Messages in this thread | | | Date | Thu, 7 Sep 2006 04:23:03 +0200 | From | Adrian Bunk <> | Subject | Re: [2.6 patch] re-add -ffreestanding |
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On Thu, Sep 07, 2006 at 03:23:31AM +0200, Roman Zippel wrote: > Hi, > > On Thu, 7 Sep 2006, Adrian Bunk wrote: > > > > Define "full libc". > > > > Everything described in clause 7 of ISO/IEC 9899:1999. > > Its behaviour is also defined by the environment, so what gcc can assume > is rather limited and you have not shown a single example, that any such > assumption would be invalid for the kernel.
ISO/IEC 9899:1999 clause 7 defines the libc part of a hosted environment.
> > > Explain what exactly -ffreestanding fixes, which is not valid for the > > > kernel. > > > > It's simply correct since the kernel doesn't provide everything > > described in clause 7 of ISO/IEC 9899:1999. > > > > And it fixes compile errors caused by the fact that gcc is otherwise > > allowed to replace calls to any standard C function with semantically > > equivalent calls to other standard C functions - in a hosted environment > > the latter are guaranteed to be present. > > The kernel uses standard C, so your point is?
A standard C freestanding environment or a standard C hosted environment?
> You already got two NACKs from arch maintainers, why the hell are you > still pushing this patch? The builtin functions are useful and you want to
The same people who justified removing -ffreestanding with the "it was only added for x86-64, so dropping it should be safe" that has proven wrong now put their arch maintainers hats on for NACKing reverting this patch...
> force arch maintainers to have to enable every single one manually and > to maintain a list of these functions over multiple versions of gcc?
It could be done per architecture or globally for some functions.
And it doesn't sound like a bad idea to check the current code and think of what it does and what it should do - many architecture specific things (like much of include/asm-i386/string.h) seem to be more historically than architecture specific.
> bye, Roman
cu Adrian
--
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