[cleanup] Fix objects classes, removing unnecessary copies.

Fixing clang-tidy warning.

Bug: v8:8015
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I722e15193b3b269e94dc8e5aba80f6f73c95cda8
Reviewed-on: https://chromium-review.googlesource.com/1228036
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56109}

src/objects/intl-objects.cc

@@ -1221,15 +1221,15 @@ std::unique_ptr<icu::RegexMatcher> GetAnyExtensionRegexpMatcher() {
 // ECMA 402 9.2.7 LookupSupportedLocales(availableLocales, requestedLocales)
 // https://tc39.github.io/ecma402/#sec-lookupsupportedlocales
 std::vector<std::string> LookupSupportedLocales(
-    std::set<std::string> available_locales,
-    std::vector<std::string> requested_locales) {
+    const std::set<std::string>& available_locales,
+    const std::vector<std::string>& requested_locales) {
   std::unique_ptr<icu::RegexMatcher> matcher = GetAnyExtensionRegexpMatcher();
 
   // 1. Let subset be a new empty List.
   std::vector<std::string> subset;
 
   // 2. For each element locale of requestedLocales in List order, do
-  for (auto locale : requested_locales) {
+  for (const auto& locale : requested_locales) {
     // 2.a. Let noExtensionsLocale be the String value that is locale with all
     //      Unicode locale extension sequences removed.
     icu::UnicodeString locale_uni(locale.c_str(), -1, US_INV);
@@ -1276,8 +1276,8 @@ std::vector<std::string> LookupSupportedLocales(
 // ECMA 402 9.2.8 BestFitSupportedLocales(availableLocales, requestedLocales)
 // https://tc39.github.io/ecma402/#sec-bestfitsupportedlocales
 std::vector<std::string> BestFitSupportedLocales(
-    std::set<std::string> available_locales,
-    std::vector<std::string> requested_locales) {
+    const std::set<std::string>& available_locales,
+    const std::vector<std::string>& requested_locales) {
   return LookupSupportedLocales(available_locales, requested_locales);
 }
 
@@ -1324,9 +1324,9 @@ MaybeHandle<JSObject> CreateReadOnlyArray(Isolate* isolate,
 // ECMA 402 9.2.9 SupportedLocales(availableLocales, requestedLocales, options)
 // https://tc39.github.io/ecma402/#sec-supportedlocales
 MaybeHandle<JSObject> SupportedLocales(
-    Isolate* isolate, std::string service,
-    std::set<std::string> available_locales,
-    std::vector<std::string> requested_locales, Handle<Object> options) {
+    Isolate* isolate, const std::string& service,
+    const std::set<std::string>& available_locales,
+    const std::vector<std::string>& requested_locales, Handle<Object> options) {
   std::vector<std::string> supported_locales;
 
   // 1. If options is not undefined, then

src/objects/js-date-time-format.cc

@@ -32,7 +32,7 @@ namespace {
 class PatternMap {
  public:
   PatternMap(std::string pattern, std::string value)
-      : pattern(pattern), value(value) {}
+      : pattern(std::move(pattern)), value(std::move(value)) {}
   virtual ~PatternMap() = default;
   std::string pattern;
   std::string value;
@@ -42,7 +42,9 @@ class PatternItem {
  public:
   PatternItem(const std::string property, std::vector<PatternMap> pairs,
               std::vector<const char*>* allowed_values)
-      : property(property), pairs(pairs), allowed_values(allowed_values) {}
+      : property(std::move(property)),
+        pairs(std::move(pairs)),
+        allowed_values(allowed_values) {}
   virtual ~PatternItem() = default;
 
   const std::string property;
@@ -102,7 +104,7 @@ class PatternData {
  public:
   PatternData(const std::string property, std::vector<PatternMap> pairs,
               std::vector<const char*>* allowed_values)
-      : property(property), allowed_values(allowed_values) {
+      : property(std::move(property)), allowed_values(allowed_values) {
     for (const auto& pair : pairs) {
       map.insert(std::make_pair(pair.value, pair.pattern));
     }
@@ -180,12 +182,12 @@ void SetPropertyFromPattern(Isolate* isolate, const std::string& pattern,
   //  ii. If hc is "h11" or "h12", let v be true.
   //  iii. Else if, hc is "h23" or "h24", let v be false.
   //  iv. Else, let v be undefined.
-  if (pattern.find("h") != std::string::npos) {
+  if (pattern.find('h') != std::string::npos) {
     CHECK(JSReceiver::CreateDataProperty(
               isolate, options, factory->NewStringFromStaticChars("hour12"),
               factory->true_value(), kDontThrow)
               .FromJust());
-  } else if (pattern.find("H") != std::string::npos) {
+  } else if (pattern.find('H') != std::string::npos) {
     CHECK(JSReceiver::CreateDataProperty(
               isolate, options, factory->NewStringFromStaticChars("hour12"),
               factory->false_value(), kDontThrow)
@@ -702,7 +704,7 @@ std::unique_ptr<icu::Calendar> CreateCalendar(Isolate* isolate,
 
 std::unique_ptr<icu::SimpleDateFormat> CreateICUDateFormat(
     Isolate* isolate, const icu::Locale& icu_locale,
-    const std::string skeleton) {
+    const std::string& skeleton) {
   // See https://github.com/tc39/ecma402/issues/225 . The best pattern
   // generation needs to be done in the base locale according to the
   // current spec however odd it may be. See also crbug.com/826549 .

src/objects/js-relative-time-format.cc

@@ -238,8 +238,8 @@ Handle<String> UnitAsString(Isolate* isolate, URelativeDateTimeUnit unit_enum) {
 }
 
 MaybeHandle<JSArray> GenerateRelativeTimeFormatParts(
-    Isolate* isolate, icu::UnicodeString formatted,
-    icu::UnicodeString integer_part, URelativeDateTimeUnit unit_enum) {
+    Isolate* isolate, const icu::UnicodeString& formatted,
+    const icu::UnicodeString& integer_part, URelativeDateTimeUnit unit_enum) {
   Factory* factory = isolate->factory();
   Handle<JSArray> array = factory->NewJSArray(0);
   int32_t found = formatted.indexOf(integer_part);