Prevent defaults modules from expanding path property dependencies

Defaults modules should not have dependencies added to them for
path properties, the properties will already have been squashed
into other modules that depend on the defaults modules, and the
path dependencies will be added to those modules.

Fixes: 321056451
Test: TestDefaultsPathProperties
Change-Id: I59049f94b7a0924a7b1d997d15723901b0d522ee

android/defaults_test.go

@@ -16,10 +16,13 @@ package android
 
 import (
 	"testing"
+
+	"github.com/google/blueprint"
 )
 
 type defaultsTestProperties struct {
-	Foo []string
+	Foo       []string
+	Path_prop []string `android:"path"`
 }
 
 type defaultsTestModule struct {
@@ -130,3 +133,40 @@ func TestDefaultsAllowMissingDependencies(t *testing.T) {
 	// TODO: missing transitive defaults is currently not handled
 	_ = missingTransitiveDefaults
 }
+
+func TestDefaultsPathProperties(t *testing.T) {
+	bp := `
+		defaults {
+			name: "defaults",
+			path_prop: [":gen"],
+		}
+
+		test {
+			name: "foo",
+			defaults: ["defaults"],
+		}
+
+		test {
+			name: "gen",
+		}
+	`
+
+	result := GroupFixturePreparers(
+		prepareForDefaultsTest,
+		FixtureWithRootAndroidBp(bp),
+	).RunTest(t)
+
+	collectDeps := func(m Module) []string {
+		var deps []string
+		result.VisitDirectDeps(m, func(dep blueprint.Module) {
+			deps = append(deps, result.ModuleName(dep))
+		})
+		return deps
+	}
+
+	foo := result.Module("foo", "")
+	defaults := result.Module("defaults", "")
+
+	AssertStringListContains(t, "foo should depend on gen", collectDeps(foo), "gen")
+	AssertStringListDoesNotContain(t, "defaults should not depend on gen", collectDeps(defaults), "gen")
+}

android/path_properties.go

@@ -33,6 +33,11 @@ func registerPathDepsMutator(ctx RegisterMutatorsContext) {
 // The pathDepsMutator automatically adds dependencies on any module that is listed with the
 // ":module" module reference syntax in a property that is tagged with `android:"path"`.
 func pathDepsMutator(ctx BottomUpMutatorContext) {
+	if _, ok := ctx.Module().(DefaultsModule); ok {
+		// Defaults modules shouldn't have dependencies added for path properties, they have already been
+		// squashed into the real modules.
+		return
+	}
 	props := ctx.Module().base().GetProperties()
 	addPathDepsForProps(ctx, props)
 }