diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs index 57d2a3c5ce9..0761d63c665 100644 --- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs @@ -40,6 +40,7 @@ impl ConstraintDescription for ConstraintCategory { ConstraintCategory::CopyBound => "copying this value ", ConstraintCategory::OpaqueType => "opaque type ", ConstraintCategory::ClosureUpvar(_) => "closure capture ", + ConstraintCategory::Usage => "this usage ", ConstraintCategory::Boring | ConstraintCategory::BoringNoLocation | ConstraintCategory::Internal => "", diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index 3e757827a5e..98d2e915028 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -1388,11 +1388,24 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { ConstraintCategory::Return(ReturnConstraint::Normal) } } + Some(l) + if matches!( + body.local_decls[l].local_info, + Some(box LocalInfo::AggregateTemp) + ) => + { + ConstraintCategory::Usage + } Some(l) if !body.local_decls[l].is_user_variable() => { ConstraintCategory::Boring } _ => ConstraintCategory::Assignment, }; + debug!( + "assignment category: {:?} {:?}", + category, + place.as_local().map(|l| &body.local_decls[l]) + ); let place_ty = place.ty(body, tcx).ty; let place_ty = self.normalize(place_ty, location); diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs index e8d30034dc4..3e9c02ee268 100644 --- a/compiler/rustc_middle/src/mir/mod.rs +++ b/compiler/rustc_middle/src/mir/mod.rs @@ -992,6 +992,9 @@ pub enum LocalInfo<'tcx> { StaticRef { def_id: DefId, is_thread_local: bool }, /// A temporary created that references the const with the given `DefId` ConstRef { def_id: DefId }, + /// A temporary created during the creation of an aggregate + /// (e.g. a temporary for `foo` in `MyStruct { my_field: foo }`) + AggregateTemp, } impl<'tcx> LocalDecl<'tcx> { diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs index 567f65e83d9..b003a504691 100644 --- a/compiler/rustc_middle/src/mir/query.rs +++ b/compiler/rustc_middle/src/mir/query.rs @@ -332,17 +332,15 @@ pub enum ConstraintCategory { CopyBound, SizedBound, Assignment, + /// A constraint that came from a usage of a variable (e.g. in an ADT expression + /// like `Foo { field: my_val }`) + Usage, OpaqueType, ClosureUpvar(hir::HirId), /// A "boring" constraint (caused by the given location) is one that /// the user probably doesn't want to see described in diagnostics, /// because it is kind of an artifact of the type system setup. - /// Example: `x = Foo { field: y }` technically creates - /// intermediate regions representing the "type of `Foo { field: y - /// }`", and data flows from `y` into those variables, but they - /// are not very interesting. The assignment into `x` on the other - /// hand might be. Boring, // Boring and applicable everywhere. BoringNoLocation, diff --git a/compiler/rustc_mir_build/src/build/expr/as_operand.rs b/compiler/rustc_mir_build/src/build/expr/as_operand.rs index bbb2f89fda9..b627b0763a2 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_operand.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_operand.rs @@ -20,7 +20,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { expr: &Expr<'tcx>, ) -> BlockAnd> { let local_scope = self.local_scope(); - self.as_operand(block, Some(local_scope), expr) + self.as_operand(block, Some(local_scope), expr, None) } /// Returns an operand suitable for use until the end of the current scope expression and @@ -85,6 +85,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { /// temporary `tmp = x`, so that we capture the value of `x` at /// this time. /// + /// If we end up needing to create a temporary, then we will use + /// `local_info` as its `LocalInfo`, unless `as_temporary` + /// has already assigned it a non-`None` `LocalInfo`. + /// Normally, you should use `None` for `local_info` + /// /// The operand is known to be live until the end of `scope`. /// /// Like `as_local_call_operand`, except that the argument will @@ -94,15 +99,16 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { mut block: BasicBlock, scope: Option, expr: &Expr<'tcx>, + local_info: Option>>, ) -> BlockAnd> { - debug!("as_operand(block={:?}, expr={:?})", block, expr); + debug!("as_operand(block={:?}, expr={:?} local_info={:?})", block, expr, local_info); let this = self; if let ExprKind::Scope { region_scope, lint_level, value } = expr.kind { let source_info = this.source_info(expr.span); let region_scope = (region_scope, source_info); return this.in_scope(region_scope, lint_level, |this| { - this.as_operand(block, scope, &this.thir[value]) + this.as_operand(block, scope, &this.thir[value], local_info) }); } @@ -115,6 +121,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } Category::Place | Category::Rvalue(..) => { let operand = unpack!(block = this.as_temp(block, scope, expr, Mutability::Mut)); + if this.local_decls[operand].local_info.is_none() { + this.local_decls[operand].local_info = local_info; + } block.and(Operand::Move(Place::from(operand))) } } @@ -167,6 +176,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } } - this.as_operand(block, scope, expr) + this.as_operand(block, scope, expr, None) } } diff --git a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs index be0d5d2f1b2..4b40faaf195 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs @@ -52,16 +52,16 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } ExprKind::Repeat { value, count } => { let value_operand = - unpack!(block = this.as_operand(block, scope, &this.thir[value])); + unpack!(block = this.as_operand(block, scope, &this.thir[value], None)); block.and(Rvalue::Repeat(value_operand, count)) } ExprKind::Binary { op, lhs, rhs } => { - let lhs = unpack!(block = this.as_operand(block, scope, &this.thir[lhs])); - let rhs = unpack!(block = this.as_operand(block, scope, &this.thir[rhs])); + let lhs = unpack!(block = this.as_operand(block, scope, &this.thir[lhs], None)); + let rhs = unpack!(block = this.as_operand(block, scope, &this.thir[rhs], None)); this.build_binary_op(block, op, expr_span, expr.ty, lhs, rhs) } ExprKind::Unary { op, arg } => { - let arg = unpack!(block = this.as_operand(block, scope, &this.thir[arg])); + let arg = unpack!(block = this.as_operand(block, scope, &this.thir[arg], None)); // Check for -MIN on signed integers if this.check_overflow && op == UnOp::Neg && expr.ty.is_signed() { let bool_ty = this.tcx.types.bool; @@ -116,11 +116,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block.and(Rvalue::Use(Operand::Move(Place::from(result)))) } ExprKind::Cast { source } => { - let source = unpack!(block = this.as_operand(block, scope, &this.thir[source])); + let source = + unpack!(block = this.as_operand(block, scope, &this.thir[source], None)); block.and(Rvalue::Cast(CastKind::Misc, source, expr.ty)) } ExprKind::Pointer { cast, source } => { - let source = unpack!(block = this.as_operand(block, scope, &this.thir[source])); + let source = + unpack!(block = this.as_operand(block, scope, &this.thir[source], None)); block.and(Rvalue::Cast(CastKind::Pointer(cast), source, expr.ty)) } ExprKind::Array { ref fields } => { @@ -155,7 +157,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fields: Vec<_> = fields .into_iter() .copied() - .map(|f| unpack!(block = this.as_operand(block, scope, &this.thir[f]))) + .map(|f| unpack!(block = this.as_operand(block, scope, &this.thir[f], None))) .collect(); block.and(Rvalue::Aggregate(Box::new(AggregateKind::Array(el_ty)), fields)) @@ -166,7 +168,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fields: Vec<_> = fields .into_iter() .copied() - .map(|f| unpack!(block = this.as_operand(block, scope, &this.thir[f]))) + .map(|f| unpack!(block = this.as_operand(block, scope, &this.thir[f], None))) .collect(); block.and(Rvalue::Aggregate(Box::new(AggregateKind::Tuple), fields)) @@ -242,7 +244,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { &this.thir[arg], ) ), - _ => unpack!(block = this.as_operand(block, scope, upvar)), + _ => { + unpack!(block = this.as_operand(block, scope, upvar, None)) + } } } } @@ -304,7 +308,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { Category::of(&expr.kind), Some(Category::Rvalue(RvalueFunc::AsRvalue)) )); - let operand = unpack!(block = this.as_operand(block, scope, expr)); + let operand = unpack!(block = this.as_operand(block, scope, expr, None)); block.and(Rvalue::Use(operand)) } } diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs index e30e758e637..1803a18441c 100644 --- a/compiler/rustc_mir_build/src/build/expr/into.rs +++ b/compiler/rustc_mir_build/src/build/expr/into.rs @@ -326,10 +326,16 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { let fields_map: FxHashMap<_, _> = fields .into_iter() .map(|f| { + let local_info = Box::new(LocalInfo::AggregateTemp); ( f.name, unpack!( - block = this.as_operand(block, Some(scope), &this.thir[f.expr]) + block = this.as_operand( + block, + Some(scope), + &this.thir[f.expr], + Some(local_info) + ) ), ) }) @@ -508,7 +514,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ExprKind::Yield { value } => { let scope = this.local_scope(); - let value = unpack!(block = this.as_operand(block, Some(scope), &this.thir[value])); + let value = + unpack!(block = this.as_operand(block, Some(scope), &this.thir[value], None)); let resume = this.cfg.start_new_block(); this.cfg.terminate( block, diff --git a/src/test/ui/async-await/issue-76547.nll.stderr b/src/test/ui/async-await/issue-76547.nll.stderr index 2456d6a1474..0ac2a396669 100644 --- a/src/test/ui/async-await/issue-76547.nll.stderr +++ b/src/test/ui/async-await/issue-76547.nll.stderr @@ -1,20 +1,22 @@ error: lifetime may not live long enough - --> $DIR/issue-76547.rs:19:14 + --> $DIR/issue-76547.rs:20:13 | LL | async fn fut(bufs: &mut [&mut [u8]]) { - | ^^^^ - - let's call the lifetime of this reference `'2` - | | | - | | let's call the lifetime of this reference `'1` - | assignment requires that `'1` must outlive `'2` + | - - let's call the lifetime of this reference `'2` + | | + | let's call the lifetime of this reference `'1` +LL | ListFut(bufs).await + | ^^^^ this usage requires that `'1` must outlive `'2` error: lifetime may not live long enough - --> $DIR/issue-76547.rs:33:15 + --> $DIR/issue-76547.rs:34:14 | LL | async fn fut2(bufs: &mut [&mut [u8]]) -> i32 { - | ^^^^ - - let's call the lifetime of this reference `'2` - | | | - | | let's call the lifetime of this reference `'1` - | assignment requires that `'1` must outlive `'2` + | - - let's call the lifetime of this reference `'2` + | | + | let's call the lifetime of this reference `'1` +LL | ListFut2(bufs).await + | ^^^^ this usage requires that `'1` must outlive `'2` error: aborting due to 2 previous errors diff --git a/src/test/ui/issues/issue-61882-2.stderr b/src/test/ui/issues/issue-61882-2.stderr index 03a65540ced..0b8e134c966 100644 --- a/src/test/ui/issues/issue-61882-2.stderr +++ b/src/test/ui/issues/issue-61882-2.stderr @@ -5,7 +5,7 @@ LL | Self(&x); | ^^ | | | borrowed value does not live long enough - | requires that `x` is borrowed for `'static` + | this usage requires that `x` is borrowed for `'static` LL | LL | } | - `x` dropped here while still borrowed diff --git a/src/test/ui/nll/issue-46036.stderr b/src/test/ui/nll/issue-46036.stderr index 49dd0e267b8..e6e95ee6136 100644 --- a/src/test/ui/nll/issue-46036.stderr +++ b/src/test/ui/nll/issue-46036.stderr @@ -5,7 +5,7 @@ LL | let foo = Foo { x: &a }; | ^^ | | | borrowed value does not live long enough - | requires that `a` is borrowed for `'static` + | this usage requires that `a` is borrowed for `'static` LL | loop { } LL | } | - `a` dropped here while still borrowed diff --git a/src/test/ui/nll/user-annotations/adt-brace-enums.stderr b/src/test/ui/nll/user-annotations/adt-brace-enums.stderr index e38b77fdcea..253e3825110 100644 --- a/src/test/ui/nll/user-annotations/adt-brace-enums.stderr +++ b/src/test/ui/nll/user-annotations/adt-brace-enums.stderr @@ -5,7 +5,7 @@ LL | SomeEnum::SomeVariant::<&'static u32> { t: &c }; | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'static` + | this usage requires that `c` is borrowed for `'static` LL | } | - `c` dropped here while still borrowed @@ -19,7 +19,7 @@ LL | SomeEnum::SomeVariant::<&'a u32> { t: &c }; | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | } | - `c` dropped here while still borrowed @@ -33,7 +33,7 @@ LL | SomeEnum::SomeVariant::<&'a u32> { t: &c }; | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | }; | - `c` dropped here while still borrowed diff --git a/src/test/ui/nll/user-annotations/adt-brace-structs.stderr b/src/test/ui/nll/user-annotations/adt-brace-structs.stderr index 3c3003477c2..8b9d1705df6 100644 --- a/src/test/ui/nll/user-annotations/adt-brace-structs.stderr +++ b/src/test/ui/nll/user-annotations/adt-brace-structs.stderr @@ -5,7 +5,7 @@ LL | SomeStruct::<&'static u32> { t: &c }; | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'static` + | this usage requires that `c` is borrowed for `'static` LL | } | - `c` dropped here while still borrowed @@ -19,7 +19,7 @@ LL | SomeStruct::<&'a u32> { t: &c }; | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | } | - `c` dropped here while still borrowed @@ -33,7 +33,7 @@ LL | SomeStruct::<&'a u32> { t: &c }; | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | }; | - `c` dropped here while still borrowed diff --git a/src/test/ui/nll/user-annotations/adt-tuple-enums.stderr b/src/test/ui/nll/user-annotations/adt-tuple-enums.stderr index 810912bf886..2fa7042631d 100644 --- a/src/test/ui/nll/user-annotations/adt-tuple-enums.stderr +++ b/src/test/ui/nll/user-annotations/adt-tuple-enums.stderr @@ -5,7 +5,7 @@ LL | SomeEnum::SomeVariant::<&'static u32>(&c); | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'static` + | this usage requires that `c` is borrowed for `'static` LL | } | - `c` dropped here while still borrowed @@ -19,7 +19,7 @@ LL | SomeEnum::SomeVariant::<&'a u32>(&c); | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | } | - `c` dropped here while still borrowed @@ -33,7 +33,7 @@ LL | SomeEnum::SomeVariant::<&'a u32>(&c); | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | }; | - `c` dropped here while still borrowed diff --git a/src/test/ui/nll/user-annotations/adt-tuple-struct.stderr b/src/test/ui/nll/user-annotations/adt-tuple-struct.stderr index 4d2140eca1b..76b5252258c 100644 --- a/src/test/ui/nll/user-annotations/adt-tuple-struct.stderr +++ b/src/test/ui/nll/user-annotations/adt-tuple-struct.stderr @@ -5,7 +5,7 @@ LL | SomeStruct::<&'static u32>(&c); | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'static` + | this usage requires that `c` is borrowed for `'static` LL | } | - `c` dropped here while still borrowed @@ -19,7 +19,7 @@ LL | SomeStruct::<&'a u32>(&c); | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | } | - `c` dropped here while still borrowed @@ -33,7 +33,7 @@ LL | SomeStruct::<&'a u32>(&c); | ^^ | | | borrowed value does not live long enough - | requires that `c` is borrowed for `'a` + | this usage requires that `c` is borrowed for `'a` LL | }; | - `c` dropped here while still borrowed diff --git a/src/test/ui/nll/where_clauses_in_structs.stderr b/src/test/ui/nll/where_clauses_in_structs.stderr index 2e990131e61..8499b00f6f5 100644 --- a/src/test/ui/nll/where_clauses_in_structs.stderr +++ b/src/test/ui/nll/where_clauses_in_structs.stderr @@ -6,7 +6,7 @@ LL | fn bar<'a, 'b>(x: Cell<&'a u32>, y: Cell<&'b u32>) { | | | lifetime `'a` defined here LL | Foo { x, y }; - | ^ requires that `'a` must outlive `'b` + | ^ this usage requires that `'a` must outlive `'b` | = help: consider adding the following bound: `'a: 'b`