Rollup of 17 pull requests

Cargo.lock

@@ -6070,6 +6070,7 @@ checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
 name = "unicode-table-generator"
 version = "0.1.0"
 dependencies = [
+ "rustc-hash 2.1.1",
  "ucd-parse",
 ]
 

compiler/rustc_abi/src/canon_abi.rs

@@ -28,6 +28,7 @@ pub enum CanonAbi {
     Rust,
     RustCold,
     RustPreserveNone,
+    RustTail,
 
     /// An ABI that rustc does not know how to call or define.
     Custom,
@@ -59,7 +60,10 @@ pub enum CanonAbi {
 impl CanonAbi {
     pub fn is_rustic_abi(self) -> bool {
         match self {
-            CanonAbi::Rust | CanonAbi::RustCold | CanonAbi::RustPreserveNone => true,
+            CanonAbi::Rust
+            | CanonAbi::RustCold
+            | CanonAbi::RustPreserveNone
+            | CanonAbi::RustTail => true,
             CanonAbi::C
             | CanonAbi::Custom
             | CanonAbi::Swift
@@ -81,6 +85,7 @@ impl fmt::Display for CanonAbi {
             CanonAbi::Rust => ExternAbi::Rust,
             CanonAbi::RustCold => ExternAbi::RustCold,
             CanonAbi::RustPreserveNone => ExternAbi::RustPreserveNone,
+            CanonAbi::RustTail => ExternAbi::RustTail,
             CanonAbi::Custom => ExternAbi::Custom,
             CanonAbi::Swift => ExternAbi::Swift,
             CanonAbi::Arm(arm_call) => match arm_call {

compiler/rustc_abi/src/extern_abi.rs

@@ -49,6 +49,11 @@ pub enum ExternAbi {
     /// forcing callers to save all registers.
     RustPreserveNone,
 
+    /// Ensures that calls in tail position can always be optimized into a jump.
+    ///
+    /// This ABI is not stable, and relies on LLVM implementation details.
+    RustTail,
+
     /// Unstable impl detail that directly uses Rust types to describe the ABI to LLVM.
     /// Even normally-compatible Rust types can become ABI-incompatible with this ABI!
     Unadjusted,
@@ -205,6 +210,7 @@ abi_impls! {
             System { unwind: true } =><= "system-unwind",
             SysV64 { unwind: false } =><= "sysv64",
             SysV64 { unwind: true } =><= "sysv64-unwind",
+            RustTail =><= "tail",
             Thiscall { unwind: false } =><= "thiscall",
             Thiscall { unwind: true } =><= "thiscall-unwind",
             Unadjusted =><= "unadjusted",
@@ -280,7 +286,7 @@ impl ExternAbi {
     /// - are subject to change between compiler versions
     pub fn is_rustic_abi(self) -> bool {
         use ExternAbi::*;
-        matches!(self, Rust | RustCall | RustCold | RustPreserveNone)
+        matches!(self, Rust | RustCall | RustCold | RustPreserveNone | RustTail)
     }
 
     /// Returns whether the ABI supports C variadics. This only controls whether we allow *imports*
@@ -354,6 +360,7 @@ impl ExternAbi {
             | Self::SysV64 { .. }
             | Self::Win64 { .. }
             | Self::RustPreserveNone
+            | Self::RustTail
             | Self::Swift => true,
         }
     }

compiler/rustc_ast_lowering/src/asm.rs

@@ -9,16 +9,17 @@ use rustc_session::errors::feature_err;
 use rustc_span::{Span, sym};
 use rustc_target::asm;
 
-use super::LoweringContext;
-use super::errors::{
+use crate::diagnostics::{
     AbiSpecifiedMultipleTimes, AttSyntaxOnlyX86, ClobberAbiNotSupported,
     InlineAsmUnsupportedTarget, InvalidAbiClobberAbi, InvalidAsmTemplateModifierConst,
     InvalidAsmTemplateModifierLabel, InvalidAsmTemplateModifierRegClass,
     InvalidAsmTemplateModifierRegClassSub, InvalidAsmTemplateModifierSym, InvalidRegister,
     InvalidRegisterClass, RegisterClassOnlyClobber, RegisterClassOnlyClobberStable,
     RegisterConflict,
 };
-use crate::{AllowReturnTypeNotation, ImplTraitContext, ImplTraitPosition, ParamMode};
+use crate::{
+    AllowReturnTypeNotation, ImplTraitContext, ImplTraitPosition, LoweringContext, ParamMode,
+};
 
 impl<'hir> LoweringContext<'_, 'hir> {
     pub(crate) fn lower_inline_asm(

compiler/rustc_ast_lowering/src/delegation.rs

@@ -56,7 +56,7 @@ use rustc_span::symbol::kw;
 use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol};
 
 use crate::delegation::generics::{GenericsGenerationResult, GenericsGenerationResults};
-use crate::errors::{
+use crate::diagnostics::{
     CycleInDelegationSignatureResolution, DelegationAttemptedBlockWithDefsDeletion,
     DelegationBlockSpecifiedWhenNoParams, UnresolvedDelegationCallee,
 };

compiler/rustc_ast_lowering/src/expr.rs

@@ -19,17 +19,17 @@ use visit::{Visitor, walk_expr};
 
 mod closure;
 
-use super::errors::{
+use crate::diagnostics::{
     AsyncCoroutinesNotSupported, AwaitOnlyInAsyncFnAndBlocks,
-    FunctionalRecordUpdateDestructuringAssignment, InclusiveRangeWithNoEnd, MatchArmWithNoBody,
-    MoveExprOnlyInPlainClosures, NeverPatternWithBody, NeverPatternWithGuard,
-    UnderscoreExprLhsAssign,
+    FunctionalRecordUpdateDestructuringAssignment, InclusiveRangeWithNoEnd,
+    InvalidLegacyConstGenericArg, MatchArmWithNoBody, MoveExprOnlyInPlainClosures,
+    NeverPatternWithBody, NeverPatternWithGuard, UnderscoreExprLhsAssign, UseConstGenericArg,
+    YieldInClosure,
 };
-use super::{
-    GenericArgsMode, ImplTraitContext, LoweringContext, ParamMode, ResolverAstLoweringExt,
+use crate::{
+    AllowReturnTypeNotation, GenericArgsMode, ImplTraitContext, ImplTraitPosition, LoweringContext,
+    ParamMode, ResolverAstLoweringExt, TryBlockScope,
 };
-use crate::errors::{InvalidLegacyConstGenericArg, UseConstGenericArg, YieldInClosure};
-use crate::{AllowReturnTypeNotation, ImplTraitPosition, TryBlockScope};
 
 pub(super) struct WillCreateDefIdsVisitor;
 

compiler/rustc_ast_lowering/src/expr/closure.rs

@@ -7,7 +7,7 @@ use rustc_span::Span;
 
 use super::{LoweringContext, MoveExprInitializerFinder, MoveExprState};
 use crate::FnDeclKind;
-use crate::errors::{ClosureCannotBeStatic, CoroutineTooManyParameters};
+use crate::diagnostics::{ClosureCannotBeStatic, CoroutineTooManyParameters};
 
 impl<'hir> LoweringContext<'_, 'hir> {
     // Entry point for `ExprKind::Closure`. Plain closures go through

compiler/rustc_ast_lowering/src/item.rs

@@ -19,7 +19,9 @@ use smallvec::{SmallVec, smallvec};
 use thin_vec::ThinVec;
 use tracing::instrument;
 
-use super::errors::{InvalidAbi, InvalidAbiSuggestion, TupleStructWithDefault, UnionWithDefault};
+use super::diagnostics::{
+    InvalidAbi, InvalidAbiSuggestion, TupleStructWithDefault, UnionWithDefault,
+};
 use super::stability::{enabled_names, gate_unstable_abi};
 use super::{
     AstOwner, FnDeclKind, GenericArgsMode, ImplTraitContext, ImplTraitPosition, LoweringContext,

compiler/rustc_ast_lowering/src/lib.rs

@@ -70,7 +70,7 @@ use smallvec::SmallVec;
 use thin_vec::ThinVec;
 use tracing::{debug, instrument, trace};
 
-use crate::errors::{AssocTyParentheses, AssocTyParenthesesSub, MisplacedImplTrait};
+use crate::diagnostics::{AssocTyParentheses, AssocTyParenthesesSub, MisplacedImplTrait};
 use crate::item::Owners;
 
 macro_rules! arena_vec {
@@ -83,7 +83,7 @@ mod asm;
 mod block;
 mod contract;
 mod delegation;
-mod errors;
+mod diagnostics;
 mod expr;
 mod format;
 mod index;
@@ -1145,17 +1145,21 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     {
                         let err = match (&data.inputs[..], &data.output) {
                             ([_, ..], FnRetTy::Default(_)) => {
-                                errors::BadReturnTypeNotation::Inputs { span: data.inputs_span }
+                                diagnostics::BadReturnTypeNotation::Inputs {
+                                    span: data.inputs_span,
+                                }
                             }
                             ([], FnRetTy::Default(_)) => {
-                                errors::BadReturnTypeNotation::NeedsDots { span: data.inputs_span }
+                                diagnostics::BadReturnTypeNotation::NeedsDots {
+                                    span: data.inputs_span,
+                                }
                             }
                             // The case `T: Trait<method(..) -> Ret>` is handled in the parser.
                             (_, FnRetTy::Ty(ty)) => {
                                 let span = data.inputs_span.shrink_to_hi().to(ty.span);
-                                errors::BadReturnTypeNotation::Output {
+                                diagnostics::BadReturnTypeNotation::Output {
                                     span,
-                                    suggestion: errors::RTNSuggestion {
+                                    suggestion: diagnostics::RTNSuggestion {
                                         output: span,
                                         input: data.inputs_span,
                                     },
@@ -1226,7 +1230,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         _ => None,
                     };
 
-                    let guar = self.dcx().emit_err(errors::MisplacedAssocTyBinding {
+                    let guar = self.dcx().emit_err(diagnostics::MisplacedAssocTyBinding {
                         span: constraint.span,
                         suggestion,
                     });
@@ -1529,7 +1533,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                             ast::GenericBound::Use(_, span) => Some(span),
                             _ => None,
                         }) {
-                            self.tcx.dcx().emit_err(errors::NoPreciseCapturesOnApit { span });
+                            self.tcx.dcx().emit_err(diagnostics::NoPreciseCapturesOnApit { span });
                         }
 
                         let def_id = self.local_def_id(*def_node_id);
@@ -2123,7 +2127,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     .filter(|_| match source {
                         hir::GenericParamSource::Generics => true,
                         hir::GenericParamSource::Binder => {
-                            self.dcx().emit_err(errors::GenericParamDefaultInBinder {
+                            self.dcx().emit_err(diagnostics::GenericParamDefaultInBinder {
                                 span: param.span(),
                             });
 
@@ -2154,7 +2158,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     .filter(|anon_const| match source {
                         hir::GenericParamSource::Generics => true,
                         hir::GenericParamSource::Binder => {
-                            let err = errors::GenericParamDefaultInBinder { span: param.span() };
+                            let err =
+                                diagnostics::GenericParamDefaultInBinder { span: param.span() };
                             if expr::WillCreateDefIdsVisitor
                                 .visit_expr(&anon_const.value)
                                 .is_break()

compiler/rustc_ast_lowering/src/pat.rs

@@ -7,10 +7,10 @@ use rustc_hir::{self as hir, LangItem, Target};
 use rustc_middle::span_bug;
 use rustc_span::{DesugaringKind, Ident, Span, Spanned, respan};
 
-use super::errors::{
+use crate::diagnostics::{
     ArbitraryExpressionInPattern, ExtraDoubleDot, MisplacedDoubleDot, SubTupleBinding,
 };
-use super::{
+use crate::{
     AllowReturnTypeNotation, ImplTraitContext, ImplTraitPosition, LoweringContext, ParamMode,
 };
 

compiler/rustc_ast_lowering/src/path.rs

@@ -11,11 +11,11 @@ use rustc_span::{BytePos, DUMMY_SP, DesugaringKind, Ident, Span, Symbol, sym};
 use smallvec::smallvec;
 use tracing::{debug, instrument};
 
-use super::errors::{
+use crate::diagnostics::{
     AsyncBoundNotOnTrait, AsyncBoundOnlyForFnTraits, BadReturnTypeNotation,
     GenericTypeWithParentheses, RTNSuggestion, UseAngleBrackets,
 };
-use super::{
+use crate::{
     AllowReturnTypeNotation, GenericArgsCtor, GenericArgsMode, ImplTraitContext, ImplTraitPosition,
     LifetimeRes, LoweringContext, ParamMode,
 };

compiler/rustc_ast_lowering/src/stability.rs

@@ -100,6 +100,9 @@ pub fn extern_abi_stability(abi: ExternAbi) -> Result<(), UnstableAbi> {
             feature: sym::rust_preserve_none_cc,
             explain: GateReason::Experimental,
         }),
+        ExternAbi::RustTail => {
+            Err(UnstableAbi { abi, feature: sym::rust_tail_cc, explain: GateReason::Experimental })
+        }
         ExternAbi::RustInvalid => {
             Err(UnstableAbi { abi, feature: sym::rustc_attrs, explain: GateReason::ImplDetail })
         }