Changeset 4206 in webkit for trunk/JavaScriptCore/kjs/identifier.cpp

Timestamp:

Apr 29, 2003, 11:26:29 AM (22 years ago)

Author:

darin

Message:

Reviewed by John.

• fixed 2959353 -- eliminate globally initialized objects from JavaScriptCore

• JavaScriptCore.pbproj/project.pbxproj: Added fpconst.cpp.
• kjs/fpconst.cpp: Added. Defines KJS::NaN and KJS::Inf in a way that does not require a framework init routine.

• kjs/identifier.h: Use a new KJS_IDENTIFIER_EACH_GLOBAL macro so we can do things to the entire set of identifiers easily. Also added an init function that sets up these globals in a way that does not require a framework init routine.
• kjs/identifier.cpp: (Identifier::init): Initialize the property ane globals in a way that does not require a framework init routine.

• kjs/internal.cpp: (InterpreterImp::initGlobalObject): Call Identifier::init.

• kjs/ustring.h: Remove UChar::null and UString::null, and add UString::null(). We can't have a global object of a class that has a constructor if we want to avoid framework init routines, and luckily very little code relies on these.
• kjs/ustring.cpp: (UCharReference::ref): Use our own global specific to this function rather than returning UChar::null when past the end of the string. This is dangerous because if the caller modifies it, that affects what all subsequent callers will see. (UString::Rep::create): Added assertions. (UString::UString): Got rid of code here that used to set up UString::null. (UString::null): Added. Returns a global null string, and can be used in some of the places where we used to use the UString::null global. (UString::operator[]): Fixed case where this used to return UChar::null to return '\0' instead.

• kjs/regexp.cpp: (RegExp::match): Change uses of UString::null to UString::null().

File:

• trunk/JavaScriptCore/kjs/identifier.cpp (modified) (3 diffs)

trunk/JavaScriptCore/kjs/identifier.cpp

@@ -20 +20 @@
  */
 
+// For JavaScriptCore we need to avoid having static constructors.
+// Our strategy is to declare the global objects with a different type (initialized to 0)
+// and then use placement new to initialize the global objects later. This is not completely
+// portable, and it would be good to figure out a 100% clean way that still avoids code that
+// runs at init time.
+
+#if APPLE_CHANGES
+#define AVOID_STATIC_CONSTRUCTORS 1
+#endif
+
+#if AVOID_STATIC_CONSTRUCTORS
+#define KJS_IDENTIFIER_HIDE_GLOBALS 1
+#endif
+
 #include "identifier.h"
 
@@ -43 +57 @@
 
 #endif
-
-extern const Identifier argumentsPropertyName("arguments");
-extern const Identifier calleePropertyName("callee");
-extern const Identifier constructorPropertyName("constructor");
-extern const Identifier lengthPropertyName("length");
-extern const Identifier messagePropertyName("message");
-extern const Identifier namePropertyName("name");
-extern const Identifier prototypePropertyName("prototype");
-extern const Identifier specialPrototypePropertyName("__proto__");
-extern const Identifier toLocaleStringPropertyName("toLocaleString");
-extern const Identifier toStringPropertyName("toString");
-extern const Identifier valueOfPropertyName("valueOf");
 
 const int _minTableSize = 64;
@@ -301 +303 @@
 }
 
+// Global constants for property name strings.
+
+#if !AVOID_STATIC_CONSTRUCTORS
+    // Define an Identifier in the normal way.
+    #define DEFINE_GLOBAL(name, string) extern const Identifier name ## PropertyName(string);
+#else
+    // Define an Identifier-sized array of pointers to avoid static initialization.
+    // Use an array of pointers instead of an array of char in case there is some alignment issue.
+    #define DEFINE_GLOBAL(name, string) \
+        void * name ## PropertyName[(sizeof(Identifier) + sizeof(void *) - 1) / sizeof(void *)];
+#endif
+
+#define CALL_DEFINE_GLOBAL(name) DEFINE_GLOBAL(name, #name)
+KJS_IDENTIFIER_EACH_GLOBAL(CALL_DEFINE_GLOBAL)
+DEFINE_GLOBAL(specialPrototype, "__proto__")
+
+void Identifier::init()
+{
+#if AVOID_STATIC_CONSTRUCTORS
+    static bool initialized;
+    if (!initialized) {
+        // Use placement new to initialize the globals.
+        #define PLACEMENT_NEW_GLOBAL(name, string) new (&name ## PropertyName) Identifier(string);
+        #define CALL_PLACEMENT_NEW_GLOBAL(name) PLACEMENT_NEW_GLOBAL(name, #name)
+        KJS_IDENTIFIER_EACH_GLOBAL(CALL_PLACEMENT_NEW_GLOBAL)
+        PLACEMENT_NEW_GLOBAL(specialPrototype, "__proto__")
+        initialized = true;
+    }
+#endif
+}
+
 } // namespace KJS