Fix for bug 756257 (Replace xpc_qsDOMString with a conversion function in new DOM bindings). r=bz.

--HG--
extra : rebase_source : 3f5ac89f72fade970f9f3505b93e51ac44ee7525

dom/bindings/BindingUtils.h

@@ -669,6 +669,58 @@ protected:
 #endif
 };
 
+enum StringificationBehavior {
+  eStringify,
+  eEmpty,
+  eNull
+};
+
+static inline bool
+ConvertJSValueToString(JSContext* cx, const JS::Value& v, JS::Value* pval,
+                       StringificationBehavior nullBehavior,
+                       StringificationBehavior undefinedBehavior,
+                       nsDependentString& result)
+{
+  JSString *s;
+  if (v.isString()) {
+    s = v.toString();
+  } else {
+    StringificationBehavior behavior;
+    if (v.isNull()) {
+      behavior = nullBehavior;
+    } else if (v.isUndefined()) {
+      behavior = undefinedBehavior;
+    } else {
+      behavior = eStringify;
+    }
+
+    // If pval is null, that means the argument was optional and
+    // not passed; turn those into void strings if they're
+    // supposed to be stringified.
+    if (behavior != eStringify || !pval) {
+      // Here behavior == eStringify implies !pval, so both eNull and
+      // eStringify should end up with void strings.
+      result.SetIsVoid(behavior != eEmpty);
+      return true;
+    }
+
+    s = JS_ValueToString(cx, v);
+    if (!s) {
+      return false;
+    }
+    pval->setString(s);  // Root the new string.
+  }
+
+  size_t len;
+  const jschar *chars = JS_GetStringCharsZAndLength(cx, s, &len);
+  if (!chars) {
+    return false;
+  }
+
+  result.Rebind(chars, len);
+  return true;
+}
+
 } // namespace dom
 } // namespace mozilla
 

dom/bindings/Codegen.py

@@ -1440,12 +1440,11 @@ ${declName}.SwapElements(arr);
             undefinedBehavior = "eStringify"
 
         return (
-            "const xpc_qsDOMString ${declName}(cx, ${val}, ${valPtr},\n"
-            "                           xpc_qsDOMString::%s,\n"
-            "                           xpc_qsDOMString::%s);\n"
-            "if (!${declName}.IsValid()) {\n"
+            "if (!ConvertJSValueToString(cx, ${val}, ${valPtr}, %s, %s, ${holderName})) {\n"
             "  return false;\n"
-            "}" % (nullBehavior, undefinedBehavior), None, None)
+            "}\n"
+            "${declName} = &${holderName};" % (nullBehavior, undefinedBehavior),
+            CGGeneric("NonNull<const nsAString>"), CGGeneric("nsDependentString"))
 
     if type.isEnum():
         if type.nullable():