nickdesaulniers added a comment.
In D141451#4100432 <https://reviews.llvm.org/D141451#4100432>, @dblaikie wrote:
> I guess my only other question (worth mentioning in the RFC,
> perhaps)/direction would be that any of these "things that are expensive but
> make backend diagnostics better" could be to put them under a different
> warning flag (if making `-Wattribute-{warning|error}` off by default isn't
> feasible - leaving them on-by-default but less than great user experience
> when optimizing code, and have the warning suggest enabling a different
> warning flag that's more verbose but off by default and also enables the
> extra location tracking - so codebases that generally do use these attributes
> can opt in to that, while codebases that generally don't do that don't
> entirely lose/ignore the attributes).
I don't think it's worth it to try to make these "zero cost." There are two
function attributes here: `__attribute__((error("")))` and
`__attribute__((warning("")))`. They are basically implemented precisely the
same way except how diagnostics are finally emitted by the frontend:
For `__attribute__((error("")))`, we always emit an error. There is no
`-Wno-error=XXX` or `-Wno-XXX` flag to change that. (i.e. no such
`-Wattribute-error`)
For `__attribute__((warning("")))`, we emit a warning by default, an error if
`-Werror=attribute-warning` is set, and nothing if `-Wno-attribute-warning` is
set (unlikely).
Since `-Wno-attribute-warning` is unlikely to ever be set, it's not worth
making that case "zero cost."
---
Will work on that RFC though!
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D141451/new/
https://reviews.llvm.org/D141451
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
