Move response file handling to a separate package
sbox is going to need to read and write response files, move ReadRspFile
to its own package.
Test: response_test.go
Change-Id: Iecb5486b4aaeb2531828743ad8ef784df675e18e
diff --git a/response/response.go b/response/response.go
new file mode 100644
index 0000000..e8ff4b2
--- /dev/null
+++ b/response/response.go
@@ -0,0 +1,70 @@
+// Copyright 2021 Google Inc. All rights reserved.
+//
+// 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 response
+
+import (
+ "io"
+ "io/ioutil"
+ "unicode"
+)
+
+const noQuote = '\x00'
+
+// ReadRspFile reads a file in Ninja's response file format and returns its contents.
+func ReadRspFile(r io.Reader) ([]string, error) {
+ var files []string
+ var file []byte
+
+ buf, err := ioutil.ReadAll(r)
+ if err != nil {
+ return nil, err
+ }
+
+ isEscaping := false
+ quotingStart := byte(noQuote)
+ for _, c := range buf {
+ switch {
+ case isEscaping:
+ if quotingStart == '"' {
+ if !(c == '"' || c == '\\') {
+ // '\"' or '\\' will be escaped under double quoting.
+ file = append(file, '\\')
+ }
+ }
+ file = append(file, c)
+ isEscaping = false
+ case c == '\\' && quotingStart != '\'':
+ isEscaping = true
+ case quotingStart == noQuote && (c == '\'' || c == '"'):
+ quotingStart = c
+ case quotingStart != noQuote && c == quotingStart:
+ quotingStart = noQuote
+ case quotingStart == noQuote && unicode.IsSpace(rune(c)):
+ // Current character is a space outside quotes
+ if len(file) != 0 {
+ files = append(files, string(file))
+ }
+ file = file[:0]
+ default:
+ file = append(file, c)
+ }
+ }
+
+ if len(file) != 0 {
+ files = append(files, string(file))
+ }
+
+ return files, nil
+}