[incremental] Don't panic if decoding the cache fails
If the cached data can't be loaded from disk, just issue a warning to
the user so they know why compilation is taking longer than usual but
don't fail the entire compilation since we can recover by ignorning the
on disk cache.
In the same way, if the disk cache can't be deserialized (because it has
been corrupted for some reason), report the issue as a warning and
continue without failing the compilation. `Decodable::decode()` tends to
panic with various errors like "entered unreachable code" or "index out
of range" if the input data is corrupted. Work around this by catching
panics from the `decode()` calls and continuing without the cached data.
Fixes#48847
If the cached data can't be loaded from disk, just issue a warning to
the user so they know why compilation is taking longer than usual but
don't fail the entire compilation since we can recover by ignorning the
on disk cache.
In the same way, if the disk cache can't be deserialized (because it has
been corrupted for some reason), report the issue as a warning and
continue without failing the compilation. `Decodable::decode()` tends to
panic with various errors like "entered unreachable code" or "index out
of range" if the input data is corrupted. Work around this by catching
panics from the `decode()` calls when joining the thread and continuing
without the cached data.
Fixes#48847
No longer parse it.
Remove AutoTrait variant from AST and HIR.
Remove backwards compatibility lint.
Remove coherence checks, they make no sense for the new syntax.
Remove from rustdoc.
Use the new fs_read_write functions in rustc internals
Uses `fs::read` and `fs::write` (added by #45837) where appropriate, to simplify code and dog-food these new APIs. This also improves performance, when combined with #47324.
Replace uses of DepGraph.in_ignore with DepGraph.with_ignore
I currently plan to track tasks in thread local storage. Ignoring things in a closure ensures that the ignore tasks do not overlap the beginning or end of any other task. The TLS API will also use a closure to change a TLS value, so having the ignore task be a closure also helps there.
It also adds `assert_ignored` which is used before a `TyCtxt` is created. Instead of adding a new ignore task this simply ensures that we are in a context where reads are ignored.
r? @michaelwoerister
This commit removes the `rand` crate from the standard library facade as
well as the `__rand` module in the standard library. Neither of these
were used in any meaningful way in the standard library itself. The only
need for randomness in libstd is to initialize the thread-local keys of
a `HashMap`, and that unconditionally used `OsRng` defined in the
standard library anyway.
The cruft of the `rand` crate and the extra `rand` support in the
standard library makes libstd slightly more difficult to port to new
platforms, namely WebAssembly which doesn't have any randomness at all
(without interfacing with JS). The purpose of this commit is to clarify
and streamline randomness in libstd, focusing on how it's only required
in one location, hashmap seeds.
Note that the `rand` crate out of tree has almost always been a drop-in
replacement for the `rand` crate in-tree, so any usage (accidental or
purposeful) of the crate in-tree should switch to the `rand` crate on
crates.io. This then also has the further benefit of avoiding
duplication (mostly) between the two crates!
incr.comp.: Implement compiler diagnostic persistence.
This PR implements storing and loading diagnostics that the compiler generates and thus allows for emitting warnings during incremental compilation without actually re-evaluating the thing the warning originally came from. It also lays some groundwork for storing and loading type information and MIR in the incr. comp. cache.
~~It is still work in progress:~~
- ~~There's still some documentation to be added.~~
- ~~The way anonymous queries are handled might lead to duplicated emissions of warnings. Not sure if there is a better way or how frequent such duplication would be in practice.~~
Diagnostic message duplication is addressed separately in #45519.
r? @nikomatsakis
