Sender: |
|
Date: |
Wed, 5 Sep 2007 15:57:30 -0500 |
MIME-version: |
1.0 |
Reply-To: |
|
Content-type: |
TEXT/PLAIN; format=flowed; charset=US-ASCII |
Subject: |
|
From: |
|
In-Reply-To: |
|
Comments: |
|
Parts/Attachments: |
|
|
On Wed, 5 Sep 2007, Glenn Horton-Smith wrote:
> Greetings,
>
> It seems that SL4's gcc4-c++ package ("GCC version 4.1 preview")
> doesn't install gcc 4.1's include files, but instead g++4 is configured
> to use gcc3.4.3's include files ("g++4 -v" reports the
> "--with-gxx-include-dir=/usr/include/c++/3.4.3" option was used). This
> causes an enormous quantity of dire warning messages from various
> standard library classes (including <string>) when compiling almost
> anything with -O2 (such as CLHEP2 uses by default). These warnings are
> all to the effect that "dereferencing type-punned pointer will break
> strict-aliasing rules."
>
> This almost seems like it might be a mistake, and it is actually a
> problem for me, as my whole reason for trying to compare gcc4 and
> gcc3.4.3 was to try to diagnose a discrepancy we think we're seeing in
> the behavior of a Geant4 simulation compiled with gcc4 on one system vs.
> gcc3.4.3 on another. In particular, I've become somewhat suspicious of
> the type-punning in CLHEP2 because of a number of gcc bug reports of
> incorrect code being generated by gcc4.1 due to incorrect
> strict-aliasing optimizations. But with g++4 configured to use a
> standard template library that's not compatible with g++4, I don't see
> there's much point in proceeding with it as is.
>
> So, my question: is it possible to get gcc4* rpms for SL4 which
> install and use /usr/include/c++/4.1.1? (Also the corresponding version
> of libstdc++, for that matter.) If yes, it will save me some work; if
> not, I guess I'll have to install GCC4 from source if I want to make the
> comparison.
Can you tell me the exact g++4 rpm name in question.
rpm -qa | grep g++
I will research this.
-Connie Sieh
>
> Best regards,
> -Glenn Horton-Smith
>
|
|
|