Raise an error instead of panic in SplitApexJarPairs.

Test: aosp_walleye-userdebug boots
Change-Id: I9a1c4ec5c8862b1936820b3cee6db9a85015cb0e
diff --git a/android/config.go b/android/config.go
index ee31c10..59118ce 100644
--- a/android/config.go
+++ b/android/config.go
@@ -897,27 +897,31 @@
 }
 
 // Expected format for apexJarValue = <apex name>:<jar name>
-func SplitApexJarPair(apexJarValue string) (string, string) {
-	var apexJarPair []string = strings.SplitN(apexJarValue, ":", 2)
-	if apexJarPair == nil || len(apexJarPair) != 2 {
-		panic(fmt.Errorf("malformed apexJarValue: %q, expected format: <apex>:<jar>",
-			apexJarValue))
+func SplitApexJarPair(ctx PathContext, str string) (string, string) {
+	pair := strings.SplitN(str, ":", 2)
+	if len(pair) == 2 {
+		return pair[0], pair[1]
+	} else {
+		reportPathErrorf(ctx, "malformed (apex, jar) pair: '%s', expected format: <apex>:<jar>", str)
+		return "error-apex", "error-jar"
 	}
-	return apexJarPair[0], apexJarPair[1]
 }
 
-func GetJarsFromApexJarPairs(apexJarPairs []string) []string {
+func GetJarsFromApexJarPairs(ctx PathContext, apexJarPairs []string) []string {
 	modules := make([]string, len(apexJarPairs))
 	for i, p := range apexJarPairs {
-		_, jar := SplitApexJarPair(p)
+		_, jar := SplitApexJarPair(ctx, p)
 		modules[i] = jar
 	}
 	return modules
 }
 
 func (c *config) BootJars() []string {
-	return append(GetJarsFromApexJarPairs(c.productVariables.BootJars),
-		GetJarsFromApexJarPairs(c.productVariables.UpdatableBootJars)...)
+	ctx := NullPathContext{Config{
+		config: c,
+	}}
+	return append(GetJarsFromApexJarPairs(ctx, c.productVariables.BootJars),
+		GetJarsFromApexJarPairs(ctx, c.productVariables.UpdatableBootJars)...)
 }
 
 func (c *config) DexpreoptGlobalConfig(ctx PathContext) ([]byte, error) {
diff --git a/android/paths.go b/android/paths.go
index 8bb9a96..fcea65c 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -43,6 +43,14 @@
 var _ PathContext = SingletonContext(nil)
 var _ PathContext = ModuleContext(nil)
 
+// "Null" path context is a minimal path context for a given config.
+type NullPathContext struct {
+	config Config
+}
+
+func (NullPathContext) AddNinjaFileDeps(...string) {}
+func (ctx NullPathContext) Config() Config         { return ctx.config }
+
 type ModuleInstallPathContext interface {
 	BaseModuleContext
 
diff --git a/dexpreopt/dexpreopt.go b/dexpreopt/dexpreopt.go
index f1dde9c..fc03563 100644
--- a/dexpreopt/dexpreopt.go
+++ b/dexpreopt/dexpreopt.go
@@ -82,7 +82,7 @@
 
 	if !dexpreoptDisabled(ctx, global, module) {
 		// Don't preopt individual boot jars, they will be preopted together.
-		if !contains(android.GetJarsFromApexJarPairs(global.BootJars), module.Name) {
+		if !contains(android.GetJarsFromApexJarPairs(ctx, global.BootJars), module.Name) {
 			appImage := (generateProfile || module.ForceCreateAppImage || global.DefaultAppImages) &&
 				!module.NoCreateAppImage
 
@@ -104,7 +104,7 @@
 
 	// Don't preopt system server jars that are updatable.
 	for _, p := range global.UpdatableSystemServerJars {
-		if _, jar := android.SplitApexJarPair(p); jar == module.Name {
+		if _, jar := android.SplitApexJarPair(ctx, p); jar == module.Name {
 			return true
 		}
 	}
@@ -113,7 +113,7 @@
 	// Also preopt system server jars since selinux prevents system server from loading anything from
 	// /data. If we don't do this they will need to be extracted which is not favorable for RAM usage
 	// or performance. If PreoptExtractedApk is true, we ignore the only preopt boot image options.
-	if global.OnlyPreoptBootImageAndSystemServer && !contains(android.GetJarsFromApexJarPairs(global.BootJars), module.Name) &&
+	if global.OnlyPreoptBootImageAndSystemServer && !contains(android.GetJarsFromApexJarPairs(ctx, global.BootJars), module.Name) &&
 		!contains(global.SystemServerJars, module.Name) && !module.PreoptExtractedApk {
 		return true
 	}
@@ -561,8 +561,8 @@
 }
 
 // Expected format for apexJarValue = <apex name>:<jar name>
-func GetJarLocationFromApexJarPair(apexJarValue string) string {
-	apex, jar := android.SplitApexJarPair(apexJarValue)
+func GetJarLocationFromApexJarPair(ctx android.PathContext, apexJarValue string) string {
+	apex, jar := android.SplitApexJarPair(ctx, apexJarValue)
 	return filepath.Join("/apex", apex, "javalib", jar+".jar")
 }
 
@@ -573,7 +573,7 @@
 func NonUpdatableSystemServerJars(ctx android.PathContext, global *GlobalConfig) []string {
 	return ctx.Config().Once(nonUpdatableSystemServerJarsKey, func() interface{} {
 		return android.RemoveListFromList(global.SystemServerJars,
-			android.GetJarsFromApexJarPairs(global.UpdatableSystemServerJars))
+			android.GetJarsFromApexJarPairs(ctx, global.UpdatableSystemServerJars))
 	}).([]string)
 }
 
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index dffdc24..90457d0 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -109,11 +109,11 @@
 	return nil
 }
 
-func (image bootImageConfig) moduleName(idx int) string {
+func (image bootImageConfig) moduleName(ctx android.PathContext, idx int) string {
 	// Dexpreopt on the boot class path produces multiple files. The first dex file
 	// is converted into 'name'.art (to match the legacy assumption that 'name'.art
 	// exists), and the rest are converted to 'name'-<jar>.art.
-	_, m := android.SplitApexJarPair(image.modules[idx])
+	_, m := android.SplitApexJarPair(ctx, image.modules[idx])
 	name := image.stem
 	if idx != 0 || image.extends != nil {
 		name += "-" + stemOf(m)
@@ -121,9 +121,9 @@
 	return name
 }
 
-func (image bootImageConfig) firstModuleNameOrStem() string {
+func (image bootImageConfig) firstModuleNameOrStem(ctx android.PathContext) string {
 	if len(image.modules) > 0 {
-		return image.moduleName(0)
+		return image.moduleName(ctx, 0)
 	} else {
 		return image.stem
 	}
@@ -132,7 +132,7 @@
 func (image bootImageConfig) moduleFiles(ctx android.PathContext, dir android.OutputPath, exts ...string) android.OutputPaths {
 	ret := make(android.OutputPaths, 0, len(image.modules)*len(exts))
 	for i := range image.modules {
-		name := image.moduleName(i)
+		name := image.moduleName(ctx, i)
 		for _, ext := range exts {
 			ret = append(ret, dir.Join(ctx, name+ext))
 		}
@@ -261,7 +261,7 @@
 	}
 
 	name := ctx.ModuleName(module)
-	index := android.IndexList(name, android.GetJarsFromApexJarPairs(image.modules))
+	index := android.IndexList(name, android.GetJarsFromApexJarPairs(ctx, image.modules))
 	if index == -1 {
 		return -1, nil
 	}
@@ -314,7 +314,7 @@
 	// Ensure all modules were converted to paths
 	for i := range bootDexJars {
 		if bootDexJars[i] == nil {
-			_, m := android.SplitApexJarPair(image.modules[i])
+			_, m := android.SplitApexJarPair(ctx, image.modules[i])
 			if ctx.Config().AllowMissingDependencies() {
 				missingDeps = append(missingDeps, m)
 				bootDexJars[i] = android.PathForOutput(ctx, "missing")
@@ -614,7 +614,7 @@
 
 	return ctx.Config().Once(updatableBcpPackagesRuleKey, func() interface{} {
 		global := dexpreopt.GetGlobalConfig(ctx)
-		updatableModules := android.GetJarsFromApexJarPairs(global.UpdatableBootJars)
+		updatableModules := android.GetJarsFromApexJarPairs(ctx, global.UpdatableBootJars)
 
 		// Collect `permitted_packages` for updatable boot jars.
 		var updatablePackages []string
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index 41a2ca7..f13d9f2 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -39,7 +39,7 @@
 		// 2) The jars that are from an updatable apex.
 		for _, m := range global.UpdatableSystemServerJars {
 			systemServerClasspathLocations = append(systemServerClasspathLocations,
-				dexpreopt.GetJarLocationFromApexJarPair(m))
+				dexpreopt.GetJarLocationFromApexJarPair(ctx, m))
 		}
 		if len(systemServerClasspathLocations) != len(global.SystemServerJars)+len(global.UpdatableSystemServerJars) {
 			panic(fmt.Errorf("Wrong number of system server jars, got %d, expected %d",
@@ -80,7 +80,7 @@
 }
 
 func getDexLocation(ctx android.PathContext, target android.Target, module string) string {
-	apex, jar := android.SplitApexJarPair(module)
+	apex, jar := android.SplitApexJarPair(ctx, module)
 
 	name := stemOf(jar) + ".jar"
 
@@ -156,7 +156,7 @@
 			c.symbolsDir = deviceDir.Join(ctx, "dex_"+c.name+"jars_unstripped")
 
 			// expands to <stem>.art for primary image and <stem>-<1st module>.art for extension
-			imageName := c.firstModuleNameOrStem() + ".art"
+			imageName := c.firstModuleNameOrStem(ctx) + ".art"
 
 			// The path to bootclasspath dex files needs to be known at module
 			// GenerateAndroidBuildAction time, before the bootclasspath modules have been compiled.
@@ -164,7 +164,7 @@
 			// TODO(b/143682396): use module dependencies instead
 			inputDir := deviceDir.Join(ctx, "dex_"+c.name+"jars_input")
 			for _, m := range c.modules {
-				_, jar := android.SplitApexJarPair(m)
+				_, jar := android.SplitApexJarPair(ctx, m)
 				c.dexPaths = append(c.dexPaths, inputDir.Join(ctx, stemOf(jar)+".jar"))
 			}
 			c.dexPathsDeps = c.dexPaths
@@ -215,7 +215,7 @@
 
 		updatableBootclasspath := make([]string, len(global.UpdatableBootJars))
 		for i, p := range global.UpdatableBootJars {
-			updatableBootclasspath[i] = dexpreopt.GetJarLocationFromApexJarPair(p)
+			updatableBootclasspath[i] = dexpreopt.GetJarLocationFromApexJarPair(ctx, p)
 		}
 
 		bootclasspath := append(copyOf(image.getAnyAndroidVariant().dexLocationsDeps), updatableBootclasspath...)