Fix build failure when building unbundled apps (second try)

The previous attempt, which simply skipped the hidden API processing
altogether when unbundled builds were enabled failed when attempting to
build module snapshots as while they enabled an unbundled build they
actually need the hidden API processing to be performed.

This change just checks whether missing dependencies are allowed and if
so it fakes up any missing files so that the build will only fail if
they are not present AND they are used.

Bug: 186695448
Bug: 185828824
Test: tapas Calendar
      m -j60

Change-Id: Ie13fed05af0aba51f45f6791fce944d0e4285037

1 files changed, 56 insertions, 17 deletions

diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index 9f1629428..29d2df0cd 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -198,6 +198,17 @@ func (b *platformBootclasspathModule) getImageConfig(ctx android.EarlyModuleCont
 	return defaultBootImageConfig(ctx)
 }
 
+// hiddenAPISupportingModule encapsulates the information provided by any module that contributes to
+// the hidden API processing.
+type hiddenAPISupportingModule struct {
+	module android.Module
+
+	bootDexJar  android.Path
+	flagsCSV    android.Path
+	indexCSV    android.Path
+	metadataCSV android.Path
+}
+
 // generateHiddenAPIBuildActions generates all the hidden API related build rules.
 func (b *platformBootclasspathModule) generateHiddenAPIBuildActions(ctx android.ModuleContext, modules []android.Module, fragments []android.Module) {
 
@@ -220,27 +231,55 @@ func (b *platformBootclasspathModule) generateHiddenAPIBuildActions(ctx android.
 		return
 	}
 
-	hiddenAPISupportingModules := []hiddenAPISupportingModule{}
-	for _, module := range modules {
-		if h, ok := module.(hiddenAPISupportingModule); ok {
-			if h.bootDexJar() == nil {
-				ctx.ModuleErrorf("module %s does not provide a bootDexJar file", module)
-			}
-			if h.flagsCSV() == nil {
-				ctx.ModuleErrorf("module %s does not provide a flagsCSV file", module)
+	// nilPathHandler will check the supplied path and if it is nil then it will either immediately
+	// report an error, or it will defer the error reporting until it is actually used, depending
+	// whether missing dependencies are allowed.
+	var nilPathHandler func(path android.Path, name string, module android.Module) android.Path
+	if ctx.Config().AllowMissingDependencies() {
+		nilPathHandler = func(path android.Path, name string, module android.Module) android.Path {
+			if path == nil {
+				outputPath := android.PathForModuleOut(ctx, "missing", module.Name(), name)
+				path = outputPath
+
+				// Create an error rule that pretends to create the output file but will actually fail if it
+				// is run.
+				ctx.Build(pctx, android.BuildParams{
+					Rule:   android.ErrorRule,
+					Output: outputPath,
+					Args: map[string]string{
+						"error": fmt.Sprintf("missing hidden API file: %s for %s", name, module),
+					},
+				})
 			}
-			if h.indexCSV() == nil {
-				ctx.ModuleErrorf("module %s does not provide an indexCSV file", module)
+			return path
+		}
+	} else {
+		nilPathHandler = func(path android.Path, name string, module android.Module) android.Path {
+			if path == nil {
+				ctx.ModuleErrorf("module %s does not provide a %s file", module, name)
 			}
-			if h.metadataCSV() == nil {
-				ctx.ModuleErrorf("module %s does not provide a metadataCSV file", module)
+			return path
+		}
+	}
+
+	hiddenAPISupportingModules := []hiddenAPISupportingModule{}
+	for _, module := range modules {
+		if h, ok := module.(hiddenAPIIntf); ok {
+			hiddenAPISupportingModule := hiddenAPISupportingModule{
+				module:      module,
+				bootDexJar:  nilPathHandler(h.bootDexJar(), "bootDexJar", module),
+				flagsCSV:    nilPathHandler(h.flagsCSV(), "flagsCSV", module),
+				indexCSV:    nilPathHandler(h.indexCSV(), "indexCSV", module),
+				metadataCSV: nilPathHandler(h.metadataCSV(), "metadataCSV", module),
 			}
 
+			// If any errors were reported when trying to populate the hiddenAPISupportingModule struct
+			// then don't add it to the list.
 			if ctx.Failed() {
 				continue
 			}
 
-			hiddenAPISupportingModules = append(hiddenAPISupportingModules, h)
+			hiddenAPISupportingModules = append(hiddenAPISupportingModules, hiddenAPISupportingModule)
 		} else {
 			ctx.ModuleErrorf("module %s of type %s does not support hidden API processing", module, ctx.OtherModuleType(module))
 		}
@@ -248,7 +287,7 @@ func (b *platformBootclasspathModule) generateHiddenAPIBuildActions(ctx android.
 
 	moduleSpecificFlagsPaths := android.Paths{}
 	for _, module := range hiddenAPISupportingModules {
-		moduleSpecificFlagsPaths = append(moduleSpecificFlagsPaths, module.flagsCSV())
+		moduleSpecificFlagsPaths = append(moduleSpecificFlagsPaths, module.flagsCSV)
 	}
 
 	flagFileInfo := b.properties.Hidden_api.hiddenAPIFlagFileInfo(ctx)
@@ -274,7 +313,7 @@ func (b *platformBootclasspathModule) generateHiddenAPIBuildActions(ctx android.
 func (b *platformBootclasspathModule) generateHiddenAPIStubFlagsRules(ctx android.ModuleContext, modules []hiddenAPISupportingModule) {
 	bootDexJars := android.Paths{}
 	for _, module := range modules {
-		bootDexJars = append(bootDexJars, module.bootDexJar())
+		bootDexJars = append(bootDexJars, module.bootDexJar)
 	}
 
 	sdkKindToStubPaths := hiddenAPIGatherStubLibDexJarPaths(ctx)
@@ -287,7 +326,7 @@ func (b *platformBootclasspathModule) generateHiddenAPIStubFlagsRules(ctx androi
 func (b *platformBootclasspathModule) generateHiddenAPIIndexRules(ctx android.ModuleContext, modules []hiddenAPISupportingModule) {
 	indexes := android.Paths{}
 	for _, module := range modules {
-		indexes = append(indexes, module.indexCSV())
+		indexes = append(indexes, module.indexCSV)
 	}
 
 	rule := android.NewRuleBuilder(pctx, ctx)
@@ -303,7 +342,7 @@ func (b *platformBootclasspathModule) generateHiddenAPIIndexRules(ctx android.Mo
 func (b *platformBootclasspathModule) generatedHiddenAPIMetadataRules(ctx android.ModuleContext, modules []hiddenAPISupportingModule) {
 	metadataCSVFiles := android.Paths{}
 	for _, module := range modules {
-		metadataCSVFiles = append(metadataCSVFiles, module.metadataCSV())
+		metadataCSVFiles = append(metadataCSVFiles, module.metadataCSV)
 	}
 
 	rule := android.NewRuleBuilder(pctx, ctx)