mcpp-plugins

The build plugins the mcpp project maintains, published as one package, mcpp:plugins. A consumer selects the members it needs through features and imports each one from build.mcpp under the module name the member declares.

[dependencies.mcpp]
plugins = { version = "0.1.0", features = ["rules-spirv"], host-module = true }

// build.mcpp
import std;
import mcpp;
import mcpp.rules.spirv;

int main() {
    mcpp::rules::spirv::options opt;
    opt.includes = { "shaders" };
    return mcpp::rules::spirv::compile(opt) ? 0 : 1;
}

Naming

family	module name	purpose
rules	mcpp.rules.<x>	how one kind of translation unit is compiled by a compiler mcpp does not drive: the spelling of its flags, the probe of its toolkit, the actions it submits
tools	mcpp.tools.<x>	a build-time utility independent of any compiler; see tools/README.md
identity	mcpp.plugins	the lib root, compiled before every member; it states the collection's version

The mcpp. prefix is reserved for this package: mcpp warns when a module under it is declared by a package outside the mcpp namespace. mcpp.build.* is the engine's own module family and is not used here.

Members

feature	module	since mcpp	what it needs
rules-cuda	mcpp.rules.cuda	2026.9.5.2	the toolkit named in [xlings.workspace] (xim:cuda-nvcc, xim:cuda-cudart, and xim:libcurand for the clang route, whose wrapper includes a cuRAND header unconditionally), [build] accel = "cuda…", a constrained glob for *.cu; the clang route with an LLVM toolchain, the nvcc route with a GCC one
rules-spirv	mcpp.rules.spirv	2026.9.5.3	xim:glslang in [xlings.workspace], [build] accel = "vulkan1.2", a constrained glob for the shader stages; emits one header per shader through a role = "source" action

The floor is the mcpp release whose engine carries what the member relies on: rules-spirv needs the device-source table that classifies shader extensions, which 2026.9.5.3 introduced. The index descriptor states the floor; a project on an older mcpp is refused at resolution rather than at the first shader.

How the engine sees this package

mcpp compiles every module interface unit among a host-module package's resolved sources as a host module of its own, the lib root first (2026.9.5.3+). [features.<f>] sources is what puts a member into that set, so the module set a consumer can import is exactly its feature set. A member is compiled alone, in the same command as the consumer's build.mcpp, and may import std, mcpp and mcpp.plugins.

Layout

mcpp.toml          the package: one feature per member
src/plugins.cppm   export module mcpp.plugins;
rules/<x>.cppm     export module mcpp.rules.<x>;
tools/<x>.cppm     export module mcpp.tools.<x>;
tests/<consumer>/  one project per member, built by CI with the pinned mcpp

Adding a member

1. One file, rules/<x>.cppm or tools/<x>.cppm, declaring its module name. The engine owns the graph — the accelerator axis, the constrained globs, the action edges, the fingerprint — and the member owns the spelling: which tool, which flags, what is generated. A member does not read /usr; a tool comes from mcpp::toolchain_dir(), mcpp::xpkg_dir() or an explicit option, and a missing one is refused naming the [xlings.workspace] entry to add.
2. A feature in mcpp.toml adding that one source.
3. A consumer under tests/ that builds through it and asserts on the artefact, and a row in the table above with the mcpp floor.
4. A version bump: mcpp identifies an installed package by (name, version), so a changed payload under an unchanged version is not reinstalled.

Releases

A tag v<version> publishes the source archive; the index descriptor (mcpp-index/pkgs/m/mcpp.plugins.lua) names the GitHub archive and its GitCode mirror with one sha256.