build: build lix-doc with Meson! 🎉

lix-doc is now built with Meson, with lix-doc's dependencies built as
Meson subprojects, either fetched on demand with .wrap files, or fetched
in advance by Nix with importCargoLock. It even builds statically.

Fixes #256.

Co-authored-by: Lunaphied <lunaphied@lunaphied.me>
Co-authored-by: Jade Lovelace <lix@jade.fyi>

Change-Id: I3a4731ff13278e7117e0316bc0d7169e85f5eb0c

1 files changed, 43 insertions, 0 deletions

diff --git a/meson/cargo-lock-to-wraps.py b/meson/cargo-lock-to-wraps.py
new file mode 100755
index 000000000..811d7a219
--- /dev/null
+++ b/meson/cargo-lock-to-wraps.py
@@ -0,0 +1,43 @@
+#!/usr/bin/env python3
+
+import argparse
+import tomllib
+import sys
+
+DOWNLOAD_URI_FORMAT = 'https://crates.io/api/v1/crates/{crate}/{version}/download'
+
+WRAP_TEMPLATE = """
+[wrap-file]
+method = cargo
+directory = {crate}-{version}
+source_url = {url}
+source_filename = {crate}-{version}.tar.gz
+source_hash = {hash}
+""".lstrip()
+
+parser = argparse.ArgumentParser()
+parser.add_argument('lockfile', help='path to the Cargo lockfile to generate wraps from')
+parser.add_argument('outdir', help="the 'subprojects' directory to write .wrap files to")
+
+args = parser.parse_args()
+
+with open(args.lockfile, 'rb') as f:
+    lock_toml = tomllib.load(f)
+
+for dependency in lock_toml['package']:
+    try:
+        hash = dependency['checksum']
+    except KeyError:
+        # The base package, e.g. lix-doc, won't have a checksum, and conveniently
+        # the base package is also not something we want a wrap file for.
+        # Doesn't that work out nicely?
+        continue
+
+    crate = dependency['name']
+    version = dependency['version']
+
+    url = DOWNLOAD_URI_FORMAT.format(crate=crate, version=version)
+
+    wrap_text = WRAP_TEMPLATE.format(crate=crate, version=version, url=url, hash=hash)
+    with open(f'{args.outdir}/{crate}-rs.wrap', 'w') as f:
+        f.write(wrap_text)