[NTLUG:Discuss] New gcc how-to

[Kelledin]

On Saturday 12 October 2002 01:59 pm, Geremy L. Hamlett wrote:
> OK, I am running a RedHat 7.3 box w/ gcc 2.96.  I would like
> to upgrade my gcc to the new 3.2.  However, for what ever
> reason I do not want to use the rpms.  RedHat installs their
> gcc in a diffrent place than the default gcc souce install.  I
> have read that people install the second and just leave the
> two gcc's on their system.  This sounds redundant to me and I
> don't want two gcc's.

Whatever you do, you will _need_ to keep at least part of 
gcc-2.96--specifically, the libstdc++ dynamic libraries.  These 
libraries encapsulate the C++ application binary interface 
(ABI), and just about any application coded in C++ gets linked 
to them.  This includes most window managers, Qt, KDE, XFree86, 
and various other apps.

If gcc includes libgcc_s dynamic libraries, you should probably 
keep these as well.  All these libraries should be backed up 
before you begin.

> First Question:  Can I just use the default install of gcc-3.2

There are some nice instructions on how to best go about that 
here:

http://www.linuxfromscratch.org/view/4.0/chapter06/gcc.html

The only thing I'd do different from these instructions is use 
"--prefix=/usr/local" instead of "--prefix=/usr" (just for your 
case).  Also, those instructions mention a patch; get that patch 
here:

ftp://ftp.linuxfromscratch.org/lfs-packages/4.0/gcc-3.2.patch.bz2

The patch fixes some nasty gcc miscompilation bugs, so I would 
strongly recommend that you use it.

> Second Qustion: after the gcc-3.2 source install, can I remove
> the gcc-2.69 rpms

As long as you back up the libstdc++/libgcc_s libraries from 
gcc-2.96 first. ;)  Just save them and copy them to /usr/lib 
after you're done, and you should be fine.

> I know gcc is not something you really want to mess with
> unless you know what you are doing.
>
> I have not been able to find any documentation on the internet
> on how to replace the 2.96 w/ anoter version. I know it has
> been done,
>
> Has anybody in the NTLUG done this?

I've never had the dubious pleasure of dealing with gcc-2.96.  
I've dealt with several other gcc versions, though, and I've 
been through several compiler replacements.  Just follow the 
steps above, and you should be in the clear...

-- 
Kelledin
"If a server crashes in a server farm and no one pings it, does 
it still cost four figures to fix?"