On 12/23/2010 03:37 PM, ronny meeus wrote:
we are changing our compiler from gcc version 2.95.3 to a more recent version (gcc version 3.4.6).
Are you sure about this? This is 2010, nearly 2011. You are changing to a 2004 compiler, last updated in 2006.
What we have observed is that the memory layout of C++ objects with virtual functions has been changed.
This is all to do with the multi-vendor C++ ABI. We had to change gcc in order to conform to this.
Now that we are moving to a newer version, our SW is broken since the virtual table ptr is stored as first entry in the object's memory. As soon as we insert an object in a list, we simply corrupt the VTABLE pointer and the SW soon crashes. Now my questions are: - is there a kind of mode / compiler option to make the new compiler use the old memory layout?
I don't think so.
- does somebody know a solution (except rewriting the complete code base) ?
It doesn't sound so terribly hard to fix your macros in order to make this correct code. In addition to the layout problem you're having, (void**)&aptr isn't even well-defined C++ and may generate incorect code on recent compilers. So, I think you're going to have to clean this up anyway, I'm afraid. Andrew.
