Rollup merge of #101086 - cjgillot:thir-param, r=oli-obk

Compute information about function parameters on THIR

This avoids some manipulation of typeck results while building MIR.

Author: matthiaskrgr

compiler/rustc_borrowck/src/diagnostics/move_errors.rs

@@ -360,7 +360,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
                 diag.span_label(upvar_span, "captured outer variable");
                 diag.span_label(
-                    self.body.span,
+                    self.infcx.tcx.def_span(def_id),
                     format!("captured by this `{closure_kind}` closure"),
                 );
 

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -9,10 +9,7 @@ use rustc_middle::mir::{Mutability, Place, PlaceRef, ProjectionElem};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::{
     hir::place::PlaceBase,
-    mir::{
-        self, BindingForm, ClearCrossCrate, ImplicitSelfKind, Local, LocalDecl, LocalInfo,
-        LocalKind, Location,
-    },
+    mir::{self, BindingForm, ClearCrossCrate, Local, LocalDecl, LocalInfo, LocalKind, Location},
 };
 use rustc_span::source_map::DesugaringKind;
 use rustc_span::symbol::{kw, Symbol};
@@ -312,7 +309,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     && !matches!(
                         decl.local_info,
                         Some(box LocalInfo::User(ClearCrossCrate::Set(BindingForm::ImplicitSelf(
-                            ImplicitSelfKind::MutRef
+                            hir::ImplicitSelfKind::MutRef
                         ))))
                     )
                 {
@@ -976,6 +973,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         let hir = self.infcx.tcx.hir();
         let closure_id = self.mir_hir_id();
+        let closure_span = self.infcx.tcx.def_span(self.mir_def_id());
         let fn_call_id = hir.get_parent_node(closure_id);
         let node = hir.get(fn_call_id);
         let def_id = hir.enclosing_body_owner(fn_call_id);
@@ -1027,7 +1025,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 if let Some(span) = arg {
                     err.span_label(span, "change this to accept `FnMut` instead of `Fn`");
                     err.span_label(func.span, "expects `Fn` instead of `FnMut`");
-                    err.span_label(self.body.span, "in this closure");
+                    err.span_label(closure_span, "in this closure");
                     look_at_return = false;
                 }
             }
@@ -1053,7 +1051,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                         sig.decl.output.span(),
                         "change this to return `FnMut` instead of `Fn`",
                     );
-                    err.span_label(self.body.span, "in this closure");
+                    err.span_label(closure_span, "in this closure");
                 }
                 _ => {}
             }
@@ -1077,7 +1075,7 @@ fn mut_borrow_of_mutable_ref(local_decl: &LocalDecl<'_>, local_name: Option<Symb
             //
             // Deliberately fall into this case for all implicit self types,
             // so that we don't fall in to the next case with them.
-            *kind == mir::ImplicitSelfKind::MutRef
+            *kind == hir::ImplicitSelfKind::MutRef
         }
         _ if Some(kw::SelfLower) == local_name => {
             // Otherwise, check if the name is the `self` keyword - in which case

compiler/rustc_borrowck/src/nll.rs

@@ -389,8 +389,9 @@ pub(super) fn dump_annotation<'a, 'tcx>(
     // viewing the intraprocedural state, the -Zdump-mir output is
     // better.
 
+    let def_span = tcx.def_span(body.source.def_id());
     let mut err = if let Some(closure_region_requirements) = closure_region_requirements {
-        let mut err = tcx.sess.diagnostic().span_note_diag(body.span, "external requirements");
+        let mut err = tcx.sess.diagnostic().span_note_diag(def_span, "external requirements");
 
         regioncx.annotate(tcx, &mut err);
 
@@ -409,7 +410,7 @@ pub(super) fn dump_annotation<'a, 'tcx>(
 
         err
     } else {
-        let mut err = tcx.sess.diagnostic().span_note_diag(body.span, "no external requirements");
+        let mut err = tcx.sess.diagnostic().span_note_diag(def_span, "no external requirements");
         regioncx.annotate(tcx, &mut err);
 
         err

compiler/rustc_hir/src/hir.rs

@@ -2642,7 +2642,7 @@ pub struct FnDecl<'hir> {
 }
 
 /// Represents what type of implicit self a function has, if any.
-#[derive(Copy, Clone, Encodable, Decodable, Debug, HashStable_Generic)]
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub enum ImplicitSelfKind {
     /// Represents a `fn x(self);`.
     Imm,

compiler/rustc_middle/src/mir/mod.rs

@@ -18,7 +18,7 @@ use rustc_data_structures::captures::Captures;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def::{CtorKind, Namespace};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
-use rustc_hir::{self, GeneratorKind};
+use rustc_hir::{self, GeneratorKind, ImplicitSelfKind};
 use rustc_hir::{self as hir, HirId};
 use rustc_session::Session;
 use rustc_target::abi::{Size, VariantIdx};
@@ -653,22 +653,6 @@ pub enum BindingForm<'tcx> {
     RefForGuard,
 }
 
-/// Represents what type of implicit self a function has, if any.
-#[derive(Clone, Copy, PartialEq, Debug, TyEncodable, TyDecodable, HashStable)]
-pub enum ImplicitSelfKind {
-    /// Represents a `fn x(self);`.
-    Imm,
-    /// Represents a `fn x(mut self);`.
-    Mut,
-    /// Represents a `fn x(&self);`.
-    ImmRef,
-    /// Represents a `fn x(&mut self);`.
-    MutRef,
-    /// Represents when a function does not have a self argument or
-    /// when a function has a `self: X` argument.
-    None,
-}
-
 TrivialTypeTraversalAndLiftImpls! { BindingForm<'tcx>, }
 
 mod binding_form_impl {

compiler/rustc_middle/src/thir.rs

@@ -73,11 +73,29 @@ macro_rules! thir_with_elements {
     }
 }
 
+pub const UPVAR_ENV_PARAM: ParamId = ParamId::from_u32(0);
+
 thir_with_elements! {
     arms: ArmId => Arm<'tcx> => "a{}",
     blocks: BlockId => Block => "b{}",
     exprs: ExprId => Expr<'tcx> => "e{}",
     stmts: StmtId => Stmt<'tcx> => "s{}",
+    params: ParamId => Param<'tcx> => "p{}",
+}
+
+/// Description of a type-checked function parameter.
+#[derive(Clone, Debug, HashStable)]
+pub struct Param<'tcx> {
+    /// The pattern that appears in the parameter list, or None for implicit parameters.
+    pub pat: Option<Pat<'tcx>>,
+    /// The possibly inferred type.
+    pub ty: Ty<'tcx>,
+    /// Span of the explicitly provided type, or None if inferred for closures.
+    pub ty_span: Option<Span>,
+    /// Whether this param is `self`, and how it is bound.
+    pub self_kind: Option<hir::ImplicitSelfKind>,
+    /// HirId for lints.
+    pub hir_id: Option<hir::HirId>,
 }
 
 #[derive(Copy, Clone, Debug, HashStable)]
@@ -548,6 +566,15 @@ impl<'tcx> Pat<'tcx> {
     pub fn wildcard_from_ty(ty: Ty<'tcx>) -> Self {
         Pat { ty, span: DUMMY_SP, kind: Box::new(PatKind::Wild) }
     }
+
+    pub fn simple_ident(&self) -> Option<Symbol> {
+        match &*self.kind {
+            PatKind::Binding { name, mode: BindingMode::ByValue, subpattern: None, .. } => {
+                Some(*name)
+            }
+            _ => None,
+        }
+    }
 }
 
 #[derive(Clone, Debug, HashStable)]

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -573,15 +573,15 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
             _ => {
                 let place_builder = unpack!(block = self.as_place_builder(block, initializer));
-                self.place_into_pattern(block, irrefutable_pat, place_builder, true)
+                self.place_into_pattern(block, &irrefutable_pat, place_builder, true)
             }
         }
     }
 
     pub(crate) fn place_into_pattern(
         &mut self,
         block: BasicBlock,
-        irrefutable_pat: Pat<'tcx>,
+        irrefutable_pat: &Pat<'tcx>,
         initializer: PlaceBuilder<'tcx>,
         set_match_place: bool,
     ) -> BlockAnd<()> {