Re: Support for NOINLINE attribute

[Steve Kargl <sgk@troutmask.apl.washington.edu>]

On Fri, Feb 10, 2023 at 10:38:04AM +0200, Rimvydas Jasinskas wrote:
> On Fri, Feb 10, 2023 at 10:24 AM Steve Kargl via Fortran
> <fortran@gcc.gnu.org> wrote:
> > > would it be possible to extend gfortran attribute support to handle
> > > NOINLINE too? Like: "!GCC$ ATTRIBUTES noinline :: ...".
> >
> > It looks to me like you are conflating three independent topics.
> > What does NOINLINE have to do with WEAK?  What does WEAK have
> > to do with NORETURN?
> 
> As I wrote these are optional (different issues, quite useful to have
> but still easy to work around with different means), the main issue is
> still missing NOINLINE for -flto.

Unfortunately, conflating unrelated topics can lead to distraction.
I do however see value in NORETURN.  I suppose a person writing a
library may find WEAK useful.

> > More importantly what is the effect of NOINLINE if a user
> > does not specify the -flto option?  Does this block inlining
> > regardless of LTO?
> >
> > --
> > steve
> Yes, there is no way to differentiate between LTO and non-LTO
> compilations (at least from what I have seen in the code).
> As long as subroutines/functions are in separate compilation units,
> this has no effect for non-LTO builds anyway.  Main issue is to deal
> with unintentional over inlining between different compilation units
> with lto1 backend.

I haven't studied your patch in detail, so apologies up front
if this is already available.  Can attribute be applied to only
a block of code in a file?.  Suppose there are 3 functions in a
file.  Can the attribute be toggled on and off? Something like


function bar()
...
end function bar()

!GCC$ ATTRIBUTES noinline on
function foo()
...
end function foo()
!GCC$ ATTRIBUTES noinline off

function bah()
...
end function bah()

bar() and bah() can be inlined while inlining foo() is prevented.

-- 
Steve