Move generation of global hidden API flags to platform_bootclasspath

This change moves the generation of the global hidden API flags from
the singleton to the platform_bootclasspath module. It involves:
1. Moving the ruleToGenerateHiddenApiFlags to hiddenapi_modular.go.
2. Adding HiddenAPIAugmentationProperties to be used by the
   platform_bootclasspath type.
3. Moving the file paths into the platform-bootclasspath module
   definition in frameworks/base/boot/Android.bp.

The flagsRule is kept as a placeholder for now. The emptyFlagsRule is
also kept so that builds continue to work even when the frameworks/base
repository is not present.

Bug: 177892522
Test: verified that the out/soong/hiddenapi/... files are unchanged
      by this change
Change-Id: Idf4dd414a016831bfe04a01f93234c1c33819881
diff --git a/java/hiddenapi_modular.go b/java/hiddenapi_modular.go
index eef0320..bed11fe 100644
--- a/java/hiddenapi_modular.go
+++ b/java/hiddenapi_modular.go
@@ -20,7 +20,7 @@
 
 // Contains support for processing hiddenAPI in a modular fashion.
 
-// hiddenAPIAugmentationInfo contains paths to the files that can be used to augment the information
+// HiddenAPIAugmentationProperties contains paths to the files that can be used to augment the information
 // obtained from annotations within the source code in order to create the complete set of flags
 // that should be applied to the dex implementation jars on the bootclasspath.
 //
@@ -31,31 +31,142 @@
 // The Unsupported_packages property contains a list of paths, each of which is a plain text file
 // with one Java package per line. All members of all classes within that package (but not nested
 // packages) will be updated in a property specific way.
-type hiddenAPIAugmentationInfo struct {
+type HiddenAPIAugmentationProperties struct {
 	// Marks each signature in the referenced files as being unsupported.
-	Unsupported android.Paths
+	Unsupported []string `android:"path"`
 
 	// Marks each signature in the referenced files as being unsupported because it has been removed.
 	// Any conflicts with other flags are ignored.
-	Removed android.Paths
+	Removed []string `android:"path"`
 
 	// Marks each signature in the referenced files as being supported only for targetSdkVersion <= R
 	// and low priority.
-	Max_target_r_low_priority android.Paths
+	Max_target_r_low_priority []string `android:"path"`
 
 	// Marks each signature in the referenced files as being supported only for targetSdkVersion <= Q.
-	Max_target_q android.Paths
+	Max_target_q []string `android:"path"`
 
 	// Marks each signature in the referenced files as being supported only for targetSdkVersion <= P.
-	Max_target_p android.Paths
+	Max_target_p []string `android:"path"`
 
 	// Marks each signature in the referenced files as being supported only for targetSdkVersion <= O
 	// and low priority. Any conflicts with other flags are ignored.
-	Max_target_o_low_priority android.Paths
+	Max_target_o_low_priority []string `android:"path"`
 
 	// Marks each signature in the referenced files as being blocked.
-	Blocked android.Paths
+	Blocked []string `android:"path"`
 
 	// Marks each signature in every package in the referenced files as being unsupported.
+	Unsupported_packages []string `android:"path"`
+}
+
+func (p *HiddenAPIAugmentationProperties) hiddenAPIAugmentationInfo(ctx android.ModuleContext) hiddenAPIAugmentationInfo {
+	paths := func(paths []string) android.Paths { return android.PathsForModuleSrc(ctx, paths) }
+	return hiddenAPIAugmentationInfo{
+		Unsupported:               paths(p.Unsupported),
+		Removed:                   paths(p.Removed),
+		Max_target_r_low_priority: paths(p.Max_target_r_low_priority),
+		Max_target_q:              paths(p.Max_target_q),
+		Max_target_p:              paths(p.Max_target_p),
+		Max_target_o_low_priority: paths(p.Max_target_o_low_priority),
+		Blocked:                   paths(p.Blocked),
+		Unsupported_packages:      paths(p.Unsupported_packages),
+	}
+}
+
+// hiddenAPIAugmentationInfo contains paths resolved from HiddenAPIAugmentationProperties
+type hiddenAPIAugmentationInfo struct {
+	// See HiddenAPIAugmentationProperties.Unsupported
+	Unsupported android.Paths
+
+	// See HiddenAPIAugmentationProperties.Removed
+	Removed android.Paths
+
+	// See HiddenAPIAugmentationProperties.Max_target_r_low_priority
+	Max_target_r_low_priority android.Paths
+
+	// See HiddenAPIAugmentationProperties.Max_target_q
+	Max_target_q android.Paths
+
+	// See HiddenAPIAugmentationProperties.Max_target_p
+	Max_target_p android.Paths
+
+	// See HiddenAPIAugmentationProperties.Max_target_o_low_priority
+	Max_target_o_low_priority android.Paths
+
+	// See HiddenAPIAugmentationProperties.Blocked
+	Blocked android.Paths
+
+	// See HiddenAPIAugmentationProperties.Unsupported_packages
 	Unsupported_packages android.Paths
 }
+
+// ruleToGenerateHiddenApiFlags creates a rule to create the monolithic hidden API flags from the
+// flags from all the modules, the stub flags, augmented with some additional configuration files.
+//
+// baseFlagsPath is the path to the flags file containing all the information from the stubs plus
+// an entry for every single member in the dex implementation jars of the individual modules. Every
+// signature in any of the other files MUST be included in this file.
+//
+// moduleSpecificFlagsPaths are the paths to the flags files generated by each module using
+// information from the baseFlagsPath as well as from annotations within the source.
+//
+// augmentationInfo is a struct containing paths to files that augment the information provided by
+// the moduleSpecificFlagsPaths.
+// ruleToGenerateHiddenApiFlags creates a rule to create the monolithic hidden API flags from the
+// flags from all the modules, the stub flags, augmented with some additional configuration files.
+//
+// baseFlagsPath is the path to the flags file containing all the information from the stubs plus
+// an entry for every single member in the dex implementation jars of the individual modules. Every
+// signature in any of the other files MUST be included in this file.
+//
+// moduleSpecificFlagsPaths are the paths to the flags files generated by each module using
+// information from the baseFlagsPath as well as from annotations within the source.
+//
+// augmentationInfo is a struct containing paths to files that augment the information provided by
+// the moduleSpecificFlagsPaths.
+func ruleToGenerateHiddenApiFlags(ctx android.BuilderContext, outputPath android.WritablePath, baseFlagsPath android.Path, moduleSpecificFlagsPaths android.Paths, augmentationInfo hiddenAPIAugmentationInfo) {
+	tempPath := android.PathForOutput(ctx, outputPath.Rel()+".tmp")
+	rule := android.NewRuleBuilder(pctx, ctx)
+	command := rule.Command().
+		BuiltTool("generate_hiddenapi_lists").
+		FlagWithInput("--csv ", baseFlagsPath).
+		Inputs(moduleSpecificFlagsPaths).
+		FlagWithOutput("--output ", tempPath)
+
+	for _, path := range augmentationInfo.Unsupported {
+		command.FlagWithInput("--unsupported ", path)
+	}
+
+	for _, path := range augmentationInfo.Removed {
+		command.FlagWithInput("--unsupported ", path).Flag("--ignore-conflicts ").FlagWithArg("--tag ", "removed")
+	}
+
+	for _, path := range augmentationInfo.Max_target_r_low_priority {
+		command.FlagWithInput("--max-target-r ", path).FlagWithArg("--tag ", "lo-prio")
+	}
+
+	for _, path := range augmentationInfo.Max_target_q {
+		command.FlagWithInput("--max-target-q ", path)
+	}
+
+	for _, path := range augmentationInfo.Max_target_p {
+		command.FlagWithInput("--max-target-p ", path)
+	}
+
+	for _, path := range augmentationInfo.Max_target_o_low_priority {
+		command.FlagWithInput("--max-target-o ", path).Flag("--ignore-conflicts ").FlagWithArg("--tag ", "lo-prio")
+	}
+
+	for _, path := range augmentationInfo.Blocked {
+		command.FlagWithInput("--blocked ", path)
+	}
+
+	for _, path := range augmentationInfo.Unsupported_packages {
+		command.FlagWithInput("--unsupported ", path).Flag("--packages ")
+	}
+
+	commitChangeForRestat(rule, tempPath, outputPath)
+
+	rule.Build("hiddenAPIFlagsFile", "hiddenapi flags")
+}
diff --git a/java/hiddenapi_singleton.go b/java/hiddenapi_singleton.go
index 341381a..641e19f 100644
--- a/java/hiddenapi_singleton.go
+++ b/java/hiddenapi_singleton.go
@@ -18,7 +18,6 @@
 	"fmt"
 
 	"android/soong/android"
-	"android/soong/genrule"
 )
 
 func init() {
@@ -321,109 +320,13 @@
 	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.
+// flagsRule is a placeholder that simply returns the location of the file, the generation of the
+// ninja rules is done in generateHiddenAPIBuildActions.
 func flagsRule(ctx android.SingletonContext) android.Path {
-	var flagsCSV android.Paths
-	var combinedRemovedApis android.Path
-
-	ctx.VisitAllModules(func(module android.Module) {
-		if h, ok := module.(hiddenAPIIntf); ok {
-			if csv := h.flagsCSV(); csv != nil {
-				flagsCSV = append(flagsCSV, csv)
-			}
-		} else if g, ok := module.(*genrule.Module); ok {
-			if ctx.ModuleName(module) == "combined-removed-dex" {
-				if len(g.GeneratedSourceFiles()) != 1 || combinedRemovedApis != nil {
-					ctx.Errorf("Expected 1 combined-removed-dex module that generates 1 output file.")
-				}
-				combinedRemovedApis = g.GeneratedSourceFiles()[0]
-			}
-		}
-	})
-
-	if combinedRemovedApis == nil {
-		ctx.Errorf("Failed to find combined-removed-dex.")
-	}
-
 	outputPath := hiddenAPISingletonPaths(ctx).flags
-
-	stubFlags := hiddenAPISingletonPaths(ctx).stubFlags
-
-	pathsForSource := func(paths ...string) android.Paths { return android.PathsForSource(ctx, paths) }
-
-	ruleToGenerateHiddenApiFlags(ctx, outputPath, stubFlags, flagsCSV, hiddenAPIAugmentationInfo{
-		Unsupported:               pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-unsupported.txt"),
-		Removed:                   android.Paths{combinedRemovedApis},
-		Max_target_r_low_priority: pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-max-target-r-loprio.txt"),
-		Max_target_q:              pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-max-target-q.txt"),
-		Max_target_p:              pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-max-target-p.txt"),
-		Max_target_o_low_priority: pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-max-target-o.txt"),
-		Blocked:                   pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-force-blocked.txt"),
-		Unsupported_packages:      pathsForSource("frameworks/base/boot/hiddenapi/hiddenapi-unsupported-packages.txt"),
-	})
-
 	return outputPath
 }
 
-// ruleToGenerateHiddenApiFlags creates a rule to create the monolithic hidden API flags from the
-// flags from all the modules, the stub flags, augmented with some additional configuration files.
-//
-// baseFlagsPath is the path to the flags file containing all the information from the stubs plus
-// an entry for every single member in the dex implementation jars of the individual modules. Every
-// signature in any of the other files MUST be included in this file.
-//
-// moduleSpecificFlagsPaths are the paths to the flags files generated by each module using
-// information from the baseFlagsPath as well as from annotations within the source.
-//
-// augmentationInfo is a struct containing paths to files that augment the information provided by
-// the moduleSpecificFlagsPaths.
-func ruleToGenerateHiddenApiFlags(ctx android.BuilderContext, outputPath android.WritablePath, baseFlagsPath android.Path, moduleSpecificFlagsPaths android.Paths, augmentationInfo hiddenAPIAugmentationInfo) {
-	tempPath := android.PathForOutput(ctx, outputPath.Rel()+".tmp")
-	rule := android.NewRuleBuilder(pctx, ctx)
-	command := rule.Command().
-		BuiltTool("generate_hiddenapi_lists").
-		FlagWithInput("--csv ", baseFlagsPath).
-		Inputs(moduleSpecificFlagsPaths).
-		FlagWithOutput("--output ", tempPath)
-
-	for _, path := range augmentationInfo.Unsupported {
-		command.FlagWithInput("--unsupported ", path)
-	}
-
-	for _, path := range augmentationInfo.Removed {
-		command.FlagWithInput("--unsupported ", path).Flag("--ignore-conflicts ").FlagWithArg("--tag ", "removed")
-	}
-
-	for _, path := range augmentationInfo.Max_target_r_low_priority {
-		command.FlagWithInput("--max-target-r ", path).FlagWithArg("--tag ", "lo-prio")
-	}
-
-	for _, path := range augmentationInfo.Max_target_q {
-		command.FlagWithInput("--max-target-q ", path)
-	}
-
-	for _, path := range augmentationInfo.Max_target_p {
-		command.FlagWithInput("--max-target-p ", path)
-	}
-
-	for _, path := range augmentationInfo.Max_target_o_low_priority {
-		command.FlagWithInput("--max-target-o ", path).Flag("--ignore-conflicts ").FlagWithArg("--tag ", "lo-prio")
-	}
-
-	for _, path := range augmentationInfo.Blocked {
-		command.FlagWithInput("--blocked ", path)
-	}
-
-	for _, path := range augmentationInfo.Unsupported_packages {
-		command.FlagWithInput("--unsupported ", path).Flag("--packages ")
-	}
-
-	commitChangeForRestat(rule, tempPath, outputPath)
-
-	rule.Build("hiddenAPIFlagsFile", "hiddenapi flags")
-}
-
 // emptyFlagsRule creates a rule to build an empty hiddenapi-flags.csv, which is needed by master-art-host builds that
 // have a partial manifest without frameworks/base but still need to build a boot image.
 func emptyFlagsRule(ctx android.SingletonContext) android.Path {
diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index 95d19b9..e292d80 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -84,10 +84,11 @@
 }
 
 type platformBootclasspathProperties struct {
-
 	// The names of the bootclasspath_fragment modules that form part of this
 	// platform_bootclasspath.
 	Fragments []ApexVariantReference
+
+	Hidden_api HiddenAPIAugmentationProperties
 }
 
 func platformBootclasspathFactory() android.Module {
@@ -191,6 +192,8 @@
 		}
 	})
 
+	b.generateHiddenAPIBuildActions(ctx, b.configuredModules)
+
 	// Nothing to do if skipping the dexpreopt of boot image jars.
 	if SkipDexpreoptBootJars(ctx) {
 		return
@@ -215,3 +218,24 @@
 func (b *platformBootclasspathModule) getImageConfig(ctx android.EarlyModuleContext) *bootImageConfig {
 	return defaultBootImageConfig(ctx)
 }
+
+// generateHiddenAPIBuildActions generates all the hidden API related build rules.
+func (b *platformBootclasspathModule) generateHiddenAPIBuildActions(ctx android.ModuleContext, modules []android.Module) {
+
+	moduleSpecificFlagsPaths := android.Paths{}
+	for _, module := range modules {
+		if h, ok := module.(hiddenAPIIntf); ok {
+			if csv := h.flagsCSV(); csv != nil {
+				moduleSpecificFlagsPaths = append(moduleSpecificFlagsPaths, csv)
+			}
+		} else {
+			ctx.ModuleErrorf("module %s of type %s does not implement hiddenAPIIntf", module, ctx.OtherModuleType(module))
+		}
+	}
+
+	augmentationInfo := b.properties.Hidden_api.hiddenAPIAugmentationInfo(ctx)
+
+	outputPath := hiddenAPISingletonPaths(ctx).flags
+	baseFlagsPath := hiddenAPISingletonPaths(ctx).stubFlags
+	ruleToGenerateHiddenApiFlags(ctx, outputPath, baseFlagsPath, moduleSpecificFlagsPaths, augmentationInfo)
+}