Auto merge of #147862 - cjgillot:noinit-box, r=<try>

Remove `box_new` intrinsic

Author: rust-bors[bot]

compiler/rustc_borrowck/src/lib.rs

@@ -1533,8 +1533,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
             Rvalue::Use(operand)
             | Rvalue::Repeat(operand, _)
             | Rvalue::UnaryOp(_ /*un_op*/, operand)
-            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/)
-            | Rvalue::ShallowInitBox(operand, _ /*ty*/) => {
+            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/) => {
                 self.consume_operand(location, (operand, span), state)
             }
 

compiler/rustc_borrowck/src/polonius/legacy/loan_invalidations.rs

@@ -297,8 +297,9 @@ impl<'a, 'tcx> LoanInvalidationsGenerator<'a, 'tcx> {
             Rvalue::Use(operand)
             | Rvalue::Repeat(operand, _)
             | Rvalue::UnaryOp(_ /*un_op*/, operand)
-            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/)
-            | Rvalue::ShallowInitBox(operand, _ /*ty*/) => self.consume_operand(location, operand),
+            | Rvalue::Cast(_ /*cast_kind*/, operand, _ /*ty*/) => {
+                self.consume_operand(location, operand)
+            }
 
             &Rvalue::Discriminant(place) => {
                 self.access_place(

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1059,17 +1059,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             &Rvalue::NullaryOp(NullOp::ContractChecks, _) => {}
             &Rvalue::NullaryOp(NullOp::UbChecks, _) => {}
 
-            Rvalue::ShallowInitBox(_operand, ty) => {
-                let trait_ref =
-                    ty::TraitRef::new(tcx, tcx.require_lang_item(LangItem::Sized, span), [*ty]);
-
-                self.prove_trait_ref(
-                    trait_ref,
-                    location.to_locations(),
-                    ConstraintCategory::SizedBound,
-                );
-            }
-
             Rvalue::Cast(cast_kind, op, ty) => {
                 match *cast_kind {
                     CastKind::PointerCoercion(PointerCoercion::ReifyFnPointer, coercion_source) => {
@@ -2211,7 +2200,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             | Rvalue::Ref(..)
             | Rvalue::RawPtr(..)
             | Rvalue::Cast(..)
-            | Rvalue::ShallowInitBox(..)
             | Rvalue::BinaryOp(..)
             | Rvalue::NullaryOp(..)
             | Rvalue::CopyForDeref(..)

compiler/rustc_codegen_cranelift/example/mini_core.rs

@@ -619,11 +619,6 @@ impl<T: ?Sized> Deref for Box<T> {
     }
 }
 
-#[lang = "exchange_malloc"]
-unsafe fn allocate(size: usize, _align: usize) -> *mut u8 {
-    libc::malloc(size)
-}
-
 #[lang = "drop"]
 pub trait Drop {
     fn drop(&mut self);

compiler/rustc_codegen_cranelift/src/base.rs

@@ -829,13 +829,6 @@ fn codegen_stmt<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, cur_block: Block, stmt:
                         fx.bcx.ins().nop();
                     }
                 }
-                Rvalue::ShallowInitBox(ref operand, content_ty) => {
-                    let content_ty = fx.monomorphize(content_ty);
-                    let box_layout = fx.layout_of(Ty::new_box(fx.tcx, content_ty));
-                    let operand = codegen_operand(fx, operand);
-                    let operand = operand.load_scalar(fx);
-                    lval.write_cvalue(fx, CValue::by_val(operand, box_layout));
-                }
                 Rvalue::NullaryOp(ref null_op, ty) => {
                     assert!(lval.layout().ty.is_sized(fx.tcx, fx.typing_env()));
                     let layout = fx.layout_of(fx.monomorphize(ty));

compiler/rustc_codegen_gcc/example/mini_core.rs

@@ -628,11 +628,6 @@ impl<T: ?Sized, A: Allocator> Deref for Box<T, A> {
     }
 }
 
-#[lang = "exchange_malloc"]
-unsafe fn allocate(size: usize, _align: usize) -> *mut u8 {
-    libc::malloc(size)
-}
-
 #[lang = "drop"]
 pub trait Drop {
     fn drop(&mut self);

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -724,15 +724,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     }
                 }
             }
-            mir::Rvalue::ShallowInitBox(ref operand, content_ty) => {
-                let operand = self.codegen_operand(bx, operand);
-                let val = operand.immediate();
-
-                let content_ty = self.monomorphize(content_ty);
-                let box_layout = bx.cx().layout_of(Ty::new_box(bx.tcx(), content_ty));
-
-                OperandRef { val: OperandValue::Immediate(val), layout: box_layout }
-            }
             mir::Rvalue::WrapUnsafeBinder(ref operand, binder_ty) => {
                 let operand = self.codegen_operand(bx, operand);
                 let binder_ty = self.monomorphize(binder_ty);

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -653,7 +653,6 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 | NullOp::ContractChecks,
                 _,
             ) => {}
-            Rvalue::ShallowInitBox(_, _) => {}
 
             Rvalue::UnaryOp(op, operand) => {
                 let ty = operand.ty(self.body, self.tcx);
@@ -853,7 +852,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 }
 
                 // This can be called on stable via the `vec!` macro.
-                if tcx.is_lang_item(callee, LangItem::ExchangeMalloc) {
+                if tcx.is_diagnostic_item(sym::box_new, callee) {
                     self.check_op(ops::HeapAllocation);
                     // Allow this call, skip all the checks below.
                     return;

compiler/rustc_const_eval/src/check_consts/qualifs.rs

@@ -239,8 +239,7 @@ where
         Rvalue::Use(operand)
         | Rvalue::Repeat(operand, _)
         | Rvalue::UnaryOp(_, operand)
-        | Rvalue::Cast(_, operand, _)
-        | Rvalue::ShallowInitBox(operand, _) => in_operand::<Q, _>(cx, in_local, operand),
+        | Rvalue::Cast(_, operand, _) => in_operand::<Q, _>(cx, in_local, operand),
 
         Rvalue::BinaryOp(_, box (lhs, rhs)) => {
             in_operand::<Q, _>(cx, in_local, lhs) || in_operand::<Q, _>(cx, in_local, rhs)

compiler/rustc_const_eval/src/check_consts/resolver.rs

@@ -192,7 +192,6 @@ where
             }
 
             mir::Rvalue::Cast(..)
-            | mir::Rvalue::ShallowInitBox(..)
             | mir::Rvalue::Use(..)
             | mir::Rvalue::CopyForDeref(..)
             | mir::Rvalue::ThreadLocalRef(..)