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2021-09-01Fix drop handling for `if let` expressionsMatthew Jasper-5/+6
MIR lowering for `if let` expressions is now more complicated now that `if let` exists in HIR. This PR adds a scope for the variables bound in an `if let` expression and then uses an approach similar to how we handle loops to ensure that we reliably drop the correct variables.
2021-09-01Rollup merge of #86376 - asquared31415:extern-no-mangle-84204, r=Mark-SimulacrumMara Bos-0/+30
Emit specific warning to clarify that `#[no_mangle]` should not be applied on foreign statics or functions Foreign statics and foreign functions should not have `#[no_mangle]` applied, as it does nothing to the name and has some extra hidden behavior that is normally unwanted. There was an existing warning for this, but it says the attribute is only allowed on "statics or functions", which to the user can be confusing. This PR adds a specific version of the unused `#[no_mangle]` warning that explains that the target is a *foreign* static or function and that they do not need the attribute. Fixes #78989
2021-08-29emit specific warning to clarify that foreign items can't have no_mangleasquared31415-0/+30
remove extra commented code Deduplicate some diagnostics code add code symbols, machine applicable suggestion clarify error message
2021-08-29Auto merge of #88337 - eddyb:field-failure-is-not-an-option, r=nagisabors-1/+1
rustc_target: `TyAndLayout::field` should never error. This refactor (making `TyAndLayout::field` return `TyAndLayout` without any `Result` around it) is based on a simple observation, regarding `TyAndLayout::field`: If `cx.layout_of(ty)` succeeds (for some `cx` and `ty`), then `.field(cx, i)` on the resulting `TyAndLayout` should *always* succeed in computing `cx.layout_of(field_ty)` (where `field_ty` is the type of the `i`th field of `ty`). The reason for this is that no matter which field is chosen, `cx.layout_of(field_ty)` *will have already been computed*, as part of computing `cx.layout_of(ty)`, as we cannot determine the layout of *any* type without considering the layouts of *all* of its fields. And so it should be fine to turn any errors into ICEs, since they likely indicate a `cx` mismatch, or some other edge case that is due to a compiler bug (as opposed to ever being an user-facing error). <hr/> Each commit should probably be reviewed separately, though note that there's some `where` clauses (in `rustc_target::abi::call::*`) that change in most commits. cc `@nagisa` `@oli-obk`
2021-08-28Remove obsolete `MacroDef` variant of `OwnerNode`inquisitivecrystal-2/+1
2021-08-28Treat macros as HIR itemsinquisitivecrystal-38/+15
2021-08-27rustc_target: add lifetime parameter to `LayoutOf`.Eduard-Mihai Burtescu-1/+1
2021-08-25Auto merge of #87875 - asquared31415:generic-lang-items, r=cjgillotbors-87/+35
Improve detection of generics on lang items Adds detection for the required generics for all lang items. Many lang items require an exact or minimum amount of generic arguments and if they don't exist, the compiler will ICE. This does not add any additional validation about bounds on generics or any other lang item restrictions. Fixes one of the ICEs in #87573 cc `@FabianWolff`
2021-08-25Auto merge of #84333 - tmiasko:liveness-yield, r=tmandrybors-3/+11
Improve liveness analysis for generators Liveness analysis for generators assumes that execution always continues normally after a yield point, not accounting for the fact that generator could be dropped before completion. If generators captures any variables by reference, those variables could be used within a generator, or when the generator completes, but also after each yield point in the case the generator is dropped. Account for the case when generator is dropped after yielding, but before running to the completion. This effectively considers all variables captured by reference to be used after a yield point. Fixes #84292.
2021-08-24Auto merge of #88271 - sexxi-goose:liveness, r=nikomatsakisbors-30/+6
2229: Consider varaiables mentioned in closure as used Fixes: https://github.com/rust-lang/project-rfc-2229/issues/57 r? `@nikomatsakis`
2021-08-24Improve liveness analysis for generatorsTomasz Miąsko-3/+11
Liveness analysis for generators assumes that execution always continues normally after a yield point, not accounting for the fact that generator could be dropped before completion. If generators captures any variables by reference, those variables could be used within a generator, or when the generator completes, but also after each yield point in the case the generator is dropped. Account for the case when generator is dropped after yielding, but before running to the completion. This effectively considers all variables captured by reference to be used after a yield point.
2021-08-24Auto merge of #87739 - Aaron1011:remove-used-attrs, r=wesleywiserbors-17/+174
Remove `Session.used_attrs` and move logic to `CheckAttrVisitor` Instead of updating global state to mark attributes as used, we now explicitly emit a warning when an attribute is used in an unsupported position. As a side effect, we are to emit more detailed warning messages (instead of just a generic "unused" message). `Session.check_name` is removed, since its only purpose was to mark the attribute as used. All of the callers are modified to use `Attribute.has_name` Additionally, `AttributeType::AssumedUsed` is removed - an 'assumed used' attribute is implemented by simply not performing any checks in `CheckAttrVisitor` for a particular attribute. We no longer emit unused attribute warnings for the `#[rustc_dummy]` attribute - it's an internal attribute used for tests, so it doesn't mark sense to treat it as 'unused'. With this commit, a large source of global untracked state is removed.
2021-08-24Auto merge of #85556 - FabianWolff:issue-85071, r=estebank,jackh726bors-31/+72
Warn about unreachable code following an expression with an uninhabited type This pull request fixes #85071. The issue is that liveness analysis currently is "smarter" than reachability analysis when it comes to detecting uninhabited types: Unreachable code is detected during type checking, where full type information is not yet available. Therefore, the check for type inhabitedness is quite crude: https://github.com/rust-lang/rust/blob/fc81ad22c453776de16acf9938976930cf8c9401/compiler/rustc_typeck/src/check/expr.rs#L202-L205 i.e. it only checks for `!`, but not other, non-trivially uninhabited types, such as empty enums, structs containing an uninhabited type, etc. By contrast, liveness analysis, which runs after type checking, can benefit from the more sophisticated `tcx.is_ty_uninhabited_from()`: https://github.com/rust-lang/rust/blob/fc81ad22c453776de16acf9938976930cf8c9401/compiler/rustc_passes/src/liveness.rs#L981 https://github.com/rust-lang/rust/blob/fc81ad22c453776de16acf9938976930cf8c9401/compiler/rustc_passes/src/liveness.rs#L996 This can lead to confusing warnings when a variable is reported as unused, but the use of the variable is not reported as unreachable. For instance: ```rust enum Foo {} fn f() -> Foo {todo!()} fn main() { let x = f(); let _ = x; } ``` currently leads to ``` warning: unused variable: `x` --> t1.rs:5:9 | 5 | let x = f(); | ^ help: if this is intentional, prefix it with an underscore: `_x` | = note: `#[warn(unused_variables)]` on by default warning: 1 warning emitted ``` which is confusing, because `x` _appears_ to be used in line 6. With my changes, I get: ``` warning: unreachable expression --> t1.rs:6:13 | 5 | let x = f(); | --- any code following this expression is unreachable 6 | let _ = x; | ^ unreachable expression | = note: `#[warn(unreachable_code)]` on by default note: this expression has type `Foo`, which is uninhabited --> t1.rs:5:13 | 5 | let x = f(); | ^^^ warning: unused variable: `x` --> t1.rs:5:9 | 5 | let x = f(); | ^ help: if this is intentional, prefix it with an underscore: `_x` | = note: `#[warn(unused_variables)]` on by default warning: 2 warnings emitted ``` My implementation is slightly inelegant because unreachable code warnings can now be issued in two different places (during type checking and during liveness analysis), but I think it is the solution with the least amount of unnecessary code duplication, given that the new warning integrates nicely with liveness analysis, where unreachable code is already implicitly detected for the purpose of finding unused variables.
2021-08-232229: Consider varaiables mentioned in closure as usedAman Arora-30/+6
2021-08-23Detect incorrect number of lang item genericsasquared31415-87/+35
2021-08-21Address review commentsAaron Hill-1/+6
2021-08-21Remove `Session.used_attrs` and move logic to `CheckAttrVisitor`Aaron Hill-17/+169
Instead of updating global state to mark attributes as used, we now explicitly emit a warning when an attribute is used in an unsupported position. As a side effect, we are to emit more detailed warning messages (instead of just a generic "unused" message). `Session.check_name` is removed, since its only purpose was to mark the attribute as used. All of the callers are modified to use `Attribute.has_name` Additionally, `AttributeType::AssumedUsed` is removed - an 'assumed used' attribute is implemented by simply not performing any checks in `CheckAttrVisitor` for a particular attribute. We no longer emit unused attribute warnings for the `#[rustc_dummy]` attribute - it's an internal attribute used for tests, so it doesn't mark sense to treat it as 'unused'. With this commit, a large source of global untracked state is removed.
2021-08-18Rollup merge of #88036 - nbdd0121:const3, r=petrochenkovGuillaume Gomez-0/+7
Fix dead code warning when inline const is used in pattern Fixes #78171
2021-08-18Auto merge of #87985 - nbdd0121:asm, r=Amanieubors-5/+10
Forbid `!` from being used in `asm!` output Fixes #87802 r? `@Amanieu`
2021-08-16Add check for doc(test(...)) attributeGuillaume Gomez-2/+43
2021-08-16Auto merge of #87050 - jyn514:no-doc-primitive, r=manishearthbors-1/+16
Add future-incompat lint for `doc(primitive)` ## What is `doc(primitive)`? `doc(primitive)` is an attribute recognized by rustdoc which adds documentation for the built-in primitive types, such as `usize` and `()`. It has been stable since Rust 1.0. ## Why change anything? `doc(primitive)` is useless for anyone outside the standard library. Since rustdoc provides no way to combine the documentation on two different primitive items, you can only replace the docs, and since the standard library already provides extensive documentation there is no reason to do so. While fixing rustdoc's handling of primitive items (https://github.com/rust-lang/rust/pull/87073) I discovered that even rustdoc's existing handling of primitive items was broken if you had more than two crates using it (it would pick randomly between them). That meant both: - Keeping rustdoc's existing treatment was nigh-impossible, because it was random. - doc(primitive) was even more useless than it would otherwise be. The only use-case for this outside the standard library is for no-std libraries which want to link to primitives (https://github.com/rust-lang/rust/issues/73423) which is being fixed in https://github.com/rust-lang/rust/pull/87073. https://github.com/rust-lang/rust/pull/87073 makes various breaking changes to `doc(primitive)` (breaking in the sense that they change the semantics, not in that they cause code to fail to compile). It's not possible to avoid these and still fix rustdoc's issues. ## What can we do about it? As shown by the crater run (https://github.com/rust-lang/rust/pull/87050#issuecomment-886166706), no one is actually using doc(primitive), there wasn't a single true regression in the whole run. We can either: 1. Feature gate it completely, breaking anyone who crater missed. They can easily fix the breakage just by removing the attribute. 2. add it to the `INVALID_DOC_ATTRIBUTES` future-incompat lint, and at the same time make it a no-op unless you add a feature gate. That would mean rustdoc has to look at the features of dependent crates, because it needs to know where primitives are defined in order to link to them. 3. add it to `INVALID_DOC_ATTRIBUTES`, but still use it to determine where primitives come from 4. do nothing; the behavior will silently change in https://github.com/rust-lang/rust/pull/87073. My preference is for 2, but I would also be happy with 1 or 3. I don't think we should silently change the behavior. This PR currently implements 3.
2021-08-16Auto merge of #88032 - hyd-dev:no-mangle-method, r=petrochenkovbors-15/+16
Fix `reachable_set` for non-function items in non-library crates I unintentionally changed `reachable_set` to ignore non-function items when `!self.any_library` in https://github.com/rust-lang/rust/pull/86492, which can lead to "undefined reference" errors in non-library (`cdylib`/`staticlib`/`bin`) crates, for example: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=6bb2c5065a9be7e40943d0541e161b5a This PR restores the behavior of `reachable_set` for non-function items. Fixes https://github.com/rust-lang/rust/issues/88016. <details> <summary>The modified test will fail with this output without the `reachable_set` change</summary> ``` ---- [codegen] codegen/external-no-mangle-statics.rs#staticlib stdout ---- error in revision `staticlib`: verification with 'FileCheck' failed status: exit status: 1 command: "/checkout/build/x86_64-unknown-linux-gnu/ci-llvm/bin/FileCheck" "--input-file" "/checkout/build/x86_64-unknown-linux-gnu/test/codegen/external-no-mangle-statics.staticlib/external-no-mangle-statics.ll" "/checkout/src/test/codegen/external-no-mangle-statics.rs" "--check-prefixes" "CHECK,NONMSVC,staticlib" stdout: ------------------------------------------ ------------------------------------------ stderr: ------------------------------------------ /checkout/src/test/codegen/external-no-mangle-statics.rs:10:11: error: CHECK: expected string not found in input // CHECK: `@A` = local_unnamed_addr constant ^ /checkout/build/x86_64-unknown-linux-gnu/test/codegen/external-no-mangle-statics.staticlib/external-no-mangle-statics.ll:1:1: note: scanning from here ; ModuleID = 'external_no_mangle_statics.b50529d3-cgu.0' ^ /checkout/build/x86_64-unknown-linux-gnu/test/codegen/external-no-mangle-statics.staticlib/external-no-mangle-statics.ll:1:6: note: possible intended match here ; ModuleID = 'external_no_mangle_statics.b50529d3-cgu.0' ^ Input file: /checkout/build/x86_64-unknown-linux-gnu/test/codegen/external-no-mangle-statics.staticlib/external-no-mangle-statics.ll Check file: /checkout/src/test/codegen/external-no-mangle-statics.rs -dump-input=help explains the following input dump. Input was: <<<<<< 1: ; ModuleID = 'external_no_mangle_statics.b50529d3-cgu.0' check:10'0 X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found check:10'1 ? possible intended match 2: source_filename = "external_no_mangle_statics.b50529d3-cgu.0" check:10'0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 3: target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" check:10'0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4: target triple = "x86_64-unknown-linux-gnu" check:10'0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 5: check:10'0 ~ 6: !llvm.module.flags = !{!0, !1} check:10'0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ . . . >>>>>> ------------------------------------------ failures: [codegen] codegen/external-no-mangle-statics.rs#staticlib ``` </details>
2021-08-16feature gate doc(primitive)Joshua Nelson-1/+16
2021-08-15Introduce hir::ExprKind::Let - Take 2Caio-9/+18
2021-08-15Use correct drop scopes for if expressionsMatthew Jasper-4/+20
2021-08-14Fix dead code warning when inline const is used in patternGary Guo-0/+7
2021-08-15Fix `reachable_set` for non-function items in non-library crateshyd-dev-15/+16
2021-08-12Forbid `!` from being used in `asm!` outputGary Guo-5/+10
2021-08-12Adjust `check_no_mangle` and `check_export_name` to warn/error on ↵hyd-dev-12/+20
`#[no_mangle]`/`#[export_name]` on trait methods
2021-08-12Add associated functions that have custom linkage to `reachable_set`hyd-dev-13/+21
2021-08-07Auto merge of #87772 - npmccallum:naked_abi, r=Amanieubors-1/+2
Move naked function ABI check to its own lint This check was previously categorized under the lint named `UNSUPPORTED_NAKED_FUNCTIONS`. That lint is future incompatible and will be turned into an error in a future release. However, as defined in the Constrained Naked Functions RFC, this check should only be a warning. This is because it is possible for a naked function to be implemented in such a way that it does not break even the undefined ABI. For example, a `jmp` to a `const`. Therefore, this patch defines a new lint named `UNDEFINED_NAKED_FUNCTION_ABI` which contains just this single check. Unlike `UNSUPPORTED_NAKED_FUNCTIONS`, `UNDEFINED_NAKED_FUNCTION_ABI` will not be converted to an error in the future. rust-lang/rfcs#2774 rust-lang/rfcs#2972
2021-08-04Disable unused variable lint for naked functionsNathaniel McCallum-0/+5
In most calling conventions, accessing function parameters may require stack access. However, naked functions have no assembly prelude to set up stack access. This is why naked functions may only contain a single `asm!()` block. All parameter access is done inside the `asm!()` block, so we cannot validate the liveness of the input parameters. Therefore, we should disable the lint for naked functions. rust-lang/rfcs#2774 rust-lang/rfcs#2972
2021-08-04Move naked function ABI check to its own lintNathaniel McCallum-1/+2
This check was previously categorized under the lint named `UNSUPPORTED_NAKED_FUNCTIONS`. That lint is future incompatible and will be turned into an error in a future release. However, as defined in the Constrained Naked Functions RFC, this check should only be a warning. This is because it is possible for a naked function to be implemented in such a way that it does not break even the undefined ABI. For example, a `jmp` to a `const`. Therefore, this patch defines a new lint named `UNDEFINED_NAKED_FUNCTION_ABI` which contains just this single check. Unlike `UNSUPPORTED_NAKED_FUNCTIONS`, `UNDEFINED_NAKED_FUNCTION_ABI` will not be converted to an error in the future. rust-lang/rfcs#2774 rust-lang/rfcs#2972
2021-08-04Auto merge of #87568 - petrochenkov:localevel, r=cjgillotbors-103/+96
rustc: Replace `HirId`s with `LocalDefId`s in `AccessLevels` tables and passes using those tables - primarily privacy checking, stability checking and dead code checking. All these passes work with definitions rather than with arbitrary HIR nodes. r? `@cjgillot` cc `@lambinoo` (#87487)
2021-08-02Validate that naked functions are never inlinedNathaniel McCallum-1/+11
Reject all uses of the inline attribute on naked functions. rust-lang/rfcs#2774 rust-lang/rfcs#2972
2021-08-01Auto merge of #87449 - matthiaskrgr:clippyy_v2, r=nagisabors-2/+2
more clippy::complexity fixes (also a couple of clippy::perf fixes)
2021-07-31rustc: Replace `HirId`s with `LocalDefId`s in `AccessLevels` tablesVadim Petrochenkov-103/+96
and passes using them - primarily privacy checking, stability checking and dead code checking. WIP
2021-07-29Add feature gates for `for` and `?` in constsJonas Schievink-4/+5
2021-07-25clippy::useless_formatMatthias Krüger-2/+2
2021-07-25Only check macro attributes when checking the crate root.Camille GILLOT-2/+2
2021-07-25Introduce OwnerNode::Crate.Camille GILLOT-3/+3
2021-07-25Merge the BTreeMap in hir::Crate.Camille GILLOT-1/+1
2021-07-21Allow some temporarily dead code.Felix S. Klock II-0/+2
I expect these two methods to come back very soon; noise of removing them to satisfy lint seems wrong.
2021-07-21Revert PR 81473 to resolve (on mainline) issues 81626 and 81658.Felix S. Klock II-6/+0
Revert "Add missing brace" This reverts commit 85ad773049536d7fed9a94ae0ac74f97135c8655. Revert "Simplify base_expr" This reverts commit 899aae465eb4ef295dc1eeb2603f744568e0768c. Revert "Warn write-only fields" This reverts commit d3c69a4c0dd98af2611b7553d1a65afef6a6ccb0.
2021-07-14Warn about useless assignments of variables/fields to themselvesFabian Wolff-0/+54
2021-07-13Auto merge of #86857 - fee1-dead:add-attr, r=oli-obkbors-18/+52
Add #[default_method_body_is_const] `@rustbot` label F-const_trait_impl
2021-07-12Auto merge of #86320 - hi-rustin:rustin-patch-fix-span, r=estebankbors-1/+2
shrinking the deprecated span ref: https://github.com/rust-lang/rust/pull/85617#issuecomment-854947988 part of #85403 r? `@estebank` The reason is that if we use method_span directly, it will cause the in_derive_expansion judgment to fail.
2021-07-11Auto merge of #85941 - cjgillot:qresolve, r=Aaron1011bors-24/+27
Reduce the amount of untracked state in TyCtxt -- Take 2 Main part of #85153 The offending line (https://github.com/rust-lang/rust/pull/85153#discussion_r642866298) is replaced by a FIXME until the possible bug and the perf concern are both resolved. r? `@Aaron1011`
2021-07-10Check if the attribute is applied correctlyDeadbeef-0/+26
2021-07-10Applied suggestionsDeadbeef-11/+6
generated by cgit-pink 1.4.1-3-g733a5 (git 2.37.1) at 2026-07-10 22:08:24 +0000