Config variables reader
Fixes: 182330871
Test: go test config_variables_test.go
Change-Id: I89240fb0f1900172cb4d62057c86907bb9a1f58f
diff --git a/mk2rbc/config_variables.go b/mk2rbc/config_variables.go
new file mode 100644
index 0000000..dac509c
--- /dev/null
+++ b/mk2rbc/config_variables.go
@@ -0,0 +1,67 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mk2rbc
+
+import (
+ "bytes"
+ "fmt"
+ "io/ioutil"
+ "os"
+ "strings"
+
+ mkparser "android/soong/androidmk/parser"
+)
+
+// Extracts the list of product config variables from a file, calling
+// given registrar for each variable.
+func FindConfigVariables(mkFile string, vr variableRegistrar) error {
+ mkContents, err := ioutil.ReadFile(mkFile)
+ if err != nil {
+ return err
+ }
+ parser := mkparser.NewParser(mkFile, bytes.NewBuffer(mkContents))
+ nodes, errs := parser.Parse()
+ if len(errs) > 0 {
+ for _, e := range errs {
+ fmt.Fprintln(os.Stderr, "ERROR:", e)
+ }
+ return fmt.Errorf("cannot parse %s", mkFile)
+ }
+ for _, node := range nodes {
+ asgn, ok := node.(*mkparser.Assignment)
+ if !ok {
+ continue
+ }
+ // We are looking for a variable called '_product_list_vars'
+ // or '_product_single_value_vars'.
+ if !asgn.Name.Const() {
+ continue
+ }
+ varName := asgn.Name.Strings[0]
+ var starType starlarkType
+ if varName == "_product_list_vars" {
+ starType = starlarkTypeList
+ } else if varName == "_product_single_value_vars" {
+ starType = starlarkTypeUnknown
+ } else {
+ continue
+ }
+ for _, name := range strings.Fields(asgn.Value.Dump()) {
+ vr.NewVariable(name, VarClassConfig, starType)
+ }
+
+ }
+ return nil
+}