Merge "Expose ParseBool from libbase"

base/Android.bp

@@ -58,6 +58,7 @@ cc_defaults {
         "file.cpp",
         "logging.cpp",
         "mapped_file.cpp",
+        "parsebool.cpp",
         "parsenetaddress.cpp",
         "process.cpp",
         "properties.cpp",
@@ -149,6 +150,7 @@ cc_test {
         "macros_test.cpp",
         "mapped_file_test.cpp",
         "parsedouble_test.cpp",
+        "parsebool_test.cpp",
         "parseint_test.cpp",
         "parsenetaddress_test.cpp",
         "process_test.cpp",

base/include/android-base/parsebool.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <string_view>
+
+namespace android {
+namespace base {
+
+// Parse the given string as yes or no inactivation of some sort. Return one of the
+// ParseBoolResult enumeration values.
+//
+// The following values parse as true:
+//
+//   1
+//   on
+//   true
+//   y
+//   yes
+//
+//
+// The following values parse as false:
+//
+//   0
+//   false
+//   n
+//   no
+//   off
+//
+// Anything else is a parse error.
+//
+// The purpose of this function is to have a single canonical parser for yes-or-no indications
+// throughout the system.
+
+enum class ParseBoolResult {
+  kError,
+  kFalse,
+  kTrue,
+};
+
+ParseBoolResult ParseBool(std::string_view s);
+
+}  // namespace base
+}  // namespace android

base/parsebool.cpp

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include "android-base/parsebool.h"
+#include <errno.h>
+
+namespace android {
+namespace base {
+
+ParseBoolResult ParseBool(std::string_view s) {
+  if (s == "1" || s == "y" || s == "yes" || s == "on" || s == "true") {
+    return ParseBoolResult::kTrue;
+  }
+  if (s == "0" || s == "n" || s == "no" || s == "off" || s == "false") {
+    return ParseBoolResult::kFalse;
+  }
+  return ParseBoolResult::kError;
+}
+
+}  // namespace base
+}  // namespace android

base/parsebool_test.cpp

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include "android-base/parsebool.h"
+
+#include <errno.h>
+
+#include <gtest/gtest.h>
+#include <string_view>
+
+using android::base::ParseBool;
+using android::base::ParseBoolResult;
+
+TEST(parsebool, true_) {
+  static const char* yes[] = {
+      "1", "on", "true", "y", "yes",
+  };
+  for (const char* s : yes) {
+    ASSERT_EQ(ParseBoolResult::kTrue, ParseBool(s));
+  }
+}
+
+TEST(parsebool, false_) {
+  static const char* no[] = {
+      "0", "false", "n", "no", "off",
+  };
+  for (const char* s : no) {
+    ASSERT_EQ(ParseBoolResult::kFalse, ParseBool(s));
+  }
+}
+
+TEST(parsebool, invalid) {
+  ASSERT_EQ(ParseBoolResult::kError, ParseBool("blarg"));
+  ASSERT_EQ(ParseBoolResult::kError, ParseBool(""));
+}

base/properties.cpp

@@ -28,19 +28,22 @@
 #include <map>
 #include <string>
 
+#include <android-base/parsebool.h>
 #include <android-base/parseint.h>
 
 namespace android {
 namespace base {
 
 bool GetBoolProperty(const std::string& key, bool default_value) {
-  std::string value = GetProperty(key, "");
-  if (value == "1" || value == "y" || value == "yes" || value == "on" || value == "true") {
-    return true;
-  } else if (value == "0" || value == "n" || value == "no" || value == "off" || value == "false") {
-    return false;
+  switch (ParseBool(GetProperty(key, ""))) {
+    case ParseBoolResult::kError:
+      return default_value;
+    case ParseBoolResult::kFalse:
+      return false;
+    case ParseBoolResult::kTrue:
+      return true;
   }
-  return default_value;
+  __builtin_unreachable();
 }
 
 template <typename T>