Introduce StringImpl::createPreallocatedStatic

third_party/WebKit/Source/build/scripts/templates/MakeQualifiedNames.cpp.tmpl

 {% from "macros.tmpl" import license %}
 {{ license() }}
 
 #include "config.h"
 
 #include "{{namespace}}Names.h"
 
 #include "wtf/StaticConstructors.h"
 #include "wtf/StdLibExtras.h"
 
@@ skipping 36 matching lines @@
     OwnPtr<const QualifiedName*[]> attrs = adoptArrayPtr(new const QualifiedName*[{{namespace}}AttrsCount]);
     for (size_t i = 0; i < {{namespace}}AttrsCount; i++)
         attrs[i] = reinterpret_cast<QualifiedName*>(&{{suffix}}AttrStorage) + i;
     return attrs.release();
 }
 {% endif %}
 
 
 void init()
 {
-    struct NameEntry {
-        const char* name;
-        unsigned hash;
-        unsigned char length;
-        unsigned char isTag;
-        unsigned char isAttr;
-    };
-
     // Use placement new to initialize the globals.
     AtomicString {{namespace_prefix}}NS("{{namespace_uri}}", AtomicString::ConstructFromLiteral);
 
     // Namespace
     new ((void*)&{{namespace_prefix}}NamespaceURI) AtomicString({{namespace_prefix}}NS);
     {% set tagnames = tags|map(attribute='name')|list() %}
     {% set attrnames = attrs|map(attribute='name')|list() %}
-    static const NameEntry kNames[] = {
+    const int kMaxNameLength = {{(tagnames + attrnames)|map('length')|max}} + 1;
+    struct NameEntry {
+        // StringImpl instances are created at |stringImplStorage| in-place.
+        // |name| must be placed soon after |stringImplStorage| to match the memory layout requirement of StringImpl.
+        char stringImplStorage[sizeof(StringImpl)];
+        char name[kMaxNameLength];
+        unsigned hash;
+        unsigned char length;
+        unsigned char isTag;
+        unsigned char isAttr;
+    };
+
+    static NameEntry kNames[] = {
     {% for name, tag_list in (tags + attrs)|groupby('name')|sort(attribute=0, case_sensitive=True) %}
-        { "{{name}}", {{name|hash}}, {{name|length}}, {{ (name in tagnames)|int }}, {{ (name in attrnames)|int }} },
+        { "", "{{name}}", {{name|hash}}, {{name|length}}, {{ (name in tagnames)|int }}, {{ (name in attrnames)|int }} },
     {% endfor %}
     };
 
     {% if tags %}
     size_t tag_i = 0;
     {% endif %}
     size_t attr_i = 0;
     for (size_t i = 0; i < WTF_ARRAY_LENGTH(kNames); i++) {
-        StringImpl* stringImpl = StringImpl::createStatic(kNames[i].name, kNames[i].length, kNames[i].hash);
+        StringImpl* stringImpl = StringImpl::createPreallocatedStatic(kNames[i].stringImplStorage, kNames[i].length, kNames[i].hash);
         {% if tags %}
         if (kNames[i].isTag) {
             void* address = reinterpret_cast<{{namespace}}QualifiedName*>(&{{suffix}}TagStorage) + tag_i;
             QualifiedName::createStatic(address, stringImpl, {{namespace_prefix}}NS);
             tag_i++;
         }
 
         if (!kNames[i].isAttr)
             continue;
         {% endif %}
         void* address = reinterpret_cast<QualifiedName*>(&{{suffix}}AttrStorage) + attr_i;
         {% if use_namespace_for_attrs %}
         QualifiedName::createStatic(address, stringImpl, {{namespace_prefix}}NS);
         {% else %}
         QualifiedName::createStatic(address, stringImpl);
         {% endif %}
         attr_i++;
     }
     {% if tags %}
     ASSERT(tag_i == {{namespace}}TagsCount);
     {% endif %}
     ASSERT(attr_i == {{namespace}}AttrsCount);
 }
 
 } // {{namespace}}
 } // namespace blink