rules_cc_autoconf

Autoconf-style configuration checks for Bazel. This module lets you generate config.h files by running compilation checks against Bazel’s configured cc_toolchain, using Starlark macros instead of shell-driven configure scripts.

Setup

Add the following to your MODULE.bazel file:

bazel_dep(name = "rules_cc_autoconf", version = "{version}")

Documentation

For full documentation and examples, see: https://periareon.github.io/rules_cc_autoconf/

Why not just run Autoconf?

GNU Autoconf is excellent at probing platform capabilities and generating Make-based build trees. However, dropping ./configure into a Bazel build has a few downsides:

• Non-hermetic: traditional Autoconf expects to mutate the source tree (creating config.status, config.log, generated headers, etc.), which conflicts with Bazel’s sandboxing and caching model.
• Opaque, coarse-grained actions: a single configure step can do dozens of unrelated checks at once, making cache behaviour and debugging harder.
• Environment-sensitive: running shell scripts and toolchain discovery inside a Bazel action is fragile across platforms, remote execution, and containerized builds.

Projects in the Bazel Central Registry often reimplement the build logic in Bazel, but they still miss Autoconf’s convenient config.h generation. rules_cc_autoconf focuses on that gap: it provides autoconf-like checks in a hermetic, deterministic way, driven entirely by Bazel’s C/C++ toolchain configuration.