c3pm For the C3 programming language

Guides

Link libraries and projects

Link native libraries, Nix packages, and C3 library targets with c3pm.

Use c3pm link to add a native package, an imported Nix package, or a static or dynamic library target from another C3 project.

Adding/linking system libraries

c3pm makes native libraries available through Nix packages in your project’s build environment.

From nixpkgs

c3pm link add sqlite3 --nix-package sqlite --runtime

From a local Nix package definition

c3pm link add custom --nix-package path:./nix/custom.nix

c3pm imports a path: Nix file with an explicit pkgs argument instead of resolving it as a nixpkgs attribute.

Adding/linking other C3 projects

Fetch a C3 project and select the library target to build and link:

c3pm link add protocol \
  --source git+ssh://git@example.com/acme/protocol.git \
  --rev v1.0.0 \
  --c3c-target protocol-static \
  --passthrough \
  --for-target server

The selected --c3c-target must be a static-lib or dynamic-lib target. It defaults to none when omitted. Use --subdir PATH if the project is below the source root.

For a link with its own fetched source, --nix-package path:./package.nix resolves inside that source and evaluates as:

import path { inherit pkgs; }

These modes apply to both system libraries and linked C3 projects. --runtime is the default. Both modes make the input available while c3pm builds the current project; the difference is whether consumers inherit it:

  • --runtime keeps the input private to the current project. c3pm places the package in the generated Nix buildInputs. Use this mode for an application dependency or an implementation detail that downstream projects do not need.
  • --passthrough passes the input to consumers. c3pm places the package in propagatedBuildInputs, so projects that consume this project also receive it. Use this mode when a library exposes the dependency through its public API or requires consumers to link it.

For example, an application that uses SQLite internally should normally choose --runtime. A reusable C3 library whose public API exposes types or symbols from another native library should normally choose --passthrough.

These modes do not select static or dynamic linking, and they do not change the name c3c passes to the linker. --c3c-target selects a static-lib or dynamic-lib target. --runtime and --passthrough control only Nix dependency propagation.

c3pm link list
c3pm link list --for-target server
c3pm link remove sqlite3

To remove a target-specific link, pass the same --for-target TARGET used to add it.