Move dexpreopt.Script to android.RuleBuilder

Move dexpreopt.Script to android.RuleBuilder so that the builder
style can be used in more places.  Also add tests for it.

Test: rule_builder_test.go
Change-Id: I92a963bd112bf033b08899e930094b908acfcdfd
diff --git a/java/dexpreopt.go b/java/dexpreopt.go
index 6e46bc9..bb72b7d 100644
--- a/java/dexpreopt.go
+++ b/java/dexpreopt.go
@@ -15,12 +15,6 @@
 package java
 
 import (
-	"path/filepath"
-	"strings"
-
-	"github.com/google/blueprint"
-	"github.com/google/blueprint/proptools"
-
 	"android/soong/android"
 	"android/soong/dexpreopt"
 )
@@ -185,69 +179,19 @@
 		return dexJarFile
 	}
 
-	var inputs android.Paths
-	for _, input := range dexpreoptRule.Inputs() {
-		if input == "" {
-			// Tests sometimes have empty configuration values that lead to empty inputs
-			continue
-		}
-		rel, isRel := android.MaybeRel(ctx, android.PathForModuleOut(ctx).String(), input)
-		if isRel {
-			inputs = append(inputs, android.PathForModuleOut(ctx, rel))
-		} else {
-			// TODO: use PathForOutput once boot image is moved to where PathForOutput can find it.
-			inputs = append(inputs, &bootImagePath{input})
-		}
-	}
-
-	var outputs android.WritablePaths
-	for _, output := range dexpreoptRule.Outputs() {
-		rel := android.Rel(ctx, android.PathForModuleOut(ctx).String(), output)
-		outputs = append(outputs, android.PathForModuleOut(ctx, rel))
-	}
+	dexpreoptRule.Build(pctx, ctx, "dexpreopt", "dexpreopt")
 
 	for _, install := range dexpreoptRule.Installs() {
 		d.builtInstalled = append(d.builtInstalled, install.From+":"+install.To)
 	}
 
-	if len(dexpreoptRule.Commands()) > 0 {
-		ctx.Build(pctx, android.BuildParams{
-			Rule: ctx.Rule(pctx, "dexpreopt", blueprint.RuleParams{
-				Command:     strings.Join(proptools.NinjaEscape(dexpreoptRule.Commands()), " && "),
-				CommandDeps: dexpreoptRule.Tools(),
-			}),
-			Implicits:   inputs,
-			Outputs:     outputs,
-			Description: "dexpreopt",
-		})
-	}
-
 	stripRule, err := dexpreopt.GenerateStripRule(globalConfig, dexpreoptConfig)
 	if err != nil {
 		ctx.ModuleErrorf("error generating dexpreopt strip rule: %s", err.Error())
 		return dexJarFile
 	}
 
-	ctx.Build(pctx, android.BuildParams{
-		Rule: ctx.Rule(pctx, "dexpreopt_strip", blueprint.RuleParams{
-			Command:     strings.Join(proptools.NinjaEscape(stripRule.Commands()), " && "),
-			CommandDeps: stripRule.Tools(),
-		}),
-		Input:       dexJarFile,
-		Output:      strippedDexJarFile,
-		Description: "dexpreopt strip",
-	})
+	stripRule.Build(pctx, ctx, "dexpreopt_strip", "dexpreopt strip")
 
 	return strippedDexJarFile
 }
-
-type bootImagePath struct {
-	path string
-}
-
-var _ android.Path = (*bootImagePath)(nil)
-
-func (p *bootImagePath) String() string { return p.path }
-func (p *bootImagePath) Ext() string    { return filepath.Ext(p.path) }
-func (p *bootImagePath) Base() string   { return filepath.Base(p.path) }
-func (p *bootImagePath) Rel() string    { return p.path }
diff --git a/java/hiddenapi.go b/java/hiddenapi.go
index 67df575..983daa7 100644
--- a/java/hiddenapi.go
+++ b/java/hiddenapi.go
@@ -15,6 +15,7 @@
 package java
 
 import (
+	"path/filepath"
 	"sort"
 	"strings"
 	"sync"
@@ -32,7 +33,7 @@
 func hiddenAPIGenerateCSV(ctx android.ModuleContext, classesJar android.Path) {
 	flagsCSV := android.PathForModuleOut(ctx, "hiddenapi", "flags.csv")
 	metadataCSV := android.PathForModuleOut(ctx, "hiddenapi", "metadata.csv")
-	stubFlagsCSV := &bootImagePath{ctx.Config().HiddenAPIStubFlags()}
+	stubFlagsCSV := &hiddenAPIPath{ctx.Config().HiddenAPIStubFlags()}
 
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        hiddenAPIGenerateCSVRule,
@@ -80,7 +81,7 @@
 func hiddenAPIEncodeDex(ctx android.ModuleContext, output android.WritablePath, dexInput android.WritablePath,
 	uncompressDex bool) {
 
-	flagsCsv := &bootImagePath{ctx.Config().HiddenAPIFlags()}
+	flagsCsv := &hiddenAPIPath{ctx.Config().HiddenAPIFlags()}
 
 	// The encode dex rule requires unzipping and rezipping the classes.dex files, ensure that if it was uncompressed
 	// in the input it stays uncompressed in the output.
@@ -168,3 +169,14 @@
 	export("SOONG_HIDDENAPI_GREYLIST_METADATA", metadataCSVList)
 	export("SOONG_HIDDENAPI_DEX_INPUTS", dexInputList)
 }
+
+type hiddenAPIPath struct {
+	path string
+}
+
+var _ android.Path = (*hiddenAPIPath)(nil)
+
+func (p *hiddenAPIPath) String() string { return p.path }
+func (p *hiddenAPIPath) Ext() string    { return filepath.Ext(p.path) }
+func (p *hiddenAPIPath) Base() string   { return filepath.Base(p.path) }
+func (p *hiddenAPIPath) Rel() string    { return p.path }