1 files changed, 20 insertions, 119 deletions

diff --git a/compiler/rustc_hir_typeck/src/check.rs b/compiler/rustc_hir_typeck/src/check.rs
index 7f76364e1..32f86b804 100644
--- a/compiler/rustc_hir_typeck/src/check.rs
+++ b/compiler/rustc_hir_typeck/src/check.rs
@@ -1,18 +1,16 @@
 use crate::coercion::CoerceMany;
 use crate::gather_locals::GatherLocalsVisitor;
-use crate::{FnCtxt, Inherited};
-use crate::{GeneratorTypes, UnsafetyState};
+use crate::FnCtxt;
+use crate::GeneratorTypes;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::{ImplicitSelfKind, ItemKind, Node};
 use rustc_hir_analysis::check::fn_maybe_err;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::RegionVariableOrigin;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::def_id::LocalDefId;
-use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
 use std::cell::RefCell;
 
@@ -22,22 +20,16 @@ use std::cell::RefCell;
 ///
 /// * ...
 /// * inherited: other fields inherited from the enclosing fn (if any)
-#[instrument(skip(inherited, body), level = "debug")]
+#[instrument(skip(fcx, body), level = "debug")]
 pub(super) fn check_fn<'a, 'tcx>(
-    inherited: &'a Inherited<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    fcx: &mut FnCtxt<'a, 'tcx>,
     fn_sig: ty::FnSig<'tcx>,
     decl: &'tcx hir::FnDecl<'tcx>,
-    fn_id: hir::HirId,
+    fn_def_id: LocalDefId,
     body: &'tcx hir::Body<'tcx>,
     can_be_generator: Option<hir::Movability>,
-    return_type_pre_known: bool,
-) -> (FnCtxt<'a, 'tcx>, Option<GeneratorTypes<'tcx>>) {
-    // Create the function context. This is either derived from scratch or,
-    // in the case of closures, based on the outer context.
-    let mut fcx = FnCtxt::new(inherited, param_env, body.value.hir_id);
-    fcx.ps.set(UnsafetyState::function(fn_sig.unsafety, fn_id));
-    fcx.return_type_pre_known = return_type_pre_known;
+) -> Option<GeneratorTypes<'tcx>> {
+    let fn_id = fcx.tcx.hir().local_def_id_to_hir_id(fn_def_id);
 
     let tcx = fcx.tcx;
     let hir = tcx.hir();
@@ -49,11 +41,8 @@ pub(super) fn check_fn<'a, 'tcx>(
             declared_ret_ty,
             body.value.hir_id,
             decl.output.span(),
-            param_env,
+            fcx.param_env,
         ));
-    // If we replaced declared_ret_ty with infer vars, then we must be inferring
-    // an opaque type, so set a flag so we can improve diagnostics.
-    fcx.return_type_has_opaque = ret_ty != declared_ret_ty;
 
     fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(ret_ty)));
 
@@ -61,45 +50,15 @@ pub(super) fn check_fn<'a, 'tcx>(
 
     fn_maybe_err(tcx, span, fn_sig.abi);
 
-    if fn_sig.abi == Abi::RustCall {
-        let expected_args = if let ImplicitSelfKind::None = decl.implicit_self { 1 } else { 2 };
-
-        let err = || {
-            let item = match tcx.hir().get(fn_id) {
-                Node::Item(hir::Item { kind: ItemKind::Fn(header, ..), .. }) => Some(header),
-                Node::ImplItem(hir::ImplItem {
-                    kind: hir::ImplItemKind::Fn(header, ..), ..
-                }) => Some(header),
-                Node::TraitItem(hir::TraitItem {
-                    kind: hir::TraitItemKind::Fn(header, ..),
-                    ..
-                }) => Some(header),
-                // Closures are RustCall, but they tuple their arguments, so shouldn't be checked
-                Node::Expr(hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => None,
-                node => bug!("Item being checked wasn't a function/closure: {:?}", node),
-            };
-
-            if let Some(header) = item {
-                tcx.sess.span_err(header.span, "functions with the \"rust-call\" ABI must take a single non-self argument that is a tuple");
-            }
-        };
-
-        if fn_sig.inputs().len() != expected_args {
-            err()
+    if let Some(kind) = body.generator_kind && can_be_generator.is_some() {
+        let yield_ty = if kind == hir::GeneratorKind::Gen {
+            let yield_ty = fcx
+                .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::TypeInference, span });
+            fcx.require_type_is_sized(yield_ty, span, traits::SizedYieldType);
+            yield_ty
         } else {
-            // FIXME(CraftSpider) Add a check on parameter expansion, so we don't just make the ICE happen later on
-            //   This will probably require wide-scale changes to support a TupleKind obligation
-            //   We can't resolve this without knowing the type of the param
-            if !matches!(fn_sig.inputs()[expected_args - 1].kind(), ty::Tuple(_) | ty::Param(_)) {
-                err()
-            }
-        }
-    }
-
-    if body.generator_kind.is_some() && can_be_generator.is_some() {
-        let yield_ty = fcx
-            .next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::TypeInference, span });
-        fcx.require_type_is_sized(yield_ty, span, traits::SizedYieldType);
+            tcx.mk_unit()
+        };
 
         // Resume type defaults to `()` if the generator has no argument.
         let resume_ty = fn_sig.inputs().get(0).copied().unwrap_or_else(|| tcx.mk_unit());
@@ -140,10 +99,9 @@ pub(super) fn check_fn<'a, 'tcx>(
         fcx.write_ty(param.hir_id, param_ty);
     }
 
-    inherited.typeck_results.borrow_mut().liberated_fn_sigs_mut().insert(fn_id, fn_sig);
+    fcx.typeck_results.borrow_mut().liberated_fn_sigs_mut().insert(fn_id, fn_sig);
 
-    fcx.in_tail_expr = true;
-    if let ty::Dynamic(..) = declared_ret_ty.kind() {
+    if let ty::Dynamic(_, _, ty::Dyn) = declared_ret_ty.kind() {
         // FIXME: We need to verify that the return type is `Sized` after the return expression has
         // been evaluated so that we have types available for all the nodes being returned, but that
         // requires the coerced evaluated type to be stored. Moving `check_return_expr` before this
@@ -161,7 +119,6 @@ pub(super) fn check_fn<'a, 'tcx>(
         fcx.require_type_is_sized(declared_ret_ty, decl.output.span(), traits::SizedReturnType);
         fcx.check_return_expr(&body.value, false);
     }
-    fcx.in_tail_expr = false;
 
     // We insert the deferred_generator_interiors entry after visiting the body.
     // This ensures that all nested generators appear before the entry of this generator.
@@ -211,14 +168,7 @@ pub(super) fn check_fn<'a, 'tcx>(
         check_panic_info_fn(tcx, panic_impl_did.expect_local(), fn_sig, decl, declared_ret_ty);
     }
 
-    // Check that a function marked as `#[alloc_error_handler]` has signature `fn(Layout) -> !`
-    if let Some(alloc_error_handler_did) = tcx.lang_items().oom()
-        && alloc_error_handler_did == hir.local_def_id(fn_id).to_def_id()
-    {
-        check_alloc_error_fn(tcx, alloc_error_handler_did.expect_local(), fn_sig, decl, declared_ret_ty);
-    }
-
-    (fcx, gen_ty)
+    gen_ty
 }
 
 fn check_panic_info_fn(
@@ -246,7 +196,7 @@ fn check_panic_info_fn(
     let arg_is_panic_info = match *inputs[0].kind() {
         ty::Ref(region, ty, mutbl) => match *ty.kind() {
             ty::Adt(ref adt, _) => {
-                adt.did() == panic_info_did && mutbl == hir::Mutability::Not && !region.is_static()
+                adt.did() == panic_info_did && mutbl.is_not() && !region.is_static()
             }
             _ => false,
         },
@@ -273,52 +223,3 @@ fn check_panic_info_fn(
         tcx.sess.span_err(span, "should have no const parameters");
     }
 }
-
-fn check_alloc_error_fn(
-    tcx: TyCtxt<'_>,
-    fn_id: LocalDefId,
-    fn_sig: ty::FnSig<'_>,
-    decl: &hir::FnDecl<'_>,
-    declared_ret_ty: Ty<'_>,
-) {
-    let Some(alloc_layout_did) = tcx.lang_items().alloc_layout() else {
-        tcx.sess.err("language item required, but not found: `alloc_layout`");
-        return;
-    };
-
-    if *declared_ret_ty.kind() != ty::Never {
-        tcx.sess.span_err(decl.output.span(), "return type should be `!`");
-    }
-
-    let inputs = fn_sig.inputs();
-    if inputs.len() != 1 {
-        tcx.sess.span_err(tcx.def_span(fn_id), "function should have one argument");
-        return;
-    }
-
-    let arg_is_alloc_layout = match inputs[0].kind() {
-        ty::Adt(ref adt, _) => adt.did() == alloc_layout_did,
-        _ => false,
-    };
-
-    if !arg_is_alloc_layout {
-        tcx.sess.span_err(decl.inputs[0].span, "argument should be `Layout`");
-    }
-
-    let DefKind::Fn = tcx.def_kind(fn_id) else {
-        let span = tcx.def_span(fn_id);
-        tcx.sess.span_err(span, "`#[alloc_error_handler]` should be a function");
-        return;
-    };
-
-    let generic_counts = tcx.generics_of(fn_id).own_counts();
-    if generic_counts.types != 0 {
-        let span = tcx.def_span(fn_id);
-        tcx.sess.span_err(span, "`#[alloc_error_handler]` function should have no type parameters");
-    }
-    if generic_counts.consts != 0 {
-        let span = tcx.def_span(fn_id);
-        tcx.sess
-            .span_err(span, "`#[alloc_error_handler]` function should have no const parameters");
-    }
-}