Add support for using prebuilt libraries as static dependencies

Extract files out of prebuilt libraries and create list files
for classes and resources in order to allow including them in
other jars.

Change-Id: I9269d1fd6e0f570811a00bf319098ac1f7cdc816

java/builder.go

@@ -61,6 +61,16 @@ var (
 			Description: "dex $out",
 		},
 		"outDir", "dxFlags")
+
+	extractPrebuilt = pctx.StaticRule("extractPrebuilt",
+		blueprint.RuleParams{
+			Command: `rm -rf $outDir && unzip -qo $in -d $outDir && ` +
+				`find $outDir -name "*.class" > $classFile && ` +
+				`find $outDir -type f -a \! -name "*.class" -a \! -name "MANIFEST.MF" > $resourceFile || ` +
+				`(rm -rf $outDir; exit 42)`,
+			Description: "extract java prebuilt $outDir",
+		},
+		"outDir", "classFile", "resourceFile")
 )
 
 func init() {
@@ -187,3 +197,24 @@ func TransformDexToJavaLib(ctx common.AndroidModuleContext, resources []jarSpec,
 
 	return outputFile
 }
+
+func TransformPrebuiltJarToClasses(ctx common.AndroidModuleContext,
+	prebuilt string) (classJarSpec, resourceJarSpec jarSpec) {
+
+	classDir := filepath.Join(common.ModuleOutDir(ctx), "classes")
+	classFileList := filepath.Join(classDir, "classes.list")
+	resourceFileList := filepath.Join(classDir, "resources.list")
+
+	ctx.Build(pctx, blueprint.BuildParams{
+		Rule:    extractPrebuilt,
+		Outputs: []string{classFileList, resourceFileList},
+		Inputs:  []string{prebuilt},
+		Args: map[string]string{
+			"outDir":       classDir,
+			"classFile":    classFileList,
+			"resourceFile": resourceFileList,
+		},
+	})
+
+	return jarSpec{classFileList, classDir}, jarSpec{resourceFileList, classDir}
+}