mcpp

mcpp [global-options] command [args]

mcpp is a modern C++ build tool aimed at C++23 module-first development. It creates, builds, tests, and packages projects that use `import std`, module interface units, and module partitions, with automatic module dependency analysis and file-level incremental builds.Projects are described by a mcpp.toml manifest. By convention, `src/main.cpp` becomes a binary target and tests under `tests/` are discovered by mcpp test. The first build downloads a host-aware default toolchain (GCC or LLVM depending on platform) into an isolated sandbox under ~/.mcpp/, so system compilers are not required.Dependency management resolves SemVer constraints against package indices (default: mcpp-index / mcpplibs), writes a lockfile, and can pull modules from index, Git, or local paths. Multi-package workspaces share one lockfile and target directory. mcpp pack produces distributable artifacts (system, vendored, self-contained, or fully static musl builds on Linux).The tool is early-stage and self-hosted (written in pure C++23 modules). Full option lists for each subcommand are available via mcpp command --help.

new name

Scaffold a modular project (optional --template for library-provided templates).

Compile the project (incremental; Ninja backend).

Build and run the default target.

Discover, build, and run tests; filter by name pattern.

Remove build outputs under the target directory.

Manage dependencies declared in mcpp.toml.

Search configured package indices.

Bundle a release package (--mode system | vendored | self-contained | static).

Publish a package to a configured index.

Install, list, or select sandboxed compiler toolchains.

Manage BMI/build cache and package indices.

Environment checks and self-maintenance commands.

Explain resolved build decisions.

Print a detailed explanation for an error code.

Use only already available local state (no downloads or index refresh). Also MCPP_OFFLINE=1.

Print the mcpp version.

Project manifest: mcpp.toml (package metadata, dependencies, toolchains, workspaces).Lockfile: mcpp.lock.Per-user data and sandboxed toolchains: ~/.mcpp/ (registry, caches, install layout).

Name clash: many Linux/Homebrew distributions ship an unrelated mcpp C preprocessor. Package names for this build tool are often mcpp-m / mcpp-bin (AUR) or the Homebrew tap formula mcpp-m, while the installed command remains mcpp. Prefer the install paths from the project README if which mcpp points at the preprocessor.Early-stage software: interfaces and behavior may change between releases. The first build can take a long time while toolchains download into ~/.mcpp/.

mcpp is a community project under mcpp-community focused on native C++23 modules and self-hosting. It builds on the xlings toolchain/package foundation and is inspired by tools such as Cargo, xmake, and Ninja.

xmake(1), cargo(1), ninja(1), cmake(1), meson(1)

Source code · Documentation