Rust cdylib/statliclib support for vendor snapshot.

Adds support for platform vendor_available Rust FFI libraries and
binaries to be included in the vendor snapshot.

Because rlib and dylibs are not yet in snapshots, libstd cannot be
included in a vendor snapshot. As a result, vendor-specific Rust code
can't be guaranteed to work with the platform-provided vendor_available
modules built with a newer toolchain. For now, a check is added
indicating vendor-specific Rust code is unsupported.

This changes the linkage for vendor variants of these modules to default
to rlib linkage since dylibs cannot be included in the snapshot yet.

Bug: 184042776
Test: m nothing # new Soong tests pass
Change-Id: I502eaa4bb962eb87ff868fcf49b435f0d2f982e6

1 files changed, 25 insertions, 8 deletions

diff --git a/rust/snapshot_utils.go b/rust/snapshot_utils.go
index 943c79098..9d5154ce2 100644
--- a/rust/snapshot_utils.go
+++ b/rust/snapshot_utils.go
@@ -18,18 +18,34 @@ import (
 	"android/soong/android"
 )
 
+// snapshotLibraryInterface is an interface for libraries captured to VNDK / vendor snapshots.
+type snapshotLibraryInterface interface {
+	libraryInterface
+
+	// collectHeadersForSnapshot is called in GenerateAndroidBuildActions for snapshot aware
+	// modules (See isSnapshotAware below).
+	// This function should gather all headers needed for snapshot.
+	collectHeadersForSnapshot(ctx android.ModuleContext, deps PathDeps)
+
+	// snapshotHeaders should return collected headers by collectHeadersForSnapshot.
+	// Calling snapshotHeaders before collectHeadersForSnapshot is an error.
+	snapshotHeaders() android.Paths
+}
+
 func (mod *Module) ExcludeFromVendorSnapshot() bool {
-	// TODO Rust does not yet support snapshotting
-	return false
+	return Bool(mod.Properties.Exclude_from_vendor_snapshot)
 }
 
 func (mod *Module) ExcludeFromRecoverySnapshot() bool {
-	// TODO Rust does not yet support snapshotting
-	return false
+	return Bool(mod.Properties.Exclude_from_recovery_snapshot)
 }
 
 func (mod *Module) IsSnapshotLibrary() bool {
-	// TODO Rust does not yet support snapshotting
+	if lib, ok := mod.compiler.(libraryInterface); ok {
+		// Rust-native dylibs and rlibs are not snapshot supported yet, so only
+		// return true if this module produces a C shared or static library.
+		return lib.shared() || lib.static()
+	}
 	return false
 }
 
@@ -39,8 +55,7 @@ func (mod *Module) SnapshotRuntimeLibs() []string {
 }
 
 func (mod *Module) SnapshotSharedLibs() []string {
-	// TODO Rust does not yet support snapshotting
-	return []string{}
+	return mod.Properties.SnapshotSharedLibs
 }
 
 func (mod *Module) Symlinks() []string {
@@ -49,6 +64,8 @@ func (mod *Module) Symlinks() []string {
 }
 
 func (m *Module) SnapshotHeaders() android.Paths {
-	// TODO Rust does not yet support snapshotting
+	if l, ok := m.compiler.(snapshotLibraryInterface); ok {
+		return l.snapshotHeaders()
+	}
 	return android.Paths{}
 }