Re: Problem Executing Application Beginning at gcc Version 4.1.3

[Ian Lance Taylor <iant at google dot com>]

Marshall Lake <mlake@mlake.net> writes:

> I have an application which compiles cleanly (on i386 Linux using
> options -g -O2 -pedantic -I../include -Wall `pkg-config --cflags
> gtk+-2.0`) and executes cleanly using gcc versions 4.1.2 and earlier
> (I've tried 3.4.1, 4.0.2 & 4.1.2).
> 
> But starting with version 4.1.3 (I've tried 4.1.3 & 4.2.1) my
> application compiles cleanly but does not execute properly.  I'm
> having a very difficult time trying to pinpoint the exact cause.  The
> change in execution is subtle but affects the same area of the
> application everytime.
> 
> I've tried to locate a CHANGES file for 4.1.3 to no avail.  Can
> someone point me to one?  That may give me some insight.
> 
> Also, I see on http://gcc.gnu.org/ that it indicates the latest
> version in the 4.1.x series is 4.1.2.  Is that correct or in error?

That is correct.  There is no gcc 4.1.3 release.  I don't know what
code you are using.

Since you mention 4.2.1, the list of changes in the gcc 4.2 series can
be found here: http://gcc.gnu.org/gcc-4.2/changes.html .

If you can't figure out why code is not executing properly, a good
thing to try is -fno-strict-aliasing.  Another is
-fno-strict-overflow.  If either of those options fixes the problem,
then it is likely that your code is accidentally relying on undefined
behaviour.

Ian