[Issue 20925] pragma(inline) should emit code to the calling CU + appropriate linker flags

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20925

kinke <kinke at gmx.net> changed:

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                 CC|                            |kinke at gmx.net

--- Comment #5 from kinke <kinke at gmx.net> ---
(In reply to Manu from comment #4)
> Which is why I proposed allowing more fidelity in the argument to the pragma.
> Perhaps something like:
>   pragma(inline, true) - linkonce
>   pragma(inline, always) - strong hint that inlining should occur if possible
>   pragma(inline, force) - compile error if inline fails
> 
> These map to the 3 distinct use cases I referred to in my forum OP.
> What alternative proposal would you suggest for `linkonce`? That's what
> 'inline' actually means to most native programmers... deviating from that
> precedent would likely be _more_ confusing rather than less.

That's wild speculation on your part. ;) I don't find anything with `inline`
acceptable; I'm a C++ guy too, but I also try to keep in mind future
generations of D devs.

pragma(inline, <true|false>) are already reserved and make sense. Making
`pragma(inline, true)` mean linkonce_odr emission into each referencing CU (and
absolutely having to do nothing with actual inlining into callers), and
`pragma(inline, false)` mean
never-inline-into-any-callers-and-only-emit-into-owning-CU just isn't sound.

I don't have a thought-through alternative proposal because this isn't of high
enough interest to me. From the LDC side, we could simply add a UDA and allow
the user to specify the LLVM linkage directly if desired - à la `@linkonce`.

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