Can arguments be corrupted on passing in to function?

Question

Hello,
I'm seeing something that's got me stumped. Maybe you folks can advise.
What appears to be a valid arguments are getting corrupted when passed to a different function.
Here is my set up:
- LibA.a
- LibB.a
- SampleApp
- MyApp
The bad function call is going from LibA in to LibB.
LibA, LibB and SampleApp have all been pre-complied (thankfully in debug mode) by an older version of Sun Studio on Solaris x86/64. SampleApp uses both LibA and LibB and runs just fine on my system.
MyApp uses both LibA and LibB in a manner similar to SampleApp. Yet, MyApp crashes due to this pointer corruption.
When single stepping the code, I see the pointer in the caller being valid and being passed as a parameter. In the callee, the value of the passed-in parameter pointer in simply wrong.
Note: The caller is in the pre-compiled LibA.a and the callee is in the pre-compiled LibB.a I'm never even touching that code to recompile it. Further, the code itself must be correct since SampleApp uses those functions, and runs fine.
Thus, I'm thinking that my error is in the linking stage, but I'm not sure what it could be.
Any ideas?
Thank you,
David
Edited by: 878694 on Aug 11, 2011 3:52 PM

Answer 1

It's impossible to say what is wrong without a fairly complete example, preferably one that could be compiled and run to see the problem. Some generic guesses:
1. Compiler bug. The code should be recompiled with a new compiler where the bug has been fixed. Impossible to say what sort of bug that might be without a test case.
2. As in my original comment, the two libraries see inconsistent declarations. For example, after one library was built, a declaration in a common header was changed and the other library, or some binary in it, was built using the different declaration. This kind of error is common when makefiles do not express all the needed dependencies. The fix is to delete all binaries and recompile everything (to be sure no change is missed).
2a. A related error is when common declarations are repeated in .cc files instead of being placed only in header files and included where needed. What are supposed to be identical declarations get out of sync. The fix is to reorganize the source code to eliminate copies of declarations, delete all binaries and recompile everything (to be sure no change is missed).
3. You are not seeing what you think you are seeing. For example, if the address of a derived class is passed to a pointer-to-base-class, the address might need to be adjusted. In this case, the difference in values is correct, and something else is causing whatever incorrect program behavior you see.