Repeat kapt processor argument for multiple processors

kapt claims to support a comma separated list of annotation
processors, but it errors if multiple annotation processors
are given.  Surrounding the the list with {} does not error,
but it also doesn't even warn if the second element in the
list is garbage, so it may not be running the second
processor.  Repeat the processor argument for each
annotation processor class instead.

Bug: 154736649
Test: TestKapt
Test: m checkbuild
Change-Id: I4c7c161dbf867d7fba1aaf16fd5e502647e3f682

java/builder.go

@@ -191,7 +191,7 @@ type javaBuilderFlags struct {
 	classpath      classpath
 	java9Classpath classpath
 	processorPath  classpath
-	processor      string
+	processors     []string
 	systemModules  *systemModules
 	aidlFlags      string
 	aidlDeps       android.Paths
@@ -265,8 +265,8 @@ func emitXrefRule(ctx android.ModuleContext, xrefFile android.WritablePath, idx
 	deps = append(deps, flags.processorPath...)
 
 	processor := "-proc:none"
-	if flags.processor != "" {
-		processor = "-processor " + flags.processor
+	if len(flags.processors) > 0 {
+		processor = "-processor " + strings.Join(flags.processors, ",")
 	}
 
 	intermediatesDir := "xref"
@@ -380,8 +380,8 @@ func transformJavaToClasses(ctx android.ModuleContext, outputFile android.Writab
 	deps = append(deps, flags.processorPath...)
 
 	processor := "-proc:none"
-	if flags.processor != "" {
-		processor = "-processor " + flags.processor
+	if len(flags.processors) > 0 {
+		processor = "-processor " + strings.Join(flags.processors, ",")
 	}
 
 	srcJarDir := "srcjars"

java/java.go

@@ -1130,7 +1130,8 @@ func (j *Module) collectBuilderFlags(ctx android.ModuleContext, deps deps) javaB
 	flags.java9Classpath = append(flags.java9Classpath, deps.java9Classpath...)
 	flags.processorPath = append(flags.processorPath, deps.processorPath...)
 
-	flags.processor = strings.Join(deps.processorClasses, ",")
+	flags.processors = append(flags.processors, deps.processorClasses...)
+	flags.processors = android.FirstUniqueStrings(flags.processors)
 
 	if len(flags.bootClasspath) == 0 && ctx.Host() && !flags.javaVersion.usesJavaModules() &&
 		decodeSdkDep(ctx, sdkContext(j)).hasStandardLibs() {
@@ -1265,7 +1266,7 @@ func (j *Module) compile(ctx android.ModuleContext, aaptSrcJar android.Path) {
 			srcJars = append(srcJars, kaptSrcJar)
 			// Disable annotation processing in javac, it's already been handled by kapt
 			flags.processorPath = nil
-			flags.processor = ""
+			flags.processors = nil
 		}
 
 		kotlinJar := android.PathForModuleOut(ctx, "kotlin", jarName)

java/kotlin.go

@@ -136,8 +136,11 @@ func kotlinKapt(ctx android.ModuleContext, outputFile android.WritablePath,
 	kaptProcessorPath := flags.processorPath.FormRepeatedClassPath("-P plugin:org.jetbrains.kotlin.kapt3:apclasspath=")
 
 	kaptProcessor := ""
-	if flags.processor != "" {
-		kaptProcessor = "-P plugin:org.jetbrains.kotlin.kapt3:processors=" + flags.processor
+	for i, p := range flags.processors {
+		if i > 0 {
+			kaptProcessor += " "
+		}
+		kaptProcessor += "-P plugin:org.jetbrains.kotlin.kapt3:processors=" + p
 	}
 
 	encodedJavacFlags := kaptEncodeFlags([][2]string{

java/kotlin_test.go

@@ -88,7 +88,7 @@ func TestKapt(t *testing.T) {
 		java_library {
 			name: "foo",
 			srcs: ["a.java", "b.kt"],
-			plugins: ["bar"],
+			plugins: ["bar", "baz"],
 		}
 
 		java_plugin {
@@ -96,6 +96,12 @@ func TestKapt(t *testing.T) {
 			processor_class: "com.bar",
 			srcs: ["b.java"],
 		}
+
+		java_plugin {
+			name: "baz",
+			processor_class: "com.baz",
+			srcs: ["b.java"],
+		}
 		`)
 
 	buildOS := android.BuildOs.String()
@@ -105,6 +111,7 @@ func TestKapt(t *testing.T) {
 	javac := ctx.ModuleForTests("foo", "android_common").Rule("javac")
 
 	bar := ctx.ModuleForTests("bar", buildOS+"_common").Rule("javac").Output.String()
+	baz := ctx.ModuleForTests("baz", buildOS+"_common").Rule("javac").Output.String()
 
 	// Test that the kotlin and java sources are passed to kapt and kotlinc
 	if len(kapt.Inputs) != 2 || kapt.Inputs[0].String() != "a.java" || kapt.Inputs[1].String() != "b.kt" {
@@ -136,11 +143,12 @@ func TestKapt(t *testing.T) {
 	}
 
 	// Test that the processors are passed to kapt
-	expectedProcessorPath := "-P plugin:org.jetbrains.kotlin.kapt3:apclasspath=" + bar
+	expectedProcessorPath := "-P plugin:org.jetbrains.kotlin.kapt3:apclasspath=" + bar +
+		" -P plugin:org.jetbrains.kotlin.kapt3:apclasspath=" + baz
 	if kapt.Args["kaptProcessorPath"] != expectedProcessorPath {
 		t.Errorf("expected kaptProcessorPath %q, got %q", expectedProcessorPath, kapt.Args["kaptProcessorPath"])
 	}
-	expectedProcessor := "-P plugin:org.jetbrains.kotlin.kapt3:processors=com.bar"
+	expectedProcessor := "-P plugin:org.jetbrains.kotlin.kapt3:processors=com.bar -P plugin:org.jetbrains.kotlin.kapt3:processors=com.baz"
 	if kapt.Args["kaptProcessor"] != expectedProcessor {
 		t.Errorf("expected kaptProcessor %q, got %q", expectedProcessor, kapt.Args["kaptProcessor"])
 	}