Commit Graph

394 Commits

Author SHA1 Message Date
kadmin
67f56671d0 Use Term in ProjectionPredicate
ProjectionPredicate should be able to handle both associated types and consts so this adds the
first step of that. It mainly just pipes types all the way down, not entirely sure how to handle
consts, but hopefully that'll come with time.
2022-01-17 17:44:56 +00:00
kadmin
fb57b7518d Add term
Instead of having a separate enum variant for types and consts have one but have either a const
or type.
2022-01-17 17:20:57 +00:00
kadmin
0765999622 add eq constraints on associated constants 2022-01-17 17:20:57 +00:00
bjorn3
042aa379a5 Pass target_features set instead of has_feature closure
This avoids unnecessary monomorphizations in codegen backends
2022-01-17 18:06:30 +01:00
bjorn3
991cbd1503 Use Symbol for target features in asm handling
This saves a couple of Symbol::intern calls
2022-01-17 18:06:27 +01:00
bors
ee5d8d37ba Auto merge of #90986 - camsteffen:nested-filter, r=cjgillot
Replace `NestedVisitorMap` with generic `NestedFilter`

This is an attempt to make the `intravisit::Visitor` API simpler and "more const" with regard to nested visiting.

With this change, `intravisit::Visitor` does not visit nested things by default, unless you specify `type NestedFilter = nested_filter::OnlyBodies` (or `All`). `nested_visit_map` returns `Self::Map` instead of `NestedVisitorMap<Self::Map>`. It panics by default (unreachable if `type NestedFilter` is omitted).

One somewhat trixty thing here is that `nested_filter::{OnlyBodies, All}` live in `rustc_middle` so that they may have `type Map = map::Map` and so that `impl Visitor`s never need to specify `type Map` - it has a default of `Self::NestedFilter::Map`.
2022-01-17 14:50:50 +00:00
bors
a34c079752 Auto merge of #92816 - tmiasko:rm-llvm-asm, r=Amanieu
Remove deprecated LLVM-style inline assembly

The `llvm_asm!` was deprecated back in #87590 1.56.0, with intention to remove
it once `asm!` was stabilized, which already happened in #91728 1.59.0. Now it
is time to remove `llvm_asm!` to avoid continued maintenance cost.

Closes #70173.
Closes #92794.
Closes #87612.
Closes #82065.

cc `@rust-lang/wg-inline-asm`

r? `@Amanieu`
2022-01-17 09:40:29 +00:00
Cameron Steffen
45db716902 Replace NestedVisitorMap with NestedFilter 2022-01-16 16:02:36 -06:00
bors
ec4bcaac45 Auto merge of #92441 - cjgillot:resolve-trait-impl-item, r=matthewjasper
Link impl items to corresponding trait items in late resolver.

Hygienically linking trait impl items to declarations in the trait can be done directly by the late resolver. In fact, it is already done to diagnose unknown items.

This PR uses this resolution work and stores the `DefId` of the trait item in the HIR. This avoids having to do this resolution manually later.

r? `@matthewjasper`
Related to #90639. The added `trait_item_id` field can be moved to `ImplItemRef` to be used directly by your PR.
2022-01-15 14:43:45 +00:00
Tomasz Miąsko
000b36c505 Remove deprecated LLVM-style inline assembly 2022-01-12 18:51:31 +01:00
bjorn3
ec9c949946 Use pre-interned symbols in a couple of places 2022-01-10 17:13:33 +01:00
Camille GILLOT
1be6e2d6e9 Link impl items to corresponding trait items in late resolver. 2022-01-08 20:45:59 +01:00
Matthias Krüger
ac7a867715
Rollup merge of #91907 - lcnr:const-arg-infer, r=BoxyUwU
Allow `_` as the length of array types and repeat expressions

r? `@BoxyUwU` cc `@varkor`
2022-01-04 21:23:06 +01:00
Aaron Hill
137c374c41
Move PatKind::Lit checking from ast_validation to ast lowering
Fixes #92074

This allows us to insert an `ExprKind::Err` when an invalid expression
is used in a literal pattern, preventing later stages of compilation
from seeing an unexpected literal pattern.
2022-01-01 15:10:43 -05:00
Michael Goulet
e37d012a06 Tighten span when suggesting lifetime on path 2021-12-27 23:34:52 -08:00
lcnr
e3f5cc6c38 implement generic_arg_infer for array lengths 2021-12-23 10:09:35 +01:00
bors
a41a6925ba Auto merge of #91957 - nnethercote:rm-SymbolStr, r=oli-obk
Remove `SymbolStr`

This was originally proposed in https://github.com/rust-lang/rust/pull/74554#discussion_r466203544. As well as removing the icky `SymbolStr` type, it allows the removal of a lot of `&` and `*` occurrences.

Best reviewed one commit at a time.

r? `@oli-obk`
2021-12-19 09:31:37 +00:00
Matthias Krüger
7a626cf7ce
Rollup merge of #89090 - cjgillot:bare-dyn, r=jackh726
Lint bare traits in AstConv.

Removing the lint from lowering allows to:
- make lowering querification easier;
- have the lint implementation in only one place.

r? `@estebank`
2021-12-18 08:16:26 +01:00
bors
dde825db46 Auto merge of #89841 - cormacrelf:let-else-typed, r=nagisa
Implement let-else type annotations natively

Tracking issue: #87335

Fixes #89688, fixes #89807, edit: fixes  #89960 as well

As explained in https://github.com/rust-lang/rust/issues/89688#issuecomment-940405082, the previous desugaring moved the let-else scrutinee into a dummy variable, which meant if you wanted to refer to it again in the else block, it had moved.

This introduces a new hir type, ~~`hir::LetExpr`~~ `hir::Let`, which takes over all the fields of `hir::ExprKind::Let(...)` and adds an optional type annotation. The `hir::Let` is then treated like a `hir::Local` when type checking a function body, specifically:

* `GatherLocalsVisitor` overrides a new `Visitor::visit_let_expr` and does pretty much exactly what it does for `visit_local`, assigning a local type to the `hir::Let` ~~(they could be deduplicated but they are right next to each other, so at least we know they're the same)~~
* It reuses the code in `check_decl_local` to typecheck the `hir::Let`, simply returning 'bool' for the expression type after doing that.

* ~~`FnCtxt::check_expr_let` passes this local type in to `demand_scrutinee_type`, and then imitates check_decl_local's pattern checking~~
* ~~`demand_scrutinee_type` (the blindest change for me, please give this extra scrutiny) uses this local type instead of of creating a new one~~
    * ~~Just realised the `check_expr_with_needs` was passing NoExpectation further down, need to pass the type there too. And apparently this Expectation API already exists.~~

Some other misc notes:

* ~~Is the clippy code supposed to be autoformatted? I tried not to give huge diffs but maybe some rustfmt changes simply haven't hit it yet.~~
* in `rustc_ast_lowering/src/block.rs`, I noticed some existing `self.alias_attrs()` calls in `LoweringContext::lower_stmts` seem to be copying attributes from the lowered locals/etc to the statements. Is that right? I'm new at this, I don't know.
2021-12-17 22:12:34 +00:00
Matthias Krüger
6b00227666
Rollup merge of #91888 - BoxyUwU:generic_arg_infer_aaaa, r=lcnr
Handle unordered const/ty generics for object lifetime defaults

*feel like I should have a PR description but cant think of what to put here*

r? ```@lcnr```
2021-12-15 08:36:23 +01:00
Matthias Krüger
d258e92900
Rollup merge of #90521 - jhpratt:stabilize-destructuring_assignment, r=jackh726,pnkfelix
Stabilize `destructuring_assignment`

Closes #71126

- [Stabilization report](https://github.com/rust-lang/rust/issues/71126#issuecomment-941148058)
- [Completed FCP](https://github.com/rust-lang/rust/issues/71126#issuecomment-954914819)

`@rustbot` label +F-destructuring-assignment +T-lang
Also needs +relnotes but I don't have permission to add that tag.
2021-12-15 08:36:19 +01:00
Nicholas Nethercote
056d48a2c9 Remove unnecessary sigils around Symbol::as_str() calls. 2021-12-15 17:32:14 +11:00
Jacob Pratt
d95f749f14
Stabilize destructuring_assignment 2021-12-14 22:38:51 -05:00
Matthias Krüger
4e7497bda0
Rollup merge of #91881 - Patrick-Poitras:stabilize-iter-zip, r=scottmcm
Stabilize `iter::zip`

Hello all!

As the tracking issue (#83574) for `iter::zip` completed the final commenting period without any concerns being raised, I hereby submit this stabilization PR on the issue.

As the pull request that introduced the feature (#82917) states, the `iter::zip` function is a shorter way to zip two iterators. As it's generally a quality-of-life/ergonomic improvement, it has been integrated into the codebase without any trouble, and has been
used in many places across the rust compiler and standard library since March without any issues.

For more details, I would refer to `@cuviper's` original PR, or the [function's documentation](https://doc.rust-lang.org/std/iter/fn.zip.html).
2021-12-15 01:28:08 +01:00
PFPoitras
304ede6bcc Stabilize iter::zip. 2021-12-14 18:50:31 -04:00
Ellen
7175980ff5 awdawdawd 2021-12-14 03:32:58 +00:00
Esteban Kuber
b825b0fe63 Fix rebase and clippy tests 2021-12-13 17:09:16 +00:00
Esteban Kuber
f640438b40 Keep info on pre-desugaring expression for better "incorrect .await" suggestion
Keep the `HirId` of `.await`ed expressions so in the case of a `fn` call
on on a sync `fn`, we can suggest maybe turning it into an `async fn`.
2021-12-13 17:09:16 +00:00
Esteban Kuber
7227a87371 When .await is called on a non-Future expression, suggest removal
Keep track of the origin of a `T: Future` obligation when caused by an
`.await` expression.

Address #66731.
2021-12-13 17:09:15 +00:00
Cormac Relf
9b45713b6c let-else: fix attribute aliasing + add test for issue 89807 2021-12-13 14:02:41 +11:00
Cormac Relf
af2f0e6b7c let-else: add hir::Let and type check it like a hir::Local
unify typeck of hir::Local and hir::Let
remove extraneous pub(crate/super)
2021-12-13 14:02:19 +11:00
Matthias Krüger
443ed7c620
Rollup merge of #91643 - Amanieu:r9x18, r=joshtriplett
asm: Allow using r9 (ARM) and x18 (AArch64) if they are not reserved by the current target

This supersedes https://github.com/rust-lang/rust/pull/88879.

cc `@Skirmisher`

r? `@joshtriplett`
2021-12-11 23:31:49 +01:00
Amanieu d'Antras
8716f2780e asm: Allow using r9 (ARM) and x18 (AArch64) if they are not reserved by
the current target.
2021-12-10 00:51:39 +00:00
Camille GILLOT
8576ab45e4 Store impl_trait_fn inside OpaqueTyOrigin. 2021-12-07 21:30:45 +01:00
Camille GILLOT
72b6f7049c Use collect_in_band_defs for async lifetime captures. 2021-12-07 21:21:57 +01:00
Camille GILLOT
6e7ec0c5b4 Simplify collect_in_band_defs. 2021-12-07 21:21:57 +01:00
Camille GILLOT
646f58a7e1 Lint bare traits in AstConv. 2021-12-04 23:13:58 +01:00
Mara Bos
1acb44f03c Use IntoIterator for array impl everywhere. 2021-12-04 19:40:33 +01:00
cynecx
686ace3b41 add unwind_asm feature gate for may_unwind option 2021-12-03 23:51:49 +01:00
bors
532d2b14c0 Auto merge of #90737 - eholk:intofuture, r=tmandry
Reintroduce `into_future` in `.await` desugaring

This is a reintroduction of the remaining parts from https://github.com/rust-lang/rust/pull/65244 that have not been relanded yet.

This isn't quite ready to merge yet. The last attempt was reverting due to performance regressions, so we need to make sure this does not introduce those issues again.

Issues #67644, #67982

/cc `@yoshuawuyts`
2021-12-03 19:29:21 +00:00
Matthias Krüger
a5ee722f1e
Rollup merge of #91273 - Badel2:ice-index-str, r=estebank
Fix ICE #91268 by checking that the snippet ends with a `)`

Fix #91268

Previously it was assumed that the last character of `snippet` will be a `)`, so using `snippet.len() - 1` as an index should be safe. However as we see in the test, it is possible to enter that branch without a closing `)`, and it will trigger the panic if the last character happens to be multibyte.

The fix is to ensure that the snippet ends with `)`, and skip the suggestion otherwise.
2021-12-03 06:24:14 +01:00
Camille GILLOT
aa2450f41b Merge Implicit and ImplicitMissing. 2021-11-30 22:56:47 +01:00
Camille GILLOT
b621133200 Simplify lowering. 2021-11-30 22:55:07 +01:00
Camille GILLOT
5ea7ea8a57 Lint elided lifetimes in path during lifetime resolution. 2021-11-30 22:55:07 +01:00
Badel2
0da3a0f56e Fix ICE #91268 by checking that the snippet ends with a ) 2021-11-26 23:57:21 +01:00
bors
9adfd9db78 Auto merge of #85102 - estebank:point-at-assignment, r=oli-obk
Diagnostic tweaks

* On type mismatch caused by assignment, point at the source of the expectation
* Hide redundant errors
* Suggest `while let` when `let` is missing in some cases
2021-11-26 03:57:55 +00:00
Esteban Küber
37a11a96a1 On type mismatch caused by assignment, point at assignee
* Do not emit unnecessary E0308 after E0070
* Show fewer errors on `while let` missing `let`
* Hide redundant E0308 on `while let` missing `let`
* Point at binding definition when possible on invalid assignment
* do not point at closure twice
* do not suggest `if let` for literals in lhs
* account for parameter types
2021-11-25 18:04:33 +00:00
Camille GILLOT
ae126ad282 Do not visit attributes in ItemLowerer.
By default, AST visitors visit expressions that appear in key-value attributes.
Those expressions should not be lowered to HIR, as they do not correspond to actually compiled code.

Since an attribute cannot produce meaningful HIR, just skip them altogether.
2021-11-23 22:06:22 +01:00
Eric Holk
ca2057cedf Fix comments 2021-11-22 14:57:33 -08:00
Eric Holk
dfa0db5961 Reintroduce into_future in .await desugaring
This is a reintroduction of the remaining parts from
https://github.com/rust-lang/rust/pull/65244 that have not been relanded
yet.

Issues GH-67644, GH-67982
2021-11-22 14:57:27 -08:00
Cameron Steffen
9c83f8c4d1 Simplify for loop desugar 2021-11-21 08:15:21 -06:00
Yuki Okushi
1576a7cc81
Rollup merge of #90990 - nnethercote:arenas-cleanup, r=oli-obk
Arenas cleanup

I was looking closely at the arenas code and here are some small improvement to readability.
2021-11-19 13:06:38 +09:00
Vadim Petrochenkov
91e02177a1 rustc: Remove #[rustc_synthetic]
This function parameter attribute was introduced in https://github.com/rust-lang/rust/pull/44866 as an intermediate step in implementing `impl Trait`, it's not necessary or used anywhere by itself.
2021-11-18 14:32:29 +08:00
Nicholas Nethercote
552073701f Remove unnecessary lifetime argument from arena macros.
Because it's always `'tcx`. In fact, some of them use a mixture of
passed-in `$tcx` and hard-coded `'tcx`, so no other lifetime would even
work.

This makes the code easier to read.
2021-11-17 09:38:30 +11:00
asquared31415
b233d3b5da Add support for specifying multiple clobber_abi in asm!
Allow multiple clobber_abi in asm

Update docs
Fix aarch64 test
Combine abis
Emit duplicate ABI error, empty ABI list error
multiple clobber_abi
2021-11-10 01:06:03 -05:00
Vadim Petrochenkov
2834f57c45 ast: Fix naming conventions in AST structures
TraitKind -> Trait
TyAliasKind -> TyAlias
ImplKind -> Impl
FnKind -> Fn

All `*Kind`s in AST are supposed to be enums.

Tuple structs are converted to braced structs for the types above, and fields are reordered in syntactic order.

Also, mutable AST visitor now correctly visit spans in defaultness, unsafety, impl polarity and constness.
2021-11-07 21:38:17 +08:00
Amanieu d'Antras
eb32c00216 Add features gates for experimental asm features 2021-11-07 01:23:53 +00:00
bors
88a5a984fe Auto merge of #90380 - Mark-Simulacrum:revert-89558-query-stable-lint, r=lcnr
Revert "Add rustc lint, warning when iterating over hashmaps"

Fixes perf regressions introduced in https://github.com/rust-lang/rust/pull/90235 by temporarily reverting the relevant PR.
2021-10-29 04:55:51 +00:00
Mark Rousskov
3215eeb99f
Revert "Add rustc lint, warning when iterating over hashmaps" 2021-10-28 11:01:42 -04:00
bors
c4ff03f689 Auto merge of #90145 - cjgillot:sorted-map, r=michaelwoerister
Use SortedMap in HIR.

Closes https://github.com/rust-lang/rust/issues/89788
r? `@ghost`
2021-10-28 13:04:40 +00:00
Yuki Okushi
630df7c54a
Remove unnecessary check for registers
`is_clobber()` already checks if `reg` is a register and the both
values should be the same.
2021-10-26 11:02:51 +09:00
Yuki Okushi
f5cbb9b9e6
Fix some typos 2021-10-26 11:02:47 +09:00
Matthias Krüger
87822b27ee
Rollup merge of #89558 - lcnr:query-stable-lint, r=estebank
Add rustc lint, warning when iterating over hashmaps

r? rust-lang/wg-incr-comp
2021-10-24 15:48:42 +02:00
Yuki Okushi
91fb223f59
Rollup merge of #89895 - camsteffen:for-loop-head-span, r=davidtwco
Don't mark for loop iter expression as desugared

We typically don't mark spans of lowered things as desugared. This helps Clippy rightly discern when code is (not) from expansion. This was discovered by ``@flip1995`` at https://github.com/rust-lang/rust-clippy/pull/7789#issuecomment-939289501.
2021-10-22 19:42:45 +09:00
Camille GILLOT
6f6fa8b954 Use SortedMap in HIR. 2021-10-21 23:08:57 +02:00
bors
bd41e09da3 Auto merge of #89124 - cjgillot:owner-info, r=michaelwoerister
Index and hash HIR as part of lowering

Part of https://github.com/rust-lang/rust/pull/88186
~Based on https://github.com/rust-lang/rust/pull/88880 (see merge commit).~

Once HIR is lowered, it is later indexed by the `index_hir` query and hashed for `crate_hash`. This PR moves those post-processing steps to lowering itself. As a side objective, the HIR crate data structure is refactored as an `IndexVec<LocalDefId, Option<OwnerInfo<'hir>>>` where `OwnerInfo` stores all the relevant information for an HIR owner.

r? `@michaelwoerister`
cc `@petrochenkov`
2021-10-18 19:53:05 +00:00
Vadim Petrochenkov
a6808335d4 rustc_span: Ident::invalid -> Ident::empty
The equivalent for `Symbol`s was renamed some time ago (`kw::Invalid` -> `kw::Empty`), and it makes sense to do the same thing for `Ident`s.
2021-10-17 23:20:30 +03:00
Cameron Steffen
a697aa63d6 Use more lowered spans in for loop 2021-10-15 08:04:51 -05:00
Cameron Steffen
bd1a1e4f0d Don't mark for loop head span with desugaring 2021-10-15 08:04:50 -05:00
lcnr
00e5abe9b6 allow potential_query_instability everywhere 2021-10-15 10:58:18 +02:00
Camille GILLOT
c5628a5e65 Use invalid local id for zeroth node parent. 2021-10-12 08:41:53 +02:00
Camille GILLOT
12b39e5912 Make naming more explicit. 2021-10-11 22:36:37 +02:00
Camille GILLOT
0431fdb113 Compute full HIR hash during lowering. 2021-10-10 00:05:49 +02:00
Camille GILLOT
41e80b85cf Directly use AttributeMap inside OwnerInfo. 2021-10-10 00:05:35 +02:00
Camille GILLOT
1c7f85f17c Perform indexing during lowering.
Do not access DefId<->HirId maps before they are initialized.
2021-10-09 23:47:59 +02:00
Camille GILLOT
ed3c8e86cb Hash during lowering. 2021-10-09 19:44:55 +02:00
Camille GILLOT
457de08487 Forbid hashing HIR outside of indexing. 2021-10-09 18:38:28 +02:00
Camille GILLOT
cd1ace488f Use an IndexVec for bodies. 2021-10-09 14:01:09 +02:00
Camille GILLOT
48a339ddbb Store lowering outputs per owner. 2021-10-09 11:56:29 +02:00
Matthias Krüger
5ebb6a8fd9
Rollup merge of #89641 - asquared31415:asm-feature-attr-regs, r=oli-obk
make #[target_feature] work with `asm` register classes

Fixes #89289
2021-10-09 11:56:00 +02:00
Matthias Krüger
e6f77a1787 clippy::complexity fixes 2021-10-08 20:07:44 +02:00
asquared31415
271da7d8bc make #[target_feature] work with asm register classes 2021-10-07 15:42:18 -04:00
Cameron Steffen
67ea84d97a Add desugaring mark to while loop 2021-10-02 17:41:14 -05:00
Manish Goregaokar
746e46548c
Rollup merge of #89344 - jackh726:maybe-bound-eror, r=cjgillot
Cleanup lower_generics_mut and make span be the bound itself

Closes #86298 (supersedes those changes)

r? `@cjgillot` since you reviewed the other PR

(Used wrong branch for #89338)
2021-09-30 23:41:09 -07:00
jackh726
e1a9ecca26 Cleanup lower_generics_mut and make span be the bound itself, not the type 2021-09-29 13:31:03 -04:00
Vadim Petrochenkov
fbe5e5c0ee rustc_index: Add some map-like APIs to IndexVec 2021-09-22 03:11:29 +03:00
bors
ac2d9fc509 Auto merge of #89103 - Mark-Simulacrum:migrate-2021, r=estebank
Migrate in-tree crates to 2021

This replaces #89075 (cherry picking some of the commits from there), and closes #88637 and fixes #89074.

It excludes a migration of the library crates for now (see tidy diff) because we have some pending bugs around macro spans to fix there.

I instrumented bootstrap during the migration to make sure all crates moved from 2018 to 2021 had the compatibility warnings applied first.

Originally, the intent was to support cargo fix --edition within bootstrap, but this proved fairly difficult to pull off. We'd need to architect the check functionality to support running cargo check and cargo fix within the same x.py invocation, and only resetting sysroots on check. Further, it was found that cargo fix doesn't behave too well with "not quite workspaces", such as Clippy which has several crates. Bootstrap runs with --manifest-path ... for all the tools, and this makes cargo fix only attempt migration for that crate. We can't use e.g. --workspace due to needing to maintain sysroots for different phases of compilation appropriately.

It is recommended to skip the mass migration of Cargo.toml's to 2021 for review purposes; you can also use `git diff d6cd2c6c87 -I'^edition = .20...$'` to ignore the edition = 2018/21 lines in the diff.
2021-09-21 19:25:49 +00:00
Mark Rousskov
c746be2219 Migrate to 2021 2021-09-20 22:21:42 -04:00
Camille GILLOT
a1a35576eb Make with_hir_id_owner responsible for registering the item. 2021-09-20 08:31:16 +02:00
Camille GILLOT
c1bac9229a Remove lower_node_id_with_owner. 2021-09-20 00:50:47 +02:00
Camille GILLOT
d7795d302a Do not store visibility in *ItemRef. 2021-09-20 00:29:53 +02:00
bors
7b5f95270f Auto merge of #88703 - cjgillot:lazymod, r=petrochenkov
Gather module items after lowering.

This avoids having a non-local analysis inside lowering.

By implementing `hir_module_items` using a visitor, we make sure that iterations and visitors are consistent.
2021-09-19 16:13:42 +00:00
bors
697118d23e Auto merge of #88627 - cjgillot:noallocuse, r=petrochenkov
Do not preallocate HirIds

Part of https://github.com/rust-lang/rust/pull/87234

r? `@petrochenkov`
2021-09-19 13:44:18 +00:00
Camille GILLOT
d60bbde7e2 Do not preallocate UseTree HirIds. 2021-09-18 14:41:50 +02:00
Camille GILLOT
59f43bdd29 Do not preallocate item HirIds. 2021-09-18 13:14:29 +02:00
Manish Goregaokar
fb2d7dff80
Rollup merge of #88775 - pnkfelix:revert-anon-union-parsing, r=davidtwco
Revert anon union parsing

Revert PR #84571 and #85515, which implemented anonymous union parsing in a manner that broke the context-sensitivity for the `union` keyword and thus broke stable Rust code.

Fix #88583.
2021-09-15 14:56:58 -07:00
Camille GILLOT
fa6f5adf73 Gather module items after lowering. 2021-09-12 16:33:16 +02:00
bors
547d9374d2 Auto merge of #84373 - cjgillot:resolve-span, r=michaelwoerister,petrochenkov
Encode spans relative to the enclosing item

The aim of this PR is to avoid recomputing queries when code is moved without modification.

MCP at https://github.com/rust-lang/compiler-team/issues/443

This is achieved by :
1. storing the HIR owner LocalDefId information inside the span;
2. encoding and decoding spans relative to the enclosing item in the incremental on-disk cache;
3. marking a dependency to the `source_span(LocalDefId)` query when we translate a span from the short (`Span`) representation to its explicit (`SpanData`) representation.

Since all client code uses `Span`, step 3 ensures that all manipulations
of span byte positions actually create the dependency edge between
the caller and the `source_span(LocalDefId)`.
This query return the actual absolute span of the parent item.
As a consequence, any source code motion that changes the absolute byte position of a node will either:
- modify the distance to the parent's beginning, so change the relative span's hash;
- dirty `source_span`, and trigger the incremental recomputation of all code that
  depends on the span's absolute byte position.

With this scheme, I believe the dependency tracking to be accurate.

For the moment, the spans are marked during lowering.
I'd rather do this during def-collection,
but the AST MutVisitor is not practical enough just yet.
The only difference is that we attach macro-expanded spans
to their expansion point instead of the macro itself.
2021-09-11 23:35:28 +00:00
Camille GILLOT
7842b80478 Rebase fallout. 2021-09-11 17:52:39 +02:00
bors
4e880f8cbc Auto merge of #88214 - notriddle:notriddle/for-loop-span-drop-temps-mut, r=nagisa
rustc: use more correct span data in for loop desugaring

Fixes #82462

Before:

      help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
         |
      LL |     for x in DroppingSlice(&*v).iter(); {
         |                                       +

After:

      help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
         |
      LL |     };
         |      +

This seems like a reasonable fix: since the desugared "expr_drop_temps_mut" contains the entire desugared loop construct, its span should contain the entire loop construct as well.
2021-09-11 07:11:01 +00:00