soong: Give priority to modules in exported namespaces for bootjars

* Looking for modules that provide a boot jar is currently
  done by module name match only.  This breaks when you
  have multiple copies of the same module in your build
  tree (eg in another device).

* Add a new mutator that marks the modules that should be used
  for bootjar content.

* The logic is simple: give priority to modules that are in
  exported soong namespace.

Change-Id: I2476174b892475c14a9f10b5e66b8496186f81c0

2 files changed, 124 insertions, 0 deletions

diff --git a/android/bootjar.go b/android/bootjar.go
new file mode 100644
index 00000000..ea04dc8f
--- /dev/null
+++ b/android/bootjar.go
@@ -0,0 +1,117 @@
+// Copyright (C) 2019 The LineageOS Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package android
+
+import (
+	"strings"
+)
+
+// Keys are bootjar name, value is whether or not
+// we've marked a module as being a provider for it.
+var jarMap map[string]bool
+
+func init() {
+	PreArchMutators(RegisterBootJarMutators)
+}
+
+// Note: registration function is structured this way so that it can be included
+// from soong module tests.
+func RegisterBootJarMutators(ctx RegisterMutatorsContext) {
+	// Note: can't use Parallel() since we touch global jarMap
+	ctx.TopDown("bootjar_exportednamespace", bootJarMutatorExportedNamespace)
+	ctx.TopDown("bootjar_anynamespace", bootJarMutatorAnyNamespace)
+}
+
+func mutatorInit(mctx TopDownMutatorContext) {
+	// Did we init already ?
+	if jarMap != nil {
+		return
+	}
+
+	jarMap = make(map[string]bool)
+	for _, moduleName := range mctx.Config().BootJars() {
+		jarMap[moduleName] = false
+	}
+}
+
+// Mark modules in soong exported namespace as providing a boot jar.
+func bootJarMutatorExportedNamespace(mctx TopDownMutatorContext) {
+	bootJarMutator(mctx, true)
+}
+
+// Mark modules in any namespace (incl root) as providing a boot jar.
+func bootJarMutatorAnyNamespace(mctx TopDownMutatorContext) {
+	bootJarMutator(mctx, false)
+}
+
+func bootJarMutator(mctx TopDownMutatorContext, requireExportedNamespace bool) {
+	mutatorInit(mctx)
+
+	module, ok := mctx.Module().(Module)
+	if !ok {
+		// Not a proper module
+		return
+	}
+
+	// Does this module produce a dex jar ?
+	if _, ok := module.(interface{ DexJar() Path }); !ok {
+		// No
+		return
+	}
+
+	// If jarMap is empty we must be running in a test so
+	// set boot jar provide to true for all modules.
+	if len(jarMap) == 0 {
+		module.base().commonProperties.BootJarProvider = true
+		return
+	}
+
+	name := mctx.ModuleName()
+	dir := mctx.ModuleDir()
+
+	// Special treatment for hiddenapi modules - create extra
+	// jarMap entries if needed.
+	baseName := strings.TrimSuffix(name, "-hiddenapi")
+	if name != baseName {
+		_, baseIsBootJar := jarMap[baseName]
+		_, alreadyExists := jarMap[name]
+		if baseIsBootJar && !alreadyExists {
+			// This is a hidden api module whose base name exists in the boot jar list
+			// and we've not visited it before.  Create a map entry for it.
+			jarMap[name] = false
+		}
+	}
+
+	// Does this module match the name of a boot jar ?
+	if found, exists := jarMap[name]; !exists || found {
+		// No
+		return
+	}
+
+	if requireExportedNamespace {
+		for _, n := range mctx.Config().ExportedNamespaces() {
+			if strings.HasPrefix(dir, n) {
+				jarMap[name] = true
+				module.base().commonProperties.BootJarProvider = true
+				break
+			}
+		}
+	} else {
+		jarMap[name] = true
+		module.base().commonProperties.BootJarProvider = true
+	}
+
+	return
+}
diff --git a/android/module.go b/android/module.go
index 495efbe1..17ddb050 100644
--- a/android/module.go
+++ b/android/module.go
@@ -304,6 +304,9 @@ type commonProperties struct {
 	SkipInstall bool `blueprint:"mutated"`
 
 	NamespaceExportedToMake bool `blueprint:"mutated"`
+
+	// Whether this module provides a boot jar
+	BootJarProvider bool `blueprint:"mutated"`
 }
 
 type hostAndDeviceProperties struct {
@@ -521,6 +524,10 @@ func (a *ModuleBase) Name() string {
 	return String(a.nameProperties.Name)
 }
 
+func (a *ModuleBase) BootJarProvider() bool {
+	return a.commonProperties.BootJarProvider
+}
+
 // BaseModuleName returns the name of the module as specified in the blueprints file.
 func (a *ModuleBase) BaseModuleName() string {
 	return String(a.nameProperties.Name)