Use generics for providers API

Using generics for the providers API allows a type to be associated
with a ProviderKey, resulting in a type-safe API without that doesn't
require runtime type assertions by every caller.

Unfortunately, Go does not allow generic types in methods, only in
functions [1].  This prevents a type-safe API on ModuleContext, and
requires moving the API to be functions that take a ModuleContext as
a parameter.

This CL creates the new API, but doesn't convert all of the callers.

[1] https://go.googlesource.com/proposal/+/refs/heads/master/design/43651-type-parameters.md#no-parameterized-methods)

Bug: 316410648
Test: builds
Change-Id: I3e30d68b966b730efd968166a38a25cc144bd6de

android/Android.bp

@@ -79,6 +79,7 @@ bootstrap_go_package {
         "prebuilt.go",
         "prebuilt_build_tool.go",
         "proto.go",
+        "provider.go",
         "register.go",
         "rule_builder.go",
         "sandbox.go",

android/androidmk.go

@@ -159,7 +159,7 @@ type AndroidMkEntriesContext interface {
 }
 
 type AndroidMkExtraEntriesContext interface {
-	Provider(provider blueprint.ProviderKey) interface{}
+	Provider(provider blueprint.AnyProviderKey) (any, bool)
 }
 
 type androidMkExtraEntriesContext struct {
@@ -167,8 +167,8 @@ type androidMkExtraEntriesContext struct {
 	mod blueprint.Module
 }
 
-func (a *androidMkExtraEntriesContext) Provider(provider blueprint.ProviderKey) interface{} {
-	return a.ctx.ModuleProvider(a.mod, provider)
+func (a *androidMkExtraEntriesContext) Provider(provider blueprint.AnyProviderKey) (any, bool) {
+	return a.ctx.moduleProvider(a.mod, provider)
 }
 
 type AndroidMkExtraEntriesFunc func(ctx AndroidMkExtraEntriesContext, entries *AndroidMkEntries)
@@ -492,8 +492,9 @@ type fillInEntriesContext interface {
 	ModuleDir(module blueprint.Module) string
 	ModuleSubDir(module blueprint.Module) string
 	Config() Config
-	ModuleProvider(module blueprint.Module, provider blueprint.ProviderKey) interface{}
-	ModuleHasProvider(module blueprint.Module, provider blueprint.ProviderKey) bool
+	ModuleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) any
+	ModuleHasProvider(module blueprint.Module, provider blueprint.AnyProviderKey) bool
+	moduleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) (any, bool)
 	ModuleType(module blueprint.Module) string
 }
 

android/base_module_context.go

@@ -79,26 +79,30 @@ type BaseModuleContext interface {
 	// not set it returns the zero value of the type of the provider, so the return value can always
 	// be type asserted to the type of the provider.  The value returned may be a deep copy of the
 	// value originally passed to SetProvider.
-	OtherModuleProvider(m blueprint.Module, provider blueprint.ProviderKey) interface{}
+	OtherModuleProvider(m blueprint.Module, provider blueprint.AnyProviderKey) any
 
 	// OtherModuleHasProvider returns true if the provider for the given module has been set.
-	OtherModuleHasProvider(m blueprint.Module, provider blueprint.ProviderKey) bool
+	OtherModuleHasProvider(m blueprint.Module, provider blueprint.AnyProviderKey) bool
+
+	otherModuleProvider(m blueprint.Module, provider blueprint.AnyProviderKey) (any, bool)
 
 	// Provider returns the value for a provider for the current module.  If the value is
 	// not set it returns the zero value of the type of the provider, so the return value can always
 	// be type asserted to the type of the provider.  It panics if called before the appropriate
 	// mutator or GenerateBuildActions pass for the provider.  The value returned may be a deep
 	// copy of the value originally passed to SetProvider.
-	Provider(provider blueprint.ProviderKey) interface{}
+	Provider(provider blueprint.AnyProviderKey) any
 
 	// HasProvider returns true if the provider for the current module has been set.
-	HasProvider(provider blueprint.ProviderKey) bool
+	HasProvider(provider blueprint.AnyProviderKey) bool
+
+	provider(provider blueprint.AnyProviderKey) (any, bool)
 
 	// SetProvider sets the value for a provider for the current module.  It panics if not called
 	// during the appropriate mutator or GenerateBuildActions pass for the provider, if the value
 	// is not of the appropriate type, or if the value has already been set.  The value should not
 	// be modified after being passed to SetProvider.
-	SetProvider(provider blueprint.ProviderKey, value interface{})
+	SetProvider(provider blueprint.AnyProviderKey, value interface{})
 
 	GetDirectDepsWithTag(tag blueprint.DependencyTag) []Module
 
@@ -260,19 +264,35 @@ func (b *baseModuleContext) OtherModuleReverseDependencyVariantExists(name strin
 func (b *baseModuleContext) OtherModuleType(m blueprint.Module) string {
 	return b.bp.OtherModuleType(m)
 }
-func (b *baseModuleContext) OtherModuleProvider(m blueprint.Module, provider blueprint.ProviderKey) interface{} {
+func (b *baseModuleContext) OtherModuleProvider(m blueprint.Module, provider blueprint.AnyProviderKey) any {
+	value, _ := b.bp.OtherModuleProvider(m, provider)
+	return value
+}
+
+func (b *baseModuleContext) OtherModuleHasProvider(m blueprint.Module, provider blueprint.AnyProviderKey) bool {
+	_, ok := b.bp.OtherModuleProvider(m, provider)
+	return ok
+}
+
+func (b *baseModuleContext) otherModuleProvider(m blueprint.Module, provider blueprint.AnyProviderKey) (any, bool) {
 	return b.bp.OtherModuleProvider(m, provider)
 }
-func (b *baseModuleContext) OtherModuleHasProvider(m blueprint.Module, provider blueprint.ProviderKey) bool {
-	return b.bp.OtherModuleHasProvider(m, provider)
+
+func (b *baseModuleContext) Provider(provider blueprint.AnyProviderKey) any {
+	value, _ := b.bp.Provider(provider)
+	return value
 }
-func (b *baseModuleContext) Provider(provider blueprint.ProviderKey) interface{} {
+
+func (b *baseModuleContext) HasProvider(provider blueprint.AnyProviderKey) bool {
+	_, ok := b.bp.Provider(provider)
+	return ok
+}
+
+func (b *baseModuleContext) provider(provider blueprint.AnyProviderKey) (any, bool) {
 	return b.bp.Provider(provider)
 }
-func (b *baseModuleContext) HasProvider(provider blueprint.ProviderKey) bool {
-	return b.bp.HasProvider(provider)
-}
-func (b *baseModuleContext) SetProvider(provider blueprint.ProviderKey, value interface{}) {
+
+func (b *baseModuleContext) SetProvider(provider blueprint.AnyProviderKey, value any) {
 	b.bp.SetProvider(provider, value)
 }
 

android/makevars.go

@@ -92,7 +92,8 @@ type MakeVarsContext interface {
 	ModuleDir(module blueprint.Module) string
 	ModuleSubDir(module blueprint.Module) string
 	ModuleType(module blueprint.Module) string
-	ModuleProvider(module blueprint.Module, key blueprint.ProviderKey) interface{}
+	ModuleProvider(module blueprint.Module, key blueprint.AnyProviderKey) any
+	moduleProvider(module blueprint.Module, key blueprint.AnyProviderKey) (any, bool)
 	BlueprintFile(module blueprint.Module) string
 
 	ModuleErrorf(module blueprint.Module, format string, args ...interface{})

android/mutator.go

@@ -325,7 +325,7 @@ type BottomUpMutatorContext interface {
 	// if the value is not of the appropriate type, or if the module is not a newly created
 	// variant of the current module.  The value should not be modified after being passed to
 	// SetVariationProvider.
-	SetVariationProvider(module blueprint.Module, provider blueprint.ProviderKey, value interface{})
+	SetVariationProvider(module blueprint.Module, provider blueprint.AnyProviderKey, value interface{})
 }
 
 type bottomUpMutatorContext struct {
@@ -746,6 +746,6 @@ func (b *bottomUpMutatorContext) CreateAliasVariation(fromVariationName, toVaria
 	b.bp.CreateAliasVariation(fromVariationName, toVariationName)
 }
 
-func (b *bottomUpMutatorContext) SetVariationProvider(module blueprint.Module, provider blueprint.ProviderKey, value interface{}) {
+func (b *bottomUpMutatorContext) SetVariationProvider(module blueprint.Module, provider blueprint.AnyProviderKey, value interface{}) {
 	b.bp.SetVariationProvider(module, provider, value)
 }

android/provider.go

@@ -0,0 +1,120 @@
+package android
+
+import (
+	"github.com/google/blueprint"
+)
+
+// OtherModuleProviderContext is a helper interface that is a subset of ModuleContext, BottomUpMutatorContext, or
+// TopDownMutatorContext for use in OtherModuleProvider.
+type OtherModuleProviderContext interface {
+	otherModuleProvider(m blueprint.Module, provider blueprint.AnyProviderKey) (any, bool)
+}
+
+var _ OtherModuleProviderContext = BaseModuleContext(nil)
+var _ OtherModuleProviderContext = ModuleContext(nil)
+var _ OtherModuleProviderContext = BottomUpMutatorContext(nil)
+var _ OtherModuleProviderContext = TopDownMutatorContext(nil)
+
+// OtherModuleProvider reads the provider for the given module.  If the provider has been set the value is
+// returned and the boolean is true.  If it has not been set the zero value of the provider's type  is returned
+// and the boolean is false.  The value returned may be a deep copy of the value originally passed to SetProvider.
+//
+// OtherModuleProviderContext is a helper interface that accepts ModuleContext, BottomUpMutatorContext, or
+// TopDownMutatorContext.
+func OtherModuleProvider[K any](ctx OtherModuleProviderContext, module blueprint.Module, provider blueprint.ProviderKey[K]) (K, bool) {
+	value, ok := ctx.otherModuleProvider(module, provider)
+	if !ok {
+		var k K
+		return k, false
+	}
+	return value.(K), ok
+}
+
+// ModuleProviderContext is a helper interface that is a subset of ModuleContext, BottomUpMutatorContext, or
+// TopDownMutatorContext for use in ModuleProvider.
+type ModuleProviderContext interface {
+	provider(provider blueprint.AnyProviderKey) (any, bool)
+}
+
+var _ ModuleProviderContext = BaseModuleContext(nil)
+var _ ModuleProviderContext = ModuleContext(nil)
+var _ ModuleProviderContext = BottomUpMutatorContext(nil)
+var _ ModuleProviderContext = TopDownMutatorContext(nil)
+
+// ModuleProvider reads the provider for the current module.  If the provider has been set the value is
+// returned and the boolean is true.  If it has not been set the zero value of the provider's type  is returned
+// and the boolean is false.  The value returned may be a deep copy of the value originally passed to SetProvider.
+//
+// ModuleProviderContext is a helper interface that accepts ModuleContext, BottomUpMutatorContext, or
+// TopDownMutatorContext.
+func ModuleProvider[K any](ctx ModuleProviderContext, provider blueprint.ProviderKey[K]) (K, bool) {
+	value, ok := ctx.provider(provider)
+	if !ok {
+		var k K
+		return k, false
+	}
+	return value.(K), ok
+}
+
+type SingletonModuleProviderContext interface {
+	moduleProvider(blueprint.Module, blueprint.AnyProviderKey) (any, bool)
+}
+
+var _ SingletonModuleProviderContext = SingletonContext(nil)
+var _ SingletonModuleProviderContext = (*TestContext)(nil)
+
+// SingletonModuleProvider wraps blueprint.SingletonModuleProvider to provide a type-safe method to retrieve the value
+// of the given provider from a module using a SingletonContext.  If the provider has not been set the first return
+// value will be the zero value of the provider's type, and the second return value will be false.  If the provider has
+// been set the second return value will be true.
+func SingletonModuleProvider[K any](ctx SingletonModuleProviderContext, module blueprint.Module, provider blueprint.ProviderKey[K]) (K, bool) {
+	value, ok := ctx.moduleProvider(module, provider)
+	if !ok {
+		var k K
+		return k, false
+	}
+	return value.(K), ok
+}
+
+// SetProviderContext is a helper interface that is a subset of ModuleContext, BottomUpMutatorContext, or
+// TopDownMutatorContext for use in SetProvider.
+type SetProviderContext interface {
+	SetProvider(provider blueprint.AnyProviderKey, value any)
+}
+
+var _ SetProviderContext = BaseModuleContext(nil)
+var _ SetProviderContext = ModuleContext(nil)
+var _ SetProviderContext = BottomUpMutatorContext(nil)
+var _ SetProviderContext = TopDownMutatorContext(nil)
+
+// SetProvider sets the value for a provider for the current module.  It panics if not called
+// during the appropriate mutator or GenerateBuildActions pass for the provider, if the value
+// is not of the appropriate type, or if the value has already been set.  The value should not
+// be modified after being passed to SetProvider.
+//
+// SetProviderContext is a helper interface that accepts ModuleContext, BottomUpMutatorContext, or
+// TopDownMutatorContext.
+func SetProvider[K any](ctx SetProviderContext, provider blueprint.ProviderKey[K], value K) {
+	ctx.SetProvider(provider, value)
+}
+
+var _ OtherModuleProviderContext = (*otherModuleProviderAdaptor)(nil)
+
+// An OtherModuleProviderFunc can be passed to NewOtherModuleProviderAdaptor to create an OtherModuleProviderContext
+// for use in tests.
+type OtherModuleProviderFunc func(module blueprint.Module, provider blueprint.AnyProviderKey) (any, bool)
+
+type otherModuleProviderAdaptor struct {
+	otherModuleProviderFunc OtherModuleProviderFunc
+}
+
+func (p *otherModuleProviderAdaptor) otherModuleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) (any, bool) {
+	return p.otherModuleProviderFunc(module, provider)
+}
+
+// NewOtherModuleProviderAdaptor returns an OtherModuleProviderContext that proxies calls to otherModuleProvider to
+// the provided OtherModuleProviderFunc.  It can be used in tests to unit test methods that need to call
+// android.OtherModuleProvider.
+func NewOtherModuleProviderAdaptor(otherModuleProviderFunc OtherModuleProviderFunc) OtherModuleProviderContext {
+	return &otherModuleProviderAdaptor{otherModuleProviderFunc}
+}

android/singleton.go

@@ -20,6 +20,8 @@ import (
 
 // SingletonContext
 type SingletonContext interface {
+	blueprintSingletonContext() blueprint.SingletonContext
+
 	Config() Config
 	DeviceConfig() DeviceConfig
 
@@ -38,10 +40,12 @@ type SingletonContext interface {
 	// return value can always be type-asserted to the type of the provider.  The return value should
 	// always be considered read-only.  It panics if called before the appropriate mutator or
 	// GenerateBuildActions pass for the provider on the module.
-	ModuleProvider(module blueprint.Module, provider blueprint.ProviderKey) interface{}
+	ModuleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) any
 
 	// ModuleHasProvider returns true if the provider for the given module has been set.
-	ModuleHasProvider(module blueprint.Module, provider blueprint.ProviderKey) bool
+	ModuleHasProvider(module blueprint.Module, provider blueprint.AnyProviderKey) bool
+
+	moduleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) (any, bool)
 
 	ModuleErrorf(module blueprint.Module, format string, args ...interface{})
 	Errorf(format string, args ...interface{})
@@ -135,6 +139,10 @@ type singletonContextAdaptor struct {
 	ruleParams  map[blueprint.Rule]blueprint.RuleParams
 }
 
+func (s *singletonContextAdaptor) blueprintSingletonContext() blueprint.SingletonContext {
+	return s.SingletonContext
+}
+
 func (s *singletonContextAdaptor) Config() Config {
 	return s.SingletonContext.Config().(Config)
 }
@@ -282,3 +290,18 @@ func (s *singletonContextAdaptor) ModuleVariantsFromName(referer Module, name st
 	}
 	return result
 }
+
+func (s *singletonContextAdaptor) ModuleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) any {
+	value, _ := s.SingletonContext.ModuleProvider(module, provider)
+	return value
+}
+
+// ModuleHasProvider returns true if the provider for the given module has been set.
+func (s *singletonContextAdaptor) ModuleHasProvider(module blueprint.Module, provider blueprint.AnyProviderKey) bool {
+	_, ok := s.SingletonContext.ModuleProvider(module, provider)
+	return ok
+}
+
+func (s *singletonContextAdaptor) moduleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) (any, bool) {
+	return s.SingletonContext.ModuleProvider(module, provider)
+}

android/testing.go

@@ -203,7 +203,17 @@ func (ctx *TestContext) HardCodedPreArchMutators(f RegisterMutatorFunc) {
 	ctx.PreArchMutators(f)
 }
 
-func (ctx *TestContext) ModuleProvider(m blueprint.Module, p blueprint.ProviderKey) interface{} {
+func (ctx *TestContext) ModuleProvider(m blueprint.Module, p blueprint.AnyProviderKey) any {
+	value, _ := ctx.Context.ModuleProvider(m, p)
+	return value
+}
+
+func (ctx *TestContext) ModuleHasProvider(m blueprint.Module, p blueprint.AnyProviderKey) bool {
+	_, ok := ctx.Context.ModuleProvider(m, p)
+	return ok
+}
+
+func (ctx *TestContext) moduleProvider(m blueprint.Module, p blueprint.AnyProviderKey) (any, bool) {
 	return ctx.Context.ModuleProvider(m, p)
 }
 
@@ -225,6 +235,12 @@ func (ctx *TestContext) PreArchBp2BuildMutators(f RegisterMutatorFunc) {
 	ctx.bp2buildPreArch = append(ctx.bp2buildPreArch, f)
 }
 
+func (ctx *TestContext) OtherModuleProviderAdaptor() OtherModuleProviderContext {
+	return NewOtherModuleProviderAdaptor(func(module blueprint.Module, provider blueprint.AnyProviderKey) (any, bool) {
+		return ctx.moduleProvider(module, provider)
+	})
+}
+
 // registeredComponentOrder defines the order in which a sortableComponent type is registered at
 // runtime and provides support for reordering the components registered for a test in the same
 // way.

apex/classpath_element_test.go

@@ -33,11 +33,11 @@ type testClasspathElementContext struct {
 	errs        []error
 }
 
-func (t *testClasspathElementContext) OtherModuleHasProvider(module blueprint.Module, provider blueprint.ProviderKey) bool {
+func (t *testClasspathElementContext) OtherModuleHasProvider(module blueprint.Module, provider blueprint.AnyProviderKey) bool {
 	return t.testContext.ModuleHasProvider(module, provider)
 }
 
-func (t *testClasspathElementContext) OtherModuleProvider(module blueprint.Module, provider blueprint.ProviderKey) interface{} {
+func (t *testClasspathElementContext) OtherModuleProvider(module blueprint.Module, provider blueprint.AnyProviderKey) interface{} {
 	return t.testContext.ModuleProvider(module, provider)
 }
 

bloaty/bloaty.go

@@ -26,7 +26,7 @@ const bloatyDescriptorExt = ".bloaty.csv"
 const protoFilename = "binary_sizes.pb.gz"
 
 var (
-	fileSizeMeasurerKey blueprint.ProviderKey
+	fileSizeMeasurerKey blueprint.ProviderKey[measuredFiles]
 	pctx                = android.NewPackageContext("android/soong/bloaty")
 
 	// bloaty is used to measure a binary section sizes.

cc/sanitize_test.go

@@ -49,7 +49,7 @@ var prepareForTsanTest = android.FixtureAddFile("tsan/Android.bp", []byte(`
 `))
 
 type providerInterface interface {
-	ModuleProvider(blueprint.Module, blueprint.ProviderKey) interface{}
+	ModuleProvider(blueprint.Module, blueprint.AnyProviderKey) interface{}
 }
 
 // expectSharedLinkDep verifies that the from module links against the to module as a

java/classpath_element.go

@@ -72,8 +72,8 @@ var _ ClasspathElement = (*ClasspathLibraryElement)(nil)
 
 // ClasspathElementContext defines the context methods needed by CreateClasspathElements
 type ClasspathElementContext interface {
-	OtherModuleHasProvider(m blueprint.Module, provider blueprint.ProviderKey) bool
-	OtherModuleProvider(m blueprint.Module, provider blueprint.ProviderKey) interface{}
+	OtherModuleHasProvider(m blueprint.Module, provider blueprint.AnyProviderKey) bool
+	OtherModuleProvider(m blueprint.Module, provider blueprint.AnyProviderKey) interface{}
 	ModuleErrorf(fmt string, args ...interface{})
 }