Revert "Adds support for 'ignored-on-host'"

Revert submission 1302576

Bug: 156054601
Reason for revert: Presumed root cause of build break.
Reverted Changes:
Ifc8116e11:Detect invalid arch specific properties in snapsho...
I7ebd33307:Adds support for 'ignored-on-host'
I167b47a13:Fix snapshot of a host/device cc_library with stub...

Change-Id: I2a7ac0ef0232177eefc26542c11dc675d6f4cab2

android/sdk.go

@@ -351,15 +351,6 @@ type SdkMemberType interface {
 	//   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.

sdk/sdk_test.go

@@ -289,12 +289,9 @@ func TestCommonValueOptimization(t *testing.T) {
 	}
 
 	extractor := newCommonValueExtractor(common)
+	extractor.extractCommonProperties(common, structs)
 
 	h := TestHelper{t}
-
-	err := extractor.extractCommonProperties(common, structs)
-	h.AssertDeepEquals("unexpected error", nil, err)
-
 	h.AssertDeepEquals("common properties not correct",
 		&testPropertiesStruct{
 			name:        "common",

sdk/update.go

@@ -1215,26 +1215,11 @@ func (s *sdk) getPossibleOsTypes() []android.OsType {
 // struct (or one of its embedded structs).
 type fieldAccessorFunc func(structValue reflect.Value) reflect.Value
 
-// Checks the metadata to determine whether the property should be ignored for the
-// purposes of common value extraction or not.
-type extractorMetadataPredicate func(metadata propertiesContainer) bool
-
-// Indicates whether optimizable properties are provided by a host variant or
-// not.
-type isHostVariant interface {
-	isHostVariant() bool
-}
-
 // A property that can be optimized by the commonValueExtractor.
 type extractorProperty struct {
 	// The name of the field for this property.
 	name string
 
-	// Filter that can use metadata associated with the properties being optimized
-	// to determine whether the field should be ignored during common value
-	// optimization.
-	filter extractorMetadataPredicate
-
 	// Retrieves the value on which common value optimization will be performed.
 	getter fieldAccessorFunc
 
@@ -1288,20 +1273,6 @@ func (e *commonValueExtractor) gatherFields(structType reflect.Type, containingS
 			continue
 		}
 
-		var filter extractorMetadataPredicate
-
-		// Add a filter
-		if proptools.HasTag(field, "sdk", "ignored-on-host") {
-			filter = func(metadata propertiesContainer) bool {
-				if m, ok := metadata.(isHostVariant); ok {
-					if m.isHostVariant() {
-						return false
-					}
-				}
-				return true
-			}
-		}
-
 		// Save a copy of the field index for use in the function.
 		fieldIndex := f
 
@@ -1333,7 +1304,6 @@ func (e *commonValueExtractor) gatherFields(structType reflect.Type, containingS
 		} else {
 			property := extractorProperty{
 				name,
-				filter,
 				fieldGetter,
 				reflect.Zero(field.Type),
 				proptools.HasTag(field, "android", "arch_variant"),
@@ -1402,12 +1372,6 @@ func (e *commonValueExtractor) extractCommonProperties(commonProperties interfac
 
 	for _, property := range e.properties {
 		fieldGetter := property.getter
-		filter := property.filter
-		if filter == nil {
-			filter = func(metadata propertiesContainer) bool {
-				return true
-			}
-		}
 
 		// Check to see if all the structures have the same value for the field. The commonValue
 		// is nil on entry to the loop and if it is nil on exit then there is no common value or
@@ -1425,15 +1389,6 @@ func (e *commonValueExtractor) extractCommonProperties(commonProperties interfac
 			itemValue := reflect.ValueOf(container.optimizableProperties())
 			fieldValue := fieldGetter(itemValue)
 
-			if !filter(container) {
-				expectedValue := property.emptyValue.Interface()
-				actualValue := fieldValue.Interface()
-				if !reflect.DeepEqual(expectedValue, actualValue) {
-					return fmt.Errorf("field %q is supposed to be ignored for %q but is set to %#v instead of %#v", property, container, actualValue, expectedValue)
-				}
-				continue
-			}
-
 			if commonValue == nil {
 				// Use the first value as the commonProperties value.
 				commonValue = &fieldValue