Fix generated headers of snapshot

For VNDK snapshot and SDK snapshot, deps files have been used to capture
generated headers. But exported deps might contain intermediate phony
files instead of actual header files, which are for optimization of
ninja. To correctly capture all headers, exported generated header files
are gathered separately.

Bug: 65377115
Test: m nothing
Change-Id: Ia03fa69186490a818578190e3c0bfb0261d1fd6e
diff --git a/cc/cc.go b/cc/cc.go
index e80e2a2..a56978d 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -94,6 +94,7 @@
 
 	GeneratedSources []string
 	GeneratedHeaders []string
+	GeneratedDeps    []string
 
 	ReexportGeneratedHeaders []string
 
@@ -120,14 +121,16 @@
 	// Paths to generated source files
 	GeneratedSources android.Paths
 	GeneratedHeaders android.Paths
+	GeneratedDeps    android.Paths
 
-	Flags                []string
-	IncludeDirs          android.Paths
-	SystemIncludeDirs    android.Paths
-	ReexportedDirs       android.Paths
-	ReexportedSystemDirs android.Paths
-	ReexportedFlags      []string
-	ReexportedDeps       android.Paths
+	Flags                      []string
+	IncludeDirs                android.Paths
+	SystemIncludeDirs          android.Paths
+	ReexportedDirs             android.Paths
+	ReexportedSystemDirs       android.Paths
+	ReexportedFlags            []string
+	ReexportedGeneratedHeaders android.Paths
+	ReexportedDeps             android.Paths
 
 	// Paths to crt*.o files
 	CrtBegin, CrtEnd android.OptionalPath
@@ -894,6 +897,13 @@
 	return nil
 }
 
+func (c *Module) ExportedGeneratedHeaders() android.Paths {
+	if flagsProducer, ok := c.linker.(exportedFlagsProducer); ok {
+		return flagsProducer.exportedGeneratedHeaders()
+	}
+	return nil
+}
+
 func isBionic(name string) bool {
 	switch name {
 	case "libc", "libm", "libdl", "libdl_android", "linker":
@@ -1905,6 +1915,7 @@
 		depPaths.ReexportedSystemDirs = append(depPaths.ReexportedSystemDirs, exporter.exportedSystemDirs()...)
 		depPaths.ReexportedFlags = append(depPaths.ReexportedFlags, exporter.exportedFlags()...)
 		depPaths.ReexportedDeps = append(depPaths.ReexportedDeps, exporter.exportedDeps()...)
+		depPaths.ReexportedGeneratedHeaders = append(depPaths.ReexportedGeneratedHeaders, exporter.exportedGeneratedHeaders()...)
 	}
 
 	ctx.VisitDirectDeps(func(dep android.Module) {
@@ -1928,11 +1939,15 @@
 			case genHeaderDepTag, genHeaderExportDepTag:
 				if genRule, ok := dep.(genrule.SourceFileGenerator); ok {
 					depPaths.GeneratedHeaders = append(depPaths.GeneratedHeaders,
+						genRule.GeneratedSourceFiles()...)
+					depPaths.GeneratedDeps = append(depPaths.GeneratedDeps,
 						genRule.GeneratedDeps()...)
 					dirs := genRule.GeneratedHeaderDirs()
 					depPaths.IncludeDirs = append(depPaths.IncludeDirs, dirs...)
 					if depTag == genHeaderExportDepTag {
 						depPaths.ReexportedDirs = append(depPaths.ReexportedDirs, dirs...)
+						depPaths.ReexportedGeneratedHeaders = append(depPaths.ReexportedGeneratedHeaders,
+							genRule.GeneratedSourceFiles()...)
 						depPaths.ReexportedDeps = append(depPaths.ReexportedDeps, genRule.GeneratedDeps()...)
 						// Add these re-exported flags to help header-abi-dumper to infer the abi exported by a library.
 						c.sabi.Properties.ReexportedIncludes = append(c.sabi.Properties.ReexportedIncludes, dirs.Strings()...)
@@ -2045,7 +2060,8 @@
 			if _, ok := ccDep.(*Module); ok {
 				if i, ok := ccDep.(*Module).linker.(exportedFlagsProducer); ok {
 					depPaths.SystemIncludeDirs = append(depPaths.SystemIncludeDirs, i.exportedSystemDirs()...)
-					depPaths.GeneratedHeaders = append(depPaths.GeneratedHeaders, i.exportedDeps()...)
+					depPaths.GeneratedHeaders = append(depPaths.GeneratedHeaders, i.exportedGeneratedHeaders()...)
+					depPaths.GeneratedDeps = append(depPaths.GeneratedDeps, i.exportedDeps()...)
 					depPaths.Flags = append(depPaths.Flags, i.exportedFlags()...)
 
 					if t.ReexportFlags {
@@ -2243,10 +2259,12 @@
 	depPaths.IncludeDirs = android.FirstUniquePaths(depPaths.IncludeDirs)
 	depPaths.SystemIncludeDirs = android.FirstUniquePaths(depPaths.SystemIncludeDirs)
 	depPaths.GeneratedHeaders = android.FirstUniquePaths(depPaths.GeneratedHeaders)
+	depPaths.GeneratedDeps = android.FirstUniquePaths(depPaths.GeneratedDeps)
 	depPaths.ReexportedDirs = android.FirstUniquePaths(depPaths.ReexportedDirs)
 	depPaths.ReexportedSystemDirs = android.FirstUniquePaths(depPaths.ReexportedSystemDirs)
 	depPaths.ReexportedFlags = android.FirstUniqueStrings(depPaths.ReexportedFlags)
 	depPaths.ReexportedDeps = android.FirstUniquePaths(depPaths.ReexportedDeps)
+	depPaths.ReexportedGeneratedHeaders = android.FirstUniquePaths(depPaths.ReexportedGeneratedHeaders)
 
 	if c.sabi != nil {
 		c.sabi.Properties.ReexportedIncludes = android.FirstUniqueStrings(c.sabi.Properties.ReexportedIncludes)
diff --git a/cc/compiler.go b/cc/compiler.go
index 2bc6ae2..1ced451 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -560,7 +560,7 @@
 }
 
 func (compiler *baseCompiler) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
-	pathDeps := deps.GeneratedHeaders
+	pathDeps := deps.GeneratedDeps
 	pathDeps = append(pathDeps, ndkPathDeps(ctx)...)
 
 	buildFlags := flagsToBuilderFlags(flags)
diff --git a/cc/library.go b/cc/library.go
index 60b00b1..64ee907 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -238,6 +238,7 @@
 	systemDirs android.Paths
 	flags      []string
 	deps       android.Paths
+	headers    android.Paths
 }
 
 func (f *flagExporter) exportedIncludes(ctx ModuleContext) android.Paths {
@@ -281,6 +282,12 @@
 	f.deps = append(f.deps, deps...)
 }
 
+// addExportedGeneratedHeaders does nothing but collects generated header files.
+// This can be differ to exportedDeps which may contain phony files to minimize ninja.
+func (f *flagExporter) addExportedGeneratedHeaders(headers ...android.Path) {
+	f.headers = append(f.headers, headers...)
+}
+
 func (f *flagExporter) exportedDirs() android.Paths {
 	return f.dirs
 }
@@ -297,11 +304,16 @@
 	return f.deps
 }
 
+func (f *flagExporter) exportedGeneratedHeaders() android.Paths {
+	return f.headers
+}
+
 type exportedFlagsProducer interface {
 	exportedDirs() android.Paths
 	exportedSystemDirs() android.Paths
 	exportedFlags() []string
 	exportedDeps() android.Paths
+	exportedGeneratedHeaders() android.Paths
 }
 
 var _ exportedFlagsProducer = (*flagExporter)(nil)
@@ -967,12 +979,16 @@
 	library.reexportSystemDirs(deps.ReexportedSystemDirs...)
 	library.reexportFlags(deps.ReexportedFlags...)
 	library.reexportDeps(deps.ReexportedDeps...)
+	library.addExportedGeneratedHeaders(deps.ReexportedGeneratedHeaders...)
 
 	if Bool(library.Properties.Aidl.Export_aidl_headers) {
 		if library.baseCompiler.hasSrcExt(".aidl") {
 			dir := android.PathForModuleGen(ctx, "aidl")
 			library.reexportDirs(dir)
-			library.reexportDeps(library.baseCompiler.pathDeps...) // TODO: restrict to aidl deps
+
+			// TODO: restrict to aidl deps
+			library.reexportDeps(library.baseCompiler.pathDeps...)
+			library.addExportedGeneratedHeaders(library.baseCompiler.pathDeps...)
 		}
 	}
 
@@ -984,7 +1000,10 @@
 			}
 			includes = append(includes, flags.proto.Dir)
 			library.reexportDirs(includes...)
-			library.reexportDeps(library.baseCompiler.pathDeps...) // TODO: restrict to proto deps
+
+			// TODO: restrict to proto deps
+			library.reexportDeps(library.baseCompiler.pathDeps...)
+			library.addExportedGeneratedHeaders(library.baseCompiler.pathDeps...)
 		}
 	}
 
@@ -1002,6 +1021,7 @@
 
 		library.reexportDirs(dir)
 		library.reexportDeps(library.baseCompiler.pathDeps...)
+		library.addExportedGeneratedHeaders(library.baseCompiler.pathDeps...)
 	}
 
 	if library.buildStubs() {
@@ -1448,7 +1468,7 @@
 		}
 		for _, dir := range includeDirs {
 			if _, gen := dir.(android.WritablePath); gen {
-				// generated headers are copied via exportedDeps. See below.
+				// generated headers are copied via exportedGeneratedHeaders. See below.
 				continue
 			}
 			targetDir := nativeIncludeDir
@@ -1465,7 +1485,7 @@
 			}
 		}
 
-		genHeaders := lib.exportedDeps
+		genHeaders := lib.exportedGeneratedHeaders
 		for _, file := range genHeaders {
 			targetDir := nativeGeneratedIncludeDir
 			if info.hasArchSpecificFlags {
@@ -1574,7 +1594,7 @@
 	exportedIncludeDirs       android.Paths
 	exportedSystemIncludeDirs android.Paths
 	exportedFlags             []string
-	exportedDeps              android.Paths
+	exportedGeneratedHeaders  android.Paths
 	outputFile                android.Path
 }
 
@@ -1608,7 +1628,7 @@
 			exportedIncludeDirs:       ccModule.ExportedIncludeDirs(),
 			exportedSystemIncludeDirs: ccModule.ExportedSystemIncludeDirs(),
 			exportedFlags:             ccModule.ExportedFlags(),
-			exportedDeps:              ccModule.ExportedDeps(),
+			exportedGeneratedHeaders:  ccModule.ExportedGeneratedHeaders(),
 			outputFile:                ccModule.OutputFile().Path(),
 		})
 	}
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index 4e6cdd7..32676d6 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -90,6 +90,7 @@
 		p.libraryDecorator.reexportSystemDirs(deps.ReexportedSystemDirs...)
 		p.libraryDecorator.reexportFlags(deps.ReexportedFlags...)
 		p.libraryDecorator.reexportDeps(deps.ReexportedDeps...)
+		p.libraryDecorator.addExportedGeneratedHeaders(deps.ReexportedGeneratedHeaders...)
 
 		builderFlags := flagsToBuilderFlags(flags)
 
diff --git a/cc/vndk.go b/cc/vndk.go
index f25861a..5aeb2e6 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -704,7 +704,7 @@
 		// We glob headers from include directories inside source tree. So we first gather
 		// all include directories inside our source tree. On the contrast, we manually
 		// collect generated headers from dependencies as they can't globbed.
-		generatedHeaders = append(generatedHeaders, l.exportedDeps()...)
+		generatedHeaders = append(generatedHeaders, l.exportedGeneratedHeaders()...)
 		for _, dir := range append(l.exportedDirs(), l.exportedSystemDirs()...) {
 			exportedIncludes[dir.String()] = true
 		}