From 16f504a9dca3fe3b70568f67b7d41241ae485288 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:49:04 +0200 Subject: Adding upstream version 7.0.6-dfsg. Signed-off-by: Daniel Baumann --- .../xpcom/string/public/nsObsoleteAString.h | 102 +++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 src/libs/xpcom18a4/xpcom/string/public/nsObsoleteAString.h (limited to 'src/libs/xpcom18a4/xpcom/string/public/nsObsoleteAString.h') diff --git a/src/libs/xpcom18a4/xpcom/string/public/nsObsoleteAString.h b/src/libs/xpcom18a4/xpcom/string/public/nsObsoleteAString.h new file mode 100644 index 00000000..00d5892e --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/string/public/nsObsoleteAString.h @@ -0,0 +1,102 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim:set ts=2 sw=2 sts=2 et cindent: */ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is Mozilla. + * + * The Initial Developer of the Original Code is IBM Corporation. + * Portions created by IBM Corporation are Copyright (C) 2003 + * IBM Corporation. All Rights Reserved. + * + * Contributor(s): + * Darin Fisher + * + * Alternatively, the contents of this file may be used under the terms of + * either the GNU General Public License Version 2 or later (the "GPL"), or + * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +#ifndef nsObsoleteAString_h___ +#define nsObsoleteAString_h___ + +/* + STRING INTERNALS + + This file defines nsObsoleteAString and nsObsoleteACString. These are + abstract classes (interfaces), containing only virtual functions + corresponding to the FROZEN nsA[C]String classes. They exist to provide + the new non-abstract nsA[C]String classes with a mechanism to maintain + backwards binary compatability. + + From a binary point-of-view, the new nsA[C]String classes appear to have a + vtable pointer to the vtable of nsObsoleteA[C]StringThunk. + nsObsoleteA[C]StringThunk is a subclass of nsObsoleteA[C]String that serves + as a simple bridge between the virtual functions that make up the FROZEN + nsA[C]String contract and the new ns[C]Substring, which is now our only + subclass of nsA[C]String. + + The methods on the new nsA[C]String are now all non-virtual. This reduces + codesize at the callsite, and reduces the number of memory dereferences and + jumps required to invoke a method on nsA[C]String. The result is improved + performance and reduced codesize. However, to maintain binary + compatibility, each method on nsA[C]String must check the value of its + vtable to determine if it corresponds to the built-in implementation of + nsObsoleteA[C]String (i.e., the address of the canonical vtable). If it + does, then the vtable can be ignored, and the nsA[C]String object (i.e., + |this|) can be cast to ns[C]Substring directly. In which case, the + nsA[C]String methods can be satisfied by invoking the corresponding methods + directly on ns[C]Substring. If the vtable address does not correspond to + the built-in implementation, then the virtual functions on + nsObsoleteA[C]String must be invoked instead. + + So, if a nsA[C]String reference corresponds to an external implementation + (such as the old nsEmbed[C]String that shipped with previous versions of + Mozilla), then methods invoked on that nsA[C]String will still act like + virtual function calls. This ensures binary compatibility while avoiding + virtual function calls in most cases. + + Finally, nsObsoleteA[C]String (i.e., the FROZEN nsA[C]String vtable) is + now a DEPRECATED interface. See nsStringAPI.h and nsEmbedString.h for + the new preferred way to access nsA[C]String references in an external + component or Gecko embedding application. + */ + +#ifndef nsStringFwd_h___ +#include "nsStringFwd.h" +#endif + +#ifndef nscore_h___ +#include "nscore.h" +#endif + + // declare nsObsoleteAString +#include "string-template-def-unichar.h" +#include "nsTObsoleteAString.h" +#include "string-template-undef.h" + + // declare nsObsoleteACString +#include "string-template-def-char.h" +#include "nsTObsoleteAString.h" +#include "string-template-undef.h" + +#endif // !defined(nsObsoleteAString_h___) -- cgit v1.2.3