The compiler optimizes out unused constants marked with the exportc pragma

[japplegame]

The compiler must never optimize out constants marked with the expotrc pragma.
For example:

const foo {. exportc .} = 10

Expected C output:

N_LIB_PRIVATE NIM_CONST NI foo = ((NI) 10);

Current output:
Nothing (optimized out)

[metagn]

This isn't optimized out, it's ignored. exportc should error on const. You should be using let.

[Araq]

No, const should work too.

[japplegame]

@hlaaftana, look in the corresponding thread: https://forum.nim-lang.org/t/7763
let does not guarantee that the initializing value will be evaluated at compile time and can be successfully placed in the`rodata ' section.

[PMunch]

If exportc should work for const then I would say codegenDecl should as well. Would probably solve my gripes with #17497

[auxym]

Adding on, if exportc should work on consts, then should we also be able to take the addr of a const, or at least an exported const? If so this is related to this RFC: nim-lang/RFCs#257