Remove global state from sysprop libraries

Sysprop libraries use a global list to rewrite dependencies from
implementation libraries to public stub libraries when appropriate.
Remove the global list, and instead add a dependency from the
implementation to the public stub that forwards the JavaInfo.

Bug: 181367697
Test: sysprop_test.go
Change-Id: Ia7995feb3c079ca9bb6a403daaae3e3329fd7f6a
diff --git a/java/Android.bp b/java/Android.bp
index 9bfd009..461b16d 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -58,7 +58,6 @@
         "sdk_library.go",
         "sdk_library_external.go",
         "support_libraries.go",
-        "sysprop.go",
         "system_modules.go",
         "testing.go",
         "tradefed.go",
diff --git a/java/java.go b/java/java.go
index 698c5b9..e471f0d 100644
--- a/java/java.go
+++ b/java/java.go
@@ -370,6 +370,10 @@
 	// If true, generate the signature file of APK Signing Scheme V4, along side the signed APK file.
 	// Defaults to false.
 	V4_signature *bool
+
+	// Only for libraries created by a sysprop_library module, SyspropPublicStub is the name of the
+	// public stubs library.
+	SyspropPublicStub string `blueprint:"mutated"`
 }
 
 // Functionality common to Module and Import
@@ -580,6 +584,16 @@
 
 var JavaInfoProvider = blueprint.NewProvider(JavaInfo{})
 
+// SyspropPublicStubInfo contains info about the sysprop public stub library that corresponds to
+// the sysprop implementation library.
+type SyspropPublicStubInfo struct {
+	// JavaInfo is the JavaInfoProvider of the sysprop public stub library that corresponds to
+	// the sysprop implementation library.
+	JavaInfo JavaInfo
+}
+
+var SyspropPublicStubInfoProvider = blueprint.NewProvider(SyspropPublicStubInfo{})
+
 // Methods that need to be implemented for a module that is added to apex java_libs property.
 type ApexDependency interface {
 	HeaderJars() android.Paths
@@ -649,29 +663,30 @@
 }
 
 var (
-	dataNativeBinsTag     = dependencyTag{name: "dataNativeBins"}
-	staticLibTag          = dependencyTag{name: "staticlib"}
-	libTag                = dependencyTag{name: "javalib"}
-	java9LibTag           = dependencyTag{name: "java9lib"}
-	pluginTag             = dependencyTag{name: "plugin"}
-	errorpronePluginTag   = dependencyTag{name: "errorprone-plugin"}
-	exportedPluginTag     = dependencyTag{name: "exported-plugin"}
-	bootClasspathTag      = dependencyTag{name: "bootclasspath"}
-	systemModulesTag      = dependencyTag{name: "system modules"}
-	frameworkResTag       = dependencyTag{name: "framework-res"}
-	kotlinStdlibTag       = dependencyTag{name: "kotlin-stdlib"}
-	kotlinAnnotationsTag  = dependencyTag{name: "kotlin-annotations"}
-	proguardRaiseTag      = dependencyTag{name: "proguard-raise"}
-	certificateTag        = dependencyTag{name: "certificate"}
-	instrumentationForTag = dependencyTag{name: "instrumentation_for"}
-	extraLintCheckTag     = dependencyTag{name: "extra-lint-check"}
-	jniLibTag             = dependencyTag{name: "jnilib"}
-	jniInstallTag         = installDependencyTag{name: "jni install"}
-	binaryInstallTag      = installDependencyTag{name: "binary install"}
-	usesLibTag            = makeUsesLibraryDependencyTag(dexpreopt.AnySdkVersion)
-	usesLibCompat28Tag    = makeUsesLibraryDependencyTag(28)
-	usesLibCompat29Tag    = makeUsesLibraryDependencyTag(29)
-	usesLibCompat30Tag    = makeUsesLibraryDependencyTag(30)
+	dataNativeBinsTag       = dependencyTag{name: "dataNativeBins"}
+	staticLibTag            = dependencyTag{name: "staticlib"}
+	libTag                  = dependencyTag{name: "javalib"}
+	java9LibTag             = dependencyTag{name: "java9lib"}
+	pluginTag               = dependencyTag{name: "plugin"}
+	errorpronePluginTag     = dependencyTag{name: "errorprone-plugin"}
+	exportedPluginTag       = dependencyTag{name: "exported-plugin"}
+	bootClasspathTag        = dependencyTag{name: "bootclasspath"}
+	systemModulesTag        = dependencyTag{name: "system modules"}
+	frameworkResTag         = dependencyTag{name: "framework-res"}
+	kotlinStdlibTag         = dependencyTag{name: "kotlin-stdlib"}
+	kotlinAnnotationsTag    = dependencyTag{name: "kotlin-annotations"}
+	proguardRaiseTag        = dependencyTag{name: "proguard-raise"}
+	certificateTag          = dependencyTag{name: "certificate"}
+	instrumentationForTag   = dependencyTag{name: "instrumentation_for"}
+	extraLintCheckTag       = dependencyTag{name: "extra-lint-check"}
+	jniLibTag               = dependencyTag{name: "jnilib"}
+	syspropPublicStubDepTag = dependencyTag{name: "sysprop public stub"}
+	jniInstallTag           = installDependencyTag{name: "jni install"}
+	binaryInstallTag        = installDependencyTag{name: "binary install"}
+	usesLibTag              = makeUsesLibraryDependencyTag(dexpreopt.AnySdkVersion)
+	usesLibCompat28Tag      = makeUsesLibraryDependencyTag(28)
+	usesLibCompat29Tag      = makeUsesLibraryDependencyTag(29)
+	usesLibCompat30Tag      = makeUsesLibraryDependencyTag(30)
 )
 
 func IsLibDepTag(depTag blueprint.DependencyTag) bool {
@@ -810,35 +825,17 @@
 		j.linter.deps(ctx)
 
 		sdkDeps(ctx, sdkContext(j), j.dexer)
-	}
 
-	syspropPublicStubs := syspropPublicStubs(ctx.Config())
-
-	// rewriteSyspropLibs validates if a java module can link against platform's sysprop_library,
-	// and redirects dependency to public stub depending on the link type.
-	rewriteSyspropLibs := func(libs []string, prop string) []string {
-		// make a copy
-		ret := android.CopyOf(libs)
-
-		for idx, lib := range libs {
-			stub, ok := syspropPublicStubs[lib]
-
-			if !ok {
-				continue
-			}
-
-			linkType, _ := j.getLinkType(ctx.ModuleName())
-			// only platform modules can use internal props
-			if linkType != javaPlatform {
-				ret[idx] = stub
-			}
+		if j.deviceProperties.SyspropPublicStub != "" {
+			// This is a sysprop implementation library that has a corresponding sysprop public
+			// stubs library, and a dependency on it so that dependencies on the implementation can
+			// be forwarded to the public stubs library when necessary.
+			ctx.AddVariationDependencies(nil, syspropPublicStubDepTag, j.deviceProperties.SyspropPublicStub)
 		}
-
-		return ret
 	}
 
-	libDeps := ctx.AddVariationDependencies(nil, libTag, rewriteSyspropLibs(j.properties.Libs, "libs")...)
-	ctx.AddVariationDependencies(nil, staticLibTag, rewriteSyspropLibs(j.properties.Static_libs, "static_libs")...)
+	libDeps := ctx.AddVariationDependencies(nil, libTag, j.properties.Libs...)
+	ctx.AddVariationDependencies(nil, staticLibTag, j.properties.Static_libs...)
 
 	// Add dependency on libraries that provide additional hidden api annotations.
 	ctx.AddVariationDependencies(nil, hiddenApiAnnotationsTag, j.properties.Hiddenapi_additional_annotations...)
@@ -853,15 +850,11 @@
 		//      if true, enable enforcement
 		//    PRODUCT_INTER_PARTITION_JAVA_LIBRARY_ALLOWLIST
 		//      exception list of java_library names to allow inter-partition dependency
-		for idx, lib := range j.properties.Libs {
+		for idx := range j.properties.Libs {
 			if libDeps[idx] == nil {
 				continue
 			}
 
-			if _, ok := syspropPublicStubs[lib]; ok {
-				continue
-			}
-
 			if javaDep, ok := libDeps[idx].(javaSdkLibraryEnforceContext); ok {
 				// java_sdk_library is always allowed at inter-partition dependency.
 				// So, skip check.
@@ -1131,6 +1124,8 @@
 		}
 	}
 
+	linkType, _ := j.getLinkType(ctx.ModuleName())
+
 	ctx.VisitDirectDeps(func(module android.Module) {
 		otherName := ctx.OtherModuleName(module)
 		tag := ctx.OtherModuleDependencyTag(module)
@@ -1153,6 +1148,14 @@
 			}
 		} else if ctx.OtherModuleHasProvider(module, JavaInfoProvider) {
 			dep := ctx.OtherModuleProvider(module, JavaInfoProvider).(JavaInfo)
+			if linkType != javaPlatform &&
+				ctx.OtherModuleHasProvider(module, SyspropPublicStubInfoProvider) {
+				// dep is a sysprop implementation library, but this module is not linking against
+				// the platform, so it gets the sysprop public stubs library instead.  Replace
+				// dep with the JavaInfo from the SyspropPublicStubInfoProvider.
+				syspropDep := ctx.OtherModuleProvider(module, SyspropPublicStubInfoProvider).(SyspropPublicStubInfo)
+				dep = syspropDep.JavaInfo
+			}
 			switch tag {
 			case bootClasspathTag:
 				deps.bootClasspath = append(deps.bootClasspath, dep.HeaderJars...)
@@ -1211,6 +1214,12 @@
 				deps.kotlinStdlib = append(deps.kotlinStdlib, dep.HeaderJars...)
 			case kotlinAnnotationsTag:
 				deps.kotlinAnnotations = dep.HeaderJars
+			case syspropPublicStubDepTag:
+				// This is a sysprop implementation library, forward the JavaInfoProvider from
+				// the corresponding sysprop public stub library as SyspropPublicStubInfoProvider.
+				ctx.SetProvider(SyspropPublicStubInfoProvider, SyspropPublicStubInfo{
+					JavaInfo: dep,
+				})
 			}
 		} else if dep, ok := module.(android.SourceFileProducer); ok {
 			switch tag {
diff --git a/java/sdk_library_external.go b/java/sdk_library_external.go
index 2934936..0acaa13 100644
--- a/java/sdk_library_external.go
+++ b/java/sdk_library_external.go
@@ -75,10 +75,15 @@
 	return inList(j.Name(), ctx.Config().InterPartitionJavaLibraryAllowList())
 }
 
+func (j *Module) syspropWithPublicStubs() bool {
+	return j.deviceProperties.SyspropPublicStub != ""
+}
+
 type javaSdkLibraryEnforceContext interface {
 	Name() string
 	allowListedInterPartitionJavaLibrary(ctx android.EarlyModuleContext) bool
 	partitionGroup(ctx android.EarlyModuleContext) partitionGroup
+	syspropWithPublicStubs() bool
 }
 
 var _ javaSdkLibraryEnforceContext = (*Module)(nil)
@@ -88,6 +93,10 @@
 		return
 	}
 
+	if dep.syspropWithPublicStubs() {
+		return
+	}
+
 	// If product interface is not enforced, skip check between system and product partition.
 	// But still need to check between product and vendor partition because product interface flag
 	// just represents enforcement between product and system, and vendor interface enforcement
diff --git a/java/sysprop.go b/java/sysprop.go
deleted file mode 100644
index e41aef6..0000000
--- a/java/sysprop.go
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright (C) 2019 The Android Open Source 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 java
-
-// This file contains a map to redirect dependencies towards sysprop_library. If a sysprop_library
-// is owned by Platform, and the client module links against system API, the public stub of the
-// sysprop_library should be used. The map will contain public stub names of sysprop_libraries.
-
-import (
-	"sync"
-
-	"android/soong/android"
-)
-
-type syspropLibraryInterface interface {
-	BaseModuleName() string
-	Owner() string
-	HasPublicStub() bool
-	JavaPublicStubName() string
-}
-
-var (
-	syspropPublicStubsKey  = android.NewOnceKey("syspropPublicStubsJava")
-	syspropPublicStubsLock sync.Mutex
-)
-
-func init() {
-	android.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("sysprop_java", SyspropMutator).Parallel()
-	})
-}
-
-func syspropPublicStubs(config android.Config) map[string]string {
-	return config.Once(syspropPublicStubsKey, func() interface{} {
-		return make(map[string]string)
-	}).(map[string]string)
-}
-
-// gather list of sysprop libraries owned by platform.
-func SyspropMutator(mctx android.BottomUpMutatorContext) {
-	if m, ok := mctx.Module().(syspropLibraryInterface); ok {
-		if m.Owner() != "Platform" || !m.HasPublicStub() {
-			return
-		}
-
-		syspropPublicStubs := syspropPublicStubs(mctx.Config())
-		syspropPublicStubsLock.Lock()
-		defer syspropPublicStubsLock.Unlock()
-
-		syspropPublicStubs[m.BaseModuleName()] = m.JavaPublicStubName()
-	}
-}
diff --git a/sysprop/sysprop_library.go b/sysprop/sysprop_library.go
index 2ccce15..4ad68ea 100644
--- a/sysprop/sysprop_library.go
+++ b/sysprop/sysprop_library.go
@@ -37,9 +37,10 @@
 }
 
 type syspropGenProperties struct {
-	Srcs  []string `android:"path"`
-	Scope string
-	Name  *string
+	Srcs      []string `android:"path"`
+	Scope     string
+	Name      *string
+	Check_api *string
 }
 
 type syspropJavaGenRule struct {
@@ -68,10 +69,6 @@
 func init() {
 	pctx.HostBinToolVariable("soongZipCmd", "soong_zip")
 	pctx.HostBinToolVariable("syspropJavaCmd", "sysprop_java")
-
-	android.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("sysprop_deps", syspropDepsMutator).Parallel()
-	})
 }
 
 // syspropJavaGenRule module generates srcjar containing generated java APIs.
@@ -103,6 +100,12 @@
 	}
 }
 
+func (g *syspropJavaGenRule) DepsMutator(ctx android.BottomUpMutatorContext) {
+	// Add a dependency from the stubs to sysprop library so that the generator rule can depend on
+	// the check API rule of the sysprop library.
+	ctx.AddFarVariationDependencies(nil, nil, proptools.String(g.properties.Check_api))
+}
+
 func (g *syspropJavaGenRule) OutputFiles(tag string) (android.Paths, error) {
 	switch tag {
 	case "":
@@ -157,9 +160,6 @@
 	// If set to true, build a variant of the module for the host.  Defaults to false.
 	Host_supported *bool
 
-	// Whether public stub exists or not.
-	Public_stub *bool `blueprint:"mutated"`
-
 	Cpp struct {
 		// Minimum sdk version that the artifact should support when it runs as part of mainline modules(APEX).
 		// Forwarded to cc_library.min_sdk_version
@@ -202,11 +202,8 @@
 	return "lib" + m.BaseModuleName()
 }
 
-func (m *syspropLibrary) JavaPublicStubName() string {
-	if proptools.Bool(m.properties.Public_stub) {
-		return m.BaseModuleName() + "_public"
-	}
-	return ""
+func (m *syspropLibrary) javaPublicStubName() string {
+	return m.BaseModuleName() + "_public"
 }
 
 func (m *syspropLibrary) javaGenModuleName() string {
@@ -221,10 +218,6 @@
 	return m.ModuleBase.Name()
 }
 
-func (m *syspropLibrary) HasPublicStub() bool {
-	return proptools.Bool(m.properties.Public_stub)
-}
-
 func (m *syspropLibrary) CurrentSyspropApiFile() android.OptionalPath {
 	return m.currentApiFile
 }
@@ -399,16 +392,17 @@
 }
 
 type javaLibraryProperties struct {
-	Name             *string
-	Srcs             []string
-	Soc_specific     *bool
-	Device_specific  *bool
-	Product_specific *bool
-	Required         []string
-	Sdk_version      *string
-	Installable      *bool
-	Libs             []string
-	Stem             *string
+	Name              *string
+	Srcs              []string
+	Soc_specific      *bool
+	Device_specific   *bool
+	Product_specific  *bool
+	Required          []string
+	Sdk_version       *string
+	Installable       *bool
+	Libs              []string
+	Stem              *string
+	SyspropPublicStub string
 }
 
 func syspropLibraryHook(ctx android.LoadHookContext, m *syspropLibrary) {
@@ -490,35 +484,42 @@
 	// Contrast to C++, syspropJavaGenRule module will generate srcjar and the srcjar will be fed
 	// to Java implementation library.
 	ctx.CreateModule(syspropJavaGenFactory, &syspropGenProperties{
-		Srcs:  m.properties.Srcs,
-		Scope: scope,
-		Name:  proptools.StringPtr(m.javaGenModuleName()),
-	})
-
-	ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
-		Name:             proptools.StringPtr(m.BaseModuleName()),
-		Srcs:             []string{":" + m.javaGenModuleName()},
-		Soc_specific:     proptools.BoolPtr(ctx.SocSpecific()),
-		Device_specific:  proptools.BoolPtr(ctx.DeviceSpecific()),
-		Product_specific: proptools.BoolPtr(ctx.ProductSpecific()),
-		Installable:      m.properties.Installable,
-		Sdk_version:      proptools.StringPtr("core_current"),
-		Libs:             []string{javaSyspropStub},
+		Srcs:      m.properties.Srcs,
+		Scope:     scope,
+		Name:      proptools.StringPtr(m.javaGenModuleName()),
+		Check_api: proptools.StringPtr(ctx.ModuleName()),
 	})
 
 	// if platform sysprop_library is installed in /system or /system-ext, we regard it as an API
 	// and allow any modules (even from different partition) to link against the sysprop_library.
 	// To do that, we create a public stub and expose it to modules with sdk_version: system_*.
+	var publicStub string
 	if isOwnerPlatform && installedInSystem {
-		m.properties.Public_stub = proptools.BoolPtr(true)
+		publicStub = m.javaPublicStubName()
+	}
+
+	ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
+		Name:              proptools.StringPtr(m.BaseModuleName()),
+		Srcs:              []string{":" + m.javaGenModuleName()},
+		Soc_specific:      proptools.BoolPtr(ctx.SocSpecific()),
+		Device_specific:   proptools.BoolPtr(ctx.DeviceSpecific()),
+		Product_specific:  proptools.BoolPtr(ctx.ProductSpecific()),
+		Installable:       m.properties.Installable,
+		Sdk_version:       proptools.StringPtr("core_current"),
+		Libs:              []string{javaSyspropStub},
+		SyspropPublicStub: publicStub,
+	})
+
+	if publicStub != "" {
 		ctx.CreateModule(syspropJavaGenFactory, &syspropGenProperties{
-			Srcs:  m.properties.Srcs,
-			Scope: "public",
-			Name:  proptools.StringPtr(m.javaGenPublicStubName()),
+			Srcs:      m.properties.Srcs,
+			Scope:     "public",
+			Name:      proptools.StringPtr(m.javaGenPublicStubName()),
+			Check_api: proptools.StringPtr(ctx.ModuleName()),
 		})
 
 		ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
-			Name:        proptools.StringPtr(m.JavaPublicStubName()),
+			Name:        proptools.StringPtr(publicStub),
 			Srcs:        []string{":" + m.javaGenPublicStubName()},
 			Installable: proptools.BoolPtr(false),
 			Sdk_version: proptools.StringPtr("core_current"),
@@ -537,15 +538,3 @@
 		*libraries = append(*libraries, "//"+ctx.ModuleDir()+":"+ctx.ModuleName())
 	}
 }
-
-// syspropDepsMutator adds dependencies from java implementation library to sysprop library.
-// java implementation library then depends on check API rule of sysprop library.
-func syspropDepsMutator(ctx android.BottomUpMutatorContext) {
-	if m, ok := ctx.Module().(*syspropLibrary); ok {
-		ctx.AddReverseDependency(m, nil, m.javaGenModuleName())
-
-		if proptools.Bool(m.properties.Public_stub) {
-			ctx.AddReverseDependency(m, nil, m.javaGenPublicStubName())
-		}
-	}
-}
diff --git a/sysprop/sysprop_test.go b/sysprop/sysprop_test.go
index 5cb9e64..9d914e3 100644
--- a/sysprop/sysprop_test.go
+++ b/sysprop/sysprop_test.go
@@ -26,7 +26,6 @@
 	"strings"
 	"testing"
 
-	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
@@ -61,16 +60,10 @@
 	java.RegisterRequiredBuildComponentsForTest(ctx)
 
 	ctx.PreArchMutators(android.RegisterDefaultsPreArchMutators)
-	ctx.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("sysprop_deps", syspropDepsMutator).Parallel()
-	})
 
 	android.RegisterPrebuiltMutators(ctx)
 
 	cc.RegisterRequiredBuildComponentsForTest(ctx)
-	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
-		ctx.BottomUp("sysprop_java", java.SyspropMutator).Parallel()
-	})
 
 	ctx.RegisterModuleType("sysprop_library", syspropLibraryFactory)
 
@@ -392,15 +385,9 @@
 	}
 
 	// Java modules linking against system API should use public stub
-	javaSystemApiClient := ctx.ModuleForTests("java-platform", "android_common")
-	publicStubFound := false
-	ctx.VisitDirectDeps(javaSystemApiClient.Module(), func(dep blueprint.Module) {
-		if dep.Name() == "sysprop-platform_public" {
-			publicStubFound = true
-		}
-	})
-	if !publicStubFound {
-		t.Errorf("system api client should use public stub")
+	javaSystemApiClient := ctx.ModuleForTests("java-platform", "android_common").Rule("javac")
+	syspropPlatformPublic := ctx.ModuleForTests("sysprop-platform_public", "android_common").Description("for turbine")
+	if g, w := javaSystemApiClient.Implicits.Strings(), syspropPlatformPublic.Output.String(); !android.InList(w, g) {
+		t.Errorf("system api client should use public stub %q, got %q", w, g)
 	}
-
 }