Auto merge of rust-lang#125663 - matthiaskrgr:rollup-ej3yuxm, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#117671 (NVPTX: Avoid PassMode::Direct for args in C abi)
 - rust-lang#124251 (Add an intrinsic for `ptr::metadata`)
 - rust-lang#125573 (Migrate `run-make/allow-warnings-cmdline-stability` to `rmake.rs`)
 - rust-lang#125590 (Add a "Setup Python" action for github-hosted runners and remove unnecessary `CUSTOM_MINGW` environment variable)
 - rust-lang#125598 (Make `ProofTreeBuilder` actually generic over `Interner`)
 - rust-lang#125637 (rustfmt fixes)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

.github/workflows/ci.yml

@@ -154,9 +154,12 @@ jobs:
 
       - name: checkout submodules
         run: src/ci/scripts/checkout-submodules.sh
-
-      - name: install MSYS2
-        run: src/ci/scripts/install-msys2.sh
+      
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+        if: runner.environment == 'github-hosted'
 
       - name: install MinGW
         run: src/ci/scripts/install-mingw.sh

compiler/rustc_codegen_cranelift/src/base.rs

@@ -619,9 +619,10 @@ fn codegen_stmt<'tcx>(
                 Rvalue::UnaryOp(un_op, ref operand) => {
                     let operand = codegen_operand(fx, operand);
                     let layout = operand.layout();
-                    let val = operand.load_scalar(fx);
                     let res = match un_op {
-                        UnOp::Not => match layout.ty.kind() {
+                        UnOp::Not => {
+                            let val = operand.load_scalar(fx);
+                            match layout.ty.kind() {
                             ty::Bool => {
                                 let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
                                 CValue::by_val(res, layout)
@@ -630,11 +631,22 @@ fn codegen_stmt<'tcx>(
                                 CValue::by_val(fx.bcx.ins().bnot(val), layout)
                             }
                             _ => unreachable!("un op Not for {:?}", layout.ty),
-                        },
-                        UnOp::Neg => match layout.ty.kind() {
+                            }
+                        }
+                        UnOp::Neg => {
+                            let val = operand.load_scalar(fx);
+                            match layout.ty.kind() {
                             ty::Int(_) => CValue::by_val(fx.bcx.ins().ineg(val), layout),
                             ty::Float(_) => CValue::by_val(fx.bcx.ins().fneg(val), layout),
                             _ => unreachable!("un op Neg for {:?}", layout.ty),
+                            }
+                        }
+                        UnOp::PtrMetadata => match layout.abi {
+                            Abi::Scalar(_) => CValue::zst(dest_layout),
+                            Abi::ScalarPair(_, _) => {
+                                CValue::by_val(operand.load_scalar_pair(fx).1, dest_layout)
+                            }
+                            _ => bug!("Unexpected `PtrToMetadata` operand: {operand:?}"),
                         },
                     };
                     lval.write_cvalue(fx, res);

compiler/rustc_codegen_cranelift/src/constant.rs

@@ -100,7 +100,7 @@ pub(crate) fn codegen_const_value<'tcx>(
     assert!(layout.is_sized(), "unsized const value");
 
     if layout.is_zst() {
-        return CValue::by_ref(crate::Pointer::dangling(layout.align.pref), layout);
+        return CValue::zst(layout);
     }
 
     match const_val {

compiler/rustc_codegen_cranelift/src/value_and_place.rs

@@ -95,6 +95,14 @@ impl<'tcx> CValue<'tcx> {
         CValue(CValueInner::ByValPair(value, extra), layout)
     }
 
+    /// Create an instance of a ZST
+    ///
+    /// The is represented by a dangling pointer of suitable alignment.
+    pub(crate) fn zst(layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
+        assert!(layout.is_zst());
+        CValue::by_ref(crate::Pointer::dangling(layout.align.pref), layout)
+    }
+
     pub(crate) fn layout(&self) -> TyAndLayout<'tcx> {
         self.1
     }

compiler/rustc_codegen_ssa/src/mir/operand.rs

@@ -565,6 +565,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 for elem in place_ref.projection.iter() {
                     match elem {
                         mir::ProjectionElem::Field(ref f, _) => {
+                            debug_assert!(
+                                !o.layout.ty.is_any_ptr(),
+                                "Bad PlaceRef: destructing pointers should use cast/PtrMetadata, \
+                                 but tried to access field {f:?} of pointer {o:?}",
+                            );
                             o = o.extract_field(bx, f.index());
                         }
                         mir::ProjectionElem::Index(_)

compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -480,6 +480,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             cg_base = match *elem {
                 mir::ProjectionElem::Deref => bx.load_operand(cg_base).deref(bx.cx()),
                 mir::ProjectionElem::Field(ref field, _) => {
+                    debug_assert!(
+                        !cg_base.layout.ty.is_any_ptr(),
+                        "Bad PlaceRef: destructing pointers should use cast/PtrMetadata, \
+                         but tried to access field {field:?} of pointer {cg_base:?}",
+                    );
                     cg_base.project_field(bx, field.index())
                 }
                 mir::ProjectionElem::OpaqueCast(ty) => {

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -623,19 +623,36 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
             mir::Rvalue::UnaryOp(op, ref operand) => {
                 let operand = self.codegen_operand(bx, operand);
-                let lloperand = operand.immediate();
                 let is_float = operand.layout.ty.is_floating_point();
-                let llval = match op {
-                    mir::UnOp::Not => bx.not(lloperand),
+                let (val, layout) = match op {
+                    mir::UnOp::Not => {
+                        let llval = bx.not(operand.immediate());
+                        (OperandValue::Immediate(llval), operand.layout)
+                    }
                     mir::UnOp::Neg => {
-                        if is_float {
-                            bx.fneg(lloperand)
+                        let llval = if is_float {
+                            bx.fneg(operand.immediate())
+                        } else {
+                            bx.neg(operand.immediate())
+                        };
+                        (OperandValue::Immediate(llval), operand.layout)
+                    }
+                    mir::UnOp::PtrMetadata => {
+                        debug_assert!(operand.layout.ty.is_unsafe_ptr());
+                        let (_, meta) = operand.val.pointer_parts();
+                        assert_eq!(operand.layout.fields.count() > 1, meta.is_some());
+                        if let Some(meta) = meta {
+                            (OperandValue::Immediate(meta), operand.layout.field(self.cx, 1))
                         } else {
-                            bx.neg(lloperand)
+                            (OperandValue::ZeroSized, bx.cx().layout_of(bx.tcx().types.unit))
                         }
                     }
                 };
-                OperandRef { val: OperandValue::Immediate(llval), layout: operand.layout }
+                debug_assert!(
+                    val.is_expected_variant_for_type(self.cx, layout),
+                    "Made wrong variant {val:?} for type {layout:?}",
+                );
+                OperandRef { val, layout }
             }
 
             mir::Rvalue::Discriminant(ref place) => {
@@ -718,8 +735,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     let values = op.val.immediates_or_place().left_or_else(|p| {
                         bug!("Field {field_idx:?} is {p:?} making {layout:?}");
                     });
-                    inputs.extend(values);
                     let scalars = self.value_kind(op.layout).scalars().unwrap();
+                    debug_assert_eq!(values.len(), scalars.len());
+                    inputs.extend(values);
                     input_scalars.extend(scalars);
                 }
 

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -207,7 +207,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         assert!(cast_to.ty.is_unsafe_ptr());
         // Handle casting any ptr to raw ptr (might be a fat ptr).
         if cast_to.size == src.layout.size {
-            // Thin or fat pointer that just hast the ptr kind of target type changed.
+            // Thin or fat pointer that just has the ptr kind of target type changed.
             return Ok(ImmTy::from_immediate(**src, cast_to));
         } else {
             // Casting the metadata away from a fat ptr.

compiler/rustc_const_eval/src/interpret/operator.rs

@@ -9,7 +9,7 @@ use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::sym;
 use tracing::trace;
 
-use super::{err_ub, throw_ub, ImmTy, InterpCx, Machine};
+use super::{err_ub, throw_ub, ImmTy, InterpCx, Machine, MemPlaceMeta};
 
 impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     fn three_way_compare<T: Ord>(&self, lhs: T, rhs: T) -> ImmTy<'tcx, M::Provenance> {
@@ -415,11 +415,11 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         use rustc_middle::mir::UnOp::*;
 
         let layout = val.layout;
-        let val = val.to_scalar();
         trace!("Running unary op {:?}: {:?} ({})", un_op, val, layout.ty);
 
         match layout.ty.kind() {
             ty::Bool => {
+                let val = val.to_scalar();
                 let val = val.to_bool()?;
                 let res = match un_op {
                     Not => !val,
@@ -428,6 +428,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 Ok(ImmTy::from_bool(res, *self.tcx))
             }
             ty::Float(fty) => {
+                let val = val.to_scalar();
                 // No NaN adjustment here, `-` is a bitwise operation!
                 let res = match (un_op, fty) {
                     (Neg, FloatTy::F32) => Scalar::from_f32(-val.to_f32()?),
@@ -436,8 +437,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 };
                 Ok(ImmTy::from_scalar(res, layout))
             }
-            _ => {
-                assert!(layout.ty.is_integral());
+            _ if layout.ty.is_integral() => {
+                let val = val.to_scalar();
                 let val = val.to_bits(layout.size)?;
                 let res = match un_op {
                     Not => self.truncate(!val, layout), // bitwise negation, then truncate
@@ -450,9 +451,28 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                         // Truncate to target type.
                         self.truncate(res, layout)
                     }
+                    _ => span_bug!(self.cur_span(), "Invalid integer op {:?}", un_op),
                 };
                 Ok(ImmTy::from_uint(res, layout))
             }
+            ty::RawPtr(..) => {
+                assert_eq!(un_op, PtrMetadata);
+                let (_, meta) = val.to_scalar_and_meta();
+                Ok(match meta {
+                    MemPlaceMeta::Meta(scalar) => {
+                        let ty = un_op.ty(*self.tcx, val.layout.ty);
+                        let layout = self.layout_of(ty)?;
+                        ImmTy::from_scalar(scalar, layout)
+                    }
+                    MemPlaceMeta::None => {
+                        let unit_layout = self.layout_of(self.tcx.types.unit)?;
+                        ImmTy::uninit(unit_layout)
+                    }
+                })
+            }
+            _ => {
+                bug!("Unexpected unary op argument {val:?}")
+            }
         }
     }
 }

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -130,6 +130,7 @@ pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -
         | sym::is_val_statically_known
         | sym::ptr_mask
         | sym::aggregate_raw_ptr
+        | sym::ptr_metadata
         | sym::ub_checks
         | sym::fadd_algebraic
         | sym::fsub_algebraic
@@ -576,6 +577,7 @@ pub fn check_intrinsic_type(
             // This type check is not particularly useful, but the `where` bounds
             // on the definition in `core` do the heavy lifting for checking it.
             sym::aggregate_raw_ptr => (3, 1, vec![param(1), param(2)], param(0)),
+            sym::ptr_metadata => (2, 1, vec![Ty::new_imm_ptr(tcx, param(0))], param(1)),
 
             sym::ub_checks => (0, 1, Vec::new(), tcx.types.bool),