create, but dont register, bp2build_deps mutator

This is the bulk of the "allowlist v2" feature. It will disable bp2build
generation for modules which have transitive dependencies without a
bazel build definition.

This CL includes this mutator, but doesn't register it as a bp2build
mutator (outside of a few unit tests). This allows us to easily iterate
on completion of this feature and ensure there are no launch blockers
before we finalize the change in AOSP.

Bug: 285631638
Test: Unit tests
Change-Id: Ifb0a079c409ca19b02cafa3fab2efa0d3deebc50

12 files changed, 360 insertions, 136 deletions

diff --git a/android/api_domain.go b/android/api_domain.go
index 0603c7016..38f48e3d4 100644
--- a/android/api_domain.go
+++ b/android/api_domain.go
@@ -14,12 +14,6 @@
 
 package android
 
-import (
-	"github.com/google/blueprint"
-
-	"android/soong/bazel"
-)
-
 func init() {
 	RegisterApiDomainBuildComponents(InitRegistrationContext)
 }
@@ -97,13 +91,3 @@ const (
 func ApiContributionTargetName(moduleName string) string {
 	return moduleName + apiContributionSuffix
 }
-
-// For each contributing cc_library, format the name to its corresponding contribution bazel target in the bp2build workspace
-func contributionBazelAttributes(ctx TopDownMutatorContext, contributions []string) bazel.LabelListAttribute {
-	addSuffix := func(ctx BazelConversionPathContext, module blueprint.Module) string {
-		baseLabel := BazelModuleLabel(ctx, module)
-		return ApiContributionTargetName(baseLabel)
-	}
-	bazelLabels := BazelLabelForModuleDepsWithFn(ctx, contributions, addSuffix)
-	return bazel.MakeLabelListAttribute(bazelLabels)
-}
diff --git a/android/bazel.go b/android/bazel.go
index 5df12f02e..e307b18d2 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -625,7 +625,18 @@ func registerBp2buildConversionMutator(ctx RegisterMutatorsContext) {
 	ctx.BottomUp("bp2build_conversion", bp2buildConversionMutator).Parallel()
 }
 
+func registerBp2buildDepsMutator(ctx RegisterMutatorsContext) {
+	ctx.BottomUp("bp2build_deps", bp2buildDepsMutator).Parallel()
+}
+
 func bp2buildConversionMutator(ctx BottomUpMutatorContext) {
+	// If an existing BUILD file in the module directory has a target defined
+	// with this same name as this module, assume that this is an existing
+	// definition for this target.
+	if ctx.Config().HasBazelBuildTargetInSource(ctx.ModuleDir(), ctx.ModuleName()) {
+		ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_DEFINED_IN_BUILD_FILE, ctx.ModuleName())
+		return
+	}
 	bModule, ok := ctx.Module().(Bazelable)
 	if !ok {
 		ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_TYPE_UNSUPPORTED, "")
@@ -659,6 +670,10 @@ func bp2buildConversionMutator(ctx BottomUpMutatorContext) {
 		panic(fmt.Errorf("illegal bp2build invariant: module '%s' was neither converted nor marked unconvertible", ctx.ModuleName()))
 	}
 
+	// If an existing BUILD file in the module directory has a target defined
+	// with the same name as any target generated by this module, assume that this
+	// is an existing definition for this target. (These generated target names
+	// may be different than the module name, as checked at the beginning of this function!)
 	for _, targetInfo := range ctx.Module().base().Bp2buildTargets() {
 		if ctx.Config().HasBazelBuildTargetInSource(targetInfo.TargetPackage(), targetInfo.TargetName()) {
 			// Defer to the BUILD target. Generating an additional target would
@@ -669,6 +684,27 @@ func bp2buildConversionMutator(ctx BottomUpMutatorContext) {
 	}
 }
 
+// TODO: b/285631638 - Add this as a new mutator to the bp2build conversion mutators.
+// Currently, this only exists to prepare test coverage for the launch of this feature.
+func bp2buildDepsMutator(ctx BottomUpMutatorContext) {
+	if ctx.Module().base().GetUnconvertedReason() != nil {
+		return
+	}
+
+	if len(ctx.Module().GetMissingBp2buildDeps()) > 0 {
+		exampleDep := ctx.Module().GetMissingBp2buildDeps()[0]
+		ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_UNCONVERTED_DEP, exampleDep)
+	}
+
+	ctx.VisitDirectDeps(func(dep Module) {
+		if dep.base().GetUnconvertedReason() != nil &&
+			dep.base().GetUnconvertedReason().ReasonType != int(bp2build_metrics_proto.UnconvertedReasonType_DEFINED_IN_BUILD_FILE) &&
+			ctx.OtherModuleDependencyTag(dep) == Bp2buildDepTag {
+			ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_UNCONVERTED_DEP, dep.Name())
+		}
+	})
+}
+
 // GetMainClassInManifest scans the manifest file specified in filepath and returns
 // the value of attribute Main-Class in the manifest file if it exists, or returns error.
 // WARNING: this is for bp2build converters of java_* modules only.
diff --git a/android/bazel_paths.go b/android/bazel_paths.go
index d8effaa12..d85ce4bb9 100644
--- a/android/bazel_paths.go
+++ b/android/bazel_paths.go
@@ -101,8 +101,8 @@ type BazelConversionPathContext interface {
 // BazelLabelForModuleDeps expects a list of reference to other modules, ("<module>"
 // or ":<module>") and returns a Bazel-compatible label which corresponds to dependencies on the
 // module within the given ctx.
-func BazelLabelForModuleDeps(ctx BazelConversionPathContext, modules []string) bazel.LabelList {
-	return BazelLabelForModuleDepsWithFn(ctx, modules, BazelModuleLabel)
+func BazelLabelForModuleDeps(ctx Bp2buildMutatorContext, modules []string) bazel.LabelList {
+	return BazelLabelForModuleDepsWithFn(ctx, modules, BazelModuleLabel, true)
 }
 
 // BazelLabelForModuleWholeDepsExcludes expects two lists: modules (containing modules to include in
@@ -111,15 +111,16 @@ func BazelLabelForModuleDeps(ctx BazelConversionPathContext, modules []string) b
 // list which corresponds to dependencies on the module within the given ctx, and the excluded
 // dependencies.  Prebuilt dependencies will be appended with _alwayslink so they can be handled as
 // whole static libraries.
-func BazelLabelForModuleDepsExcludes(ctx BazelConversionPathContext, modules, excludes []string) bazel.LabelList {
+func BazelLabelForModuleDepsExcludes(ctx Bp2buildMutatorContext, modules, excludes []string) bazel.LabelList {
 	return BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, BazelModuleLabel)
 }
 
 // BazelLabelForModuleDepsWithFn expects a list of reference to other modules, ("<module>"
 // or ":<module>") and applies moduleToLabelFn to determine and return a Bazel-compatible label
 // which corresponds to dependencies on the module within the given ctx.
-func BazelLabelForModuleDepsWithFn(ctx BazelConversionPathContext, modules []string,
-	moduleToLabelFn func(BazelConversionPathContext, blueprint.Module) string) bazel.LabelList {
+func BazelLabelForModuleDepsWithFn(ctx Bp2buildMutatorContext, modules []string,
+	moduleToLabelFn func(BazelConversionPathContext, blueprint.Module) string,
+	markAsDeps bool) bazel.LabelList {
 	var labels bazel.LabelList
 	// In some cases, a nil string list is different than an explicitly empty list.
 	if len(modules) == 0 && modules != nil {
@@ -133,7 +134,7 @@ func BazelLabelForModuleDepsWithFn(ctx BazelConversionPathContext, modules []str
 			module = ":" + module
 		}
 		if m, t := SrcIsModuleWithTag(module); m != "" {
-			l := getOtherModuleLabel(ctx, m, t, moduleToLabelFn)
+			l := getOtherModuleLabel(ctx, m, t, moduleToLabelFn, markAsDeps)
 			if l != nil {
 				l.OriginalModuleName = bpText
 				labels.Includes = append(labels.Includes, *l)
@@ -150,27 +151,27 @@ func BazelLabelForModuleDepsWithFn(ctx BazelConversionPathContext, modules []str
 // to other modules, ("<module>" or ":<module>"). It applies moduleToLabelFn to determine and return a
 // Bazel-compatible label list which corresponds to dependencies on the module within the given ctx, and
 // the excluded dependencies.
-func BazelLabelForModuleDepsExcludesWithFn(ctx BazelConversionPathContext, modules, excludes []string,
+func BazelLabelForModuleDepsExcludesWithFn(ctx Bp2buildMutatorContext, modules, excludes []string,
 	moduleToLabelFn func(BazelConversionPathContext, blueprint.Module) string) bazel.LabelList {
-	moduleLabels := BazelLabelForModuleDepsWithFn(ctx, RemoveListFromList(modules, excludes), moduleToLabelFn)
+	moduleLabels := BazelLabelForModuleDepsWithFn(ctx, RemoveListFromList(modules, excludes), moduleToLabelFn, true)
 	if len(excludes) == 0 {
 		return moduleLabels
 	}
-	excludeLabels := BazelLabelForModuleDepsWithFn(ctx, excludes, moduleToLabelFn)
+	excludeLabels := BazelLabelForModuleDepsWithFn(ctx, excludes, moduleToLabelFn, false)
 	return bazel.LabelList{
 		Includes: moduleLabels.Includes,
 		Excludes: excludeLabels.Includes,
 	}
 }
 
-func BazelLabelForModuleSrcSingle(ctx BazelConversionPathContext, path string) bazel.Label {
+func BazelLabelForModuleSrcSingle(ctx Bp2buildMutatorContext, path string) bazel.Label {
 	if srcs := BazelLabelForModuleSrcExcludes(ctx, []string{path}, []string(nil)).Includes; len(srcs) > 0 {
 		return srcs[0]
 	}
 	return bazel.Label{}
 }
 
-func BazelLabelForModuleDepSingle(ctx BazelConversionPathContext, path string) bazel.Label {
+func BazelLabelForModuleDepSingle(ctx Bp2buildMutatorContext, path string) bazel.Label {
 	if srcs := BazelLabelForModuleDepsExcludes(ctx, []string{path}, []string(nil)).Includes; len(srcs) > 0 {
 		return srcs[0]
 	}
@@ -183,7 +184,7 @@ func BazelLabelForModuleDepSingle(ctx BazelConversionPathContext, path string) b
 // relative if within the same package).
 // Properties must have been annotated with struct tag `android:"path"` so that dependencies modules
 // will have already been handled by the pathdeps mutator.
-func BazelLabelForModuleSrc(ctx BazelConversionPathContext, paths []string) bazel.LabelList {
+func BazelLabelForModuleSrc(ctx Bp2buildMutatorContext, paths []string) bazel.LabelList {
 	return BazelLabelForModuleSrcExcludes(ctx, paths, []string(nil))
 }
 
@@ -193,13 +194,13 @@ func BazelLabelForModuleSrc(ctx BazelConversionPathContext, paths []string) baze
 // (absolute if in a different package or relative if within the same package).
 // Properties must have been annotated with struct tag `android:"path"` so that dependencies modules
 // will have already been handled by the pathdeps mutator.
-func BazelLabelForModuleSrcExcludes(ctx BazelConversionPathContext, paths, excludes []string) bazel.LabelList {
-	excludeLabels := expandSrcsForBazel(ctx, excludes, []string(nil))
+func BazelLabelForModuleSrcExcludes(ctx Bp2buildMutatorContext, paths, excludes []string) bazel.LabelList {
+	excludeLabels := expandSrcsForBazel(ctx, excludes, []string(nil), false)
 	excluded := make([]string, 0, len(excludeLabels.Includes))
 	for _, e := range excludeLabels.Includes {
 		excluded = append(excluded, e.Label)
 	}
-	labels := expandSrcsForBazel(ctx, paths, excluded)
+	labels := expandSrcsForBazel(ctx, paths, excluded, true)
 	labels.Excludes = excludeLabels.Includes
 	labels = TransformSubpackagePaths(ctx.Config(), ctx.ModuleDir(), labels)
 	return labels
@@ -352,6 +353,12 @@ func RootToModuleRelativePaths(ctx BazelConversionPathContext, paths Paths) []ba
 	return newPaths
 }
 
+var Bp2buildDepTag bp2buildDepTag
+
+type bp2buildDepTag struct {
+	blueprint.BaseDependencyTag
+}
+
 // expandSrcsForBazel returns bazel.LabelList with paths rooted from the module's local source
 // directory and Bazel target labels, excluding those included in the excludes argument (which
 // should already be expanded to resolve references to Soong-modules). Valid elements of paths
@@ -374,7 +381,7 @@ func RootToModuleRelativePaths(ctx BazelConversionPathContext, paths Paths) []ba
 // Properties passed as the paths or excludes argument must have been annotated with struct tag
 // `android:"path"` so that dependencies on other modules will have already been handled by the
 // pathdeps mutator.
-func expandSrcsForBazel(ctx BazelConversionPathContext, paths, expandedExcludes []string) bazel.LabelList {
+func expandSrcsForBazel(ctx Bp2buildMutatorContext, paths, expandedExcludes []string, markAsDeps bool) bazel.LabelList {
 	if paths == nil {
 		return bazel.LabelList{}
 	}
@@ -391,7 +398,7 @@ func expandSrcsForBazel(ctx BazelConversionPathContext, paths, expandedExcludes
 
 	for _, p := range paths {
 		if m, tag := SrcIsModuleWithTag(p); m != "" {
-			l := getOtherModuleLabel(ctx, m, tag, BazelModuleLabel)
+			l := getOtherModuleLabel(ctx, m, tag, BazelModuleLabel, markAsDeps)
 			if l != nil && !InList(l.Label, expandedExcludes) {
 				if strings.HasPrefix(m, "//") {
 					// this is a module in a soong namespace
@@ -423,8 +430,9 @@ func expandSrcsForBazel(ctx BazelConversionPathContext, paths, expandedExcludes
 // getOtherModuleLabel returns a bazel.Label for the given dependency/tag combination for the
 // module. The label will be relative to the current directory if appropriate. The dependency must
 // already be resolved by either deps mutator or path deps mutator.
-func getOtherModuleLabel(ctx BazelConversionPathContext, dep, tag string,
-	labelFromModule func(BazelConversionPathContext, blueprint.Module) string) *bazel.Label {
+func getOtherModuleLabel(ctx Bp2buildMutatorContext, dep, tag string,
+	labelFromModule func(BazelConversionPathContext, blueprint.Module) string,
+	markAsDep bool) *bazel.Label {
 	m, _ := ctx.ModuleFromName(dep)
 	// The module was not found in an Android.bp file, this is often due to:
 	//		* a limited manifest
@@ -435,6 +443,13 @@ func getOtherModuleLabel(ctx BazelConversionPathContext, dep, tag string,
 			Label: ":" + dep + "__BP2BUILD__MISSING__DEP",
 		}
 	}
+	if markAsDep {
+		// Don't count dependencies of "libc". This is a hack to circumvent the
+		// fact that, in a variantless build graph, "libc" has a dependency on itself.
+		if ctx.ModuleName() != "libc" {
+			ctx.AddDependency(ctx.Module(), Bp2buildDepTag, dep)
+		}
+	}
 	if !convertedToBazel(ctx, m) {
 		ctx.AddUnconvertedBp2buildDep(dep)
 	}
diff --git a/android/config.go b/android/config.go
index b3ff86b49..e5db9b10a 100644
--- a/android/config.go
+++ b/android/config.go
@@ -297,6 +297,10 @@ type config struct {
 	// in tests when a path doesn't exist.
 	TestAllowNonExistentPaths bool
 
+	// If testAllowNonExistentPaths is true then PathForSource and PathForModuleSrc won't error
+	// in tests when a path doesn't exist.
+	Bp2buildDepsMutator bool
+
 	// The list of files that when changed, must invalidate soong_build to
 	// regenerate build.ninja.
 	ninjaFileDepsSet sync.Map
diff --git a/android/mutator.go b/android/mutator.go
index 57ff1e092..3d596554d 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -35,6 +35,9 @@ import (
 // RegisterMutatorsForBazelConversion is a alternate registration pipeline for bp2build. Exported for testing.
 func RegisterMutatorsForBazelConversion(ctx *Context, preArchMutators []RegisterMutatorFunc) {
 	bp2buildMutators := append(preArchMutators, registerBp2buildConversionMutator)
+	if ctx.config.Bp2buildDepsMutator {
+		bp2buildMutators = append(bp2buildMutators, registerBp2buildDepsMutator)
+	}
 	registerMutatorsForBazelConversion(ctx, bp2buildMutators)
 }
 
@@ -226,6 +229,15 @@ type Bp2buildMutatorContext interface {
 	BazelConversionPathContext
 	BaseMutatorContext
 
+	// AddDependency adds a dependency to the given module.  It returns a slice of modules for each
+	// dependency (some entries may be nil).
+	//
+	// If the mutator is parallel (see MutatorHandle.Parallel), this method will pause until the
+	// new dependencies have had the current mutator called on them.  If the mutator is not
+	// parallel this method does not affect the ordering of the current mutator pass, but will
+	// be ordered correctly for all future mutator passes.
+	AddDependency(module blueprint.Module, tag blueprint.DependencyTag, name ...string) []blueprint.Module
+
 	// CreateBazelTargetModule creates a BazelTargetModule by calling the
 	// factory method, just like in CreateModule, but also requires
 	// BazelTargetModuleProperties containing additional metadata for the
@@ -294,15 +306,6 @@ type BottomUpMutatorContext interface {
 	BaseMutatorContext
 	Bp2buildMutatorContext
 
-	// AddDependency adds a dependency to the given module.  It returns a slice of modules for each
-	// dependency (some entries may be nil).
-	//
-	// If the mutator is parallel (see MutatorHandle.Parallel), this method will pause until the
-	// new dependencies have had the current mutator called on them.  If the mutator is not
-	// parallel this method does not affect the ordering of the current mutator pass, but will
-	// be ordered correctly for all future mutator passes.
-	AddDependency(module blueprint.Module, tag blueprint.DependencyTag, name ...string) []blueprint.Module
-
 	// AddReverseDependency adds a dependency from the destination to the given module.
 	// Does not affect the ordering of the current mutator pass, but will be ordered
 	// correctly for all future mutator passes.  All reverse dependencies for a destination module are
diff --git a/bp2build/build_conversion_test.go b/bp2build/build_conversion_test.go
index afbfffacc..dc56a17b0 100644
--- a/bp2build/build_conversion_test.go
+++ b/bp2build/build_conversion_test.go
@@ -2101,3 +2101,219 @@ func TestCreateBazelTargetInDifferentDir(t *testing.T) {
 	})
 
 }
+
+func TestBp2buildDepsMutator_missingTransitiveDep(t *testing.T) {
+	bp := `
+	custom {
+		name: "foo",
+	}
+
+	custom {
+		name: "has_deps",
+	  arch_paths: [":has_missing_dep", ":foo"],
+	}
+
+	custom {
+		name: "has_missing_dep",
+	  arch_paths: [":missing"],
+	}
+	`
+	expectedBazelTargets := []string{
+		MakeBazelTarget(
+			"custom",
+			"foo",
+			AttrNameToString{},
+		),
+	}
+	registerCustomModule := func(ctx android.RegistrationContext) {
+		ctx.RegisterModuleType("custom", customModuleFactoryHostAndDevice)
+	}
+	RunBp2BuildTestCase(t, registerCustomModule, Bp2buildTestCase{
+		Blueprint:            bp,
+		ExpectedBazelTargets: expectedBazelTargets,
+		Description:          "Skipping conversion of a target with missing transitive dep",
+		DepsMutator:          true,
+	})
+}
+
+func TestBp2buildDepsMutator_missingDirectDep(t *testing.T) {
+	bp := `
+	custom {
+		name: "foo",
+	  arch_paths: [":exists"],
+	}
+	custom {
+		name: "exists",
+	}
+
+	custom {
+		name: "has_missing_dep",
+	  arch_paths: [":missing"],
+	}
+	`
+	expectedBazelTargets := []string{
+		MakeBazelTarget(
+			"custom",
+			"foo",
+			AttrNameToString{"arch_paths": `[":exists"]`},
+		),
+		MakeBazelTarget(
+			"custom",
+			"exists",
+			AttrNameToString{},
+		),
+	}
+	registerCustomModule := func(ctx android.RegistrationContext) {
+		ctx.RegisterModuleType("custom", customModuleFactoryHostAndDevice)
+	}
+	RunBp2BuildTestCase(t, registerCustomModule, Bp2buildTestCase{
+		Blueprint:            bp,
+		ExpectedBazelTargets: expectedBazelTargets,
+		Description:          "Skipping conversion of a target with missing direct dep",
+		DepsMutator:          true,
+	})
+}
+
+func TestBp2buildDepsMutator_unconvertedDirectDep(t *testing.T) {
+	bp := `
+	custom {
+		name: "has_unconverted_dep",
+	  arch_paths: [":unconvertible"],
+	}
+
+	custom {
+		name: "unconvertible",
+		does_not_convert_to_bazel: true
+	}
+	`
+	registerCustomModule := func(ctx android.RegistrationContext) {
+		ctx.RegisterModuleType("custom", customModuleFactoryHostAndDevice)
+	}
+	RunBp2BuildTestCase(t, registerCustomModule, Bp2buildTestCase{
+		Blueprint:            bp,
+		ExpectedBazelTargets: []string{},
+		Description:          "Skipping conversion of a target with unconverted direct dep",
+		DepsMutator:          true,
+	})
+}
+
+func TestBp2buildDepsMutator_unconvertedTransitiveDep(t *testing.T) {
+	bp := `
+	custom {
+		name: "foo",
+	  arch_paths: [":has_unconverted_dep", ":bar"],
+	}
+
+	custom {
+		name: "bar",
+	}
+
+	custom {
+		name: "has_unconverted_dep",
+	  arch_paths: [":unconvertible"],
+	}
+
+	custom {
+		name: "unconvertible",
+		does_not_convert_to_bazel: true
+	}
+	`
+	expectedBazelTargets := []string{
+		MakeBazelTarget(
+			"custom",
+			"bar",
+			AttrNameToString{},
+		),
+	}
+	registerCustomModule := func(ctx android.RegistrationContext) {
+		ctx.RegisterModuleType("custom", customModuleFactoryHostAndDevice)
+	}
+	RunBp2BuildTestCase(t, registerCustomModule, Bp2buildTestCase{
+		Blueprint:            bp,
+		ExpectedBazelTargets: expectedBazelTargets,
+		Description:          "Skipping conversion of a target with unconverted transitive dep",
+		DepsMutator:          true,
+	})
+}
+
+func TestBp2buildDepsMutator_alreadyExistsBuildDeps(t *testing.T) {
+	bp := `
+	custom {
+		name: "foo",
+	  arch_paths: [":bar"],
+	}
+	custom {
+		name: "bar",
+	  arch_paths: [":checked_in"],
+	}
+	custom {
+		name: "checked_in",
+	  arch_paths: [":checked_in"],
+		does_not_convert_to_bazel: true
+	}
+	`
+	expectedBazelTargets := []string{
+		MakeBazelTarget(
+			"custom",
+			"foo",
+			AttrNameToString{"arch_paths": `[":bar"]`},
+		),
+		MakeBazelTarget(
+			"custom",
+			"bar",
+			AttrNameToString{"arch_paths": `[":checked_in"]`},
+		),
+	}
+	registerCustomModule := func(ctx android.RegistrationContext) {
+		ctx.RegisterModuleType("custom", customModuleFactoryHostAndDevice)
+	}
+	RunBp2BuildTestCase(t, registerCustomModule, Bp2buildTestCase{
+		StubbedBuildDefinitions: []string{"checked_in"},
+		Blueprint:               bp,
+		ExpectedBazelTargets:    expectedBazelTargets,
+		Description:             "Convert target with already-existing build dep",
+		DepsMutator:             true,
+	})
+}
+
+// Tests that deps of libc are always considered valid for libc. This circumvents
+// an issue that, in a variantless graph (such as bp2build's), libc has the
+// unique predicament that it depends on itself.
+func TestBp2buildDepsMutator_depOnLibc(t *testing.T) {
+	bp := `
+	custom {
+		name: "foo",
+	  arch_paths: [":libc"],
+	}
+	custom {
+		name: "libc",
+	  arch_paths: [":libc_dep"],
+	}
+	custom {
+		name: "libc_dep",
+		does_not_convert_to_bazel: true
+	}
+	`
+	expectedBazelTargets := []string{
+		MakeBazelTarget(
+			"custom",
+			"foo",
+			AttrNameToString{"arch_paths": `[":libc"]`},
+		),
+		MakeBazelTarget(
+			"custom",
+			"libc",
+			AttrNameToString{"arch_paths": `[":libc_dep"]`},
+		),
+	}
+	registerCustomModule := func(ctx android.RegistrationContext) {
+		ctx.RegisterModuleType("custom", customModuleFactoryHostAndDevice)
+	}
+	RunBp2BuildTestCase(t, registerCustomModule, Bp2buildTestCase{
+		StubbedBuildDefinitions: []string{"checked_in"},
+		Blueprint:               bp,
+		ExpectedBazelTargets:    expectedBazelTargets,
+		Description:             "Convert target with dep on libc",
+		DepsMutator:             true,
+	})
+}
diff --git a/bp2build/bzl_conversion_test.go b/bp2build/bzl_conversion_test.go
index 402d4b013..645298f15 100644
--- a/bp2build/bzl_conversion_test.go
+++ b/bp2build/bzl_conversion_test.go
@@ -95,6 +95,7 @@ custom = rule(
         "bool_prop": attr.bool(),
         "bool_ptr_prop": attr.bool(),
         "dir": attr.string(),
+        "does_not_convert_to_bazel": attr.bool(),
         "embedded_prop": attr.string(),
         "int64_ptr_prop": attr.int(),
         # nested_props start
@@ -128,6 +129,7 @@ custom_defaults = rule(
         "bool_prop": attr.bool(),
         "bool_ptr_prop": attr.bool(),
         "dir": attr.string(),
+        "does_not_convert_to_bazel": attr.bool(),
         "embedded_prop": attr.string(),
         "int64_ptr_prop": attr.int(),
         # nested_props start
@@ -161,6 +163,7 @@ custom_test_ = rule(
         "bool_prop": attr.bool(),
         "bool_ptr_prop": attr.bool(),
         "dir": attr.string(),
+        "does_not_convert_to_bazel": attr.bool(),
         "embedded_prop": attr.string(),
         "int64_ptr_prop": attr.int(),
         # nested_props start
diff --git a/bp2build/testing.go b/bp2build/testing.go
index d26b346dd..690748756 100644
--- a/bp2build/testing.go
+++ b/bp2build/testing.go
@@ -124,25 +124,37 @@ type Bp2buildTestCase struct {
 	// be merged with the generated BUILD file. This allows custom BUILD targets
 	// to be used in tests, or use BUILD files to draw package boundaries.
 	KeepBuildFileForDirs []string
+
+	// If true, the bp2build_deps mutator is used for this test. This is an
+	// experimental mutator that will disable modules which have transitive
+	// dependencies with no bazel definition.
+	// TODO: b/285631638 - Enable this feature by default.
+	DepsMutator bool
 }
 
 func RunBp2BuildTestCaseExtraContext(t *testing.T, registerModuleTypes func(ctx android.RegistrationContext), modifyContext func(ctx *android.TestContext), tc Bp2buildTestCase) {
 	t.Helper()
-	bp2buildSetup := android.GroupFixturePreparers(
+	preparers := []android.FixturePreparer{
 		android.FixtureRegisterWithContext(registerModuleTypes),
-		android.FixtureModifyContext(modifyContext),
-		SetBp2BuildTestRunner,
+	}
+	if modifyContext != nil {
+		preparers = append(preparers, android.FixtureModifyContext(modifyContext))
+	}
+	if tc.DepsMutator {
+		preparers = append(preparers, android.FixtureModifyConfig(func(cfg android.Config) {
+			cfg.Bp2buildDepsMutator = true
+		}))
+	}
+	preparers = append(preparers, SetBp2BuildTestRunner)
+	bp2buildSetup := android.GroupFixturePreparers(
+		preparers...,
 	)
 	runBp2BuildTestCaseWithSetup(t, bp2buildSetup, tc)
 }
 
 func RunBp2BuildTestCase(t *testing.T, registerModuleTypes func(ctx android.RegistrationContext), tc Bp2buildTestCase) {
 	t.Helper()
-	bp2buildSetup := android.GroupFixturePreparers(
-		android.FixtureRegisterWithContext(registerModuleTypes),
-		SetBp2BuildTestRunner,
-	)
-	runBp2BuildTestCaseWithSetup(t, bp2buildSetup, tc)
+	RunBp2BuildTestCaseExtraContext(t, registerModuleTypes, nil, tc)
 }
 
 func runBp2BuildTestCaseWithSetup(t *testing.T, extraPreparer android.FixturePreparer, tc Bp2buildTestCase) {
@@ -400,6 +412,10 @@ type customProps struct {
 	// Prop used to indicate this conversion should be 1 module -> multiple targets
 	One_to_many_prop *bool
 
+	// Prop used to simulate an unsupported property in bp2build conversion. If this
+	// is true, this module should be treated as "unconvertible" via bp2build.
+	Does_not_convert_to_bazel *bool
+
 	Api *string // File describing the APIs of this module
 
 	Test_config_setting *bool // Used to test generation of config_setting targets
@@ -535,6 +551,10 @@ func (m *customModule) dir() *string {
 }
 
 func (m *customModule) ConvertWithBp2build(ctx android.Bp2buildMutatorContext) {
+	if p := m.props.Does_not_convert_to_bazel; p != nil && *p {
+		ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_PROPERTY_UNSUPPORTED, "")
+		return
+	}
 	if p := m.props.One_to_many_prop; p != nil && *p {
 		customBp2buildOneToMany(ctx, m)
 		return
diff --git a/cc/bp2build.go b/cc/bp2build.go
index 7738487db..45fbf278a 100644
--- a/cc/bp2build.go
+++ b/cc/bp2build.go
@@ -99,7 +99,7 @@ type tidyAttributes struct {
 	Tidy_timeout_srcs     bazel.LabelListAttribute
 }
 
-func (m *Module) convertTidyAttributes(ctx android.BaseMutatorContext, moduleAttrs *tidyAttributes) {
+func (m *Module) convertTidyAttributes(ctx android.Bp2buildMutatorContext, moduleAttrs *tidyAttributes) {
 	for _, f := range m.features {
 		if tidy, ok := f.(*tidyFeature); ok {
 			var tidyAttr *string
@@ -246,9 +246,9 @@ type depsPartition struct {
 	implementation bazel.LabelList
 }
 
-type bazelLabelForDepsFn func(android.BazelConversionPathContext, []string) bazel.LabelList
+type bazelLabelForDepsFn func(android.Bp2buildMutatorContext, []string) bazel.LabelList
 
-func maybePartitionExportedAndImplementationsDeps(ctx android.BazelConversionPathContext, exportsDeps bool, allDeps, exportedDeps []string, fn bazelLabelForDepsFn) depsPartition {
+func maybePartitionExportedAndImplementationsDeps(ctx android.Bp2buildMutatorContext, exportsDeps bool, allDeps, exportedDeps []string, fn bazelLabelForDepsFn) depsPartition {
 	if !exportsDeps {
 		return depsPartition{
 			implementation: fn(ctx, allDeps),
@@ -263,9 +263,9 @@ func maybePartitionExportedAndImplementationsDeps(ctx android.BazelConversionPat
 	}
 }
 
-type bazelLabelForDepsExcludesFn func(android.BazelConversionPathContext, []string, []string) bazel.LabelList
+type bazelLabelForDepsExcludesFn func(android.Bp2buildMutatorContext, []string, []string) bazel.LabelList
 
-func maybePartitionExportedAndImplementationsDepsExcludes(ctx android.BazelConversionPathContext, exportsDeps bool, allDeps, excludes, exportedDeps []string, fn bazelLabelForDepsExcludesFn) depsPartition {
+func maybePartitionExportedAndImplementationsDepsExcludes(ctx android.Bp2buildMutatorContext, exportsDeps bool, allDeps, excludes, exportedDeps []string, fn bazelLabelForDepsExcludesFn) depsPartition {
 	if !exportsDeps {
 		return depsPartition{
 			implementation: fn(ctx, allDeps, excludes),
@@ -352,7 +352,7 @@ type prebuiltAttributes struct {
 	Enabled bazel.BoolAttribute
 }
 
-func parseSrc(ctx android.BazelConversionPathContext, srcLabelAttribute *bazel.LabelAttribute, axis bazel.ConfigurationAxis, config string, srcs []string) {
+func parseSrc(ctx android.Bp2buildMutatorContext, srcLabelAttribute *bazel.LabelAttribute, axis bazel.ConfigurationAxis, config string, srcs []string) {
 	srcFileError := func() {
 		ctx.ModuleErrorf("parseSrc: Expected at most one source file for %s %s\n", axis, config)
 	}
@@ -370,7 +370,7 @@ func parseSrc(ctx android.BazelConversionPathContext, srcLabelAttribute *bazel.L
 }
 
 // NOTE: Used outside of Soong repo project, in the clangprebuilts.go bootstrap_go_package
-func Bp2BuildParsePrebuiltLibraryProps(ctx android.BazelConversionPathContext, module *Module, isStatic bool) prebuiltAttributes {
+func Bp2BuildParsePrebuiltLibraryProps(ctx android.Bp2buildMutatorContext, module *Module, isStatic bool) prebuiltAttributes {
 
 	var srcLabelAttribute bazel.LabelAttribute
 	bp2BuildPropParseHelper(ctx, module, &prebuiltLinkerProperties{}, func(axis bazel.ConfigurationAxis, config string, props interface{}) {
@@ -407,7 +407,7 @@ func Bp2BuildParsePrebuiltLibraryProps(ctx android.BazelConversionPathContext, m
 	}
 }
 
-func bp2BuildParsePrebuiltBinaryProps(ctx android.BazelConversionPathContext, module *Module) prebuiltAttributes {
+func bp2BuildParsePrebuiltBinaryProps(ctx android.Bp2buildMutatorContext, module *Module) prebuiltAttributes {
 	var srcLabelAttribute bazel.LabelAttribute
 	bp2BuildPropParseHelper(ctx, module, &prebuiltLinkerProperties{}, func(axis bazel.ConfigurationAxis, config string, props interface{}) {
 		if props, ok := props.(*prebuiltLinkerProperties); ok {
@@ -420,7 +420,7 @@ func bp2BuildParsePrebuiltBinaryProps(ctx android.BazelConversionPathContext, mo
 	}
 }
 
-func bp2BuildParsePrebuiltObjectProps(ctx android.BazelConversionPathContext, module *Module) prebuiltAttributes {
+func bp2BuildParsePrebuiltObjectProps(ctx android.Bp2buildMutatorContext, module *Module) prebuiltAttributes {
 	var srcLabelAttribute bazel.LabelAttribute
 	bp2BuildPropParseHelper(ctx, module, &prebuiltObjectProperties{}, func(axis bazel.ConfigurationAxis, config string, props interface{}) {
 		if props, ok := props.(*prebuiltObjectProperties); ok {
@@ -555,7 +555,7 @@ func parseCommandLineFlags(soongFlags []string, filterOut ...filterOutFn) []stri
 	return result
 }
 
-func (ca *compilerAttributes) bp2buildForAxisAndConfig(ctx android.BazelConversionPathContext, axis bazel.ConfigurationAxis, config string, props *BaseCompilerProperties) {
+func (ca *compilerAttributes) bp2buildForAxisAndConfig(ctx android.Bp2buildMutatorContext, axis bazel.ConfigurationAxis, config string, props *BaseCompilerProperties) {
 	// If there's arch specific srcs or exclude_srcs, generate a select entry for it.
 	// TODO(b/186153868): do this for OS specific srcs and exclude_srcs too.
 	srcsList, ok := parseSrcs(ctx, props)
@@ -680,7 +680,7 @@ func (ca *compilerAttributes) finalize(ctx android.BazelConversionPathContext, i
 }
 
 // Parse srcs from an arch or OS's props value.
-func parseSrcs(ctx android.BazelConversionPathContext, props *BaseCompilerProperties) (bazel.LabelList, bool) {
+func parseSrcs(ctx android.Bp2buildMutatorContext, props *BaseCompilerProperties) (bazel.LabelList, bool) {
 	anySrcs := false
 	// Add srcs-like dependencies such as generated files.
 	// First create a LabelList containing these dependencies, then merge the values with srcs.
@@ -1265,7 +1265,7 @@ var (
 
 // resolveTargetApex re-adds the shared and static libs in target.apex.exclude_shared|static_libs props to non-apex variant
 // since all libs are already excluded by default
-func (la *linkerAttributes) resolveTargetApexProp(ctx android.BazelConversionPathContext, props *BaseLinkerProperties) {
+func (la *linkerAttributes) resolveTargetApexProp(ctx android.Bp2buildMutatorContext, props *BaseLinkerProperties) {
 	excludeSharedLibs := bazelLabelForSharedDeps(ctx, props.Target.Apex.Exclude_shared_libs)
 	sharedExcludes := bazel.LabelList{Excludes: excludeSharedLibs.Includes}
 	sharedExcludesLabelList := bazel.LabelListAttribute{}
@@ -1696,7 +1696,7 @@ func (la *linkerAttributes) convertStripProps(ctx android.BazelConversionPathCon
 	})
 }
 
-func (la *linkerAttributes) convertProductVariables(ctx android.BazelConversionPathContext, productVariableProps android.ProductConfigProperties) {
+func (la *linkerAttributes) convertProductVariables(ctx android.Bp2buildMutatorContext, productVariableProps android.ProductConfigProperties) {
 
 	type productVarDep struct {
 		// the name of the corresponding excludes field, if one exists
@@ -1704,7 +1704,7 @@ func (la *linkerAttributes) convertProductVariables(ctx android.BazelConversionP
 		// reference to the bazel attribute that should be set for the given product variable config
 		attribute *bazel.LabelListAttribute
 
-		depResolutionFunc func(ctx android.BazelConversionPathContext, modules, excludes []string) bazel.LabelList
+		depResolutionFunc func(ctx android.Bp2buildMutatorContext, modules, excludes []string) bazel.LabelList
 	}
 
 	// an intermediate attribute that holds Header_libs info, and will be appended to
@@ -1762,7 +1762,7 @@ func (la *linkerAttributes) convertProductVariables(ctx android.BazelConversionP
 	la.implementationDeps.Append(headerDeps)
 }
 
-func (la *linkerAttributes) finalize(ctx android.BazelConversionPathContext) {
+func (la *linkerAttributes) finalize(ctx android.Bp2buildMutatorContext) {
 	// if system dynamic deps have the default value, any use of a system dynamic library used will
 	// result in duplicate library errors for bionic OSes. Here, we explicitly exclude those libraries
 	// from bionic OSes and the no config case as these libraries only build for bionic OSes.
@@ -1903,39 +1903,39 @@ func xsdConfigCppTarget(xsd android.XsdConfigBp2buildTargets) string {
 	return xsd.CppBp2buildTargetName()
 }
 
-func bazelLabelForWholeDeps(ctx android.BazelConversionPathContext, modules []string) bazel.LabelList {
-	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForStaticWholeModuleDeps)
+func bazelLabelForWholeDeps(ctx android.Bp2buildMutatorContext, modules []string) bazel.LabelList {
+	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForStaticWholeModuleDeps, true)
 }
 
-func bazelLabelForWholeDepsExcludes(ctx android.BazelConversionPathContext, modules, excludes []string) bazel.LabelList {
+func bazelLabelForWholeDepsExcludes(ctx android.Bp2buildMutatorContext, modules, excludes []string) bazel.LabelList {
 	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForStaticWholeModuleDeps)
 }
 
-func bazelLabelForStaticDepsExcludes(ctx android.BazelConversionPathContext, modules, excludes []string) bazel.LabelList {
+func bazelLabelForStaticDepsExcludes(ctx android.Bp2buildMutatorContext, modules, excludes []string) bazel.LabelList {
 	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForStaticModule)
 }
 
-func bazelLabelForStaticDeps(ctx android.BazelConversionPathContext, modules []string) bazel.LabelList {
-	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForStaticModule)
+func bazelLabelForStaticDeps(ctx android.Bp2buildMutatorContext, modules []string) bazel.LabelList {
+	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForStaticModule, true)
 }
 
-func bazelLabelForSharedDeps(ctx android.BazelConversionPathContext, modules []string) bazel.LabelList {
-	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForSharedModule)
+func bazelLabelForSharedDeps(ctx android.Bp2buildMutatorContext, modules []string) bazel.LabelList {
+	return android.BazelLabelForModuleDepsWithFn(ctx, modules, bazelLabelForSharedModule, true)
 }
 
-func bazelLabelForHeaderDeps(ctx android.BazelConversionPathContext, modules []string) bazel.LabelList {
+func bazelLabelForHeaderDeps(ctx android.Bp2buildMutatorContext, modules []string) bazel.LabelList {
 	// This is not elegant, but bp2build's shared library targets only propagate
 	// their header information as part of the normal C++ provider.
 	return bazelLabelForSharedDeps(ctx, modules)
 }
 
-func bazelLabelForHeaderDepsExcludes(ctx android.BazelConversionPathContext, modules, excludes []string) bazel.LabelList {
+func bazelLabelForHeaderDepsExcludes(ctx android.Bp2buildMutatorContext, modules, excludes []string) bazel.LabelList {
 	// This is only used when product_variable header_libs is processed, to follow
 	// the pattern of depResolutionFunc
 	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForSharedModule)
 }
 
-func bazelLabelForSharedDepsExcludes(ctx android.BazelConversionPathContext, modules, excludes []string) bazel.LabelList {
+func bazelLabelForSharedDepsExcludes(ctx android.Bp2buildMutatorContext, modules, excludes []string) bazel.LabelList {
 	return android.BazelLabelForModuleDepsExcludesWithFn(ctx, modules, excludes, bazelLabelForSharedModule)
 }
 
diff --git a/cc/library.go b/cc/library.go
index e66ce08e6..90d91ca0e 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -547,54 +547,6 @@ func (includes *apiIncludes) addDep(name string) {
 	includes.attrs.Deps.Append(lla)
 }
 
-// includes provided to the module-lib API surface. This API surface is used by apexes.
-func getModuleLibApiIncludes(ctx android.TopDownMutatorContext, c *Module) apiIncludes {
-	flagProps := c.library.(*libraryDecorator).flagExporter.Properties
-	linkProps := c.library.(*libraryDecorator).baseLinker.Properties
-	includes := android.FirstUniqueStrings(flagProps.Export_include_dirs)
-	systemIncludes := android.FirstUniqueStrings(flagProps.Export_system_include_dirs)
-	headerLibs := android.FirstUniqueStrings(linkProps.Export_header_lib_headers)
-	attrs := bazelCcLibraryHeadersAttributes{
-		Export_includes:        bazel.MakeStringListAttribute(includes),
-		Export_system_includes: bazel.MakeStringListAttribute(systemIncludes),
-		Deps:                   bazel.MakeLabelListAttribute(apiHeaderLabels(ctx, headerLibs)),
-	}
-
-	return apiIncludes{
-		name: c.Name() + ".module-libapi.headers",
-		attrs: bazelCcApiLibraryHeadersAttributes{
-			bazelCcLibraryHeadersAttributes: attrs,
-		},
-	}
-}
-
-func getVendorApiIncludes(ctx android.TopDownMutatorContext, c *Module) apiIncludes {
-	baseProps := c.library.(*libraryDecorator).flagExporter.Properties
-	llndkProps := c.library.(*libraryDecorator).Properties.Llndk
-	includes := baseProps.Export_include_dirs
-	systemIncludes := baseProps.Export_system_include_dirs
-	// LLNDK can override the base includes
-	if llndkIncludes := llndkProps.Override_export_include_dirs; llndkIncludes != nil {
-		includes = llndkIncludes
-	}
-	if proptools.Bool(llndkProps.Export_headers_as_system) {
-		systemIncludes = append(systemIncludes, includes...)
-		includes = nil
-	}
-
-	attrs := bazelCcLibraryHeadersAttributes{
-		Export_includes:        bazel.MakeStringListAttribute(includes),
-		Export_system_includes: bazel.MakeStringListAttribute(systemIncludes),
-		Deps:                   bazel.MakeLabelListAttribute(apiHeaderLabels(ctx, llndkProps.Export_llndk_headers)),
-	}
-	return apiIncludes{
-		name: c.Name() + ".vendorapi.headers",
-		attrs: bazelCcApiLibraryHeadersAttributes{
-			bazelCcLibraryHeadersAttributes: attrs,
-		},
-	}
-}
-
 // cc_library creates both static and/or shared libraries for a device and/or
 // host. By default, a cc_library has a single variant that targets the device.
 // Specifying `host_supported: true` also creates a library that targets the
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index 56c57b94c..3a8417461 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -580,15 +580,6 @@ type bazelCcApiContributionAttributes struct {
 	Library_name string
 }
 
-// Names of the cc_api_header targets in the bp2build workspace
-func apiHeaderLabels(ctx android.TopDownMutatorContext, hdrLibs []string) bazel.LabelList {
-	addSuffix := func(ctx android.BazelConversionPathContext, module blueprint.Module) string {
-		label := android.BazelModuleLabel(ctx, module)
-		return android.ApiContributionTargetName(label)
-	}
-	return android.BazelLabelForModuleDepsWithFn(ctx, hdrLibs, addSuffix)
-}
-
 func ndkLibraryBp2build(ctx android.Bp2buildMutatorContext, c *Module) {
 	ndk, _ := c.linker.(*stubDecorator)
 	props := bazel.BazelTargetModuleProperties{
diff --git a/cc/test.go b/cc/test.go
index 8c63dc614..f128187d2 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -799,7 +799,7 @@ func testBinaryBp2build(ctx android.Bp2buildMutatorContext, m *Module) {
 
 // cc_test that builds using gtest needs some additional deps
 // addImplicitGtestDeps makes these deps explicit in the generated BUILD files
-func addImplicitGtestDeps(ctx android.BazelConversionPathContext, attrs *testBinaryAttributes, gtest, gtestIsolated bool) {
+func addImplicitGtestDeps(ctx android.Bp2buildMutatorContext, attrs *testBinaryAttributes, gtest, gtestIsolated bool) {
 	addDepsAndDedupe := func(lla *bazel.LabelListAttribute, modules []string) {
 		moduleLabels := android.BazelLabelForModuleDeps(ctx, modules)
 		lla.Value.Append(moduleLabels)