rust: Add `update_snapshot` task to generate `rust-snapshot.inc`

Everything we need for `rust-snapshot.inc` exists in `src/stage0.json`,
so just read that to generate it.

(From OE-Core rev: a07008da8b02165d271a457e4c215f35cb15b94c)

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 60 insertions, 0 deletions

diff --git a/meta/recipes-devtools/rust/rust_1.67.0.bb b/meta/recipes-devtools/rust/rust_1.67.0.bb
index 60f3daf464..2118faec8f 100644
--- a/meta/recipes-devtools/rust/rust_1.67.0.bb
+++ b/meta/recipes-devtools/rust/rust_1.67.0.bb
@@ -289,6 +289,66 @@ rust_do_install:class-target() {
     rm ${D}${libdir}/rustlib/manifest*
 }
 
+addtask do_update_snapshot after do_patch
+do_update_snapshot[nostamp] = "1"
+
+# Run with `bitbake -c update_snapshot rust` to update `rust-snapshot.inc`
+# with the checksums for the rust snapshot associated with this rustc-src
+# tarball.
+python do_update_snapshot() {
+    import json
+    import re
+    import sys
+
+    from collections import defaultdict
+
+    with open(os.path.join(d.getVar("S"), "src", "stage0.json")) as f:
+        j = json.load(f)
+
+    config_dist_server = j['config']['dist_server']
+    compiler_date = j['compiler']['date']
+    compiler_version = j['compiler']['version']
+
+    src_uri = defaultdict(list)
+    for k, v in j['checksums_sha256'].items():
+        m = re.search(f"dist/{compiler_date}/(?P<component>.*)-{compiler_version}-(?P<arch>.*)-unknown-linux-gnu\\.tar\\.xz", k)
+        if m:
+            component = m.group('component')
+            arch = m.group('arch')
+            src_uri[arch].append(f"SRC_URI[{component}-snapshot-{arch}.sha256sum] = \"{v}\"")
+
+    snapshot = """\
+## This is information on the rust-snapshot (binary) used to build our current release.
+## snapshot info is taken from rust/src/stage0.json
+## Rust is self-hosting and bootstraps itself with a pre-built previous version of itself.
+## The exact (previous) version that has been used is specified in the source tarball.
+## The version is replicated here.
+
+SNAPSHOT_VERSION = "%s"
+
+""" % compiler_version
+
+    for arch, components in src_uri.items():
+        snapshot += "\n".join(components) + "\n\n"
+
+    snapshot += """\
+SRC_URI += " \\
+    ${RUST_DIST_SERVER}/dist/${RUST_STD_SNAPSHOT}.tar.xz;name=rust-std-snapshot-${RUST_BUILD_ARCH};subdir=rust-snapshot-components \\
+    ${RUST_DIST_SERVER}/dist/${RUSTC_SNAPSHOT}.tar.xz;name=rustc-snapshot-${RUST_BUILD_ARCH};subdir=rust-snapshot-components \\
+    ${RUST_DIST_SERVER}/dist/${CARGO_SNAPSHOT}.tar.xz;name=cargo-snapshot-${RUST_BUILD_ARCH};subdir=rust-snapshot-components \\
+"
+
+RUST_DIST_SERVER = "%s"
+
+RUST_STD_SNAPSHOT = "rust-std-${SNAPSHOT_VERSION}-${RUST_BUILD_ARCH}-unknown-linux-gnu"
+RUSTC_SNAPSHOT = "rustc-${SNAPSHOT_VERSION}-${RUST_BUILD_ARCH}-unknown-linux-gnu"
+CARGO_SNAPSHOT = "cargo-${SNAPSHOT_VERSION}-${RUST_BUILD_ARCH}-unknown-linux-gnu"
+""" % config_dist_server
+
+    with open(os.path.join(d.getVar("THISDIR"), "rust-snapshot.inc"), "w") as f:
+        f.write(snapshot)
+}
+
 RUSTLIB_DEP:class-nativesdk = ""
 
 # musl builds include libunwind.a