Have you ever written a program and had a runtime bug that was almost impossible to notice and was a simple typo? Im starting this thread to help anyone with these notorious fiends that plague our code. Here are the ones i have experienced: - Ever get carried away with ; ? Well its legal to write:
and i starts off at 1 not 0. Debug time - 2 days - Ever notice how much a 1 looks like an l? Well a fool of a programmer called llvllatrix didnt. Debug time - 1 week. - Ever copy and paste code? I did once and forgot to change a 1 to a 2. Debug time - 1.5 weeks. Have you ever run into a bug like this? If you have please dial 1-800-999-9999 or post a reply to this thread. Keeping the net clean of the nets most wanted bugs(ominous music) is everyones responsibility.

hehe... Just a couple of days ago I was tracking down a bug that was damn hard to find. I was allocating memory for an array, and I was allocating to little, and when I ran the application it just stopped. I tried to debug it, but VC++ 6.0, adds extra memory around large arrays like that, so I couldn''t find the error when I was debugging! But I eventually found out, after 1 or 2 days, I think.

One thign that I have found is that the most complex bugs are often caused by errors. I now try to compile everything and test it all the time... Before, I would spend 3 hours programming a new class and then debug it. It was impossible to find bugs they componded eachother and made very wierd things happen. Now I''ll program each function one at a time, and test them with some dummy app as I go along. This reduces my debug time a lot.

Also, bugs that are linked to functions that are time independent are VERY hard to debug.... Don''t remember what it was, but I do remember it took like 1 week to find one bug that was related to time...


Dwiel

I don''t do this quite as often nowadays, but a few years ago I used to do these classic beginners mistakes (especially since I emigrated from QBASIC)

if (val1 = val2){  //Wonder why this always happens...?} 

Or this one

if (val1 == 2);{  //This always happens too...wtf?} 

/John

Here's one.

unsigned char i;for (i=0; i<256; i++){// infinite loop!!???}  

[edited by - Waverider on March 12, 2003 4:57:42 PM]

How about *iNumber++;

When what you really meant to do is increment the value that iNumber was pointing at, not to increment the pointer...

When I did this, took me a weekend to find the bug, especially because it didn't bomb in debug.

Order of operation..

(*iNumber)++;







[edited by - Ickno on March 12, 2003 8:14:37 PM]

unsigned int i;
for (i=100; i>0; i++) {
// wondered why this never exited
}

The sad thing is, that I make that typo too regularly

-----------------------
"When I have a problem on an Nvidia, I assume that it is my fault. With anyone else''s drivers, I assume it is their fault" - John Carmack

Something that always trips me up is forgetting to use the new operator e.g

CLog *gameLog; //Normally in a separate header/class

gameLog->Print("Error");

//?WTF is this crashing?

obviously thats simplified I''m not that stupid, but the first time I did it it took me a weekend to solve. Now it takes 5 minutes.



Hyperdev

"To err is human, to really mess up requires a computer"

My hardest bug was something like this:


I did this because I want to write SU_Log("Value: %d", n);
and macros don''t support variable number of parameters (I think)
Then I wrote:


When a was 0, SU_LogStoreTemps was not called but SU_LogA was called...
So in the log I found:
main.cpp(00044)::WinMain - ...
but the SU_Log command was in filesystem.cpp



PM

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Times change...

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Excuse my poor english!

Hey, let me post again here for a change. A simple mistake I''ll never make again, at a moment i was just not too bright :

procedure whatever;var MyClassInstance : TMyClass;begin	MyClassInstance.Create; // Heh, calling a constructor doesn''t really work that way 		// For the non-Delphi programmers, that should have been :	MyClassInstance := TMyClass.Create;end; 

What also tends to get me stuck is the difference between an amount of objects, and their reference. For example, the following code :

procedure Something;var ADynamicArray : Array of Boolean;var Counter : Byte;begin	// The following sets the array to a length of 10 elements	SetLength(ADynamicArray, 10); 	// But I tend to forget that those elements are 0 to 9, not 0 to 10 :	for Counter := 0 to 10 do ADynamicArray[Counter] := false;end;