The Blag Switch

Okay, so I absolutely hate Magic Code. That is, to say, code that either fixes or breaks a project, module, etc. with no real reason. For instance:

//fLog is a FILE opened elsewhere using a call to fopen

if(fLog)

{

    DoStuff();

}

else

{

    printf("%i\n",GetLastError());

} The code above is a somewhat redacted version something I was working on the other day. As it’s displayed there, DoStuff() will execute. This means that fLog opened fine. If, on the other hand, I comment out the printf statement in the else case, DoStuff() fails to execute, because fLog doesn’t open. In short: commenting out a debugging printf in an else case causes the call to fopen to fail. Why? I have NO IDEA. As a result the following line now mars my code:

printf("%i\n", GetLastError());  //Magic code

And I it drives me insane. The module’s working. It’s been unit tested and it works perfectly every time. Unless I remove one little printf statement. A printf statement which never fires. A printf which falls in an else block after the line which it “fixes”. A printf which shouldn’t have, nay, CAN’T have any effect whatsoever on the line in question. And yet if I remove said printf, the call to fopen fails and the whole module breaks. Inexplicable. Infuriating. Magic code.

This entry was posted on Saturday, July 5th, 2008 at 8:29 pm and is filed under Geekery. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.