diff --git a/meta/recipes-devtools/rust/files/0006-cargo-keep-host-deps-out-of-the-target-C-metadata-hash.patch b/meta/recipes-devtools/rust/files/0006-cargo-keep-host-deps-out-of-the-target-C-metadata-hash.patch new file mode 100644 index 0000000000..5e796b0164 --- /dev/null +++ b/meta/recipes-devtools/rust/files/0006-cargo-keep-host-deps-out-of-the-target-C-metadata-hash.patch @@ -0,0 +1,123 @@ +From f936d6a954455eff3a60968d155852f9de730228 Mon Sep 17 00:00:00 2001 +From: Sunil Dora +Date: Sun, 27 Sep 2026 08:47:23 +0530 +Subject: [PATCH] fix(compile): Keep host deps out of the target `-C metadata` + hash + +A target unit's `-C metadata` mixed in the `c_metadata` of its +host-kind dependencies (build scripts, proc-macros). Their dependency +graph depends on the host `cfg`, e.g. `cpufeatures` pulls in `libc` +only on aarch64-linux, so the build host leaked into the symbols of +cross-compiled crates such as rustdoc. + +Host-kind dependencies are not linked into the target artifact, so use +their package id instead. `unit_id`, `-C extra-filename` and +fingerprints are unchanged, as are host units and builds without +`--target`. The upstream PR also adds a testsuite test that fakes the +reported host; it is not carried here. + +Upstream-Status: Submitted [https://github.com/rust-lang/cargo/pull/17522] +Signed-off-by: Sunil Dora +--- + +diff --git a/src/tools/cargo/src/compiler/build_runner/compilation_files.rs b/src/tools/cargo/src/compiler/build_runner/compilation_files.rs +index 593e57e..63855f3 100644 +--- a/src/tools/cargo/src/compiler/build_runner/compilation_files.rs ++++ b/src/tools/cargo/src/compiler/build_runner/compilation_files.rs +@@ -89,6 +89,8 @@ impl fmt::Debug for UnitHash { + /// mangled symbols need to be stable between different builds with different + /// settings. For example, profile-guided optimizations need to swap + /// `RUSTFLAGS` between runs, but needs to keep the same symbol names. ++/// Likewise a target unit only mixes the package id of its host-kind ++/// dependencies into `c_metadata`, see `compute_metadata`. + #[derive(Copy, Clone, Debug)] + pub struct Metadata { + unit_id: UnitHash, +@@ -744,7 +746,7 @@ fn compute_metadata( + let deps_metadata = build_runner + .unit_deps(unit) + .iter() +- .map(|dep| *metadata_of(&dep.unit, build_runner, metas)) ++ .map(|dep| (&dep.unit, *metadata_of(&dep.unit, build_runner, metas))) + .collect::>(); + let c_extra_filename = use_extra_filename(bcx, unit); + let pkg_dir = use_pkg_dir(bcx, unit); +@@ -843,16 +845,28 @@ fn compute_metadata( + + let mut c_metadata_hasher = shared_hasher.clone(); + // Mix in the target-metadata of all the dependencies of this target. ++ // Host-kind deps of a target unit (build scripts, proc-macros) are not ++ // linked into it, and their metadata depends on the build host, so use ++ // a host independent stand-in for them (rust-lang/cargo#8140). + let mut dep_c_metadata_hashes = deps_metadata + .iter() +- .map(|m| m.c_metadata) ++ .map(|(dep, m)| { ++ if !unit.kind.is_host() && dep.kind.is_host() { ++ host_independent_c_metadata(dep, ws_root) ++ } else { ++ m.c_metadata ++ } ++ }) + .collect::>(); + dep_c_metadata_hashes.sort(); + dep_c_metadata_hashes.hash(&mut c_metadata_hasher); + + let mut unit_id_hasher = shared_hasher.clone(); + // Mix in the target-metadata of all the dependencies of this target. +- let mut dep_unit_id_hashes = deps_metadata.iter().map(|m| m.unit_id).collect::>(); ++ let mut dep_unit_id_hashes = deps_metadata ++ .iter() ++ .map(|(_, m)| m.unit_id) ++ .collect::>(); + dep_unit_id_hashes.sort(); + dep_unit_id_hashes.hash(&mut unit_id_hasher); + // Avoid trashing the caches on RUSTFLAGS changing via `unit_id` +@@ -884,6 +898,15 @@ fn compute_metadata( + } + } + ++/// Stand-in `c_metadata` for a host-kind dependency of a target unit: ++/// only the dependency's package id, see `compute_metadata`. ++fn host_independent_c_metadata(dep: &Unit, ws_root: &Path) -> UnitHash { ++ let mut hasher = StableHasher::new(); ++ METADATA_VERSION.hash(&mut hasher); ++ dep.pkg.package_id().stable_hash(ws_root).hash(&mut hasher); ++ UnitHash(Hasher::finish(&hasher)) ++} ++ + /// HACK: Detect the *potential* presence of `--remap-path-prefix` + /// + /// As CLI parsing is contextual and dependent on the CLI definition to understand the context, we +diff --git a/src/tools/cargo/src/compiler/fingerprint/mod.rs b/src/tools/cargo/src/compiler/fingerprint/mod.rs +index 172165d..d7f1e55 100644 +--- a/src/tools/cargo/src/compiler/fingerprint/mod.rs ++++ b/src/tools/cargo/src/compiler/fingerprint/mod.rs +@@ -74,7 +74,7 @@ + //! `TargetKind` (bin/lib/etc.) | ✓ | ✓ | ✓ + //! Enabled Features | ✓ | ✓ | ✓ + //! Declared Features | ✓ | | +-//! Immediate dependency’s hashes | ✓[^1] | ✓ | ✓ ++//! Immediate dependency’s hashes | ✓[^1] | ✓ | ✓[^9] + //! [`CompileKind`] (host/target) | ✓ | ✓ | ✓ + //! `__CARGO_DEFAULT_LIB_METADATA`[^4] | | ✓ | ✓ + //! `__CARGO_RUSTC_BOOTSTRAP_WS_REMAP`[^2] | ✓ | | +@@ -91,7 +91,7 @@ + //! `[lints.rust.unexpected_cfgs.check-cfg]` | ✓ | | + //! `--extern priv:` | ✓ | | + //! +-//! [^1]: Bin dependencies are not included. ++//! [^1]: Bin dependencies other than artifact dependencies are not included. + //! + //! [^2]: `__CARGO_RUSTC_BOOTSTRAP_WS_REMAP` is set by rustc bootstrap + //! to customize remap-path-prefix +@@ -111,6 +111,9 @@ + //! + //! [^8]: including `-Cextra-filename` + //! ++//! [^9]: For a target-kind unit, host-kind dependencies (build scripts, ++//! proc-macros) contribute only their `package_id`. ++//! + //! When deciding what should go in the Metadata vs the Fingerprint, consider + //! that some files (like dylibs) do not have a hash in their filename. Thus, + //! if a value changes, only the fingerprint will detect the change (consider, diff --git a/meta/recipes-devtools/rust/rust-source.inc b/meta/recipes-devtools/rust/rust-source.inc index b384a0c76e..42d45a1ca6 100644 --- a/meta/recipes-devtools/rust/rust-source.inc +++ b/meta/recipes-devtools/rust/rust-source.inc @@ -8,6 +8,7 @@ SRC_URI += "https://static.rust-lang.org/dist/rustc-${RUST_VERSION}-src.tar.xz;n file://0003-bootstrap-skip-StdarchVerify-when-remote-testing.patch;patchdir=${RUSTSRC} \ file://0004-cargo-omit-host-triple-from-unit-metadata-hash.patch;patchdir=${RUSTSRC} \ file://0005-rustc-span-make-hygiene-encoding-order-deterministic.patch;patchdir=${RUSTSRC} \ + file://0006-cargo-keep-host-deps-out-of-the-target-C-metadata-hash.patch;patchdir=${RUSTSRC} \ " SRC_URI[rust.sha256sum] = "6451598a99e77f07571960f6b21d577399d3a30f33e80cbd2e3a4aae6535d265"