Allow soong config value variables to set nested properties

Previously, it would error out if it saw anything that wasn't a string
or slice of strings. Now it will also recurse in sub-structs.

Fixes: 326255534
Test: go test
Change-Id: Icbca8e4a2cf54b5610599a10805550fed05eb396

android/soongconfig/modules.go

@@ -681,6 +681,14 @@ func (s *valueVariable) PropertiesToApply(config SoongConfig, values reflect.Val
 	if !propStruct.IsValid() {
 		return nil, nil
 	}
+	if err := s.printfIntoPropertyRecursive(nil, propStruct, configValue); err != nil {
+		return nil, err
+	}
+
+	return values.Interface(), nil
+}
+
+func (s *valueVariable) printfIntoPropertyRecursive(fieldName []string, propStruct reflect.Value, configValue string) error {
 	for i := 0; i < propStruct.NumField(); i++ {
 		field := propStruct.Field(i)
 		kind := field.Kind()
@@ -695,23 +703,31 @@ func (s *valueVariable) PropertiesToApply(config SoongConfig, values reflect.Val
 		case reflect.String:
 			err := printfIntoProperty(field, configValue)
 			if err != nil {
-				return nil, fmt.Errorf("soong_config_variables.%s.%s: %s", s.variable, propStruct.Type().Field(i).Name, err)
+				fieldName = append(fieldName, propStruct.Type().Field(i).Name)
+				return fmt.Errorf("soong_config_variables.%s.%s: %s", s.variable, strings.Join(fieldName, "."), err)
 			}
 		case reflect.Slice:
 			for j := 0; j < field.Len(); j++ {
 				err := printfIntoProperty(field.Index(j), configValue)
 				if err != nil {
-					return nil, fmt.Errorf("soong_config_variables.%s.%s: %s", s.variable, propStruct.Type().Field(i).Name, err)
+					fieldName = append(fieldName, propStruct.Type().Field(i).Name)
+					return fmt.Errorf("soong_config_variables.%s.%s: %s", s.variable, strings.Join(fieldName, "."), err)
 				}
 			}
 		case reflect.Bool:
 			// Nothing to do
+		case reflect.Struct:
+			fieldName = append(fieldName, propStruct.Type().Field(i).Name)
+			if err := s.printfIntoPropertyRecursive(fieldName, field, configValue); err != nil {
+				return err
+			}
+			fieldName = fieldName[:len(fieldName)-1]
 		default:
-			return nil, fmt.Errorf("soong_config_variables.%s.%s: unsupported property type %q", s.variable, propStruct.Type().Field(i).Name, kind)
+			fieldName = append(fieldName, propStruct.Type().Field(i).Name)
+			return fmt.Errorf("soong_config_variables.%s.%s: unsupported property type %q", s.variable, strings.Join(fieldName, "."), kind)
 		}
 	}
-
-	return values.Interface(), nil
+	return nil
 }
 
 func printfIntoProperty(propertyValue reflect.Value, configValue string) error {

android/soongconfig/modules_test.go

@@ -429,6 +429,76 @@ func Test_PropertiesToApply_Value(t *testing.T) {
 	}
 }
 
+func Test_PropertiesToApply_Value_Nested(t *testing.T) {
+	mt, _ := newModuleType(&ModuleTypeProperties{
+		Module_type:      "foo",
+		Config_namespace: "bar",
+		Value_variables:  []string{"my_value_var"},
+		Properties:       []string{"a.b"},
+	})
+	type properties struct {
+		A struct {
+			B string
+		}
+	}
+	conditionsDefault := &properties{
+		A: struct{ B string }{
+			B: "default",
+		},
+	}
+	type valueVarProps struct {
+		A struct {
+			B string
+		}
+		Conditions_default *properties
+	}
+	actualProps := &struct {
+		Soong_config_variables valueSoongConfigVars
+	}{
+		Soong_config_variables: valueSoongConfigVars{
+			My_value_var: &valueVarProps{
+				A: struct{ B string }{
+					B: "A.B=%s",
+				},
+				Conditions_default: conditionsDefault,
+			},
+		},
+	}
+	props := reflect.ValueOf(actualProps)
+
+	testCases := []struct {
+		name      string
+		config    SoongConfig
+		wantProps []interface{}
+	}{
+		{
+			name:      "no_vendor_config",
+			config:    Config(map[string]string{}),
+			wantProps: []interface{}{conditionsDefault},
+		},
+		{
+			name:   "value_var_set",
+			config: Config(map[string]string{"my_value_var": "Hello"}),
+			wantProps: []interface{}{&properties{
+				A: struct{ B string }{
+					B: "A.B=Hello",
+				},
+			}},
+		},
+	}
+
+	for _, tc := range testCases {
+		gotProps, err := PropertiesToApply(mt, props, tc.config)
+		if err != nil {
+			t.Errorf("%s: Unexpected error in PropertiesToApply: %s", tc.name, err)
+		}
+
+		if !reflect.DeepEqual(gotProps, tc.wantProps) {
+			t.Errorf("%s: Expected %s, got %s", tc.name, tc.wantProps, gotProps)
+		}
+	}
+}
+
 func Test_PropertiesToApply_String_Error(t *testing.T) {
 	mt, _ := newModuleType(&ModuleTypeProperties{
 		Module_type:      "foo",