Support autoconverted modules in mixed builds

modules converted with bp2build_available are will also be available to
be used in mixed builds.

Test: build/bazel/scripts/milestone-2/demo.sh full
Test: go tests
Change-Id: I49f16ec3ba5bb11dfed8066af069c27eb04371fb
diff --git a/android/bazel.go b/android/bazel.go
index 09a2c3a..683495b 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -20,6 +20,7 @@
 	"path/filepath"
 	"strings"
 
+	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
@@ -51,9 +52,11 @@
 type Bazelable interface {
 	bazelProps() *properties
 	HasHandcraftedLabel() bool
-	GetBazelLabel() string
+	HandcraftedLabel() string
+	GetBazelLabel(ctx BazelConversionPathContext, module blueprint.Module) string
 	ConvertWithBp2build() bool
 	GetBazelBuildFileContents(c Config, path, name string) (string, error)
+	ConvertedToBazel() bool
 }
 
 // BazelModule is a lightweight wrapper interface around Module for Bazel-convertible modules.
@@ -84,8 +87,14 @@
 }
 
 // GetBazelLabel returns the Bazel label for the given BazelModuleBase.
-func (b *BazelModuleBase) GetBazelLabel() string {
-	return proptools.String(b.bazelProperties.Bazel_module.Label)
+func (b *BazelModuleBase) GetBazelLabel(ctx BazelConversionPathContext, module blueprint.Module) string {
+	if b.HasHandcraftedLabel() {
+		return b.HandcraftedLabel()
+	}
+	if b.ConvertWithBp2build() {
+		return bp2buildModuleLabel(ctx, module)
+	}
+	return "" // no label for unconverted module
 }
 
 // ConvertWithBp2build returns whether the given BazelModuleBase should be converted with bp2build.
@@ -98,8 +107,8 @@
 // TODO(b/181575318): currently we append the whole BUILD file, let's change that to do
 // something more targeted based on the rule type and target.
 func (b *BazelModuleBase) GetBazelBuildFileContents(c Config, path, name string) (string, error) {
-	if !strings.Contains(b.GetBazelLabel(), path) {
-		return "", fmt.Errorf("%q not found in bazel_module.label %q", path, b.GetBazelLabel())
+	if !strings.Contains(b.HandcraftedLabel(), path) {
+		return "", fmt.Errorf("%q not found in bazel_module.label %q", path, b.HandcraftedLabel())
 	}
 	name = filepath.Join(path, name)
 	f, err := c.fs.Open(name)
@@ -114,3 +123,9 @@
 	}
 	return string(data[:]), nil
 }
+
+// ConvertedToBazel returns whether this module has been converted to Bazel, whether automatically
+// or manually
+func (b *BazelModuleBase) ConvertedToBazel() bool {
+	return b.ConvertWithBp2build() || b.HasHandcraftedLabel()
+}
diff --git a/android/paths.go b/android/paths.go
index 3f4d3f2..f648c55 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -339,6 +339,7 @@
 	EarlyModulePathContext
 
 	GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)
+	Module() Module
 	OtherModuleName(m blueprint.Module) string
 	OtherModuleDir(m blueprint.Module) string
 }
@@ -434,15 +435,45 @@
 // already be resolved by either deps mutator or path deps mutator.
 func getOtherModuleLabel(ctx BazelConversionPathContext, dep, tag string) bazel.Label {
 	m, _ := ctx.GetDirectDep(dep)
-	// TODO(b/165114590): Convert tag (":name{.tag}") to corresponding Bazel implicit output targets.
-	otherModuleName := ctx.OtherModuleName(m)
-	var label bazel.Label
-	if otherDir, dir := ctx.OtherModuleDir(m), ctx.ModuleDir(); otherDir != dir {
-		label.Label = fmt.Sprintf("//%s:%s", otherDir, otherModuleName)
-	} else {
-		label.Label = fmt.Sprintf(":%s", otherModuleName)
+	otherLabel := bazelModuleLabel(ctx, m, tag)
+	label := bazelModuleLabel(ctx, ctx.Module(), "")
+	if samePackage(label, otherLabel) {
+		otherLabel = bazelShortLabel(otherLabel)
 	}
-	return label
+
+	return bazel.Label{
+		Label: otherLabel,
+	}
+}
+
+func bazelModuleLabel(ctx BazelConversionPathContext, module blueprint.Module, tag string) string {
+	// TODO(b/165114590): Convert tag (":name{.tag}") to corresponding Bazel implicit output targets.
+	b, ok := module.(Bazelable)
+	// TODO(b/181155349): perhaps return an error here if the module can't be/isn't being converted
+	if !ok || !b.ConvertedToBazel() {
+		return bp2buildModuleLabel(ctx, module)
+	}
+	return b.GetBazelLabel(ctx, module)
+}
+
+func bazelShortLabel(label string) string {
+	i := strings.Index(label, ":")
+	return label[i:]
+}
+
+func bazelPackage(label string) string {
+	i := strings.Index(label, ":")
+	return label[0:i]
+}
+
+func samePackage(label1, label2 string) bool {
+	return bazelPackage(label1) == bazelPackage(label2)
+}
+
+func bp2buildModuleLabel(ctx BazelConversionPathContext, module blueprint.Module) string {
+	moduleName := ctx.OtherModuleName(module)
+	moduleDir := ctx.OtherModuleDir(module)
+	return fmt.Sprintf("//%s:%s", moduleDir, moduleName)
 }
 
 // OutputPaths is a slice of OutputPath objects, with helpers to operate on the collection.