Auto merge of rust-lang#141753 - matthiaskrgr:rollup-bw4j2u0, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#133823 (Use `cfg_attr_trace` in AST with a placeholder attribute for accurate suggestion)
 - rust-lang#141004 (Report text_direction_codepoint_in_literal when parsing)
 - rust-lang#141407 (Refactor the two-phase check for impls and impl items)
 - rust-lang#141430 (remove `visit_clobber` and move `DummyAstNode` to `rustc_expand`)
 - rust-lang#141507 (atomic_load intrinsic: use const generic parameter for ordering)
 - rust-lang#141538 (implement `va_arg` for x86_64 systemv)
 - rust-lang#141669 (float: Replace some approximate assertions with exact)
 - rust-lang#141747 (rustdoc: display doc(cfg(false)) properly)

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

Author: bors

Cargo.lock

@@ -2171,6 +2171,7 @@ dependencies = [
 name = "lint-docs"
 version = "0.1.0"
 dependencies = [
+ "rustc-literal-escaper",
  "serde_json",
  "tempfile",
  "walkdir",

compiler/rustc_ast/src/ast.rs

@@ -32,7 +32,7 @@ use rustc_data_structures::tagged_ptr::Tag;
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 pub use rustc_span::AttrId;
 use rustc_span::source_map::{Spanned, respan};
-use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
+use rustc_span::{DUMMY_SP, ErrorGuaranteed, Ident, Span, Symbol, kw, sym};
 use thin_vec::{ThinVec, thin_vec};
 
 pub use crate::format::*;
@@ -1526,6 +1526,19 @@ impl Expr {
                 | ExprKind::Struct(_)
         )
     }
+
+    /// Creates a dummy `P<Expr>`.
+    ///
+    /// Should only be used when it will be replaced afterwards or as a return value when an error was encountered.
+    pub fn dummy() -> P<Expr> {
+        P(Expr {
+            id: DUMMY_NODE_ID,
+            kind: ExprKind::Dummy,
+            span: DUMMY_SP,
+            attrs: ThinVec::new(),
+            tokens: None,
+        })
+    }
 }
 
 #[derive(Clone, Encodable, Decodable, Debug)]

compiler/rustc_ast/src/ast_traits.rs

@@ -304,6 +304,7 @@ impl HasAttrs for Stmt {
 }
 
 /// A newtype around an AST node that implements the traits above if the node implements them.
+#[repr(transparent)]
 pub struct AstNodeWrapper<Wrapped, Tag> {
     pub wrapped: Wrapped,
     pub tag: PhantomData<Tag>,
@@ -313,6 +314,11 @@ impl<Wrapped, Tag> AstNodeWrapper<Wrapped, Tag> {
     pub fn new(wrapped: Wrapped, _tag: Tag) -> AstNodeWrapper<Wrapped, Tag> {
         AstNodeWrapper { wrapped, tag: Default::default() }
     }
+
+    pub fn from_mut(wrapped: &mut Wrapped, _tag: Tag) -> &mut AstNodeWrapper<Wrapped, Tag> {
+        // SAFETY: `AstNodeWrapper` is `repr(transparent)` w.r.t `Wrapped`
+        unsafe { &mut *<*mut Wrapped>::cast(wrapped) }
+    }
 }
 
 impl<Wrapped: HasNodeId, Tag> HasNodeId for AstNodeWrapper<Wrapped, Tag> {

compiler/rustc_ast/src/mut_visit.rs

@@ -368,14 +368,6 @@ pub trait MutVisitor: Sized {
 
 super::common_visitor_and_walkers!((mut) MutVisitor);
 
-/// Use a map-style function (`FnOnce(T) -> T`) to overwrite a `&mut T`. Useful
-/// when using a `flat_map_*` or `filter_map_*` method within a `visit_`
-/// method.
-pub fn visit_clobber<T: DummyAstNode>(t: &mut T, f: impl FnOnce(T) -> T) {
-    let old_t = std::mem::replace(t, T::dummy());
-    *t = f(old_t);
-}
-
 #[inline]
 fn visit_vec<T, F>(elems: &mut Vec<T>, mut visit_elem: F)
 where
@@ -1417,101 +1409,6 @@ fn walk_capture_by<T: MutVisitor>(vis: &mut T, capture_by: &mut CaptureBy) {
     }
 }
 
-/// Some value for the AST node that is valid but possibly meaningless. Similar
-/// to `Default` but not intended for wide use. The value will never be used
-/// meaningfully, it exists just to support unwinding in `visit_clobber` in the
-/// case where its closure panics.
-pub trait DummyAstNode {
-    fn dummy() -> Self;
-}
-
-impl<T> DummyAstNode for Option<T> {
-    fn dummy() -> Self {
-        Default::default()
-    }
-}
-
-impl<T: DummyAstNode + 'static> DummyAstNode for P<T> {
-    fn dummy() -> Self {
-        P(DummyAstNode::dummy())
-    }
-}
-
-impl DummyAstNode for Item {
-    fn dummy() -> Self {
-        Item {
-            attrs: Default::default(),
-            id: DUMMY_NODE_ID,
-            span: Default::default(),
-            vis: Visibility {
-                kind: VisibilityKind::Public,
-                span: Default::default(),
-                tokens: Default::default(),
-            },
-            kind: ItemKind::ExternCrate(None, Ident::dummy()),
-            tokens: Default::default(),
-        }
-    }
-}
-
-impl DummyAstNode for Expr {
-    fn dummy() -> Self {
-        Expr {
-            id: DUMMY_NODE_ID,
-            kind: ExprKind::Dummy,
-            span: Default::default(),
-            attrs: Default::default(),
-            tokens: Default::default(),
-        }
-    }
-}
-
-impl DummyAstNode for Ty {
-    fn dummy() -> Self {
-        Ty {
-            id: DUMMY_NODE_ID,
-            kind: TyKind::Dummy,
-            span: Default::default(),
-            tokens: Default::default(),
-        }
-    }
-}
-
-impl DummyAstNode for Pat {
-    fn dummy() -> Self {
-        Pat {
-            id: DUMMY_NODE_ID,
-            kind: PatKind::Wild,
-            span: Default::default(),
-            tokens: Default::default(),
-        }
-    }
-}
-
-impl DummyAstNode for Stmt {
-    fn dummy() -> Self {
-        Stmt { id: DUMMY_NODE_ID, kind: StmtKind::Empty, span: Default::default() }
-    }
-}
-
-impl DummyAstNode for Crate {
-    fn dummy() -> Self {
-        Crate {
-            attrs: Default::default(),
-            items: Default::default(),
-            spans: Default::default(),
-            id: DUMMY_NODE_ID,
-            is_placeholder: Default::default(),
-        }
-    }
-}
-
-impl<N: DummyAstNode, T: DummyAstNode> DummyAstNode for crate::ast_traits::AstNodeWrapper<N, T> {
-    fn dummy() -> Self {
-        crate::ast_traits::AstNodeWrapper::new(N::dummy(), T::dummy())
-    }
-}
-
 #[derive(Debug)]
 pub enum FnKind<'a> {
     /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.

compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs

@@ -870,11 +870,12 @@ fn codegen_regular_intrinsic_call<'tcx>(
             // FIXME use a compiler fence once Cranelift supports it
             fx.bcx.ins().fence();
         }
-        _ if intrinsic.as_str().starts_with("atomic_load") => {
+        sym::atomic_load => {
             intrinsic_args!(fx, args => (ptr); intrinsic);
             let ptr = ptr.load_scalar(fx);
 
             let ty = generic_args.type_at(0);
+            let _ord = generic_args.const_at(1).to_value(); // FIXME: forward this to cranelift once they support that
             match ty.kind() {
                 ty::Uint(UintTy::U128) | ty::Int(IntTy::I128) => {
                     // FIXME implement 128bit atomics

compiler/rustc_codegen_gcc/src/builder.rs

@@ -12,7 +12,7 @@ use rustc_abi::{Align, HasDataLayout, Size, TargetDataLayout, WrappingRange};
 use rustc_apfloat::{Float, Round, Status, ieee};
 use rustc_codegen_ssa::MemFlags;
 use rustc_codegen_ssa::common::{
-    AtomicOrdering, AtomicRmwBinOp, IntPredicate, RealPredicate, SynchronizationScope, TypeKind,
+    AtomicRmwBinOp, IntPredicate, RealPredicate, SynchronizationScope, TypeKind,
 };
 use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
 use rustc_codegen_ssa::mir::place::PlaceRef;
@@ -26,7 +26,7 @@ use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::ty::layout::{
     FnAbiError, FnAbiOfHelpers, FnAbiRequest, HasTyCtxt, HasTypingEnv, LayoutError, LayoutOfHelpers,
 };
-use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
+use rustc_middle::ty::{self, AtomicOrdering, Instance, Ty, TyCtxt};
 use rustc_span::Span;
 use rustc_span::def_id::DefId;
 use rustc_target::callconv::FnAbi;
@@ -75,7 +75,7 @@ impl<'a, 'gcc, 'tcx> Builder<'a, 'gcc, 'tcx> {
 
         let load_ordering = match order {
             // TODO(antoyo): does this make sense?
-            AtomicOrdering::AcquireRelease | AtomicOrdering::Release => AtomicOrdering::Acquire,
+            AtomicOrdering::AcqRel | AtomicOrdering::Release => AtomicOrdering::Acquire,
             _ => order,
         };
         let previous_value =
@@ -2474,8 +2474,8 @@ impl ToGccOrdering for AtomicOrdering {
             AtomicOrdering::Relaxed => __ATOMIC_RELAXED, // TODO(antoyo): check if that's the same.
             AtomicOrdering::Acquire => __ATOMIC_ACQUIRE,
             AtomicOrdering::Release => __ATOMIC_RELEASE,
-            AtomicOrdering::AcquireRelease => __ATOMIC_ACQ_REL,
-            AtomicOrdering::SequentiallyConsistent => __ATOMIC_SEQ_CST,
+            AtomicOrdering::AcqRel => __ATOMIC_ACQ_REL,
+            AtomicOrdering::SeqCst => __ATOMIC_SEQ_CST,
         };
         ordering as i32
     }

compiler/rustc_codegen_llvm/src/builder.rs

@@ -612,7 +612,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         &mut self,
         ty: &'ll Type,
         ptr: &'ll Value,
-        order: rustc_codegen_ssa::common::AtomicOrdering,
+        order: rustc_middle::ty::AtomicOrdering,
         size: Size,
     ) -> &'ll Value {
         unsafe {
@@ -851,7 +851,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         &mut self,
         val: &'ll Value,
         ptr: &'ll Value,
-        order: rustc_codegen_ssa::common::AtomicOrdering,
+        order: rustc_middle::ty::AtomicOrdering,
         size: Size,
     ) {
         debug!("Store {:?} -> {:?}", val, ptr);
@@ -1307,8 +1307,8 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         dst: &'ll Value,
         cmp: &'ll Value,
         src: &'ll Value,
-        order: rustc_codegen_ssa::common::AtomicOrdering,
-        failure_order: rustc_codegen_ssa::common::AtomicOrdering,
+        order: rustc_middle::ty::AtomicOrdering,
+        failure_order: rustc_middle::ty::AtomicOrdering,
         weak: bool,
     ) -> (&'ll Value, &'ll Value) {
         let weak = if weak { llvm::True } else { llvm::False };
@@ -1334,7 +1334,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         op: rustc_codegen_ssa::common::AtomicRmwBinOp,
         dst: &'ll Value,
         mut src: &'ll Value,
-        order: rustc_codegen_ssa::common::AtomicOrdering,
+        order: rustc_middle::ty::AtomicOrdering,
     ) -> &'ll Value {
         // The only RMW operation that LLVM supports on pointers is compare-exchange.
         let requires_cast_to_int = self.val_ty(src) == self.type_ptr()
@@ -1360,7 +1360,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
 
     fn atomic_fence(
         &mut self,
-        order: rustc_codegen_ssa::common::AtomicOrdering,
+        order: rustc_middle::ty::AtomicOrdering,
         scope: SynchronizationScope,
     ) {
         let single_threaded = match scope {

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -426,14 +426,14 @@ pub(crate) enum AtomicOrdering {
 }
 
 impl AtomicOrdering {
-    pub(crate) fn from_generic(ao: rustc_codegen_ssa::common::AtomicOrdering) -> Self {
-        use rustc_codegen_ssa::common::AtomicOrdering as Common;
+    pub(crate) fn from_generic(ao: rustc_middle::ty::AtomicOrdering) -> Self {
+        use rustc_middle::ty::AtomicOrdering as Common;
         match ao {
             Common::Relaxed => Self::Monotonic,
             Common::Acquire => Self::Acquire,
             Common::Release => Self::Release,
-            Common::AcquireRelease => Self::AcquireRelease,
-            Common::SequentiallyConsistent => Self::SequentiallyConsistent,
+            Common::AcqRel => Self::AcquireRelease,
+            Common::SeqCst => Self::SequentiallyConsistent,
         }
     }
 }