build(meson): link migrated Rust code into native libraries

Build a configuration-matched Cargo archive from Meson and flatten its object members into static libzstd. This gives C consumers one archive even though the migrated Rust objects and remaining C code refer to each other. Shared libraries whole-archive the Cargo output to retain Rust-only ABI exports. The implementation supports Meson 0.50's generated-archive linking rules, matching HUF mode and 32-bit configuration, and documents cross-build target and archiver selection. Test Plan: - fresh Meson both-build smoke consumers and invalidDictionaries - modern static/shared/both, forced-HUF, i686, install, and fuzzer paths - real Meson 0.50 static and shared smoke builds - cargo clippy, cargo clippy --benches, cargo clippy --tests, and nightly fmt Refs: build/meson/README.md archive and cross-build documentation
2026-07-10 22:08:55 +02:00
parent 6a762660b7
commit 3d679116d8
6 changed files with 405 additions and 36 deletions
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+# ################################################################
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under both the BSD-style license (found in the
+# LICENSE file in the root directory of this source tree) and the GPLv2 (found
+# in the COPYING file in the root directory of this source tree).
+# You may select, at your option, one of the above-listed licenses.
+# ################################################################
+
+"""Flatten Cargo's staticlib into Meson's libzstd static archive."""
+
+from __future__ import print_function
+
+import argparse
+import os
+from pathlib import Path
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def run(command, **kwargs):
+    try:
+        return subprocess.run(command, check=True, **kwargs)
+    except subprocess.CalledProcessError as error:
+        print('command failed: {}'.format(' '.join(command)), file=sys.stderr)
+        return error
+
+
+def extract_members(archiver, archive, destination, prefix):
+    members = subprocess.check_output(
+        [archiver, 't', str(archive)], universal_newlines=True
+    ).splitlines()
+    if not members:
+        raise RuntimeError('{} contains no object members'.format(archive))
+
+    objects = []
+    for index, member in enumerate(members):
+        object_file = destination / '{}-{:04d}.o'.format(prefix, index)
+        with object_file.open('wb') as output:
+            run_result = run(
+                [archiver, 'p', str(archive), member], stdout=output
+            )
+        if isinstance(run_result, subprocess.CalledProcessError):
+            raise RuntimeError('could not extract {} from {}'.format(member, archive))
+        objects.append(object_file)
+    return objects
+
+
+def merge_with_ar(args, output):
+    with tempfile.TemporaryDirectory(prefix='zstd-rust-archive-') as temporary:
+        temporary_path = Path(temporary)
+        c_objects = extract_members(
+            args.archiver, Path(args.c_archive), temporary_path, 'c'
+        )
+        rust_objects = extract_members(
+            args.archiver, Path(args.rust_archive), temporary_path, 'rust'
+        )
+        temporary_output = temporary_path / output.name
+        run_result = run(
+            [args.archiver, 'rcs', str(temporary_output)]
+            + [str(object_file) for object_file in c_objects + rust_objects]
+        )
+        if isinstance(run_result, subprocess.CalledProcessError):
+            raise RuntimeError('could not create {}'.format(output))
+        shutil.move(str(temporary_output), str(output))
+
+
+def merge_with_msvc(args, output):
+    temporary_output = output.with_name(output.name + '.tmp')
+    run_result = run(
+        [
+            args.archiver,
+            '/OUT:{}'.format(temporary_output),
+            args.c_archive,
+            args.rust_archive,
+        ]
+    )
+    if isinstance(run_result, subprocess.CalledProcessError):
+        raise RuntimeError('could not create {}'.format(output))
+    os.replace(str(temporary_output), str(output))
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--archiver', required=True)
+    parser.add_argument('--c-archive', required=True)
+    parser.add_argument('--rust-archive', required=True)
+    parser.add_argument('--output', required=True)
+    parser.add_argument('--msvc', action='store_true')
+    args = parser.parse_args()
+
+    output = Path(args.output)
+    output.parent.mkdir(parents=True, exist_ok=True)
+    try:
+        if args.msvc:
+            merge_with_msvc(args, output)
+        else:
+            merge_with_ar(args, output)
+    except (OSError, RuntimeError, subprocess.CalledProcessError) as error:
+        print('could not merge Rust archive: {}'.format(error), file=sys.stderr)
+        return 1
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())