[Bug c++/13005] [3.3/3.4 Regresssion] [aliasing] Pointer wrongly adjusted for derived class containing virtual function

["stephenma at telus dot net" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From stephenma at telus dot net  2004-01-08 02:01 -------
I will attach a patch against the mainline snapshot gcc-3.4-20031231.   But
first, a bit of discussion.

Andrew Pinski wrote:
> A lot of ARM conferming code cannot be compiled with standard C++ compilers.

I am not suggesting that g++ needs to support the sort of gratuitous
incompatibilities that a certain company in Redmond likes to introduce.  A
program that breaks the rules gets no sympathy from me.

However, there are billions of lines of *working* code that conform to the old
rules (the ARM).  Perfectly compiling all of it may not be possible, but
fairness to these law-abiding programs should compel us to handle as many of
them as we can, or at least to have the compiler warn the programmer when
failure is probable.  Retroactively breaking a working, standard-conforming
program would be unfair, especially if the breakage happens silently.

In my patch I have taken the "warning" approach.  A longer-term solution may
also be possible, as I have hinted before, but the patch is adequate for now.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|INVALID                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13005