Allow for instantiating statics from upstream crates
This PR makes the infrastructure around translating statics a bit more flexible so that it can also instantiate statics from upstream crates if the need arises. This is preparatory work for a MIR-only RLIBs prototype, where the instantiation of a `static` may be deferred until a leaf crate.
r? @eddyb (feel free to assign to someone else if you're busy)
A new section is added to both both struct and trait doc pages.
On struct/enum pages, a new 'Auto Trait Implementations' section displays any
synthetic implementations for auto traits. Currently, this is only done
for Send and Sync.
On trait pages, a new 'Auto Implementors' section displays all types
which automatically implement the trait. Effectively, this is a list of
all public types in the standard library.
Synthesized impls for a particular auto trait ('synthetic impls') take
into account generic bounds. For example, a type 'struct Foo<T>(T)' will
have 'impl<T> Send for Foo<T> where T: Send' generated for it.
Manual implementations of auto traits are also taken into account. If we have
the following types:
'struct Foo<T>(T)'
'struct Wrapper<T>(Foo<T>)'
'unsafe impl<T> Send for Wrapper<T>' // pretend that Wrapper<T> makes
this sound somehow
Then Wrapper will have the following impl generated:
'impl<T> Send for Wrapper<T>'
reflecting the fact that 'T: Send' need not hold for 'Wrapper<T>: Send'
to hold
Lifetimes, HRTBS, and projections (e.g. '<T as Iterator>::Item') are
taken into account by synthetic impls
However, if a type can *never* implement a particular auto trait
(e.g. 'struct MyStruct<T>(*const T)'), then a negative impl will be
generated (in this case, 'impl<T> !Send for MyStruct<T>')
All of this means that a user should be able to copy-paste a synthetic
impl into their code, without any observable changes in behavior
(assuming the rest of the program remains unchanged).
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 DefIndex encoding that works better with on-disk variable length integer representations.
Use the least instead of the most significant bit for representing the address space.
r? @eddyb
incr.comp.: Use an array instead of a hashmap for storing result hashes.
Doing so should result in some of the core tracking components being faster.
r? @nikomatsakis
The Generics now contain one Vec of an enum for the generic parameters,
rather than two separate Vec's for lifetime and type parameters.
Additionally, places that previously used Vec<LifetimeDef> now use
Vec<GenericParam> instead.
incr.comp.: Incorporate the stable commandline arg hash and SVHs of upstream crates into the SVH.
So far the SVH detected changes in the HIR, which is already very sensitive, but in order for `eval_always` queries to also be sensitive to changes in upstream crates, the SVH also needs to capture changes there.
This PR fixes [rust-icci/crossbeam](https://travis-ci.org/rust-icci/crossbeam/builds/308936448), but I have not yet been able to come up with a minimal regression test.
r? @nikomatsakis
incr.comp.: Implement query result cache and use it to cache type checking tables.
This is a spike implementation of caching more than LLVM IR and object files when doing incremental compilation. At the moment, only the `typeck_tables_of` query is cached but MIR and borrow-check will follow shortly. The feature is activated by running with `-Zincremental-queries` in addition to `-Zincremental`, it is not yet active by default.
r? @nikomatsakis
DefaultImpl is a highly confusing name for what we now call auto impls,
as in `impl Send for ..`. The name auto impl is not formally decided
but for sanity anything is better than `DefaultImpl` which refers
neither to `default impl` nor to `impl Default`.
incr.comp.: Move task result fingerprinting into DepGraph.
This PR
- makes the DepGraph store all `Fingerprints` of task results,
- allows `DepNode` to be marked as input nodes,
- makes HIR node hashing use the regular fingerprinting infrastructure,
- removes the now unused `IncrementalHashesMap`, and
- makes sure that `traits_in_scope_map` fingerprints are stable.
r? @nikomatsakis
cc @alexcrichton
Previously a `Symbol` was stored there, but this ended up causing hash
collisions in situations that otherwise shouldn't have a hash collision. Only
the symbol's string value was hashed, but it was possible for distinct symbols
to have the same string value, fooling various calcuations into thinking that
these paths *didn't* need disambiguating data when in fact they did!
By storing `InternedString` instead we're hopefully triggering all the exising
logic to disambiguate paths with same-name `Symbol` but actually distinct
locations.
This commit primarily removes the `stability` field from `TyCtxt` as well as its
internal mutable state, instead using a query to build the stability index as
well as primarily using queries for other related lookups.
Like previous commits the calculation of the stability index is wrapped in a
`with_ignore` node to avoid regressing the current tests, and otherwise this
commit also introduces #44232 but somewhat intentionally so.
