Make sure prebuilt modules are exported before attempting to use them

Fixes an issue where prebuilt module under unexported soong
namespace overrides source modules when flag `prefer` was set.

Test: Create two modules under the same name, use cc_library_shared
      for first one and cc_prebuilt_library_shared with `prefer` set
      to true.
      Then put the prebuilt module under `soong_namespace {}` and
      attempt to compile it without appending the namespace path to
      product namespaces.
      Without this change it should fail to resolve the
      cc_library_shared module even if it should be available.

Change-Id: I506641218e6af94a0b5f048e09e06d83602e50f5

1 files changed, 10 insertions, 3 deletions

diff --git a/android/prebuilt.go b/android/prebuilt.go
index dfab13b92..340d286d8 100644
--- a/android/prebuilt.go
+++ b/android/prebuilt.go
@@ -230,12 +230,12 @@ func PrebuiltSelectModuleMutator(ctx TopDownMutatorContext) {
 			panic(fmt.Errorf("prebuilt module did not have InitPrebuiltModule called on it"))
 		}
 		if !p.properties.SourceExists {
-			p.properties.UsePrebuilt = p.usePrebuilt(ctx, nil)
+			p.properties.UsePrebuilt = p.usePrebuilt(ctx, nil, m)
 		}
 	} else if s, ok := ctx.Module().(Module); ok {
 		ctx.VisitDirectDepsWithTag(PrebuiltDepTag, func(m Module) {
 			p := m.(PrebuiltInterface).Prebuilt()
-			if p.usePrebuilt(ctx, s) {
+			if p.usePrebuilt(ctx, s, m) {
 				p.properties.UsePrebuilt = true
 				s.SkipInstall()
 			}
@@ -270,11 +270,18 @@ func PrebuiltPostDepsMutator(ctx BottomUpMutatorContext) {
 
 // usePrebuilt returns true if a prebuilt should be used instead of the source module.  The prebuilt
 // will be used if it is marked "prefer" or if the source module is disabled.
-func (p *Prebuilt) usePrebuilt(ctx TopDownMutatorContext, source Module) bool {
+func (p *Prebuilt) usePrebuilt(ctx TopDownMutatorContext, source Module, prebuilt Module) bool {
 	if p.srcsSupplier != nil && len(p.srcsSupplier()) == 0 {
 		return false
 	}
 
+	// Skip prebuilt modules under unexported namespaces so that we won't
+	// end up shadowing non-prebuilt module when prebuilt module under same
+	// name happens to have a `Prefer` property set to true.
+	if !prebuilt.ExportedToMake() {
+		return false
+	}
+
 	// TODO: use p.Properties.Name and ctx.ModuleDir to override preference
 	if Bool(p.properties.Prefer) {
 		return true