rust: Remove libtest from stdlibs list

libtest does not need to be linked for every module type, so remove it
from the stdlibs list. Instead, link it only when building benchmarks or
tests.

Bug: 193782599
Test: cd external/rust/crates/; mma
Test: Rust tests still run correctly.
Change-Id: I536be8754da0987e09340744d9ebf668b8e734d0
diff --git a/rust/benchmark.go b/rust/benchmark.go
index b89f5cd..0e84243 100644
--- a/rust/benchmark.go
+++ b/rust/benchmark.go
@@ -101,6 +101,7 @@
 func (benchmark *benchmarkDecorator) compilerDeps(ctx DepsContext, deps Deps) Deps {
 	deps = benchmark.binaryDecorator.compilerDeps(ctx, deps)
 
+	deps.Rustlibs = append(deps.Rustlibs, "libtest")
 	deps.Rustlibs = append(deps.Rustlibs, "libcriterion")
 
 	return deps
diff --git a/rust/config/global.go b/rust/config/global.go
index 43b49d1..1b56237 100644
--- a/rust/config/global.go
+++ b/rust/config/global.go
@@ -29,7 +29,6 @@
 	DefaultEdition     = "2018"
 	Stdlibs            = []string{
 		"libstd",
-		"libtest",
 	}
 
 	// Mapping between Soong internal arch types and std::env constants.
diff --git a/rust/test.go b/rust/test.go
index 6caa7b1..e95b47c 100644
--- a/rust/test.go
+++ b/rust/test.go
@@ -169,3 +169,11 @@
 func (test *testDecorator) stdLinkage(ctx *depsContext) RustLinkage {
 	return RlibLinkage
 }
+
+func (test *testDecorator) compilerDeps(ctx DepsContext, deps Deps) Deps {
+	deps = test.binaryDecorator.compilerDeps(ctx, deps)
+
+	deps.Rustlibs = append(deps.Rustlibs, "libtest")
+
+	return deps
+}
diff --git a/rust/testing.go b/rust/testing.go
index 72f87e1..94cdd9d 100644
--- a/rust/testing.go
+++ b/rust/testing.go
@@ -170,12 +170,10 @@
 			name: "libtest",
 			crate_name: "test",
 			srcs: ["foo.rs"],
-			no_stdlibs: true,
 			host_supported: true,
 			vendor_available: true,
 			vendor_ramdisk_available: true,
 			native_coverage: false,
-			sysroot: true,
 			apex_available: ["//apex_available:platform", "//apex_available:anyapex"],
 			min_sdk_version: "29",
 		}
diff --git a/rust/vendor_snapshot_test.go b/rust/vendor_snapshot_test.go
index 815f80e..60ddb65 100644
--- a/rust/vendor_snapshot_test.go
+++ b/rust/vendor_snapshot_test.go
@@ -569,7 +569,6 @@
 				],
 				rlibs: [
 					"libstd",
-					"libtest",
 					"librust_vendor_available",
 				],
 				binaries: [
@@ -597,7 +596,6 @@
 				],
 				rlibs: [
 					"libstd",
-					"libtest",
 					"librust_vendor_available",
 				],
 				binaries: [
@@ -665,22 +663,6 @@
 	}
 
 	vendor_snapshot_rlib {
-		name: "libtest",
-		version: "30",
-		target_arch: "arm64",
-		vendor: true,
-		sysroot: true,
-		arch: {
-			arm64: {
-				src: "libtest.rlib",
-			},
-			arm: {
-				src: "libtest.rlib",
-			},
-		},
-	}
-
-	vendor_snapshot_rlib {
 		name: "librust_vendor_available",
 		version: "30",
 		target_arch: "arm64",
@@ -917,7 +899,6 @@
 		"vendor/lib64.so":                               nil,
 		"vendor/liblog.so":                              nil,
 		"vendor/libstd.rlib":                            nil,
-		"vendor/libtest.rlib":                           nil,
 		"vendor/librust_vendor_available.rlib":          nil,
 		"vendor/crtbegin_so.o":                          nil,
 		"vendor/crtend_so.o":                            nil,
@@ -962,7 +943,7 @@
 	}
 
 	libclientAndroidMkRlibs := ctx.ModuleForTests("libclient", sharedVariant).Module().(*Module).Properties.AndroidMkRlibs
-	if g, w := libclientAndroidMkRlibs, []string{"librust_vendor_available.vendor_rlib.30.arm64.rlib-std", "libstd.vendor_rlib.30.arm64", "libtest.vendor_rlib.30.arm64"}; !reflect.DeepEqual(g, w) {
+	if g, w := libclientAndroidMkRlibs, []string{"librust_vendor_available.vendor_rlib.30.arm64.rlib-std", "libstd.vendor_rlib.30.arm64"}; !reflect.DeepEqual(g, w) {
 		t.Errorf("wanted libclient libclientAndroidMkRlibs %q, got %q", w, g)
 	}
 
@@ -977,7 +958,7 @@
 	}
 
 	libclientRustAndroidMkRlibs := ctx.ModuleForTests("libclient_rust", rlibVariant).Module().(*Module).Properties.AndroidMkRlibs
-	if g, w := libclientRustAndroidMkRlibs, []string{"librust_vendor_available.vendor_rlib.30.arm64.rlib-std", "libstd.vendor_rlib.30.arm64", "libtest.vendor_rlib.30.arm64"}; !reflect.DeepEqual(g, w) {
+	if g, w := libclientRustAndroidMkRlibs, []string{"librust_vendor_available.vendor_rlib.30.arm64.rlib-std", "libstd.vendor_rlib.30.arm64"}; !reflect.DeepEqual(g, w) {
 		t.Errorf("wanted libclient libclientAndroidMkRlibs %q, got %q", w, g)
 	}