add crate_root property to rust modules

The crate_root property will be used to specify the entry point for a
rustc compilation. This will allow the srcs property to be used to
collect all src inputs to rustc rather than just the entry point.

Bug: 286077158
Test: m libnum_traits
Change-Id: I1a167182305dcc11cc927d562ceed622153111d3

1 files changed, 13 insertions, 6 deletions

diff --git a/rust/toolchain_library.go b/rust/toolchain_library.go
index 801c0c271..e118f92be 100644
--- a/rust/toolchain_library.go
+++ b/rust/toolchain_library.go
@@ -40,8 +40,10 @@ func init() {
 }
 
 type toolchainLibraryProperties struct {
-	// path to the toolchain source, relative to the top of the toolchain source
-	Toolchain_src *string `android:"arch_variant"`
+	// path to the toolchain crate root, relative to the top of the toolchain source
+	Toolchain_crate_root *string `android:"arch_variant"`
+	// path to the rest of the toolchain srcs, relative to the top of the toolchain source
+	Toolchain_srcs []string `android:"arch_variant"`
 }
 
 type toolchainLibraryDecorator struct {
@@ -87,15 +89,20 @@ func initToolchainLibrary(module *Module, library *libraryDecorator) android.Mod
 func rustSetToolchainSource(ctx android.LoadHookContext) {
 	if toolchainLib, ok := ctx.Module().(*Module).compiler.(*toolchainLibraryDecorator); ok {
 		prefix := "linux-x86/" + GetRustPrebuiltVersion(ctx)
-		newSrcs := []string{path.Join(prefix, android.String(toolchainLib.Properties.Toolchain_src))}
+		versionedCrateRoot := path.Join(prefix, android.String(toolchainLib.Properties.Toolchain_crate_root))
+		versionedSrcs := make([]string, len(toolchainLib.Properties.Toolchain_srcs))
+		for i, src := range toolchainLib.Properties.Toolchain_srcs {
+			versionedSrcs[i] = path.Join(prefix, src)
+		}
 
 		type props struct {
-			Srcs []string
+			Crate_root *string
+			Srcs       []string
 		}
 		p := &props{}
-		p.Srcs = newSrcs
+		p.Crate_root = &versionedCrateRoot
+		p.Srcs = versionedSrcs
 		ctx.AppendProperties(p)
-
 	} else {
 		ctx.ModuleErrorf("Called rustSetToolchainSource on a non-Rust Module.")
 	}