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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>This is my function that seems to cause this more than anything else… it’s ridiculously simple… <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Function ExtractFilePathAndNameWithoutExt(Filenametouse:String):String;<o:p></o:p></p><p class=MsoNormal>Begin<o:p></o:p></p><p class=MsoNormal> ExtractFilePathAndNameWithoutExt := copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1);<o:p></o:p></p><p class=MsoNormal>End;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I stuck a bunch of Writeln’s in it to try to figure out what the heck is happening… my normal response when I need to track something down and the debug information is not clear.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Function ExtractFilePathAndNameWithoutExt(Filenametouse:String):String;<o:p></o:p></p><p class=MsoNormal>Begin<o:p></o:p></p><p class=MsoNormal> Writeln('Filenametouse: ',Filenametouse);<o:p></o:p></p><p class=MsoNormal> Writeln('ExtractFileExt(Filenametouse): ',ExtractFileExt(Filenametouse));<o:p></o:p></p><p class=MsoNormal> Writeln('rpos(ExtractFileExt(Filenametouse),Filenametouse): ',rpos(ExtractFileExt(Filenametouse),Filenametouse));<o:p></o:p></p><p class=MsoNormal> Writeln('Length(Filenametouse): ',Length(Filenametouse));<o:p></o:p></p><p class=MsoNormal> Writeln('copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1): ',copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1));<o:p></o:p></p><p class=MsoNormal> ExtractFilePathAndNameWithoutExt := copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1);<o:p></o:p></p><p class=MsoNormal>End;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The results I get when it fails are :<o:p></o:p></p><p class=MsoNormal> Writeln('Filenametouse: ',Filenametouse); This gives me what I expect: a valid filename with full path<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> Writeln('ExtractFileExt(Filenametouse): ',ExtractFileExt(Filenametouse)); This gives me what I expect: the extension only from the above file name<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> Writeln('rpos(ExtractFileExt(Filenametouse),Filenametouse): ',rpos(ExtractFileExt(Filenametouse),Filenametouse)); This is what’s causing the error… strangely it does the Writeln AFTER the error.. I don’t understand how that can even happen.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I tested this selecting the same 3 files over and over until it failed. Here is the Console output showing the last good set and the failre:<o:p></o:p></p><p class=MsoNormal>-------------------------------------- Console Output-----------------------------<o:p></o:p></p><p class=MsoNormal>M:\<o:p></o:p></p><p class=MsoNormal>elipse_1.dpax<o:p></o:p></p><p class=MsoNormal>elipse_2.dpax<o:p></o:p></p><p class=MsoNormal>elipse_3.dpax<o:p></o:p></p><p class=MsoNormal>4 Files Selected<o:p></o:p></p><p class=MsoNormal>Filenametouse: M:\elipse_1.dpax<o:p></o:p></p><p class=MsoNormal>ExtractFileExt(Filenametouse): .dpax<o:p></o:p></p><p class=MsoNormal>rpos(ExtractFileExt(Filenametouse),Filenametouse): 12<o:p></o:p></p><p class=MsoNormal>Length(Filenametouse): 16<o:p></o:p></p><p class=MsoNormal>copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1): M:\elipse_1<o:p></o:p></p><p class=MsoNormal>Drawing: M:\elipse_1<o:p></o:p></p><p class=MsoNormal>Filenametouse: M:\elipse_2.dpax<o:p></o:p></p><p class=MsoNormal>ExtractFileExt(Filenametouse): .dpax<o:p></o:p></p><p class=MsoNormal>rpos(ExtractFileExt(Filenametouse),Filenametouse): 12<o:p></o:p></p><p class=MsoNormal>Length(Filenametouse): 16<o:p></o:p></p><p class=MsoNormal>copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1): M:\elipse_2<o:p></o:p></p><p class=MsoNormal>Drawing: M:\elipse_2<o:p></o:p></p><p class=MsoNormal>Filenametouse: M:\elipse_3.dpax<o:p></o:p></p><p class=MsoNormal>ExtractFileExt(Filenametouse): .dpax<o:p></o:p></p><p class=MsoNormal>rpos(ExtractFileExt(Filenametouse),Filenametouse): 12<o:p></o:p></p><p class=MsoNormal>Length(Filenametouse): 16<o:p></o:p></p><p class=MsoNormal>copy(Filenametouse,1,rpos(ExtractFileExt(Filenametouse),Filenametouse)-1): M:\elipse_3<o:p></o:p></p><p class=MsoNormal>Drawing: M:\elipse_3<o:p></o:p></p><p class=MsoNormal>M:\<o:p></o:p></p><p class=MsoNormal>elipse_1.dpax<o:p></o:p></p><p class=MsoNormal>elipse_2.dpax<o:p></o:p></p><p class=MsoNormal>elipse_3<o:p></o:p></p><p class=MsoNormal>4 Files Selected<o:p></o:p></p><p class=MsoNormal>Filenametouse: M:\elipse_1.dpax<o:p></o:p></p><p class=MsoNormal>ExtractFileExt(Filenametouse): .dpax<o:p></o:p></p><p class=MsoNormal>An unhandled exception occurred at $0040ED1A:<o:p></o:p></p><p class=MsoNormal>EAccessViolation: Access violation<o:p></o:p></p><p class=MsoNormal> $0040ED1A<o:p></o:p></p><p class=MsoNormal> $004026DB main, line 119 of i:/programming/gcode/mill/plotdraw.pax.pas<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>rpos(ExtractFileExt(Filenametouse),Filenametouse):<o:p></o:p></p><p class=MsoNormal>--------------------------------------End Console Output-----------------------------<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Does anyone have any idea at all why RPOS could not determine that the position of .dpax in M:\elipse_1.dpax was 12 like every other time I ran this???????????? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I ran this while looking at task manager and it starts up with 9.2MB of memory and that stays consistent, so I don’t think I have a memory leak anywhere. Any ideas?? I’m running on Windows 10, compiling with FPC 3.0.4RC1 with the FPC text IDE.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>James<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> fpc-pascal <fpc-pascal-bounces@lists.freepascal.org> <b>On Behalf Of </b>James Richters<br><b>Sent:</b> Tuesday, May 21, 2019 7:35 AM<br><b>To:</b> 'FPC-Pascal users discussions' <fpc-pascal@lists.freepascal.org><br><b>Subject:</b> [fpc-pascal] Debug Advice needed<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have this program that is confounding me. It obtains a file name with GetOpenFileNameA then it processes the file and draws stuff on the screen, then loops back and gets another file name until GetOpenFileNameA returns a false… so as long as I keep giving it files it keeps running and if I cancel the file selection, it exits. It will run in a loop like this various numbers of times… sometimes 4 times, sometimes 8 times, sometimes twice, sometimes 30 times and then I get this access violation like this:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>An unhandled exception occurred at $0040ED07:<o:p></o:p></p><p class=MsoNormal>EAccessViolation: Access violation<o:p></o:p></p><p class=MsoNormal> $0040ED07<o:p></o:p></p><p class=MsoNormal> $00411A6C<o:p></o:p></p><p class=MsoNormal> $00411F25<o:p></o:p></p><p class=MsoNormal> $00402255 PLOTDRAWPAX, line 76 of i:/programming/gcode/mill/plotdraw.pax.pas<o:p></o:p></p><p class=MsoNormal> $00402705 main, line 119 of i:/programming/gcode/mill/plotdraw.pax.pas<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Line 76 is the a call to a procedure in another unit that’s very complicated and calls a lot of other functions and procedures.<o:p></o:p></p><p class=MsoNormal>I keep testing with the same 5 files over and over, and each file has processed fine many times so there isn’t a problem with the data in my files or the way I am processing it…. and there doesn’t seem to be a particular file that causes this. I’m thinking I have some memory issue or something is not freeing or ? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It’s also not always the same exact message.. sometimes I get <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>An unhandled exception occurred at $0040ED07:<o:p></o:p></p><p class=MsoNormal>EAccessViolation: Access violation<o:p></o:p></p><p class=MsoNormal> $0040ED07<o:p></o:p></p><p class=MsoNormal> $004026DB main, line 118 of i:/programming/gcode/mill/plotdraw.pax.pas<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Line 118 is a call to a function that is in no way related to the procedure that is called on line 76… it’s actually a ridiculously simple function. Exactly one line of code to it, and I have run that function millions of times with other programs that use the same unit.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The FPC text IDE is reporting runtime error 217 which doesn’t tell me much.. just an unhandled exception occurred.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>My question is… how do I track these kinds of things down? Is there a way I can use the hex addresses to see more precisely what caused the error? <o:p></o:p></p><p class=MsoNormal>I’m confused why sometimes I get very detailed debug reports that get me to the exact command that caused the problem and other times I have some information but then it just stops and I have nothing following the hex addresses.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>James<o:p></o:p></p></div></body></html>