Hi All Below is a series of exchanges with Myles that I though was on the list (but wasn't). I particular, I posed some questions (below "sigh. Not found") which I would greatly appreciate some wider feedback on.
Mark PS what do you have to do to respond to the group, rather than just the respondant? ------- Forwarded message follows ------- Better post that one to the list ... 1. Not that common. 2. It should do - but no guarantees. 3. Yes. Myles. -----Original Message----- From: Mark Howard [mailto:[EMAIL PROTECTED] Sent: Wednesday, 3 December 2003 11:26 To: Myles Penlington Subject: RE: [DUG] Making use of AV error messages Sigh Not found. 2 questions (anyone else feel free to chime in and take the heat off Myles!) 1. How come my app will run fine on two of the client's PC's, my development PC and my Laptop and not on two of the client's Laptops? Is this behaviour common? 2. If I were to get their laptop here; install Delphi and run the app in the IDE on the laptop, would it necessarily tell me what the laptop is complaining about when it is running the EXE? 3. If so, might that be the simplest way to get to the bottom of this problem - given my complete ignorance of system level debugging? Mark On 3 Dec 2003 at 10:54, Myles Penlington wrote: > Yes. > > -----Original Message----- > From: Mark Howard [mailto:[EMAIL PROTECTED] > Sent: Wednesday, 3 December 2003 10:49 > To: Myles Penlington > Subject: RE: [DUG] Making use of AV error messages > > > It's a very big file to scan visually! > > Part of it is in the form > 0001:0003D12C TMessageForm.CreateNew > 0001:0003D1A4 TMessageForm.HelpButtonClick > 0001:0003D1BC TMessageForm.CustomKeyDown > 0001:0003D228 TMessageForm.WriteToClipBoard > > Is this where I'm looking? > > If I search for ":00691" or even just ":0069" will that get me > close to what I should be looking for? > > Mark > > On 2 Dec 2003 at 17:15, Myles Penlington wrote: > > > > > You will not find an exact match of the address. > > So look for the method that has a starting address just less than > > $691a42 eg something like $691000 (depends on the size of the > > method). If no methods have addresses of around this value, then > > the program was re-located on the machine, and then the only way > > to find the correct address is from a dr watson dump or one of the > > exception trappers. Myles > > > > -----Original Message----- > > From: Mark Howard [mailto:[EMAIL PROTECTED] > > Sent: Tuesday, 2 December 2003 17:14 > > To: Myles Penlington > > Subject: RE: [DUG] Making use of AV error messages > > > > OK > > > > One thing at a time.. > > > > I have created a .MAP file and searched it for both of the > > references in the error message (ie 00691A42 and 000002F8) and it > > comes up blank. > > > > Was this the idea? > > > > Mark > > > > On 2 Dec 2003 at 16:27, Myles Penlington wrote: > > > > > > > > > > > -----Original Message----- > > > From: Mark Howard [mailto:[EMAIL PROTECTED] > > > Sent: Tuesday, 2 December 2003 16:08 > > > To: Myles Penlington > > > Subject: RE: [DUG] Making use of AV error messages > > > > > > > > > Thanks Myles > > > > > > On 2 Dec 2003 at 15:45, Myles Penlington wrote: > > > > > > > >From this I can say two things. > > > > 1. It is a nil pointer reference - 2F8 is the offset - so it > > > > is quite a large object/array/record (Offset760). > > > What is the significance of this? > > > Because the offset is quite large it will limit your search in > > > terms of objects that could have caused the error. Most objects > > > are less than 200 bytes in size. > > > > > > 2. Create a map file for the > > > > executable. From this you can find the actual method where the > > > > AV happened. > > > OK. Er . . . How do I do this please? > > > Project linker options - check the detailed map box. The > > > alternative is to run your program and then stop/pause it and > > > use search/find error and key in the address $06 ... ie compile > > > to displacement. > > I suspect from the address given, that the > > > application has not been > > > > loaded at a different base address. What is the significance > > > > of > > > this, too.? Just helps in debugging, if the AV was mentioned at > > > say $1023304, and knowing your program is not 64Meg in size, > > > tells you it was loaded at a different address, so the address > > > then given in the AV message is no good - unless you have a dump > > > from Dr Watson that gives the load address, then you can > > > calculate the offset in the code when running on your machine of > > > the actual AV/Code address. > > > > > > Knowing the actual method may not > > > > help, you may need a stack trace instead. So as mentioned last > > > > week get one of the good AV trappers that will output you a > > > > stack trace eg www.madshi.net > > > Am I going to be able to get to the bottom of this doing these > > > things on my development machine, which is not generating these > > > errors? > > > > > > >> Probably not. But you should be able to find the line where > > > >> the error is > > > happening, and knowing that a object variable is nil is a great > > > help - it limits the kind of code to look at. eg this is > > > probably a property reference, using a nil object value. From > > > there you can work backwards to see the possible causes. > > > > > > One other thing - Delphi has issues with printers if the default > > > printer is on a network and the network cable is not plugged in > > > - so this may be a good candidate on a portable computer. If the > > > code is anywhere near the printers unit, then you need to fix > > > the code in here. > > > > > > > > > > > Myles. > > > > > > > > > > > > -----Original Message----- > > > > From: Mark Howard [mailto:[EMAIL PROTECTED] > > > > Sent: Tuesday, 2 December 2003 15:32 > > > > To: [EMAIL PROTECTED] > > > > Subject: [DUG] Making use of AV error messages > > > > > > > > > > > > Hi > > > > > > > > I have a site where my app is installed on a Server along with > > > > it's database. Various workstations have short cuts defined > > > > that point to this single instance of the app on the server. > > > > > > > > The app is running fine on several desktop PC's. They have > > > > recently tried to run it from a Laptop and get an (AV) error > > > > message as it starts up, and after that it runs wonkily, > > > > throwing other errors. (The first Laptop they tried was XP - > > > > then they tried a second that was running Win2K Pro and was in > > > > all other respects a virgin ie no Norton or anything). > > > > > > > > The first message is > > > > "Access violation at address 00691A42 in Module 'PSLog.exe' > > > > Read of address 000002F8 " > > > > > > > > I would like to use this message to try to home in on what > > > > might be causing the errors - but have never (ever) done any > > > > debugging at this level. > > > > > > > > Is it possible that I could be "talked through" whatever is > > > > necessary, or is that to big an ask? It would need to be a a > > > > very basic level. > > > > > > > > Mark > > > > _______________________________________________ > > > > Delphi mailing list > > > > [EMAIL PROTECTED] > > > > http://ns3.123.co.nz/mailman/listinfo/delphi > > > > _______________________________________________ > > > > Delphi mailing list > > > > [EMAIL PROTECTED] > > > > http://ns3.123.co.nz/mailman/listinfo/delphi > > > > > > > > > > _______________________________________________ > > > Delphi mailing list > > > [EMAIL PROTECTED] > > > http://ns3.123.co.nz/mailman/listinfo/delphi > > > > > > > > > -- > > Forest Production Systems Ltd > > Creators of PSLog Harvesting Information System > > Web: www.pslog.co.nz > > ------- End of forwarded message ------- _______________________________________________ Delphi mailing list [EMAIL PROTECTED] http://ns3.123.co.nz/mailman/listinfo/delphi
