Merge changes I167b47a1,I7ebd3330,Ifc8116e1

* changes:
  Fix snapshot of a host/device cc_library with stubs
  Adds support for 'ignored-on-host'
  Detect invalid arch specific properties in snapshot

1 files changed, 16 insertions, 1 deletions

diff --git a/android/sdk.go b/android/sdk.go
index 873e08942..e823106e8 100644
--- a/android/sdk.go
+++ b/android/sdk.go
@@ -342,9 +342,24 @@ type SdkMemberType interface {
 	//
 	// * The variant property structs are analysed to find exported (capitalized) fields which
 	//   have common values. Those fields are cleared and the common value added to the common
-	//   properties. A field annotated with a tag of `sdk:"keep"` will be treated as if it
+	//   properties.
+	//
+	//   A field annotated with a tag of `sdk:"keep"` will be treated as if it
 	//   was not capitalized, i.e. not optimized for common values.
 	//
+	//   A field annotated with a tag of `android:"arch_variant"` will be allowed to have
+	//   values that differ by arch, fields not tagged as such must have common values across
+	//   all variants.
+	//
+	// * Additional field tags can be specified on a field that will ignore certain values
+	//   for the purpose of common value optimization. A value that is ignored must have the
+	//   default value for the property type. This is to ensure that significant value are not
+	//   ignored by accident. The purpose of this is to allow the snapshot generation to reflect
+	//   the behavior of the runtime. e.g. if a property is ignored on the host then a property
+	//   that is common for android can be treated as if it was common for android and host as
+	//   the setting for host is ignored anyway.
+	//   * `sdk:"ignored-on-host" - this indicates the property is ignored on the host variant.
+	//
 	// * The sdk module type populates the BpModule structure, creating the arch specific
 	//   structure and calls AddToPropertySet(...) on the properties struct to add the member
 	//   specific properties in the correct place in the structure.