Commit Graph

215 Commits

Author SHA1 Message Date
Alex Crichton
fd0aa647f3 rustc: Remove CrateStore::crates as a method
This commit moves the `crates` method to a query and then migrates all callers
to use a query instead of the now-renamed `crates_untracked` method where
possible.

Closes #41417
2017-09-07 08:13:41 -07:00
Alex Crichton
0cdc58a1bc rustc: Store InternedString in DefPathData
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.
2017-09-05 07:47:27 -07:00
Alex Crichton
9a231961d5 rustc: Move stability functionality into queries
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.
2017-09-05 07:37:58 -07:00
Alex Crichton
0182c8bbda rustc: Rename item_body query to extern_const_body
Should hopefully more accurately reflect what's happening! This commit also
removes the cache in the cstore implementation as it's already cached through
the query infrastructure.
2017-09-05 07:37:58 -07:00
Alex Crichton
490f34ac0c rustc: Remove CrateStore::used_crate*
This commit removes the `use_crates` and `used_crate_source` methods in favor of
a mix of queries and helper methods being used now instead.
2017-09-05 07:37:58 -07:00
Alex Crichton
0b7e0aaba5 rustc: Classify two more CrateStore methods untracked
These are only called pre-TyCtxt (e.g. lowering/resolve), so make it explicit in
the name that they're untracked and therefore unsuitable to called elsewhere.
2017-09-05 07:37:58 -07:00
Alex Crichton
88399a985a rustc: Migrate visible_parent_map to a query
Turns out it was basically already a query if you squinted hard enough!
2017-09-05 07:37:58 -07:00
Alex Crichton
84ae4b75be rustc: Migrate CrateStore::item_body to a query
This commit migrates the `item_body` method on `CrateStore` to a query instead
to enable better tracking of dependencies and whatnot.
2017-09-05 07:37:58 -07:00
Alex Crichton
953490ddfa rustc: Remove lang item methods from CrateStore
Given the previous commit, these are now trivially representable as queries!
2017-09-05 07:37:58 -07:00
Alex Crichton
43ae380191 rustc: Flag some CrateStore methods as "untracked"
The main use of `CrateStore` *before* the `TyCtxt` is created is during
resolution, but we want to be sure that any methods used before resolution are
not used after the `TyCtxt` is created. This commit starts moving the methods
used by resolve to all be named `{name}_untracked` where the rest of the
compiler uses just `{name}` as a query.

During this transition a number of new queries were added to account for
post-resolve usage of these methods.
2017-09-05 07:37:39 -07:00
Alex Crichton
64a70342e6 rustc: Remove a number of mutable fields in cstore
This commit started by moving methods from `CrateStore` to queries, but it ended
up necessitating some deeper refactorings to move more items in general to
queries.

Before this commit the *resolver* would walk over the AST and process foreign
modules (`extern { .. }` blocks) and collect `#[link]` annotations. It would
then also process the command line `-l` directives and such. This information
was then stored as precalculated lists in the `CrateStore` object for iterating
over later.

After this, commit, however, this pass no longer happens during resolution but
now instead happens through queries. A query for the linked libraries of a crate
will crawl the crate for `extern` blocks and then process the linkage
annotations at that time.
2017-09-05 07:37:28 -07:00
Alex Crichton
1c7294eb54 rustc: Move implementations_of_trait to a query
While we're at it, make it two separate queries so one's for rustdoc and one's
for the compiler, hopefully being a bit more targeted.
2017-09-05 07:37:28 -07:00
Alex Crichton
52b67f988d rustc: Move original_crate_name to a query 2017-09-05 07:37:27 -07:00
Alex Crichton
d6c88f4936 rustc: Move crate_hash to a query 2017-09-05 07:37:27 -07:00
Alex Crichton
ebc1fd321d rustc: Move crate_disambiguator to queries 2017-09-05 07:37:11 -07:00
Alex Crichton
2d4445f784 rustc: Move {plugin,derive}_registrar_fn to queries 2017-09-05 07:37:11 -07:00
Alex Crichton
205bc9a80a rustc: Migrate CStore::native_libraries to a query 2017-09-05 07:37:11 -07:00
Alex Crichton
98b74c580f rustc: Migrate CStore::expored_symbols to a query 2017-09-05 07:37:11 -07:00
Alex Crichton
ed6f868bf7 rustc: Move impl_defaultness to a query 2017-09-05 07:37:11 -07:00
Alex Crichton
dff0c074e4 rustc: Move a few more cstore methods to queries
This comit applies the following changes:

* Deletes the `is_allocator` query as it's no longer used
* Moves the `is_sanitizer_runtime` method to a query
* Moves the `is_profiler_runtime` method to a query
* Moves the `panic_strategy` method to a query
* Moves the `is_no_builtins` method to a query
* Deletes the cstore method of `is_compiler_builtins`. The query was added in
  #42588 but the `CrateStore` method was not deleted

A good bit of these methods were used late in linking during trans so a new
dedicated structure was created to ship a calculated form of this information
over to the linker rather than having to ship the whole of `TyCtxt` over to
linking.
2017-09-05 07:37:11 -07:00
Eduard-Mihai Burtescu
dc563efd98 rustc_mir: actually "promote" constants' MIR to 'static by removing StorageDead's. 2017-09-02 02:17:28 +03:00
Vadim Petrochenkov
3da868dcb6 Make fields of Span private 2017-08-30 01:38:54 +03:00
John Kåre Alsaker
d29af37999 Merge branch 'master' of https://github.com/rust-lang/rust into gen 2017-08-28 02:41:16 +02:00
Tatsuyuki Ishi
611b111139 Move unused-extern-crate to late pass 2017-08-27 19:02:24 +09:00
Alex Crichton
1210ebff43 Merge remote-tracking branch 'origin/master' into gen 2017-08-16 10:03:47 -07:00
Zack M. Davis
1b6c9605e4 use field init shorthand EVERYWHERE
Like #43008 (f668999), but _much more aggressive_.
2017-08-15 15:29:17 -07:00
Alex Crichton
b8aa595e6d Merge remote-tracking branch 'origin/master' into gen 2017-08-10 14:05:58 -07:00
Alex Crichton
c25ddf21f1 Merge remote-tracking branch 'origin/master' into gen 2017-08-09 11:44:21 -07:00
Isaac van Bakel
400075d9d9 Fixed all unnecessary muts in language core 2017-08-01 23:01:24 +01:00
Michael Woerister
7e09d1e170 async-llvm(18): Instantiate OngoingCrateTranslation before starting translation. 2017-07-31 15:15:09 +02:00
Alex Crichton
9b2f7624ec syntax: Add tokens: Option<TokenStream> to Item
This commit adds a new field to the `Item` AST node in libsyntax to optionally
contain the original token stream that the item itself was parsed from. This is
currently `None` everywhere but is intended for use later with procedural
macros.
2017-07-28 07:58:20 -07:00
John Kåre Alsaker
d861982ca6 Generator literal support 2017-07-28 15:46:23 +02:00
Michael Woerister
fa91eeb99f Remove unused DefTable::retrace_path(). 2017-07-20 15:32:06 +02:00
Michael Woerister
e00bec2dd4 Allow 'tcx in define_dep_nodes! and deduplicate some DepNodes. 2017-07-10 12:20:56 +02:00
bors
1685c92986 Auto merge of #42727 - alexcrichton:allocators-new, r=eddyb
rustc: Implement the #[global_allocator] attribute

This PR is an implementation of [RFC 1974] which specifies a new method of
defining a global allocator for a program. This obsoletes the old
`#![allocator]` attribute and also removes support for it.

[RFC 1974]: https://github.com/rust-lang/rfcs/pull/1974

The new `#[global_allocator]` attribute solves many issues encountered with the
`#![allocator]` attribute such as composition and restrictions on the crate
graph itself. The compiler now has much more control over the ABI of the
allocator and how it's implemented, allowing much more freedom in terms of how
this feature is implemented.

cc #27389
2017-07-06 00:16:16 +00:00
Alex Crichton
695dee063b rustc: Implement the #[global_allocator] attribute
This PR is an implementation of [RFC 1974] which specifies a new method of
defining a global allocator for a program. This obsoletes the old
`#![allocator]` attribute and also removes support for it.

[RFC 1974]: https://github.com/rust-lang/rfcs/pull/197

The new `#[global_allocator]` attribute solves many issues encountered with the
`#![allocator]` attribute such as composition and restrictions on the crate
graph itself. The compiler now has much more control over the ABI of the
allocator and how it's implemented, allowing much more freedom in terms of how
this feature is implemented.

cc #27389
2017-07-05 14:37:01 -07:00
Alex Crichton
fd95db25b3 Merge remote-tracking branch 'origin/master' into proc_macro_api 2017-07-05 08:42:13 -07:00
Eduard-Mihai Burtescu
8e53a03d15 rustc: rename closure_type to fn_sig. 2017-06-27 16:32:48 +03:00
Jeffrey Seyfried
e42836b208 Implement quote! and other proc_macro API. 2017-06-26 02:06:26 +00:00
Jeffrey Seyfried
d4488b7df9 Simplify hygiene::Mark application, and
remove variant `Token::SubstNt` in favor of `quoted::TokenTree::MetaVar`.
2017-06-26 02:05:45 +00:00
bors
3cb803460b Auto merge of #42598 - cramertj:track-more-metadata, r=nikomatsakis
Track more crate metadata

Part of https://github.com/rust-lang/rust/issues/41417
r? @nikomatsakis
2017-06-16 21:42:17 +00:00
Taylor Cramer
c98ca953b0 Switch CrateNum queries to DefId 2017-06-14 22:49:07 -07:00
bors
dfa7e21e4e Auto merge of #42433 - marco-c:profiling, r=alexcrichton
Build instruction profiler runtime as part of compiler-rt

r? @alexcrichton

This is #38608 with some fixes.

Still missing:
- [x] testing with profiler enabled on some builders (on which ones? Should I add the option to some of the already existing configurations, or create a new configuration?);
- [x] enabling distribution (on which builders?);
- [x] documentation.
2017-06-14 08:46:14 +00:00
Taylor Cramer
48356987c1 On-demandify extern_crate 2017-06-14 00:13:35 -07:00
Taylor Cramer
b0f05d4bc5 On-demandify is_allocator and is_panic_runtime 2017-06-14 00:13:35 -07:00
Taylor Cramer
328c6c81bf on-demand dylib dependency formats 2017-06-14 00:13:33 -07:00
Taylor Cramer
532a08b947 Add CrateNum-taking ability to the provide macro 2017-06-14 00:12:59 -07:00
Taylor Cramer
9f710530a7 On-demand is_const_fn 2017-06-13 23:10:59 -07:00
bors
3f8b93693d Auto merge of #42537 - michaelwoerister:tcx-for-dep-node, r=nikomatsakis
incr.comp.: Make DepNode `Copy` and valid across compilation sessions

This PR moves `DepNode` to a representation that does not need retracing and thus simplifies comparing dep-graphs from different compilation sessions. The code also gets a lot simpler in many places, since we don't need the generic parameter on `DepNode` anymore.  See https://github.com/rust-lang/rust/issues/42294 for details.

~~NOTE: Only the last commit of this is new, the rest is already reviewed in https://github.com/rust-lang/rust/pull/42504.~~

This PR is almost done but there are some things I still want to do:
- [x] Add some module-level documentation to `dep_node.rs`, explaining especially what the `define_dep_nodes!()` macro is about.
- [x] Do another pass over the dep-graph loading logic. I suspect that we can get rid of building the `edges` map and also use arrays instead of hash maps in some places.

cc @rust-lang/compiler
r? @nikomatsakis
2017-06-12 11:39:35 +00:00
Michael Woerister
3607174909 incr.comp.: Uniformly represent DepNodes as (Kind, StableHash) pairs. 2017-06-09 15:03:34 +02:00
bors
5fe923d434 Auto merge of #42507 - ibabushkin:external-span-trans, r=eddyb
Fix translation of external spans

Previously, I noticed that spans from external crates don't generate any output. This limitation is problematic if analysis is performed on one or more external crates, as is the case with [rust-semverver](https://github.com/ibabushkin/rust-semverver). This change should address this behaviour, with the potential drawback that a minor performance hit is to be expected, as spans from potentially large crates have to be translated now.
2017-06-09 12:49:49 +00:00
Inokentiy Babushkin
9a054f2002
Fix translation of external spans. 2017-06-07 16:31:05 +02:00
Michael Woerister
8b36d3308e Allocate DefIndices for global crate metadata.
This allows for treating global crate metadata the same as regular metadata with regard to incr. comp.
2017-06-07 12:11:40 +02:00
Marco Castelluccio
ecba8d6a23 Merge branch 'profiling' of github.com:whitequark/rust into profiling 2017-06-04 15:54:39 +01:00
Michael Woerister
f854f8b366 Build DefPathHash->DefId table when incr.comp. is enabled 2017-05-31 14:53:39 +02:00
Michael Woerister
59ebe8e115 Make a newtype for DefPathHash so they are not confused with content hashes 2017-05-31 13:54:38 +02:00
Ariel Ben-Yehuda
55767702ec fix RUST_LOG ICE caused by printing a default impl's DefId 2017-05-28 10:43:25 +03:00
Jeffrey Seyfried
1f175fa35d Hygienize librustc_resolve. 2017-05-25 05:51:50 +00:00
Jeffrey Seyfried
2a1d2edb82 Declarative macros 2.0 without hygiene. 2017-05-25 05:51:06 +00:00
Jeffrey Seyfried
9c6430b325 Refactor out ast::MacroDef. 2017-05-25 05:47:25 +00:00
Michael Woerister
4549423f28 Use 128 instead of 64 bits for DefPath hashes 2017-05-18 11:10:11 +02:00
bors
4640e18572 Auto merge of #41911 - michaelwoerister:querify_trait_def, r=nikomatsakis
Remove interior mutability from TraitDef by turning fields into queries

This PR gets rid of anything `std::cell` in `TraitDef` by
- moving the global list of trait impls from `TraitDef` into a query,
- moving the list of trait impls relevent for some self-type from `TraitDef` into a query
- moving the specialization graph of trait impls into a query, and
- moving `TraitDef::object_safety` into a query.

I really like how querifying things not only helps with incremental compilation and on-demand, but also just plain makes the code cleaner `:)`

There are also some smaller fixes in the PR. Commits can be reviewed separately.

r? @eddyb or @nikomatsakis
2017-05-17 21:44:08 +00:00
Michael Woerister
c2d9b4e334 ICH: Hash lists of local trait impls as part of the HIR. 2017-05-15 15:27:49 +02:00
Robin Kruppe
1a24a591dd Remove rustc_llvm dependency from rustc_metadata
Move the code for loading metadata from rlibs and dylibs from
rustc_metadata into rustc_trans, and introduce a trait to avoid
introducing a direct dependency on rustc_trans.

This means rustc_metadata is no longer rebuilt when LLVM changes.
2017-05-14 20:30:22 +02:00
bors
4f3886abf1 Auto merge of #41847 - alexcrichton:less-unstable-annotations, r=eddyb
rustc: Add a new `-Z force-unstable-if-unmarked` flag

This commit adds a new `-Z` flag to the compiler for use when bootstrapping the
compiler itself. We want to be able to use crates.io crates, but we also want
the usage of such crates to be as ergonomic as possible! To that end compiler
crates are a little tricky in that the crates.io crates are not annotated as
unstable, nor do they expect to pull in unstable dependencies.

To cover all these situations it's intended that the compiler will forever now
bootstrap with `-Z force-unstable-if-unmarked`. This flags serves a dual purpose
of forcing crates.io crates to themselves be unstable while also allowing them
to use other "unstable" crates.io crates. This should mean that adding a
dependency to compiler no longer requires upstream modification with
unstable/staged_api attributes for inclusion!
2017-05-13 05:22:08 +00:00
Alex Crichton
99f629a931 rustc: Add a new -Z force-unstable-if-unmarked flag
This commit adds a new `-Z` flag to the compiler for use when bootstrapping the
compiler itself. We want to be able to use crates.io crates, but we also want
the usage of such crates to be as ergonomic as possible! To that end compiler
crates are a little tricky in that the crates.io crates are not annotated as
unstable, nor do they expect to pull in unstable dependencies.

To cover all these situations it's intended that the compiler will forever now
bootstrap with `-Z force-unstable-if-unmarked`. This flags serves a dual purpose
of forcing crates.io crates to themselves be unstable while also allowing them
to use other "unstable" crates.io crates. This should mean that adding a
dependency to compiler no longer requires upstream modification with
unstable/staged_api attributes for inclusion!
2017-05-10 07:42:26 -07:00
achernyak
35812d1746 resolved merge conflicts 2017-05-09 17:23:41 -05:00
Michael Woerister
6a5e2a5a9e incr.comp.: Hash more pieces of crate metadata to detect changes there. 2017-05-08 12:31:26 +02:00
achernyak
1f532bfed5 is_exported_symbol 2017-05-07 21:05:31 -05:00
achernyak
5a7946df70 is_foreign_item 2017-05-05 08:15:08 -05:00
achernyak
5b71d769ff moved metadata provider impls to decoder 2017-05-04 12:45:56 -05:00
achernyak
03fe10d91d impl_parent 2017-05-04 09:37:34 -05:00
achernyak
aa5a532046 trait_of_item 2017-05-04 08:27:48 -05:00
achernyak
c72a16b8e2 fn_arg_names 2017-05-03 09:01:49 -05:00
achernyak
a12a55f519 item_attrs 2017-05-03 08:40:32 -05:00
Corey Farwell
02274a8430 Rollup merge of #41653 - achernyak:master, r=nikomatsakis
Queries for Crate Metadata

This resolves following parts of #41417:
* `fn stability(&self, def: DefId) -> Option<attr::Stability>;`
* `fn deprecation(&self, def: DefId) -> Option<attr::Deprecation>;`

r? @nikomatsakis
2017-05-02 21:21:20 -04:00
Niko Matsakis
393fa4f1b7 rename from item_mir to optimized_mir 2017-05-02 16:21:57 -04:00
Niko Matsakis
29263fdb54 introduce idea of "stealable" MIR
This is a more principled version of the `RefCell` we were using
before. We now allocate a `Steal<Mir<'tcx>>` for each intermediate MIR
pass; when the next pass steals the entry, any later attempts to use it
will panic (there is no way to *test* if MIR is stolen, you're just
supposed to *know*).
2017-05-02 14:01:34 -04:00
Niko Matsakis
2b32cb90c7 retool MIR passes completely
The new setup is as follows. There is a pipeline of MIR passes that each
run **per def-id** to optimize a particular function. You are intended
to request MIR at whatever stage you need it. At the moment, there is
only one stage you can request:

- `optimized_mir(def_id)`

This yields the final product. Internally, it pulls the MIR for the
given def-id through a series of steps. Right now, these are still using
an "interned ref-cell" but they are intended to "steal" from one
another:

- `mir_build` -- performs the initial construction for local MIR
- `mir_pass_set` -- performs a suite of optimizations and transformations
- `mir_pass` -- an individual optimization within a suite

So, to construct the optimized MIR, we invoke:

    mir_pass_set((MIR_OPTIMIZED, def_id))

which will build up the final MIR.
2017-05-02 14:01:01 -04:00
achernyak
c1d97c7d5a query for deprecation 2017-05-02 06:53:34 -05:00
Taylor Cramer
daa0094eb7 Queryify is_item_mir_available 2017-05-01 10:24:10 -07:00
Taylor Cramer
fb4380b12d Queryify const_is_rvalue_promotable_to_static 2017-05-01 10:24:10 -07:00
Taylor Cramer
05b2081e23 Queryify item_body_nested_bodies 2017-05-01 10:24:04 -07:00
whitequark
42754ce710 Add profiling support, through the rustc -Z profile flag.
When -Z profile is passed, the GCDAProfiling LLVM pass is added
to the pipeline, which uses debug information to instrument the IR.
After compiling with -Z profile, the $(OUT_DIR)/$(CRATE_NAME).gcno
file is created, containing initial profiling information.
After running the program built, the $(OUT_DIR)/$(CRATE_NAME).gcda
file is created, containing branch counters.

The created *.gcno and *.gcda files can be processed using
the "llvm-cov gcov" and "lcov" tools. The profiling data LLVM
generates does not faithfully follow the GCC's format for *.gcno
and *.gcda files, and so it will probably not work with other tools
(such as gcov itself) that consume these files.
2017-05-01 09:16:20 +00:00
Artem Chernyak
2f73b173cb Merge branch 'master' into def_span 2017-04-28 22:44:34 -05:00
achernyak
932d251698 query for def_span 2017-04-28 10:59:57 -05:00
bors
2971d491b9 Auto merge of #41508 - michaelwoerister:generic-path-remapping, r=alexcrichton
Implement a file-path remapping feature in support of debuginfo and reproducible builds

This PR adds the `-Zremap-path-prefix-from`/`-Zremap-path-prefix-to` commandline option pair and is a more general implementation of #41419. As opposed to the previous attempt, this implementation should enable reproducible builds regardless of the working directory of the compiler.

This implementation of the feature is more general in the sense that the re-mapping will affect *all* paths the compiler emits, including the ones in error messages.

r? @alexcrichton
2017-04-28 12:09:37 +00:00
achernyak
e24003fb3c query for describe_def 2017-04-27 13:27:16 -05:00
bors
54ef80043a Auto merge of #37860 - giannicic:defaultimpl, r=nagisa
#37653 support `default impl` for specialization

this commit implements the first step of the `default impl` feature:

> all items in a `default impl` are (implicitly) `default` and hence
> specializable.

In order to test this feature I've copied all the tests provided for the
`default` method implementation (in run-pass/specialization and
compile-fail/specialization directories) and moved the `default` keyword
from the item to the impl.
See [referenced](https://github.com/rust-lang/rust/issues/37653) issue for further info

r? @aturon
2017-04-27 02:48:17 +00:00
Michael Woerister
39ffea31df Implement a file-path remapping feature in support of debuginfo and reproducible builds. 2017-04-26 15:44:02 +02:00
Gianni Ciccarelli
715811d0be support default impl for specialization
pr review
2017-04-25 05:28:22 +00:00
Eduard-Mihai Burtescu
612bb1f54e rustc: rename some of the queries to match tcx methods. 2017-04-24 15:20:52 +03:00
Gianni Ciccarelli
116e9831a5 support default impl for specialization
this commit implements the first step of the `default impl` feature:
all items in a `default impl` are (implicitly) `default` and hence
specializable.
In order to test this feature I've copied all the tests provided for the
`default` method implementation (in run-pass/specialization and
compile-fail/specialization directories) and moved the `default` keyword
from the item to the impl.
See referenced issue for further info
2017-04-24 10:08:48 +00:00
Eduard-Mihai Burtescu
e22873d912 rustc: make the const-eval cache polymorphic. 2017-04-23 11:11:54 +03:00
Ariel Ben-Yehuda
a0f145ba8c add a cache to impl_polarity
this is another one of these things that looks *much* worse on valgrind.
2017-04-22 21:02:41 +03:00
Ariel Ben-Yehuda
ece6c8434b cache attributes of items from foreign crates
this avoids parsing item attributes on each call to `item_attrs`, which takes
off 33% (!) of translation time and 50% (!) of trans-item collection time.
2017-04-22 21:00:50 +03:00
Niko Matsakis
8289e5a73e introduce is_foreign_item query
This may seem like overkill, but it's exactly what we want/need for
incremental compilation I think. In particular, while generating code
for some codegen unit X, we can wind up querying about any number of
external items, and we only want to be forced to rebuild X is some of
those changed from a foreign item to otherwise. Factoring this into a
query means we would re-run only if some `false` became `true` (or vice
versa).
2017-04-21 17:26:53 -04:00
Michael Woerister
ca2dce9b48 ICH: Replace old, transitive metadata hashing with direct hashing approach.
Instead of collecting all potential inputs to some metadata entry and
hashing those, we directly hash the values we are storing in metadata.
This is more accurate and doesn't suffer from quadratic blow-up when
many entries have the same dependencies.
2017-04-12 11:47:26 +02:00
Corey Farwell
996f06fe35 Rollup merge of #41061 - arielb1:parent-lock, r=eddyb
cstore: return an immutable borrow from `visible_parent_map`

This prevents an ICE when `visible_parent_map` is called multiple times, for example when an item referenced in an impl signature is imported from an  `extern crate` statement occurs within an impl.

Fixes #41053.

r? @eddyb
2017-04-07 09:20:06 -04:00
Michael Woerister
edc1ac3016 ICH: Centrally compute and cache DefPath hashes as part of DefPathTable. 2017-04-07 14:36:51 +02:00