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Re: PATCH: Add ifunc attribute
Shouldn't this mention what indirect function actually is?
On Fri, Jun 12, 2009 at 09:37:36AM -0700, H.J. Lu wrote:
> > all the issues of wrong optimizations when seeing the function body,
> > but at least the documentation needs to be more explicit about
> > this subtle difference.
> How about this
> `ifunc ("FUNCTION")'
> The `ifunc' attribute only applies to global function definition,
> which causes the definition to be emitted as an indirect function.
> For instance,
> void* f_ifunc () __attribute__ ((ifunc ("f")));
> defines `f_ifunc' to be an indirect function for `f'. The
> indirect function `f_ifunc', which is used by static linker and
> dynamic linker, is never called directly in the program.
It is called the first time the `f' function would be called and returns
a pointer to the actual function that should be executed as `f'.
> This attribute is ignored if `f_ifunc' is undefined in the same
> translation unit.
> See `STT_GNU_IFUNC' specified in `ifunc.txt' at
> `http://groups.google.com/group/generic-abi/files' for details.
> Not all target machines support this attribute.
Petr "Pasky" Baudis
The lyf so short, the craft so long to lerne. -- Chaucer