diff options
Diffstat (limited to 'compiler')
7 files changed, 86 insertions, 49 deletions
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs index d75a5f8806b..e54f9486f6a 100644 --- a/compiler/rustc_hir_typeck/src/expr.rs +++ b/compiler/rustc_hir_typeck/src/expr.rs @@ -1306,6 +1306,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // No way to know whether it's diverging because // of a `break` or an outer `break` or `return`. self.diverges.set(Diverges::Maybe); + } else { + self.diverges.set(self.diverges.get() | Diverges::always(expr.span)); } // If we permit break with a value, then result type is diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs index dea125bb9b1..40d9a2985da 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs @@ -48,30 +48,42 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// Produces warning on the given node, if the current point in the /// function is unreachable, and there hasn't been another warning. pub(crate) fn warn_if_unreachable(&self, id: HirId, span: Span, kind: &str) { - // FIXME: Combine these two 'if' expressions into one once - // let chains are implemented - if let Diverges::Always { span: orig_span, custom_note } = self.diverges.get() { - // If span arose from a desugaring of `if` or `while`, then it is the condition itself, - // which diverges, that we are about to lint on. This gives suboptimal diagnostics. - // Instead, stop here so that the `if`- or `while`-expression's block is linted instead. - if !span.is_desugaring(DesugaringKind::CondTemporary) - && !span.is_desugaring(DesugaringKind::Async) - && !orig_span.is_desugaring(DesugaringKind::Await) - { - self.diverges.set(Diverges::WarnedAlways); + // If span arose from a desugaring of `if` or `while`, then it is the condition itself, + // which diverges, that we are about to lint on. This gives suboptimal diagnostics. + // Instead, stop here so that the `if`- or `while`-expression's block is linted instead. + if span.is_desugaring(DesugaringKind::CondTemporary) { + return; + } - debug!("warn_if_unreachable: id={:?} span={:?} kind={}", id, span, kind); + // Don't lint if the result of an async block or async function is `!`. + // This does not affect the unreachable lints *within* the body. + if span.is_desugaring(DesugaringKind::Async) { + return; + } - let msg = format!("unreachable {kind}"); - self.tcx().node_span_lint(lint::builtin::UNREACHABLE_CODE, id, span, |lint| { - lint.primary_message(msg.clone()); - lint.span_label(span, msg).span_label( - orig_span, - custom_note.unwrap_or("any code following this expression is unreachable"), - ); - }) - } + // Don't lint *within* the `.await` operator, since that's all just desugaring junk. + // We only want to lint if there is a subsequent expression after the `.await`. + if span.is_desugaring(DesugaringKind::Await) { + return; } + + let Diverges::Always { span: orig_span, custom_note } = self.diverges.get() else { + return; + }; + + // Don't warn twice. + self.diverges.set(Diverges::WarnedAlways); + + debug!("warn_if_unreachable: id={:?} span={:?} kind={}", id, span, kind); + + let msg = format!("unreachable {kind}"); + self.tcx().node_span_lint(lint::builtin::UNREACHABLE_CODE, id, span, |lint| { + lint.primary_message(msg.clone()); + lint.span_label(span, msg).span_label( + orig_span, + custom_note.unwrap_or("any code following this expression is unreachable"), + ); + }) } /// Resolves type and const variables in `ty` if possible. Unlike the infcx diff --git a/compiler/rustc_lint/src/precedence.rs b/compiler/rustc_lint/src/precedence.rs index eb2ba397277..52321e25c7d 100644 --- a/compiler/rustc_lint/src/precedence.rs +++ b/compiler/rustc_lint/src/precedence.rs @@ -16,6 +16,7 @@ declare_lint! { /// ### Example /// /// ```rust,compile_fail + /// # #![deny(ambiguous_negative_literals)] /// # #![allow(unused)] /// -1i32.abs(); // equals -1, while `(-1i32).abs()` equals 1 /// ``` @@ -27,7 +28,7 @@ declare_lint! { /// Method calls take precedence over unary precedence. Setting the /// precedence explicitly makes the code clearer and avoid potential bugs. pub AMBIGUOUS_NEGATIVE_LITERALS, - Deny, + Allow, "ambiguous negative literals operations", report_in_external_macro } diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs index 336aa1fd43f..e16911d79c3 100644 --- a/compiler/rustc_mir_transform/src/gvn.rs +++ b/compiler/rustc_mir_transform/src/gvn.rs @@ -128,7 +128,7 @@ fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { // Clone dominators as we need them while mutating the body. let dominators = body.basic_blocks.dominators().clone(); - let mut state = VnState::new(tcx, param_env, &ssa, &dominators, &body.local_decls); + let mut state = VnState::new(tcx, body, param_env, &ssa, &dominators, &body.local_decls); ssa.for_each_assignment_mut( body.basic_blocks.as_mut_preserves_cfg(), |local, value, location| { @@ -204,6 +204,7 @@ enum Value<'tcx> { value: Const<'tcx>, /// Some constants do not have a deterministic value. To avoid merging two instances of the /// same `Const`, we assign them an additional integer index. + // `disambiguator` is 0 iff the constant is deterministic. disambiguator: usize, }, /// An aggregate value, either tuple/closure/struct/enum. @@ -266,21 +267,29 @@ struct VnState<'body, 'tcx> { impl<'body, 'tcx> VnState<'body, 'tcx> { fn new( tcx: TyCtxt<'tcx>, + body: &Body<'tcx>, param_env: ty::ParamEnv<'tcx>, ssa: &'body SsaLocals, dominators: &'body Dominators<BasicBlock>, local_decls: &'body LocalDecls<'tcx>, ) -> Self { + // Compute a rough estimate of the number of values in the body from the number of + // statements. This is meant to reduce the number of allocations, but it's all right if + // we miss the exact amount. We estimate based on 2 values per statement (one in LHS and + // one in RHS) and 4 values per terminator (for call operands). + let num_values = + 2 * body.basic_blocks.iter().map(|bbdata| bbdata.statements.len()).sum::<usize>() + + 4 * body.basic_blocks.len(); VnState { tcx, ecx: InterpCx::new(tcx, DUMMY_SP, param_env, DummyMachine), param_env, local_decls, locals: IndexVec::from_elem(None, local_decls), - rev_locals: IndexVec::default(), - values: FxIndexSet::default(), - evaluated: IndexVec::new(), - next_opaque: Some(0), + rev_locals: IndexVec::with_capacity(num_values), + values: FxIndexSet::with_capacity_and_hasher(num_values, Default::default()), + evaluated: IndexVec::with_capacity(num_values), + next_opaque: Some(1), feature_unsized_locals: tcx.features().unsized_locals, ssa, dominators, @@ -293,9 +302,15 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { let (index, new) = self.values.insert_full(value); let index = VnIndex::from_usize(index); if new { + // Grow `evaluated` and `rev_locals` here to amortize the allocations. let evaluated = self.eval_to_const(index); let _index = self.evaluated.push(evaluated); debug_assert_eq!(index, _index); + // No need to push to `rev_locals` if we finished listing assignments. + if self.next_opaque.is_some() { + let _index = self.rev_locals.push(SmallVec::new()); + debug_assert_eq!(index, _index); + } } index } @@ -332,7 +347,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { let is_sized = !self.feature_unsized_locals || self.local_decls[local].ty.is_sized(self.tcx, self.param_env); if is_sized { - self.rev_locals.ensure_contains_elem(value, SmallVec::new).push(local); + self.rev_locals[value].push(local); } } @@ -346,6 +361,8 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { let next_opaque = self.next_opaque.as_mut()?; let disambiguator = *next_opaque; *next_opaque += 1; + // `disambiguator: 0` means deterministic. + debug_assert_ne!(disambiguator, 0); disambiguator }; Some(self.insert(Value::Constant { value, disambiguator })) @@ -353,12 +370,16 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { fn insert_bool(&mut self, flag: bool) -> VnIndex { // Booleans are deterministic. - self.insert(Value::Constant { value: Const::from_bool(self.tcx, flag), disambiguator: 0 }) + let value = Const::from_bool(self.tcx, flag); + debug_assert!(value.is_deterministic()); + self.insert(Value::Constant { value, disambiguator: 0 }) } fn insert_scalar(&mut self, scalar: Scalar, ty: Ty<'tcx>) -> VnIndex { - self.insert_constant(Const::from_scalar(self.tcx, scalar, ty)) - .expect("scalars are deterministic") + // Scalars are deterministic. + let value = Const::from_scalar(self.tcx, scalar, ty); + debug_assert!(value.is_deterministic()); + self.insert(Value::Constant { value, disambiguator: 0 }) } fn insert_tuple(&mut self, values: Vec<VnIndex>) -> VnIndex { @@ -671,7 +692,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { fn simplify_place_projection(&mut self, place: &mut Place<'tcx>, location: Location) { // If the projection is indirect, we treat the local as a value, so can replace it with // another local. - if place.is_indirect() + if place.is_indirect_first_projection() && let Some(base) = self.locals[place.local] && let Some(new_local) = self.try_as_local(base, location) && place.local != new_local @@ -773,10 +794,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { location: Location, ) -> Option<VnIndex> { match *operand { - Operand::Constant(ref mut constant) => { - let const_ = constant.const_.normalize(self.tcx, self.param_env); - self.insert_constant(const_) - } + Operand::Constant(ref constant) => self.insert_constant(constant.const_), Operand::Copy(ref mut place) | Operand::Move(ref mut place) => { let value = self.simplify_place_value(place, location)?; if let Some(const_) = self.try_as_constant(value) { @@ -1371,8 +1389,13 @@ fn op_to_prop_const<'tcx>( // If this constant has scalar ABI, return it as a `ConstValue::Scalar`. if let Abi::Scalar(abi::Scalar::Initialized { .. }) = op.layout.abi && let Ok(scalar) = ecx.read_scalar(op) - && scalar.try_to_scalar_int().is_ok() { + if !scalar.try_to_scalar_int().is_ok() { + // Check that we do not leak a pointer. + // Those pointers may lose part of their identity in codegen. + // FIXME: remove this hack once https://github.com/rust-lang/rust/issues/79738 is fixed. + return None; + } return Some(ConstValue::Scalar(scalar)); } @@ -1436,12 +1459,11 @@ impl<'tcx> VnState<'_, 'tcx> { /// If `index` is a `Value::Constant`, return the `Constant` to be put in the MIR. fn try_as_constant(&mut self, index: VnIndex) -> Option<ConstOperand<'tcx>> { - // This was already constant in MIR, do not change it. - if let Value::Constant { value, disambiguator: _ } = *self.get(index) - // If the constant is not deterministic, adding an additional mention of it in MIR will - // not give the same value as the former mention. - && value.is_deterministic() - { + // This was already constant in MIR, do not change it. If the constant is not + // deterministic, adding an additional mention of it in MIR will not give the same value as + // the former mention. + if let Value::Constant { value, disambiguator: 0 } = *self.get(index) { + debug_assert!(value.is_deterministic()); return Some(ConstOperand { span: DUMMY_SP, user_ty: None, const_: value }); } diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs index 19b04607f0e..f7a6e0bd857 100644 --- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs +++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs @@ -4,10 +4,10 @@ pub fn target() -> Target { Target { llvm_target: "loongarch64-unknown-linux-musl".into(), metadata: crate::spec::TargetMetadata { - description: Some("LoongArch64 Linux (LP64D ABI) with musl 1.2.3".into()), - tier: Some(3), - host_tools: Some(false), - std: None, // ? + description: Some("LoongArch64 Linux (LP64D ABI) with musl 1.2.5".into()), + tier: Some(2), + host_tools: Some(true), + std: Some(true), }, pointer_width: 64, data_layout: "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128".into(), diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none.rs index 138491972e5..c7f47da6972 100644 --- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none.rs +++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none.rs @@ -6,7 +6,7 @@ pub fn target() -> Target { Target { llvm_target: "loongarch64-unknown-none".into(), metadata: crate::spec::TargetMetadata { - description: None, + description: Some("Freestanding/bare-metal LoongArch64".into()), tier: Some(2), host_tools: Some(false), std: Some(false), diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none_softfloat.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none_softfloat.rs index 41519078f80..21e4f4a2b05 100644 --- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none_softfloat.rs +++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_none_softfloat.rs @@ -6,7 +6,7 @@ pub fn target() -> Target { Target { llvm_target: "loongarch64-unknown-none".into(), metadata: crate::spec::TargetMetadata { - description: None, + description: Some("Freestanding/bare-metal LoongArch64 softfloat".into()), tier: Some(2), host_tools: Some(false), std: Some(false), |