[Lazarus] CFI in FpDebug

[Pascal Riekenberg]

Hi Joost,

i did this to temporary solve it for me:

 components/fpdebug/fpdbgdwarfdataclasses.pas | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/components/fpdebug/fpdbgdwarfdataclasses.pas b/components/fpdebug/fpdbgdwarfdataclasses.pas
index 67c715b762..e62726658b 100644
--- a/components/fpdebug/fpdbgdwarfdataclasses.pas
+++ b/components/fpdebug/fpdbgdwarfdataclasses.pas
@@ -4019,7 +4019,8 @@ begin
           if FDE32^.Length > 0 then
             begin
             FDE := LoadFDE(CFI, FDE32^.CIEPointer, @FDE32^.InitialLocation, @FDE32^.CIEPointer+FDE32^.Length- at FDE32^.InitialLocation);
-            CFI.AddFDE(FDE);
+            if FDE.InitialLocation <> 0 then
+              CFI.AddFDE(FDE);
             end
           else
             // This should never happen, but it did and it leads to a range-check



Pascal

> Pascal Riekenberg via lazarus <lazarus at lists.lazarus-ide.org> hat am 29.06.2022 09:41 CEST geschrieben:
> 
>  
> Hi Joost,
> 
> i think i have a problem with this. When starting to debug with FpDebug on Windows 10 64bit i get the following error:
> TApplication.HandleException: EListError
> Duplicate ID: 0000000000000000
>   Stack trace:
>   $00000001001EA1CF  Error,  line 383 of maps.pp
>   $00000001001E9DF8  InternalAdd,  line 406 of maps.pp
>   $00000001001EB362  Add,  line 763 of maps.pp
>   $0000000100D686E6  AddFDE,  line 508 of fpdbgdwarfcfi.pas
>   $0000000100D36112  LoadCallFrameInstructions,  line 4022 of fpdbgdwarfdataclasses.pas
>   $0000000100D0CDA0  LoadInfo,  line 1754 of fpdbgclasses.pp
>   $0000000100D0F172  LoadInfo,  line 2392 of fpdbgclasses.pp
>   $0000000100D70706  SendEvents,  line 1808 of fpdbgcontroller.pas
>   $0000000100FB66C8  DebugLoopFinished,  line 3850 of fpdebugdebugger.pas
>   $0000000100FA6B81  LoopFinished_DecRef,  line 677 of fpdebugdebugger.pas
>   $000000010005FD3E  ProcessAsyncCallQueue,  line 1082 of include/application.inc
>   $000000010005DD52  Idle,  line 441 of include/application.inc
>   $0000000100060759  HandleMessage,  line 1281 of include/application.inc
>   $0000000100060E77  RunLoop,  line 1417 of include/application.inc
>   $00000001000CCAD5  AppRun,  line 54 of include/interfacebase.inc
>   $0000000100060E27  Run,  line 1405 of include/application.inc
>   $0000000100003784  $main,  line 154 of lazarus.pp
> 
> Pascal
> 
> > Joost van der Sluis via lazarus <lazarus at lists.lazarus-ide.org> hat am 28.06.2022 23:21 CEST geschrieben:
> > 
> >  
> > Hi all,
> > 
> > I've just pushed a commit that changed the stack-unwinding logic for 
> > FpDebug.
> > 
> > What is new is that when the executable includes Call Frame Information 
> > (CFI) as specified by the Dwarf-format and CFI is available for the a 
> > certain location, the CFI is used to unwind the stack. (x86_64 and i386 
> > only)
> > 
> > Note however, that the CFI generated by FPC is not always correct, but 
> > in those cases is should fallback to the old implementation.
> > 
> > In principle things could only get better. But if not, please tell me.
> > 
> > Regards,
> > 
> > Joost.
> > -- 
> > _______________________________________________
> > lazarus mailing list
> > lazarus at lists.lazarus-ide.org
> > https://lists.lazarus-ide.org/listinfo/lazarus
> -- 
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