Enable prebuilt hiddenapi CSV files.

By enabling these hiddenapi CSV files to be prebuilt, it
becomes possible to create a split build that supports
the hiddenapi encode dex step, but doesn't contain all
of the java sources needed to generate the CSV files.

Bug: 175048716
Test: m nothing
Test: new TestHiddenAPISingletonWithPrebuiltCsvFile
Test: local build without prebuilt hiddenapi
Test: local build with prebuilt hiddenapi
Change-Id: I805ea3ec05860d2df211a3985ec025bf36f0d775

java/hiddenapi_singleton.go

@@ -67,6 +67,19 @@ func (h *hiddenAPISingleton) GenerateBuildActions(ctx android.SingletonContext)
 
 	stubFlagsRule(ctx)
 
+	// If there is a prebuilt hiddenapi dir, generate rules to use the
+	// files within. Generally, we build the hiddenapi files from source
+	// during the build, ensuring consistency. It's possible, in a split
+	// build (framework and vendor) scenario, for the vendor build to use
+	// prebuilt hiddenapi files from the framework build. In this scenario,
+	// the framework and vendor builds must use the same source to ensure
+	// consistency.
+
+	if ctx.Config().PrebuiltHiddenApiDir(ctx) != "" {
+		h.flags = prebuiltFlagsRule(ctx)
+		return
+	}
+
 	// These rules depend on files located in frameworks/base, skip them if running in a tree that doesn't have them.
 	if ctx.Config().FrameworksBaseDirExists(ctx) {
 		h.flags = flagsRule(ctx)
@@ -212,6 +225,19 @@ func stubFlagsRule(ctx android.SingletonContext) {
 	rule.Build("hiddenAPIStubFlagsFile", "hiddenapi stub flags")
 }
 
+func prebuiltFlagsRule(ctx android.SingletonContext) android.Path {
+	outputPath := hiddenAPISingletonPaths(ctx).flags
+	inputPath := android.PathForSource(ctx, ctx.Config().PrebuiltHiddenApiDir(ctx), "hiddenapi-flags.csv")
+
+	ctx.Build(pctx, android.BuildParams{
+		Rule:   android.Cp,
+		Output: outputPath,
+		Input:  inputPath,
+	})
+
+	return outputPath
+}
+
 // flagsRule creates a rule to build hiddenapi-flags.csv out of flags.csv files generated for boot image modules and
 // the unsupported API.
 func flagsRule(ctx android.SingletonContext) android.Path {
@@ -391,6 +417,20 @@ func (h *hiddenAPIIndexSingleton) GenerateBuildActions(ctx android.SingletonCont
 		return
 	}
 
+	if ctx.Config().PrebuiltHiddenApiDir(ctx) != "" {
+		outputPath := hiddenAPISingletonPaths(ctx).index
+		inputPath := android.PathForSource(ctx, ctx.Config().PrebuiltHiddenApiDir(ctx), "hiddenapi-index.csv")
+
+		ctx.Build(pctx, android.BuildParams{
+			Rule:   android.Cp,
+			Output: outputPath,
+			Input:  inputPath,
+		})
+
+		h.index = outputPath
+		return
+	}
+
 	indexes := android.Paths{}
 	ctx.VisitAllModules(func(module android.Module) {
 		if h, ok := module.(hiddenAPIIntf); ok {

java/hiddenapi_singleton_test.go

@@ -23,9 +23,10 @@ import (
 	"github.com/google/blueprint/proptools"
 )
 
-func testConfigWithBootJars(bp string, bootJars []string) android.Config {
+func testConfigWithBootJars(bp string, bootJars []string, prebuiltHiddenApiDir *string) android.Config {
 	config := testConfig(nil, bp, nil)
 	config.TestProductVariables.BootJars = android.CreateTestConfiguredJarList(bootJars)
+	config.TestProductVariables.PrebuiltHiddenApiDir = prebuiltHiddenApiDir
 	return config
 }
 
@@ -44,8 +45,8 @@ func testHiddenAPIWithConfig(t *testing.T, config android.Config) *android.TestC
 	return ctx
 }
 
-func testHiddenAPIBootJars(t *testing.T, bp string, bootJars []string) (*android.TestContext, android.Config) {
-	config := testConfigWithBootJars(bp, bootJars)
+func testHiddenAPIBootJars(t *testing.T, bp string, bootJars []string, prebuiltHiddenApiDir *string) (*android.TestContext, android.Config) {
+	config := testConfigWithBootJars(bp, bootJars, prebuiltHiddenApiDir)
 
 	return testHiddenAPIWithConfig(t, config), config
 }
@@ -64,7 +65,7 @@ func TestHiddenAPISingleton(t *testing.T) {
 			srcs: ["a.java"],
 			compile_dex: true,
 	}
-	`, []string{":foo"})
+	`, []string{":foo"}, nil)
 
 	hiddenAPI := ctx.SingletonForTests("hiddenapi")
 	hiddenapiRule := hiddenAPI.Rule("hiddenapi")
@@ -81,7 +82,7 @@ func TestHiddenAPISingletonWithPrebuilt(t *testing.T) {
 			jars: ["a.jar"],
 			compile_dex: true,
 	}
-	`, []string{":foo"})
+	`, []string{":foo"}, nil)
 
 	hiddenAPI := ctx.SingletonForTests("hiddenapi")
 	hiddenapiRule := hiddenAPI.Rule("hiddenapi")
@@ -105,7 +106,7 @@ func TestHiddenAPISingletonWithPrebuiltUseSource(t *testing.T) {
 			compile_dex: true,
 			prefer: false,
 	}
-	`, []string{":foo"})
+	`, []string{":foo"}, nil)
 
 	hiddenAPI := ctx.SingletonForTests("hiddenapi")
 	hiddenapiRule := hiddenAPI.Rule("hiddenapi")
@@ -134,7 +135,7 @@ func TestHiddenAPISingletonWithPrebuiltOverrideSource(t *testing.T) {
 			compile_dex: true,
 			prefer: true,
 	}
-	`, []string{":foo"})
+	`, []string{":foo"}, nil)
 
 	hiddenAPI := ctx.SingletonForTests("hiddenapi")
 	hiddenapiRule := hiddenAPI.Rule("hiddenapi")
@@ -217,3 +218,48 @@ func generateSdkDexPath(module string, unbundled bool) string {
 	}
 	return generateDexPath(module)
 }
+
+func TestHiddenAPISingletonWithPrebuiltCsvFile(t *testing.T) {
+
+	// The idea behind this test is to ensure that when the build is
+	// confugured with a PrebuiltHiddenApiDir that the rules for the
+	// hiddenapi singleton copy the prebuilts to the typical output
+	// location, and then use that output location for the hiddenapi encode
+	// dex step.
+
+	// Where to find the prebuilt hiddenapi files:
+	prebuiltHiddenApiDir := "path/to/prebuilt/hiddenapi"
+
+	ctx, _ := testHiddenAPIBootJars(t, `
+		java_import {
+			name: "foo",
+			jars: ["a.jar"],
+			compile_dex: true,
+	}
+	`, []string{":foo"}, &prebuiltHiddenApiDir)
+
+	expectedCpInput := prebuiltHiddenApiDir + "/hiddenapi-flags.csv"
+	expectedCpOutput := buildDir + "/hiddenapi/hiddenapi-flags.csv"
+	expectedFlagsCsv := buildDir + "/hiddenapi/hiddenapi-flags.csv"
+
+	foo := ctx.ModuleForTests("foo", "android_common")
+
+	hiddenAPI := ctx.SingletonForTests("hiddenapi")
+	cpRule := hiddenAPI.Rule("Cp")
+	actualCpInput := cpRule.BuildParams.Input
+	actualCpOutput := cpRule.BuildParams.Output
+	encodeDexRule := foo.Rule("hiddenAPIEncodeDex")
+	actualFlagsCsv := encodeDexRule.BuildParams.Args["flagsCsv"]
+
+	if actualCpInput.String() != expectedCpInput {
+		t.Errorf("Prebuilt hiddenapi cp rule input mismatch, actual: %s, expected: %s", actualCpInput, expectedCpInput)
+	}
+
+	if actualCpOutput.String() != expectedCpOutput {
+		t.Errorf("Prebuilt hiddenapi cp rule output mismatch, actual: %s, expected: %s", actualCpOutput, expectedCpOutput)
+	}
+
+	if actualFlagsCsv != expectedFlagsCsv {
+		t.Errorf("Prebuilt hiddenapi encode dex rule flags csv mismatch, actual: %s, expected: %s", actualFlagsCsv, expectedFlagsCsv)
+	}
+}