C

The C and C++ rules support two levels of integration. ccLibrary() and ccBinary() attach lazy handlers to exported labels, while cmakeLib() imports an existing CMake/Ninja project and discovers selectable native labels and CTest cases. Both paths use declared compiler and linker toolchains and expose their artifacts to downstream native or Odin targets.

Available goals

Set up a compiler

Import the C rules in imp.workspace.js. Raw C targets prefer the default Zig toolchain and otherwise fall back to GCC; CMake targets use the managed CMake default.

import "//rules/c";
import "//rules/c/cmake";
import "//rules/workflows/package";
import "//rules/workflows/test";

Override a rule default only when needed by declaring a replacement with { default: true }, or pass a toolchain handle explicitly on one target.

This repository's workspace imports //rules/imp/mode. Its default profile builds raw C/C++ with -O0 -g and configures CMake with CMAKE_BUILD_TYPE=Debug; --profile release uses -O2 -DNDEBUG and CMAKE_BUILD_TYPE=Release. Target copts and cmakeArgs are appended after those defaults and can override them for one target.

Declare raw targets

import { ccLibrary, ccBinary } from "//rules/c";

export const math = ccLibrary({
    srcs: ["math.c"],
    hdrs: ["math.h"],
});

export const calculator = ccBinary({
    srcs: ["main.c"],
    deps: [math],
    copts: ["-Wall", "-Wextra"],
});

Source and header globs are evaluated lazily relative to path, which defaults to the declaring BUILD.js directory. A library produces a static archive by default; a binary links an executable. Use output for an explicit output path and linkopts for options that belong only at link time.

imp build //native/calculator:calculator
imp package //native/calculator:calculator

Package handlers publish label artifacts below dist/. Dependency labels contribute both graph ordering and link inputs; they are not loose filesystem paths discovered from the host.

For bespoke builds, declare a label in the BUILD file and attach build(), test(), or packageGoal() handlers directly. The //rules/c/label_example:hasher fixture demonstrates this shape using ordinary memoized compile and link functions.

Generate declarations

The C build generator scans unowned CMake and C/C++ sources and writes appropriate declarations. Enable it explicitly:

export const cConfig = {
    buildGenerate: true,
};

Then run imp goal generate-build. Generation is opt-in so repositories with custom ownership or mixed build layouts are not rewritten unexpectedly.

Configuration

Example

export const cConfig = {
    buildGenerate: false,
};

• CMake
• GCC
• Mold
• Zig