Dependencies

spn is a real package manager, built specifically for C and C++.

Local dependencies

The simplest dependency is a path to a directory with an spn.toml:

[deps.package]
foo = { path = "packages/foo" }

And this is what the package might look like:

[package]
name = "foo"
version = "6.9.0"

[[lib]]
name = "foo"
source = ["foo.c"] # Relative to foo's manifest

This is just an old fashioned vendored dependency. You could download LLVM, check in the entire source tree, and have an spn.toml that builds this local copy. If you then regained your sanity, you can point the exact same manifest at Git and spn will manage the checkout for you exactly as if it were an “official” package:

[package.upstream]
url = "https://github.com/tspader/foo.git"
commit = "6937fa02243da7b693c5692cea84a696950d4669"

Conditional and private dependencies

Configuration

Options

Packages can provide options, either as an enumeration or a boolean. Options for foo are set in [config.foo], like this:

[config.foo]
tls = "openssl"
zstd = true

Linkage

Libraries declare the linkages they support:

shared
static
source, which compiles the package’s sources directly into your target as if they were your own files.

[config.foo]
kind = "shared"

Patching

What if you need to patch foo? You don’t want to go back to the technology of the ancients, like submodules or vendoring. You want a specific commit with just a few changes. Do this in your spn.toml:

[deps.package]
foo = "6.9.0"

[patch.foo]
files = ["patches/foo.patch"]

That’s it! Patches fold into the build system like everything else. If you change the contents of a patch, add or remove patches, you’ll still get a correct, incremental build.

Your dependencies can’t patch. If you ask for a given commit, you get exactly that commit.