Disable bazel for riscv_64

This product is experimental and unsupported for Bazel at this time

Test: lunch aosp_riscv64-userdebug && m nothing
Test: lunch aosp_arm64-userdebug && m nothing
Change-Id: I761afb9524f1008f9d5472d2de19bb84342e9e29

android/bazel.go

@@ -383,6 +383,9 @@ func MixedBuildsEnabled(ctx BaseModuleContext) bool {
 // mixedBuildPossible returns true if a module is ready to be replaced by a
 // converted or handcrafted Bazel target.
 func mixedBuildPossible(ctx BaseModuleContext) bool {
+	if !ctx.Config().IsMixedBuildsEnabled() {
+		return false
+	}
 	if ctx.Os() == Windows {
 		// Windows toolchains are not currently supported.
 		return false

android/config.go

@@ -536,7 +536,17 @@ func (c *config) mockFileSystem(bp string, fs map[string][]byte) {
 // Returns true if "Bazel builds" is enabled. In this mode, part of build
 // analysis is handled by Bazel.
 func (c *config) IsMixedBuildsEnabled() bool {
-	return c.BuildMode == BazelProdMode || c.BuildMode == BazelDevMode || c.BuildMode == BazelStagingMode
+	globalMixedBuildsSupport := c.Once(OnceKey{"globalMixedBuildsSupport"}, func() interface{} {
+		if c.productVariables.DeviceArch != nil && *c.productVariables.DeviceArch == "riscv64" {
+			fmt.Fprintln(os.Stderr, "unsupported device arch 'riscv64' for Bazel: falling back to non-mixed build")
+			return false
+		}
+		// TODO(b/253664931): Add other fallback criteria below.
+		return true
+	}).(bool)
+
+	bazelModeEnabled := c.BuildMode == BazelProdMode || c.BuildMode == BazelDevMode || c.BuildMode == BazelStagingMode
+	return globalMixedBuildsSupport && bazelModeEnabled
 }
 
 func (c *config) SetAllowMissingDependencies() {

android/test_config.go

@@ -62,6 +62,7 @@ func TestConfig(buildDir string, env map[string]string, bp string, fs map[string
 		TestAllowNonExistentPaths: true,
 
 		BazelContext:              noopBazelContext{},
+		BuildMode:                 BazelProdMode,
 		mixedBuildDisabledModules: make(map[string]struct{}),
 		mixedBuildEnabledModules:  make(map[string]struct{}),
 	}