Disable all host OS variants except those explicitly included.

Necessary to avoid problems with implicitly enabled host OS'es, e.g.
linux_glibc getting enabled when we only supply a linux_bionic linker
in runtime-module-host-exports. That will then cause a non-functional
prebuilt to take precedence over source if the prebuilt is preferred.

We don't do this for device since we so far only support a single
device OS (android).

This introduces the notion that SDK member types can be host OS
dependent or not. That way java members with host prebuilts don't get
restricted to a specific host OS.

Test: m nothing
Test: build/soong/scripts/build-aml-prebuilts.sh runtime-module-host-exports
  Check that the generated Android.bp correctly disables the bionic
  linker prebuilt for linux_glibc.
Test: art/build/apex/runtests.sh
  on master-art with an updated runtime SDK snapshot
Test: art/tools/buildbot-build.sh {--host,--target}
  on master-art with an updated runtime SDK snapshot
Bug: 160349757
Change-Id: Idad7ef138cdbcbd209d390bf6c10ca8365d4619f

1 files changed, 52 insertions, 6 deletions

diff --git a/sdk/update.go b/sdk/update.go
index 25d50d217..936696a01 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -262,7 +262,7 @@ func (s *sdk) buildSnapshot(ctx android.ModuleContext, sdkVariants []*sdk) andro
 		memberCtx := &memberContext{ctx, builder, memberType, member.name}
 
 		prebuiltModule := memberType.AddPrebuiltModule(memberCtx, member)
-		s.createMemberSnapshot(memberCtx, member, prebuiltModule)
+		s.createMemberSnapshot(memberCtx, member, prebuiltModule.(*bpModule))
 	}
 
 	// Create a transformer that will transform an unversioned module into a versioned module.
@@ -345,12 +345,37 @@ func (s *sdk) buildSnapshot(ctx android.ModuleContext, sdkVariants []*sdk) andro
 		snapshotModule.AddProperty("compile_multilib", commonVariantProperties.Compile_multilib)
 	}
 
-	// Iterate over the os types in a fixed order.
 	targetPropertySet := snapshotModule.AddPropertySet("target")
+
+	// If host is supported and any member is host OS dependent then disable host
+	// by default, so that we can enable each host OS variant explicitly. This
+	// avoids problems with implicitly enabled OS variants when the snapshot is
+	// used, which might be different from this run (e.g. different build OS).
+	hasHostOsDependentMember := false
+	if s.HostSupported() {
+		for _, memberRef := range memberRefs {
+			if memberRef.memberType.IsHostOsDependent() {
+				hasHostOsDependentMember = true
+				break
+			}
+		}
+		if hasHostOsDependentMember {
+			hostPropertySet := targetPropertySet.AddPropertySet("host")
+			hostPropertySet.AddProperty("enabled", false)
+		}
+	}
+
+	// Iterate over the os types in a fixed order.
 	for _, osType := range s.getPossibleOsTypes() {
 		if sdkVariant, ok := osTypeToMemberProperties[osType]; ok {
 			osPropertySet := targetPropertySet.AddPropertySet(sdkVariant.Target().Os.Name)
 
+			// Enable the variant explicitly when we've disabled it by default on host.
+			if hasHostOsDependentMember &&
+				(osType.Class == android.Host || osType.Class == android.HostCross) {
+				osPropertySet.AddProperty("enabled", true)
+			}
+
 			variantProps := variantToProperties[sdkVariant]
 			if variantProps.Compile_multilib != "" && variantProps.Compile_multilib != "both" {
 				osPropertySet.AddProperty("compile_multilib", variantProps.Compile_multilib)
@@ -993,9 +1018,12 @@ func (osInfo *osTypeSpecificInfo) addToPropertySet(ctx *memberContext, bpModule
 	var osPropertySet android.BpPropertySet
 	var archPropertySet android.BpPropertySet
 	var archOsPrefix string
-	if osInfo.Properties.Base().Os_count == 1 {
-		// There is only one os type present in the variants so don't bother
-		// with adding target specific properties.
+	if osInfo.Properties.Base().Os_count == 1 &&
+		(osInfo.osType.Class == android.Device || !ctx.memberType.IsHostOsDependent()) {
+		// There is only one OS type present in the variants and it shouldn't have a
+		// variant-specific target. The latter is the case if it's either for device
+		// where there is only one OS (android), or for host and the member type
+		// isn't host OS dependent.
 
 		// Create a structure that looks like:
 		// module_type {
@@ -1032,6 +1060,12 @@ func (osInfo *osTypeSpecificInfo) addToPropertySet(ctx *memberContext, bpModule
 		osPropertySet = targetPropertySet.AddPropertySet(osType.Name)
 		archPropertySet = targetPropertySet
 
+		// Enable the variant explicitly when we've disabled it by default on host.
+		if ctx.memberType.IsHostOsDependent() &&
+			(osType.Class == android.Host || osType.Class == android.HostCross) {
+			osPropertySet.AddProperty("enabled", true)
+		}
+
 		// Arch specific properties need to be added to an os and arch specific
 		// section prefixed with <os>_.
 		archOsPrefix = osType.Name + "_"
@@ -1202,7 +1236,7 @@ func (m *memberContext) Name() string {
 	return m.name
 }
 
-func (s *sdk) createMemberSnapshot(ctx *memberContext, member *sdkMember, bpModule android.BpModule) {
+func (s *sdk) createMemberSnapshot(ctx *memberContext, member *sdkMember, bpModule *bpModule) {
 
 	memberType := member.memberType
 
@@ -1256,6 +1290,18 @@ func (s *sdk) createMemberSnapshot(ctx *memberContext, member *sdkMember, bpModu
 	// added.
 	targetPropertySet := bpModule.AddPropertySet("target")
 
+	// If the member is host OS dependent and has host_supported then disable by
+	// default and enable each host OS variant explicitly. This avoids problems
+	// with implicitly enabled OS variants when the snapshot is used, which might
+	// be different from this run (e.g. different build OS).
+	if ctx.memberType.IsHostOsDependent() {
+		hostSupported := bpModule.getValue("host_supported") == true // Missing means false.
+		if hostSupported {
+			hostPropertySet := targetPropertySet.AddPropertySet("host")
+			hostPropertySet.AddProperty("enabled", false)
+		}
+	}
+
 	// Iterate over the os types in a fixed order.
 	for _, osType := range s.getPossibleOsTypes() {
 		osInfo := osTypeToInfo[osType]