gcc 4.5 side-by-side with 4.4.3?

[Marc Glisse]

On Thu, 27 May 2010, Axel Freyn wrote:

> Hi Alex,
>>
>> I would like to experiment with gcc 4.5 while keeping my current gcc
>> 4.4.3 installed. I am happy for all the current binaries and libraries
>> (of 4.4.3) to be found by default. I only want to try compiling some
>> toy programs with gcc 4.5. I guess this will involve passing some
>> custom -prefix to ./configure when I compile gcc 4.5 and then perhaps
>> something like "/path/to/4.5/gcc --sysroot=/path/to/gcc myprog.c". Can
>> anyone help me with specifics here?
>>
> See http://gcc.gnu.org/faq.html#multiple
> The easiest might be to use --prefix=/path/to/4.5 and --program-suffix=-4.5
> Then it is sufficient to either include the installation path into your
> PATH and to call the compiler as "gcc-4.5", or to call it as
> "/path/to/4.5/bin/gcc-4.5".
> It will find automatically the necesarry include paths and libraries -
> "--sysroot" is NOT necessary.

Actually, there is still a subtlety: if you don't do anything, at runtime, 
programs will use the libgcc_s, libstdc++ etc from 4.4. You will need 
something like -Wl,-rpath,... or LD_LIBRARY_PATH or a specs file to let 
them find the right library.

-- 
Marc Glisse