1 files changed, 143 insertions, 0 deletions
diff --git a/src/qml/jsruntime/qv4exception_gcc.cpp b/src/qml/jsruntime/qv4exception_gcc.cpp
new file mode 100644
index 0000000000..0324a06e0b
--- /dev/null
+++ b/src/qml/jsruntime/qv4exception_gcc.cpp
@@ -0,0 +1,143 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4exception_p.h"
+
+#include <unwind.h>
+#include <cxxabi.h>
+#include <bits/atomic_word.h>
+#include <typeinfo>
+#include <exception>
+
+/*
+ * This is a little bit hacky as it relies on the fact that exceptions are
+ * reference counted in libstdc++ and that affects the layout of the standardized
+ * cxa_exception, making it bigger. LLVM's libcxxabi stores the reference count
+ * differently, so this here is entirely GNU libstdc++ specific.
+ *
+ * Eliminating this dependency is doable but requires replacing the use of C++ exceptions
+ * with foreign exceptions (a different exception class) and then using __cxa_get_globals
+ * to get hold of the exception inside the catch (...). AFAICS that would be portable.
+ */
+
+namespace {
+
+// 2.1.1 from http://mentorembedded.github.io/cxx-abi/abi-eh.html
+struct cxa_exception {
+    std::type_info *typeInfo;
+    void (*exceptionDestructor)(void*);
+    std::unexpected_handler unexpectedHandler;
+    std::terminate_handler terminateHandler;
+    cxa_exception *nextException;
+    int handlerCount;
+#ifdef __ARM_EABI_UNWINDER__
+    cxa_exception *nextPropagatingException;
+    int propagationCount;
+#else
+    int handlerSwitchValue;
+    const char *actionRecord;
+    const char *languageSpecificData;
+    void *catchTemp;
+    void *adjustedPtr;
+#endif
+    _Unwind_Exception unwindHeader;
+};
+
+// This is what libstdc++ actually allocates
+struct gcc_refcounted_compatible_exception {
+    _Atomic_word refCount;
+    cxa_exception x;
+};
+
+}
+
+static void exception_cleanup(_Unwind_Reason_Code, _Unwind_Exception *ex)
+{
+    gcc_refcounted_compatible_exception *exception = reinterpret_cast<gcc_refcounted_compatible_exception *>(ex + 1) - 1;
+    if (!--exception->refCount) {
+        if (exception->x.exceptionDestructor)
+            exception->x.exceptionDestructor(ex + 1);
+        abi::__cxa_free_exception(ex + 1);
+    }
+}
+
+static void exception_destructor(void *ex)
+{
+    reinterpret_cast<QV4::Exception *>(ex)->~Exception();
+}
+
+QT_BEGIN_NAMESPACE
+
+using namespace QV4;
+
+void Exception::throwInternal(ExecutionContext *throwingContext, const Value &exceptionValue)
+{
+    void *rawException = abi::__cxa_allocate_exception(sizeof(QV4::Exception));
+    gcc_refcounted_compatible_exception *refCountedException = reinterpret_cast<gcc_refcounted_compatible_exception *>(rawException) - 1;
+    cxa_exception *exception = &refCountedException->x;
+
+    (void)new (rawException) Exception(throwingContext, exceptionValue);
+
+    refCountedException->refCount = 1;
+    exception->typeInfo = const_cast<std::type_info*>(&typeid(Exception));
+    exception->exceptionDestructor = &exception_destructor;
+    exception->unexpectedHandler = std::unexpected;
+    exception->terminateHandler = std::terminate;
+    exception->unwindHeader.exception_cleanup = &exception_cleanup;
+#ifdef __ARM_EABI_UNWINDER__
+    exception->unwindHeader.exception_class[0] = 'G';
+    exception->unwindHeader.exception_class[1] = 'N';
+    exception->unwindHeader.exception_class[2] = 'U';
+    exception->unwindHeader.exception_class[3] = 'C';
+    exception->unwindHeader.exception_class[4] = 'C';
+    exception->unwindHeader.exception_class[5] = '+';
+    exception->unwindHeader.exception_class[6] = '+';
+    exception->unwindHeader.exception_class[7] = 0;
+#else
+    exception->unwindHeader.exception_class = 0x474e5543432b2b00; // GNUCC++0
+#endif
+
+    _Unwind_RaiseException(&exception->unwindHeader);
+    abi::__cxa_begin_catch(rawException);
+    std::terminate();
+}
+
+QT_END_NAMESPACE