Help with slotted gcc

[dmitchell]

I have both gcc-3.3.6 and gcc-3.4.4 installed and I'd like to use 3.4.4 to compile my personal projects while keeping gcc-3.3.6 selected as the system-wide default. How can I achieve this?

The output of gcc-config -l:

[TheX]

You can change between different gcc versions with

[dmitchell]

Thanks for the reply, but the effect of gcc-config is to change the system-wide default compiler.

I'm beginning to wonder if this is feasible at all, since it appears unsafe to use compiler X to link against libraries built with compiler Y.
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Your argument is invalid.

[CMoH]

I don't have any experience at all with gcc-config and the system that portage/gcc-config developers imagined one could employ to use multiple versions of GCC on the same machine. <-- this was a disclaimer

However, I see that gcc-config also has a -L option which gives the PATH to the libraries used by the given config. I suppose using that path instead of the default compiler's path would show an improvement, since a ls there also shows libstdc++.

As a side-subject, it seems that gcc-config is underdocumented and its purpose, usage and/or internals are assumed by its developers to be prior knowledge to everybody else. (At least from google searches for "gcc-config"). It is not. Starting from this statement, I assume the main purpose of this gcc-config tool is to set a system compiler for the Gentoo distribution. From this point of view using it to handle development targeted for multiple GCC versions is a misuse. And its lack of handiness in doing that is also a hint towards this idea.

Am I assuming correctly? My previous experience with multiple GCC versions was to get those versions and bootstrap each one of them with different --suffix-es, next using CC and CXX etc. to set the needed one from my build scripts. Is there a better way on Gentoo?

[Gentree]

[dmitchell]

[Gentree]

So you are saying that you want to test your software with different compilers because you want to release it as open source and you dont know what the target system will be, right?

Then you need to test it on what you deem to be the test target system.

If that is to include a system build on 3.4 you will need to make yourself a system that was build with 3.4 to test it on. Do yourself a stage1 installation on a spare partition and boot to it.

If that is not what you are doing please post exactly what you are trying to do rather than letting us guess and give you useless advice.

Hope it fits anyway.
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Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

[dmitchell]

I've written a scientific app that needs to run on a quad-Xeon Gentoo machine built with gcc-3.3. My application uses C++ template code that requires gcc-3.4; it also has to link against several libraries. I've installed gcc-3.4.4 on the quad-Xeon and--if possible--would like to be able to build my app there.
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Your argument is invalid.

[Gentree]

So why dont you just rebuild the target with the new compiler?


_________________
Linux, because I'd rather own a free OS than steal one that's not worth paying for.
Gentoo because I'm a masochist
AthlonXP-M on A7N8X. Portage ~x86

[dmitchell]

If it were my quad-Xeon, I would. It's my boss' machine and he wants to keep it on the stable branch. Is it not possible to compile the app on the target? Is there no alternative to static compilation on a gcc-3.4 machine?
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Your argument is invalid.

[Gentree]

[CMoH]