stack problem

I got a working program compiled with gcc 3.44 but when I compiled it again using 4.44 there's something wrong. Some of the local variables in a function seems to be modified by unknown so that a for loop will not terminate because variable in its condition is constantly changing to 0 even if it's incremented. Calling a function under the loop seems to be okay because it returned to a correct address. I tried tr开发者_高级运维acing the value of the variable in which the loop is affected, I found out the the value is modified after calling a print function under an if branch, removing or adding more print call solves it but I think it has nothing to do with the print function and there's no code that modify that variable except only the increment in the loop. I also tried tracing esp at the beginning and end of the loop, it is the same. What could have caused the problem?

You stated that you're going from GCC v3.44 (where the code works) to v4.44 where the code is broken.

Make sure that all other parts of the program (all source files and library files) are also compiled with GCC v4.44. You're calling a print function, so I'm guessing you're referring to the standard printf function in glibc. So make sure that glibc is also compiled under v4.44.

If this is really a problem with your print functions, maybe you are corrupting the stack with some of the parameters of the variadic list? Maybe an assumption that you had about one of the standard data types or enumeration constants doesn't hold any more? Are these your own print functions? Then try to use the __attribute__ extension of gcc to have compile time type checks.