Use a provider for systems modules

Replace the SystemModulesProvider interface with Provider

Test: all soong tests
Flag: EXEMPT refactor
Change-Id: If313580b28094d55b71f1635259bafa850ef7af5
diff --git a/java/base.go b/java/base.go
index f820629..daa50ef 100644
--- a/java/base.go
+++ b/java/base.go
@@ -2374,16 +2374,24 @@
 			case bootClasspathTag:
 				// If a system modules dependency has been added to the bootclasspath
 				// then add its libs to the bootclasspath.
-				sm := module.(SystemModulesProvider)
-				deps.bootClasspath = append(deps.bootClasspath, sm.HeaderJars()...)
+				if sm, ok := android.OtherModuleProvider(ctx, module, SystemModulesProvider); ok {
+					depHeaderJars := sm.HeaderJars
+					deps.bootClasspath = append(deps.bootClasspath, depHeaderJars...)
+				} else {
+					ctx.PropertyErrorf("boot classpath dependency %q does not provide SystemModulesProvider",
+						ctx.OtherModuleName(module))
+				}
 
 			case systemModulesTag:
 				if deps.systemModules != nil {
 					panic("Found two system module dependencies")
 				}
-				sm := module.(SystemModulesProvider)
-				outputDir, outputDeps := sm.OutputDirAndDeps()
-				deps.systemModules = &systemModules{outputDir, outputDeps}
+				if sm, ok := android.OtherModuleProvider(ctx, module, SystemModulesProvider); ok {
+					deps.systemModules = &systemModules{sm.OutputDir, sm.OutputDirDeps}
+				} else {
+					ctx.PropertyErrorf("system modules dependency %q does not provide SystemModulesProvider",
+						ctx.OtherModuleName(module))
+				}
 
 			case instrumentationForTag:
 				ctx.PropertyErrorf("instrumentation_for", "dependency %q of type %q does not provide JavaInfo so is unsuitable for use with this property", ctx.OtherModuleName(module), ctx.OtherModuleType(module))
diff --git a/java/droiddoc.go b/java/droiddoc.go
index 730f236..f81c5ba 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -365,10 +365,10 @@
 		case bootClasspathTag:
 			if dep, ok := android.OtherModuleProvider(ctx, module, JavaInfoProvider); ok {
 				deps.bootClasspath = append(deps.bootClasspath, dep.ImplementationJars...)
-			} else if sm, ok := module.(SystemModulesProvider); ok {
+			} else if sm, ok := android.OtherModuleProvider(ctx, module, SystemModulesProvider); ok {
 				// A system modules dependency has been added to the bootclasspath
 				// so add its libs to the bootclasspath.
-				deps.bootClasspath = append(deps.bootClasspath, sm.HeaderJars()...)
+				deps.bootClasspath = append(deps.bootClasspath, sm.HeaderJars...)
 			} else {
 				panic(fmt.Errorf("unknown dependency %q for %q", otherName, ctx.ModuleName()))
 			}
@@ -396,9 +396,12 @@
 			if deps.systemModules != nil {
 				panic("Found two system module dependencies")
 			}
-			sm := module.(SystemModulesProvider)
-			outputDir, outputDeps := sm.OutputDirAndDeps()
-			deps.systemModules = &systemModules{outputDir, outputDeps}
+			if sm, ok := android.OtherModuleProvider(ctx, module, SystemModulesProvider); ok {
+				deps.systemModules = &systemModules{sm.OutputDir, sm.OutputDirDeps}
+			} else {
+				ctx.PropertyErrorf("boot classpath dependency %q does not provide SystemModulesProvider",
+					ctx.OtherModuleName(module))
+			}
 		case aconfigDeclarationTag:
 			if dep, ok := android.OtherModuleProvider(ctx, module, android.AconfigDeclarationsProviderKey); ok {
 				deps.aconfigProtoFiles = append(deps.aconfigProtoFiles, dep.IntermediateCacheOutputPath)
diff --git a/java/java.go b/java/java.go
index be3f90b..126d8f3 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2261,8 +2261,9 @@
 				staticLibs = append(staticLibs, provider.HeaderJars...)
 			}
 		case systemModulesTag:
-			module := dep.(SystemModulesProvider)
-			systemModulesPaths = append(systemModulesPaths, module.HeaderJars()...)
+			if sm, ok := android.OtherModuleProvider(ctx, dep, SystemModulesProvider); ok {
+				systemModulesPaths = append(systemModulesPaths, sm.HeaderJars...)
+			}
 		case metalavaCurrentApiTimestampTag:
 			if currentApiTimestampProvider, ok := dep.(currentApiTimestampProvider); ok {
 				al.validationPaths = append(al.validationPaths, currentApiTimestampProvider.CurrentApiTimestamp())
diff --git a/java/system_modules.go b/java/system_modules.go
index 48b33ba..5b00079 100644
--- a/java/system_modules.go
+++ b/java/system_modules.go
@@ -120,14 +120,16 @@
 	return module
 }
 
-type SystemModulesProvider interface {
-	HeaderJars() android.Paths
-	OutputDirAndDeps() (android.Path, android.Paths)
+type SystemModulesProviderInfo struct {
+	// The aggregated header jars from all jars specified in the libs property.
+	// Used when system module is added as a dependency to bootclasspath.
+	HeaderJars android.Paths
+
+	OutputDir     android.Path
+	OutputDirDeps android.Paths
 }
 
-var _ SystemModulesProvider = (*SystemModules)(nil)
-
-var _ SystemModulesProvider = (*systemModulesImport)(nil)
+var SystemModulesProvider = blueprint.NewProvider[*SystemModulesProviderInfo]()
 
 type SystemModules struct {
 	android.ModuleBase
@@ -135,9 +137,6 @@
 
 	properties SystemModulesProperties
 
-	// The aggregated header jars from all jars specified in the libs property.
-	// Used when system module is added as a dependency to bootclasspath.
-	headerJars android.Paths
 	outputDir  android.Path
 	outputDeps android.Paths
 }
@@ -147,17 +146,6 @@
 	Libs []string
 }
 
-func (system *SystemModules) HeaderJars() android.Paths {
-	return system.headerJars
-}
-
-func (system *SystemModules) OutputDirAndDeps() (android.Path, android.Paths) {
-	if system.outputDir == nil || len(system.outputDeps) == 0 {
-		panic("Missing directory for system module dependency")
-	}
-	return system.outputDir, system.outputDeps
-}
-
 func (system *SystemModules) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	var jars android.Paths
 
@@ -167,9 +155,13 @@
 		}
 	})
 
-	system.headerJars = jars
-
 	system.outputDir, system.outputDeps = TransformJarsToSystemModules(ctx, jars)
+
+	android.SetProvider(ctx, SystemModulesProvider, &SystemModulesProviderInfo{
+		HeaderJars:    jars,
+		OutputDir:     system.outputDir,
+		OutputDirDeps: system.outputDeps,
+	})
 }
 
 // ComponentDepsMutator is called before prebuilt modules without a corresponding source module are