Avoid relying on NVRO for HashMap

third_party/WebKit/Source/platform/text/LocaleToScriptMapping.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 25 matching lines @@
 
 namespace blink {
 
 struct SubtagScript {
     const char* subtag;
     UScriptCode script;
 };
 
 using SubtagScriptMap = HashMap<String, UScriptCode, CaseFoldingHash>;
 
-static SubtagScriptMap createSubtagScriptMap(const SubtagScript list[], size_t size)
+static void createSubtagScriptMap(SubtagScriptMap& map, const SubtagScript list[], size_t size)
 {
-    SubtagScriptMap map;
+    map.reserveCapacityForSize(size);
     for (size_t i = 0; i < size; ++i)
         map.set(list[i].subtag, list[i].script);
-    return map;
 }
 
 UScriptCode scriptNameToCode(const String& scriptName)
 {
     // This generally maps an ISO 15924 script code to its UScriptCode, but certain families of script codes are
     // treated as a single script for assigning a per-script font in Settings. For example, "hira" is mapped to
     // USCRIPT_KATAKANA_OR_HIRAGANA instead of USCRIPT_HIRAGANA, since we want all Japanese scripts to be rendered
     // using the same font setting.
     static const SubtagScript scriptNameCodeList[] = {
         { "zyyy", USCRIPT_COMMON },
@@ skipping 96 matching lines @@
         { "syrn", USCRIPT_EASTERN_SYRIAC },
         { "teng", USCRIPT_TENGWAR },
         { "vaii", USCRIPT_VAI },
         { "visp", USCRIPT_VISIBLE_SPEECH },
         { "xsux", USCRIPT_CUNEIFORM },
         { "jpan", USCRIPT_KATAKANA_OR_HIRAGANA },
         { "kore", USCRIPT_HANGUL },
         { "zxxx", USCRIPT_UNWRITTEN_LANGUAGES },
         { "zzzz", USCRIPT_UNKNOWN }
     };
-    DEFINE_STATIC_LOCAL(SubtagScriptMap, scriptNameCodeMap,
-        (createSubtagScriptMap(scriptNameCodeList, WTF_ARRAY_LENGTH(scriptNameCodeList))));
+    DEFINE_STATIC_LOCAL(SubtagScriptMap, scriptNameCodeMap, ());
+    if (scriptNameCodeMap.isEmpty())
+        createSubtagScriptMap(scriptNameCodeMap, scriptNameCodeList, WTF_ARRAY_LENGTH(scriptNameCodeList));
 
     const auto& it = scriptNameCodeMap.find(scriptName);
     if (it != scriptNameCodeMap.end())
         return it->value;
     return USCRIPT_INVALID_CODE;
 }
 
 UScriptCode localeToScriptCodeForFontSelection(const String& locale)
 {
     static const SubtagScript localeScriptList[] = {
@@ skipping 266 matching lines @@
         { "zh-hak", USCRIPT_TRADITIONAL_HAN },
         { "zh-lzh", USCRIPT_TRADITIONAL_HAN },
         { "zh-nan", USCRIPT_TRADITIONAL_HAN },
         { "zh-yue", USCRIPT_TRADITIONAL_HAN },
         // Chinese with regions. Logically, regions should be handled
         // separately, but this works for the current purposes.
         { "zh-hk", USCRIPT_TRADITIONAL_HAN },
         { "zh-mo", USCRIPT_TRADITIONAL_HAN },
         { "zh-tw", USCRIPT_TRADITIONAL_HAN },
     };
-    DEFINE_STATIC_LOCAL(SubtagScriptMap, localeScriptMap,
-        (createSubtagScriptMap(localeScriptList, WTF_ARRAY_LENGTH(localeScriptList))));
+    DEFINE_STATIC_LOCAL(SubtagScriptMap, localeScriptMap, ());
+    if (localeScriptMap.isEmpty())
+        createSubtagScriptMap(localeScriptMap, localeScriptList, WTF_ARRAY_LENGTH(localeScriptList));
 
     // BCP 47 uses '-' as the delimiter but ICU uses '_'.
     // https://tools.ietf.org/html/bcp47
     String canonicalLocale = locale;
     canonicalLocale.replace('_', '-');
     while (!canonicalLocale.isEmpty()) {
         const auto& it = localeScriptMap.find(canonicalLocale);
         if (it != localeScriptMap.end())
             return it->value;
         size_t pos = canonicalLocale.reverseFind('-');
@@ skipping 12 matching lines @@
 
 static UScriptCode scriptCodeForHanFromRegion(const String& region)
 {
     static const SubtagScript regionScriptList[] = {
         { "hk", USCRIPT_TRADITIONAL_HAN },
         { "jp", USCRIPT_KATAKANA_OR_HIRAGANA },
         { "kr", USCRIPT_HANGUL },
         { "mo", USCRIPT_TRADITIONAL_HAN },
         { "tw", USCRIPT_TRADITIONAL_HAN },
     };
-    DEFINE_STATIC_LOCAL(SubtagScriptMap, regionScriptMap,
-        (createSubtagScriptMap(regionScriptList, WTF_ARRAY_LENGTH(regionScriptList))));
+    DEFINE_STATIC_LOCAL(SubtagScriptMap, regionScriptMap, ());
+    if (regionScriptMap.isEmpty())
+        createSubtagScriptMap(regionScriptMap, regionScriptList, WTF_ARRAY_LENGTH(regionScriptList));
 
     const auto& it = regionScriptMap.find(region);
     return it != regionScriptMap.end() ? it->value : USCRIPT_COMMON;
 }
 
 UScriptCode scriptCodeForHanFromSubtags(const String& locale, char delimiter)
 {
     // Some sites emit lang="en-JP" when English is set as the preferred
     // language. Use script/region subtags of the content locale to pick the
     // fallback font for unified Han ideographs.
@@ skipping 12 matching lines @@
             script = scriptNameToCode(locale.substring(begin, len));
             if (script != USCRIPT_INVALID_CODE)
                 return script;
         }
     }
 
     return USCRIPT_COMMON;
 }
 
 } // namespace blink