag, tracking issue).
TLDR:
bazel run @rules_cc//tools/migration:legacy_fields_migrator -- \ --input=my_toolchain/CROSSTOOL \ --inline
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:
rules_cc mailing list#cc on slack.bazel.build