On 5/9/12 12:33 PM, "ext Olivier Goffart" <oliv...@woboq.com> wrote:
>On Wednesday 09 May 2012 11:28:30 Giuseppe D'Angelo wrote: >> On 9 May 2012 10:22, Olivier Goffart <oliv...@woboq.com> wrote: >> > On Wednesday 09 May 2012 09:45:31 Andreas Holzammer wrote: >> >> Hi, >> >> >> >> I was hitting qtxmlpatterns not compiling, because Exceptions are not >> >> enabled by default for Windows CE. My guess is that this was done for >> >> performance and or security reasons. >> >> >> >> I would like to propose that we enable the Exceptions for Windows CE >>for >> >> Qt5 as default. If you have concerns, comments or issues with that, >> >> please answer to this mail and explain it. >> > >> > You can enable exceptions only in xmlpattern. They are not suppose to >> > "traverse" other layers of Qt. >> > >> > In particular, Qt does not play well with exceptions. They won't pass >> > trough the event loop, and most of the Qt code is not exceptions safe >> > (code often do not expect a signal to throw) >> > >> > So it is probably better to leave them disabled, as exceptions still >>add >> > lot of code to the binary, and that won't be of any use >> >> I think the point here is that >> 1) xmlpatterns doesn't build under any platform if exceptions are >> disabled (it won't "expose" exceptions in its API / propagate them, >> but it uses them internally); >> 2) WinCE *always* get exceptions disabled. >> >> While 1) is of course a design decision (so far, so good) what's the >> reason for 2)? Prevent a massive code expansion? Broken MS compilers? > >Yes. My point is that one can add in the xmlpatterns.pro the proper flags >to >build with exception. But leave the exceptions disabled for the rest of >Qt >which does not need it. > >Maybe the compilers used to be broken (I don't know). But i hope that by >now >compilers have been fixed. >I suppose the reason was mainly performence. Actually I wonder why we don't compile all of Qt with exceptions disabled by default and enable them only for the places they are really needed (QtCore for exception safe signal/slot connections etc, and QtXmlPatterns because it uses them). Can anybody come up with a good reason not to do this? The other option would be to fix the -no-exceptions configure flag to mean no exceptions, except where they are really needed. Lars _______________________________________________ Development mailing list Development@qt-project.org http://lists.qt-project.org/mailman/listinfo/development
