Change v4 exceptions to use the common C++ ABIs foreign exceptions

On platforms where we use the common C++ ABI, throw the exception not using a
dummy C++ exception structure and the throw keyboard, but instead use the
lower-level _Unwind_RaiseException to throw a foreign exception.  It is caught
with the existing "catch (...)" and re-throw is implemented similarly, by
grabbing the current exception from the globals (a standardized data structure)
and re-throwing it.

On platforms such as ARM that lack hooks for supplying our unwind tables to the
system run-time, this patch will make it possible to link the unwinder
statically into libQtQml (libgcc or libunwind) and thus force it to use our
unwind tables, because throwing or re-throwing will always go through our
statically linked code through direct calls to _Unwind_RaiseException (instead
of libstdc++).

Change-Id: Ic2ac056fc7ed9e93fb51e30ab45f35b260487c5f
Reviewed-by: Lars Knoll <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 78bf662c26..4bba0bfbd1 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -648,7 +648,7 @@ void ExecutionContext::throwUnimplemented(const QString &message)
 ReturnedValue ExecutionContext::catchException(StackTrace *trace)
 {
     if (!engine->hasException)
-        throw;
+        Exception::rethrow();
     while (engine->current != this)
         engine->popContext();
     if (trace)
@@ -666,7 +666,7 @@ void ExecutionContext::rethrowException()
         while (engine->current != this)
             engine->popContext();
     }
-    throw;
+    Exception::rethrow();
 }
 
 void ExecutionContext::throwReferenceError(const ValueRef value)