reserve `impl<T> From<!> for T`
this is necessary for never-type stabilization.
cc #57012#35121
I think we wanted a crater run for this @nikomatsakis?
r? @nikomatsakis
This commit addresses #64319 by removing the `dylib` crate type from the
list of crate type that exports generic symbols. The bug in #64319
arises because a `dylib` crate type was trying to export a symbol in an
uptream crate but it miscalculated the symbol name of the uptream
symbol. This isn't really necessary, though, since `dylib` crates aren't
that heavily used, so we can just conservatively say that the `dylib`
crate type never exports generic symbols, forcibly removing them from
the exported symbol lists if were to otherwise find them.
The fix here happens in two places:
* First is in the `local_crate_exports_generics` method, indicating that
it's now `false` for the `Dylib` crate type. Only rlibs actually
export generics at this point.
* Next is when we load exported symbols from upstream crate. If, for our
compilation session, the crate may be included from a dynamic library,
then its generic symbols are removed. When the crate was linked into a
dynamic library its symbols weren't exported, so we can't consider
them a candidate to link against.
Overally this should avoid situations where we incorrectly calculate the
upstream symbol names in the face of differnet `share_generics` options,
ultimately...
Closes#64319
This commit converts a field of `Session`, `dependency_formats`, into a
query of `TyCtxt`. This information then also needed to be threaded
through to other remaining portions of the linker, but it's relatively
straightforward. The only change here is that instead of
`HashMap<CrateType, T>` the data structure changed to `Vec<(CrateType,
T)>` to make it easier to deal with in queries.
This allows lints and other diagnostics to refer to items
by a unique ID instead of relying on whacky path
resolution schemes that may break when items are
relocated.
The commit should have changed comments as well.
At the time of writting, it passes the tidy and check tool.
Revisions asked by eddyb :
- Renamed of all the occurences of {visit/super}_mir
- Renamed test structures `CachedMir` to `Cached`
Fixing the missing import on `AggregateKind`
We are going to uniform the terminology of all associated items.
Methods that may or may not have `self` are called "associated
functions". Because `AssociatedFn` is a bit long, we rename `Associated`
to `Assoc`.
