Require prebuilt_bootclasspath_fragment to provide hidden API files

Previously, the prebuilt_bootclasspath_fragment was not required to
provide hidden API files as not all usages of that module provided
them. That should no longer be the case so this change makes the
prebuilt_bootclasspath_fragment stricter and so now always require
them.

Bug: 194063708
Test: m out/soong/hiddenapi/hiddenapi-flags.csv
      - check that this does not change the contents.
Change-Id: I3f19a1b4246f09a927c0f6b0f41b8678150d6cc2
diff --git a/java/bootclasspath_fragment.go b/java/bootclasspath_fragment.go
index 503c31f..1ce9911 100644
--- a/java/bootclasspath_fragment.go
+++ b/java/bootclasspath_fragment.go
@@ -599,7 +599,7 @@
 
 	// The monolithic hidden API processing also needs access to all the output files produced by
 	// hidden API processing of this fragment.
-	hiddenAPIInfo.HiddenAPIFlagOutput = (*output).HiddenAPIFlagOutput
+	hiddenAPIInfo.HiddenAPIFlagOutput = output.HiddenAPIFlagOutput
 
 	//  Provide it for use by other modules.
 	ctx.SetProvider(HiddenAPIInfoProvider, hiddenAPIInfo)
@@ -896,10 +896,10 @@
 
 // produceHiddenAPIOutput returns a path to the prebuilt all-flags.csv or nil if none is specified.
 func (module *prebuiltBootclasspathFragmentModule) produceHiddenAPIOutput(ctx android.ModuleContext, contents []android.Module, input HiddenAPIFlagInput) *HiddenAPIOutput {
-	pathForOptionalSrc := func(src *string) android.Path {
+	pathForSrc := func(property string, src *string) android.Path {
 		if src == nil {
-			// TODO(b/179354495): Fail if this is not provided once prebuilts have been updated.
-			return nil
+			ctx.PropertyErrorf(property, "is required but was not specified")
+			return android.PathForModuleSrc(ctx, "missing", property)
 		}
 		return android.PathForModuleSrc(ctx, *src)
 	}
@@ -910,11 +910,11 @@
 
 	output := HiddenAPIOutput{
 		HiddenAPIFlagOutput: HiddenAPIFlagOutput{
-			StubFlagsPath:       pathForOptionalSrc(module.prebuiltProperties.Hidden_api.Stub_flags),
-			AnnotationFlagsPath: pathForOptionalSrc(module.prebuiltProperties.Hidden_api.Annotation_flags),
-			MetadataPath:        pathForOptionalSrc(module.prebuiltProperties.Hidden_api.Metadata),
-			IndexPath:           pathForOptionalSrc(module.prebuiltProperties.Hidden_api.Index),
-			AllFlagsPath:        pathForOptionalSrc(module.prebuiltProperties.Hidden_api.All_flags),
+			AnnotationFlagsPath: pathForSrc("hidden_api.annotation_flags", module.prebuiltProperties.Hidden_api.Annotation_flags),
+			MetadataPath:        pathForSrc("hidden_api.metadata", module.prebuiltProperties.Hidden_api.Metadata),
+			IndexPath:           pathForSrc("hidden_api.index", module.prebuiltProperties.Hidden_api.Index),
+			StubFlagsPath:       pathForSrc("hidden_api.stub_flags", module.prebuiltProperties.Hidden_api.Stub_flags),
+			AllFlagsPath:        pathForSrc("hidden_api.all_flags", module.prebuiltProperties.Hidden_api.All_flags),
 		},
 		EncodedBootDexFilesByModule: encodedBootDexJarsByModule,
 	}