[fpc-pascal] showing source linenumbers on exceptions

[Peter Vreman]

> hi,
>
> how can i show source line numbers, when an exception occurs, like
> sysutils do?
> ...
> An unhandled exception occurred at $0040E9B5 :
> EInOutError : Invalid filename
>   $0040E9B5  TDXF__LOAD,  line 271 of dxffile.pas
>   $0040EFFA  TDXF__CREATE,  line 329 of dxffile.pas
>   $0040F24A  TPAPER__CREATE,  line 48 of dxfpaper.pas
>   $00401459  INIT_OBJECTS,  line 63 of e:/_development/work/dxf2mcr.pas
>   $00401529  INITPROC,  line 87 of e:/_development/work/dxf2mcr.pas
>   $00401F1F  INIT_FRAMEWORK,  line 107 of
> E:/_development/units/uframe_sdlogl.pas
> ...
>
> the only thing i found is the ShowExeption proc. but this does not write
> what i expected.
> ...
> exception at 0040EA45:
>                       Invalid filename.
> ...
>
> is there a possibility to do this on my own?
> if found the proc:
> ...
> Procedure CatchUnhandledException (Obj : TObject; Addr: Pointer;
> FrameCount: Longint; Frames:
> PPointer);[public,alias:'FPC_BREAK_UNHANDLED_EXCEPTION'];
> ...
> but i don't how to set FrameCount and Frames.

The current code in svn trunk contains an ExceptFrames and
ExceptFramecount function to return this information. See the lazarus code
how to use the functions.