From 80342d72d0d1a1367f96a09b1d151b59fe78dd1c Mon Sep 17 00:00:00 2001
From: Paul Duffin <paulduffin@google.com>
Date: Fri, 26 Jun 2020 22:08:43 +0100
Subject: [PATCH] Restrict replacements of source dependencies with prebuilts

Previously, when java_sdk_library_import was preferred over a
java_sdk_library the latter ends up depending on the prebuilt child
modules created by the java_sdk_library_import instead of the source
child modules that it created itself. That was because all dependencies
on those source child modules were replaced with the corresponding
prebuilt child modules.

This change prevents those dependencies from being replaced to preserve
the dependencies from java_sdk_library onto its source child modules by
making the replacement conditional depending on the tag used. It also
updates the affected test.

Bug: 159902351
Test: m nothing
Change-Id: I4441b901dedfd44b9769df1ac2e248b94834cf85
---
 android/mutator.go  |  5 +++++
 android/prebuilt.go | 18 +++++++++++++++++-
 java/java_test.go   |  3 +--
 java/sdk_library.go |  6 ++++++
 4 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/android/mutator.go b/android/mutator.go
index 9454485a9..b70c4ff64 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -214,6 +214,7 @@ type BottomUpMutatorContext interface {
 	AddFarVariationDependencies([]blueprint.Variation, blueprint.DependencyTag, ...string)
 	AddInterVariantDependency(tag blueprint.DependencyTag, from, to blueprint.Module)
 	ReplaceDependencies(string)
+	ReplaceDependenciesIf(string, blueprint.ReplaceDependencyPredicate)
 	AliasVariation(variationName string)
 }
 
@@ -428,6 +429,10 @@ func (b *bottomUpMutatorContext) ReplaceDependencies(name string) {
 	b.bp.ReplaceDependencies(name)
 }
 
+func (b *bottomUpMutatorContext) ReplaceDependenciesIf(name string, predicate blueprint.ReplaceDependencyPredicate) {
+	b.bp.ReplaceDependenciesIf(name, predicate)
+}
+
 func (b *bottomUpMutatorContext) AliasVariation(variationName string) {
 	b.bp.AliasVariation(variationName)
 }
diff --git a/android/prebuilt.go b/android/prebuilt.go
index a29ec911d..9f4df2831 100644
--- a/android/prebuilt.go
+++ b/android/prebuilt.go
@@ -30,6 +30,16 @@ func RegisterPrebuiltMutators(ctx RegistrationContext) {
 	ctx.PostDepsMutators(RegisterPrebuiltsPostDepsMutators)
 }
 
+// Marks a dependency tag as possibly preventing a reference to a source from being
+// replaced with the prebuilt.
+type ReplaceSourceWithPrebuilt interface {
+	blueprint.DependencyTag
+
+	// Return true if the dependency defined by this tag should be replaced with the
+	// prebuilt.
+	ReplaceSourceWithPrebuilt() bool
+}
+
 type prebuiltDependencyTag struct {
 	blueprint.BaseDependencyTag
 }
@@ -260,7 +270,13 @@ func PrebuiltPostDepsMutator(ctx BottomUpMutatorContext) {
 		name := m.base().BaseModuleName()
 		if p.properties.UsePrebuilt {
 			if p.properties.SourceExists {
-				ctx.ReplaceDependencies(name)
+				ctx.ReplaceDependenciesIf(name, func(from blueprint.Module, tag blueprint.DependencyTag, to blueprint.Module) bool {
+					if t, ok := tag.(ReplaceSourceWithPrebuilt); ok {
+						return t.ReplaceSourceWithPrebuilt()
+					}
+
+					return true
+				})
 			}
 		} else {
 			m.SkipInstall()
diff --git a/java/java_test.go b/java/java_test.go
index 23dcd53ab..59a2ce7aa 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -718,9 +718,8 @@ func TestJavaSdkLibraryImport_Preferred(t *testing.T) {
 	checkModuleDependencies(t, ctx, "sdklib", "android_common", []string{
 		`dex2oatd`,
 		`prebuilt_sdklib`,
-		// This should be sdklib.stubs but is switched to the prebuilt because it is preferred.
-		`prebuilt_sdklib.stubs`,
 		`sdklib.impl`,
+		`sdklib.stubs`,
 		`sdklib.stubs.source`,
 		`sdklib.xml`,
 	})
diff --git a/java/sdk_library.go b/java/sdk_library.go
index 1fd109ab8..a5aa328d0 100644
--- a/java/sdk_library.go
+++ b/java/sdk_library.go
@@ -70,6 +70,12 @@ func (tag scopeDependencyTag) extractDepInfo(ctx android.ModuleContext, dep andr
 	}
 }
 
+var _ android.ReplaceSourceWithPrebuilt = (*scopeDependencyTag)(nil)
+
+func (tag scopeDependencyTag) ReplaceSourceWithPrebuilt() bool {
+	return false
+}
+
 // Provides information about an api scope, e.g. public, system, test.
 type apiScope struct {
 	// The name of the api scope, e.g. public, system, test