[8/n] rustc: clean up lookup_item_type and remove TypeScheme.#37688

eddyb · 2016-11-10T12:20:15Z

This is part of a series (prev | next) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. MIR-based early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well.
If any motivation is unclear, please ask for additional PR description clarifications or code comments.

#35605 introduced an uniform lookup_generics but didn't clean up everything. This PR changes:

tcx.tcache -> tcx.item_types
TypeScheme (grouping Ty and ty::Generics) is removed
tcx.item_types entries no longer duplicated in tcx.tables.node_types
tcx.lookup_item_type(def_id).ty -> tcx.item_type(def_id)
tcx.lookup_item_type(def_id).generics -> tcx.item_generics(def_id)
tcx.lookup_generics(def_id) -> tcx.item_generics(def_id)
tcx.lookup_{super_,}predicates(def_id) -> tcx.item_{super_,}predicates(def_id)

rust-highfive · 2016-11-10T12:20:27Z

r? @pnkfelix

(rust_highfive has picked a reviewer for you, use r? to override)

futile · 2016-11-10T14:07:55Z

src/librustc/ty/sty.rs

typo: s/and/an/

petrochenkov · 2016-11-10T20:51:25Z

src/librustc_typeck/collect.rs

 {
    let tt = ccx.icx(struct_predicates).to_ty(&ExplicitRscope, &field.ty);
    ty_f.fulfill_ty(tt);
-    write_ty_to_tcx(ccx, field.id, tt);


tables.node_types is never used for items now, that's why all write_ty_to_tcxs were removed from collect?

Correct, it was all a bit of a mess before, but that's all incompatible with per-body tables. Should add this change to the description.

petrochenkov · 2016-11-10T20:53:36Z

I've reviewed this and will r+ if nobody minds (modulo the question).

petrochenkov · 2016-11-10T20:57:44Z

@bors r+

bors · 2016-11-10T20:57:44Z

📌 Commit 3f9eba1 has been approved by petrochenkov

[8/n] rustc: clean up lookup_item_type and remove TypeScheme. _This is part of a series ([prev](rust-lang#37676) | [next]()) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well. If any motivation is unclear, please ask for additional PR description clarifications or code comments._ <hr> * `tcx.tcache` -> `tcx.item_types` * `TypeScheme` (grouping `Ty` and `ty::Generics`) is removed * `tcx.item_types` entries no longer duplicated in `tcx.tables.node_types` * `tcx.lookup_item_type(def_id).ty` -> `tcx.item_type(def_id)` * `tcx.lookup_item_type(def_id).generics` -> `tcx.item_generics(def_id)` * `tcx.lookup_generics(def_id)` -> `tcx.item_generics(def_id)` * `tcx.lookup_{super_,}predicates(def_id)` -> `tcx.item_{super_,}predicates(def_id)`

Rollup of 30 pull requests - Successful merges: #37190, #37368, #37481, #37503, #37527, #37535, #37551, #37584, #37600, #37613, #37615, #37659, #37662, #37669, #37682, #37688, #37690, #37692, #37693, #37694, #37695, #37696, #37698, #37699, #37705, #37708, #37709, #37716, #37724, #37727 - Failed merges: #37640, #37689, #37717

@petrochenkov

[7/n] rustc: desugar UFCS in HIR and don't use DefMap for associated resolutions. _This is part of a series ([prev](#37412) | [next](#37688)) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well. If any motivation is unclear, please ask for additional PR description clarifications or code comments._ <hr> Previously, a path like `T::Assoc::method`, while equivalent to `<<T>::Assoc>::method`, wasn't desugared in any way at the HIR level and everything inspecting it had to either deal with knowing only `T` (before typeck) or knowing only the definition of `method` (after typeck). Such a path also had only one `NodeId` and associated resolution during typeck modified `DefMap`, in a way that would be hard for incremental recompilation to track, and inconvenient for partial type conversions from HIR to `Ty`, which are required to break faux-cycles in on-demand type collection. The desugarings performed by this PR are as follows: * `use a::{b,c};` is flattened to `use a as _; use a::b; use a::c;` * as resolution is complete, `use a as _;` doesn't do anything, except get checked for stability * `Vec::new` (an expression) becomes `Vec<..>::new<..>`, to distinguish it from `<Vec>::new<..>` * the "infer all parameters" `<..>` form is internal and not even pretty-printed * used when there are no type parameters at all, in an expression or pattern path segment * `T::A::B` becomes `<<T>::A>::B` in a type, and `<<T<..>>::A<..>>::B<..>` in an expression/pattern * one additional `hir::Ty` node is created for each prefix, starting with the fully-resolved type (`T`) and extending it with each segment (e.g. `<T>::A`) * fully-resolved paths contain their `Def` in HIR, getting rid of the `DefMap` and absolving incremental recompilation of needing to manually look up nodes to handle that side information Not keeping the `DefMap` around meant that associated resolutions had to be stored somewhere else: * expressions and patterns use a new `NodeId -> Def` map in `ty::Tables` * compatible with the future per-body (constant / `fn` / closure) `Tables` * types are accessible via `Ty` and the usual per-item generics / predicates / type * `rustdoc` and `save-analysis` are the only situations which insist on mapping syntactical types to semantical ones, or at least understand the resolution of associated types, therefore the type conversion cache, i.e. a `NodeId -> Ty` map, is exposed by typeck for this purpose * stability had to be split into a pass that runs on HIR and checks the results of name resolution, and impromptu checks triggered by `typeck` for associated paths, methods, fields, etc. * privacy using semantic types results in accurate reachability for `impl Trait`, which fixes #35870, and thorough introspection of associated types, which may allow relaxing private-in-public checking on bounds, while keeping the intended ban on projections with private type parameters cc @petrochenkov

[9/n] rustc: move type information out of AdtDef and TraitDef. _This is part of a series ([prev](#37688) | [next]()) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well. If any motivation is unclear, please ask for additional PR description clarifications or code comments._ <hr> Both `AdtDef` and `TraitDef` contained type information (field types, generics and predicates) which was required to create them, preventing their use before that type information exists, or in the case of field types, *mutation* was required, leading to a variance-magicking implementation of `ivar`s. This PR takes that information out and the resulting cleaner setup could even eventually end up merged with HIR, because, just like `AssociatedItem` before it, there's no dependency on types anymore. (With one exception, variant discriminants should probably be moved into their own map later.)

[9/n] rustc: move type information out of AdtDef and TraitDef. _This is part of a series ([prev](rust-lang/rust#37688) | [next]()) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well. If any motivation is unclear, please ask for additional PR description clarifications or code comments._ <hr> Both `AdtDef` and `TraitDef` contained type information (field types, generics and predicates) which was required to create them, preventing their use before that type information exists, or in the case of field types, *mutation* was required, leading to a variance-magicking implementation of `ivar`s. This PR takes that information out and the resulting cleaner setup could even eventually end up merged with HIR, because, just like `AssociatedItem` before it, there's no dependency on types anymore. (With one exception, variant discriminants should probably be moved into their own map later.)

rust-highfive assigned pnkfelix Nov 10, 2016

eddyb mentioned this pull request Nov 10, 2016

[7/n] rustc: desugar UFCS in HIR and don't use DefMap for associated resolutions. #37676

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futile reviewed Nov 10, 2016

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src/librustc/ty/sty.rs Outdated

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futile Nov 10, 2016

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typo: s/and/an/

rustc: clean up lookup_item_type and remove TypeScheme.

3f9eba1

eddyb force-pushed the lazy-8 branch from 3c8c412 to 3f9eba1 Compare November 10, 2016 14:49

petrochenkov reviewed Nov 10, 2016

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alexcrichton added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Nov 10, 2016

eddyb mentioned this pull request Nov 11, 2016

Rollup of 29 pull requests #37726

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eddyb mentioned this pull request Nov 12, 2016

Rollup of 30 pull requests #37730

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bors merged commit 3f9eba1 into rust-lang:master Nov 12, 2016

eddyb deleted the lazy-8 branch November 12, 2016 12:17

mcarton mentioned this pull request Nov 16, 2016

Rustup to rustc 1.15.0-nightly (0ed951993 2016-11-14) and bump to 0.0.99 rust-lang/rust-clippy#1344

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eddyb mentioned this pull request Nov 28, 2016

[9/n] rustc: move type information out of AdtDef and TraitDef. #38053

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[8/n] rustc: clean up lookup_item_type and remove TypeScheme.#37688