Most likely it is your GTK+ theme. Many GTK+ themes and theme engines abuse floating point calculations which go unnoticed normally since the vast majority of C/C++ programs do not check for them. The solution is to do something like (IIRC):
SetExceptionMask([]); Which disables all floating point exceptions. Alternatively switch to a theme that doesn't mess FP calculations, bu you can't guarantee that your users will have it. On Thu, Mar 7, 2013 at 10:04 AM, Xiangrong Fang <xrf...@gmail.com> wrote: > 2013/3/7 leledumbo <leledumbo_c...@yahoo.co.id> > > >> Because setting the mask means telling the processor to generate (or not >> to >> generate? I forgot) SIGFPE for the given operations. e.g. exZeroDivide may >> trigger SIGFPE if there's a division by zero with floating point >> operation. >> How to trace? You already get it, the program will report the line that >> causes it, you can directly go to the respective line to see what happens. >> But this requires that the code lies in the program space (not in external >> library) and the code is compiled with runtime error backtrace (-gl). >> Otherwise, the program can only report as deep as it can find. >> > > I don't understand: > > 1) even if I set the masks, why an empty LCL application generate SIGFPE? > It means that somewhere GTK or whatever library *indeed* do things like > 1/0, only that they are normally hidden/not reported? > > 2) I already found the problem in my code which is a like look like: > > *if tbLog.Down then Y := exp(Y);* > > And Y is a big number e.g. 2500, which caused floating point overflow. > The problem was that the number itself should be Log()ed, so that exp() > only restore its original value. That was my bug, but the weird thing is > that SIGFPE is generated in unit LCLType on the line that set font height, > which is very innocent, and after I commented out the font.Height > operation, the SIGFPE slipped to somewhere else, but NEVER on the line that > generated it! > > Could you explain why? and how to locate where the SIGFPE occurred? > > Thanks! > > > > -- > _______________________________________________ > Lazarus mailing list > Lazarus@lists.lazarus.freepascal.org > http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus > >
-- _______________________________________________ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
