Marking symbols with weak linkage is common, and necessary in a lot of designs.
Currently, describing weak linkage is implementation dependent, and also platform dependent.
Since D doesn't have a preprocessor, and we have no aliasing mechanism for attributes or pragmas, it's impossible to wrangle all of this into one expression.
The language needs to specify a weak linkage pragma, which can be mapped appropriately everywhere.
`pragma(weak, true) void fun() {}` for instance; please choose you preferred name.
GDC/LDC will map this to their backend directly (where they currently expose implementation defined attributes), DMD needs to implement this, which is mostly trivial.
Posix just flags it in the output, and MS/Windows does this by embedding a linker directive in the output.
We need this. It is time.
Comment #1 by maxhaton — 2022-06-09T00:22:32Z
A UDA seems like a better option
Comment #2 by kinke — 2022-06-09T15:38:17Z
(In reply to mhh from comment #1)
> A UDA seems like a better option
Yep, and even better, it already exists - core.attribute.weak, incl. support by DMD, GDC and LDC. => closing
Comment #3 by kinke — 2022-06-09T15:40:23Z
Well, I guess it doesn't work with DMD on Windows. But LDC supports it with the linker directive emulation. Anyway, that should be filed as a separate issue then.