Auto merge of #40216 - frewsxcv:rollup, r=frewsxcv

Rollup of 7 pull requests

- Successful merges: #39832, #40104, #40110, #40117, #40129, #40139, #40166
- Failed merges:

src/libcollections/fmt.rs

@@ -524,6 +524,7 @@ use string;
 pub fn format(args: Arguments) -> string::String {
     let capacity = args.estimated_capacity();
     let mut output = string::String::with_capacity(capacity);
-    let _ = output.write_fmt(args);
+    output.write_fmt(args)
+          .expect("a formatting trait implementation returned an error");
     output
 }

src/libcollections/macros.rs

@@ -72,6 +72,12 @@ macro_rules! vec {
 ///
 /// [fmt]: ../std/fmt/index.html
 ///
+/// # Panics
+///
+/// `format!` panics if a formatting trait implementation returns an error.
+/// This indicates an incorrect implementation
+/// since `fmt::Write for String` never returns an error itself.
+///
 /// # Examples
 ///
 /// ```

src/libcollections/string.rs

@@ -1900,13 +1900,20 @@ pub trait ToString {
     fn to_string(&self) -> String;
 }
 
+/// # Panics
+///
+/// In this implementation, the `to_string` method panics
+/// if the `Display` implementation returns an error.
+/// This indicates an incorrect `Display` implementation
+/// since `fmt::Write for String` never returns an error itself.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: fmt::Display + ?Sized> ToString for T {
     #[inline]
     default fn to_string(&self) -> String {
         use core::fmt::Write;
         let mut buf = String::new();
-        let _ = buf.write_fmt(format_args!("{}", self));
+        buf.write_fmt(format_args!("{}", self))
+           .expect("a Display implementation return an error unexpectedly");
         buf.shrink_to_fit();
         buf
     }

src/libproc_macro/lib.rs

@@ -125,6 +125,10 @@ pub mod __internal {
         fn register_attr_proc_macro(&mut self,
                                     name: &str,
                                     expand: fn(TokenStream, TokenStream) -> TokenStream);
+
+        fn register_bang_proc_macro(&mut self,
+                                    name: &str,
+                                    expand: fn(TokenStream) -> TokenStream);
     }
 
     // Emulate scoped_thread_local!() here essentially

src/librustc/mir/mod.rs

@@ -983,7 +983,7 @@ pub enum Rvalue<'tcx> {
     Use(Operand<'tcx>),
 
     /// [x; 32]
-    Repeat(Operand<'tcx>, TypedConstVal<'tcx>),
+    Repeat(Operand<'tcx>, ConstUsize),
 
     /// &x or &mut x
     Ref(&'tcx Region, BorrowKind, Lvalue<'tcx>),
@@ -1038,7 +1038,8 @@ pub enum CastKind {
 
 #[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
 pub enum AggregateKind<'tcx> {
-    Array,
+    /// The type is of the element
+    Array(Ty<'tcx>),
     Tuple,
     /// The second field is variant number (discriminant), it's equal to 0
     /// for struct and union expressions. The fourth field is active field
@@ -1135,7 +1136,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                 }
 
                 match *kind {
-                    AggregateKind::Array => write!(fmt, "{:?}", lvs),
+                    AggregateKind::Array(_) => write!(fmt, "{:?}", lvs),
 
                     AggregateKind::Tuple => {
                         match lvs.len() {
@@ -1202,19 +1203,6 @@ pub struct Constant<'tcx> {
     pub literal: Literal<'tcx>,
 }
 
-#[derive(Clone, RustcEncodable, RustcDecodable)]
-pub struct TypedConstVal<'tcx> {
-    pub ty: Ty<'tcx>,
-    pub span: Span,
-    pub value: ConstUsize,
-}
-
-impl<'tcx> Debug for TypedConstVal<'tcx> {
-    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
-        write!(fmt, "const {}", ConstInt::Usize(self.value))
-    }
-}
-
 newtype_index!(Promoted, "promoted");
 
 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]

src/librustc/mir/tcx.rs

@@ -134,76 +134,70 @@ impl<'tcx> Lvalue<'tcx> {
 }
 
 impl<'tcx> Rvalue<'tcx> {
-    pub fn ty<'a, 'gcx>(&self, mir: &Mir<'tcx>, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Option<Ty<'tcx>>
+    pub fn ty<'a, 'gcx>(&self, mir: &Mir<'tcx>, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Ty<'tcx>
     {
         match *self {
-            Rvalue::Use(ref operand) => Some(operand.ty(mir, tcx)),
+            Rvalue::Use(ref operand) => operand.ty(mir, tcx),
             Rvalue::Repeat(ref operand, ref count) => {
                 let op_ty = operand.ty(mir, tcx);
-                let count = count.value.as_u64(tcx.sess.target.uint_type);
+                let count = count.as_u64(tcx.sess.target.uint_type);
                 assert_eq!(count as usize as u64, count);
-                Some(tcx.mk_array(op_ty, count as usize))
+                tcx.mk_array(op_ty, count as usize)
             }
             Rvalue::Ref(reg, bk, ref lv) => {
                 let lv_ty = lv.ty(mir, tcx).to_ty(tcx);
-                Some(tcx.mk_ref(reg,
+                tcx.mk_ref(reg,
                     ty::TypeAndMut {
                         ty: lv_ty,
                         mutbl: bk.to_mutbl_lossy()
                     }
-                ))
+                )
             }
-            Rvalue::Len(..) => Some(tcx.types.usize),
-            Rvalue::Cast(.., ty) => Some(ty),
+            Rvalue::Len(..) => tcx.types.usize,
+            Rvalue::Cast(.., ty) => ty,
             Rvalue::BinaryOp(op, ref lhs, ref rhs) => {
                 let lhs_ty = lhs.ty(mir, tcx);
                 let rhs_ty = rhs.ty(mir, tcx);
-                Some(op.ty(tcx, lhs_ty, rhs_ty))
+                op.ty(tcx, lhs_ty, rhs_ty)
             }
             Rvalue::CheckedBinaryOp(op, ref lhs, ref rhs) => {
                 let lhs_ty = lhs.ty(mir, tcx);
                 let rhs_ty = rhs.ty(mir, tcx);
                 let ty = op.ty(tcx, lhs_ty, rhs_ty);
-                let ty = tcx.intern_tup(&[ty, tcx.types.bool], false);
-                Some(ty)
+                tcx.intern_tup(&[ty, tcx.types.bool], false)
             }
             Rvalue::UnaryOp(_, ref operand) => {
-                Some(operand.ty(mir, tcx))
+                operand.ty(mir, tcx)
             }
             Rvalue::Discriminant(ref lval) => {
                 let ty = lval.ty(mir, tcx).to_ty(tcx);
                 if let ty::TyAdt(adt_def, _) = ty.sty {
-                    Some(adt_def.repr.discr_type().to_ty(tcx))
+                    adt_def.repr.discr_type().to_ty(tcx)
                 } else {
                     // Undefined behaviour, bug for now; may want to return something for
                     // the `discriminant` intrinsic later.
                     bug!("Rvalue::Discriminant on Lvalue of type {:?}", ty);
                 }
             }
             Rvalue::Box(t) => {
-                Some(tcx.mk_box(t))
+                tcx.mk_box(t)
             }
             Rvalue::Aggregate(ref ak, ref ops) => {
                 match *ak {
-                    AggregateKind::Array => {
-                        if let Some(operand) = ops.get(0) {
-                            let ty = operand.ty(mir, tcx);
-                            Some(tcx.mk_array(ty, ops.len()))
-                        } else {
-                            None
-                        }
+                    AggregateKind::Array(ty) => {
+                        tcx.mk_array(ty, ops.len())
                     }
                     AggregateKind::Tuple => {
-                        Some(tcx.mk_tup(
+                        tcx.mk_tup(
                             ops.iter().map(|op| op.ty(mir, tcx)),
                             false
-                        ))
+                        )
                     }
                     AggregateKind::Adt(def, _, substs, _) => {
-                        Some(tcx.item_type(def.did).subst(tcx, substs))
+                        tcx.item_type(def.did).subst(tcx, substs)
                     }
                     AggregateKind::Closure(did, substs) => {
-                        Some(tcx.mk_closure_from_closure_substs(did, substs))
+                        tcx.mk_closure_from_closure_substs(did, substs)
                     }
                 }
             }

src/librustc/mir/visit.rs

@@ -235,12 +235,6 @@ macro_rules! make_mir_visitor {
                 self.super_const_usize(const_usize);
             }
 
-            fn visit_typed_const_val(&mut self,
-                                     val: & $($mutability)* TypedConstVal<'tcx>,
-                                     location: Location) {
-                self.super_typed_const_val(val, location);
-            }
-
             fn visit_local_decl(&mut self,
                                 local_decl: & $($mutability)* LocalDecl<'tcx>) {
                 self.super_local_decl(local_decl);
@@ -467,9 +461,9 @@ macro_rules! make_mir_visitor {
                     }
 
                     Rvalue::Repeat(ref $($mutability)* value,
-                                   ref $($mutability)* typed_const_val) => {
+                                   ref $($mutability)* length) => {
                         self.visit_operand(value, location);
-                        self.visit_typed_const_val(typed_const_val, location);
+                        self.visit_const_usize(length, location);
                     }
 
                     Rvalue::Ref(r, bk, ref $($mutability)* path) => {
@@ -515,7 +509,8 @@ macro_rules! make_mir_visitor {
                     Rvalue::Aggregate(ref $($mutability)* kind,
                                       ref $($mutability)* operands) => {
                         match *kind {
-                            AggregateKind::Array => {
+                            AggregateKind::Array(ref $($mutability)* ty) => {
+                                self.visit_ty(ty);
                             }
                             AggregateKind::Tuple => {
                             }
@@ -647,20 +642,6 @@ macro_rules! make_mir_visitor {
                 self.visit_literal(literal, location);
             }
 
-            fn super_typed_const_val(&mut self,
-                                     constant: & $($mutability)* TypedConstVal<'tcx>,
-                                     location: Location) {
-                let TypedConstVal {
-                    ref $($mutability)* span,
-                    ref $($mutability)* ty,
-                    ref $($mutability)* value,
-                } = *constant;
-
-                self.visit_span(span);
-                self.visit_ty(ty);
-                self.visit_const_usize(value, location);
-            }
-
             fn super_literal(&mut self,
                              literal: & $($mutability)* Literal<'tcx>,
                              location: Location) {

src/librustc_llvm/ffi.rs

@@ -53,6 +53,7 @@ pub enum CallConv {
     X86_64_SysV = 78,
     X86_64_Win64 = 79,
     X86_VectorCall = 80,
+    X86_Intr = 83,
 }
 
 /// LLVMRustLinkage

src/librustc_metadata/creader.rs

@@ -586,7 +586,7 @@ impl<'a> CrateLoader<'a> {
         use proc_macro::__internal::Registry;
         use rustc_back::dynamic_lib::DynamicLibrary;
         use syntax_ext::deriving::custom::ProcMacroDerive;
-        use syntax_ext::proc_macro_impl::AttrProcMacro;
+        use syntax_ext::proc_macro_impl::{AttrProcMacro, BangProcMacro};
 
         let path = match dylib {
             Some(dylib) => dylib,
@@ -630,6 +630,15 @@ impl<'a> CrateLoader<'a> {
                 );
                 self.0.push((Symbol::intern(name), Rc::new(expand)));
             }
+
+            fn register_bang_proc_macro(&mut self,
+                                        name: &str,
+                                        expand: fn(TokenStream) -> TokenStream) {
+                let expand = SyntaxExtension::ProcMacro(
+                    Box::new(BangProcMacro { inner: expand })
+                );
+                self.0.push((Symbol::intern(name), Rc::new(expand)));
+            }
         }
 
         let mut my_registrar = MyRegistrar(Vec::new());

src/librustc_mir/build/expr/as_rvalue.rs

@@ -148,12 +148,13 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 //     to the same MIR as `let x = ();`.
 
                 // first process the set of fields
+                let el_ty = expr.ty.sequence_element_type(this.hir.tcx());
                 let fields: Vec<_> =
                     fields.into_iter()
                           .map(|f| unpack!(block = this.as_operand(block, f)))
                           .collect();
 
-                block.and(Rvalue::Aggregate(AggregateKind::Array, fields))
+                block.and(Rvalue::Aggregate(AggregateKind::Array(el_ty), fields))
             }
             ExprKind::Tuple { fields } => { // see (*) above
                 // first process the set of fields

src/librustc_mir/hair/cx/expr.rs

@@ -602,11 +602,7 @@ fn make_mirror_unadjusted<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
 
             ExprKind::Repeat {
                 value: v.to_ref(),
-                count: TypedConstVal {
-                    ty: cx.tcx.types.usize,
-                    span: c.span,
-                    value: count
-                }
+                count: count,
             }
         }
         hir::ExprRet(ref v) => ExprKind::Return { value: v.to_ref() },

src/librustc_mir/hair/mod.rs

@@ -14,7 +14,8 @@
 //! unit-tested and separated from the Rust source and compiler data
 //! structures.
 
-use rustc::mir::{BinOp, BorrowKind, Field, Literal, UnOp, TypedConstVal};
+use rustc_const_math::ConstUsize;
+use rustc::mir::{BinOp, BorrowKind, Field, Literal, UnOp};
 use rustc::hir::def_id::DefId;
 use rustc::middle::region::CodeExtent;
 use rustc::ty::subst::Substs;
@@ -219,7 +220,7 @@ pub enum ExprKind<'tcx> {
     },
     Repeat {
         value: ExprRef<'tcx>,
-        count: TypedConstVal<'tcx>,
+        count: ConstUsize,
     },
     Array {
         fields: Vec<ExprRef<'tcx>>,

src/librustc_mir/transform/qualify_consts.rs

@@ -752,7 +752,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Qualifier<'a, 'tcx, 'tcx> {
                     }
 
                     if Some(def.did) == self.tcx.lang_items.unsafe_cell_type() {
-                        let ty = rvalue.ty(self.mir, self.tcx).unwrap();
+                        let ty = rvalue.ty(self.mir, self.tcx);
                         self.add_type(ty);
                         assert!(self.qualif.intersects(Qualif::MUTABLE_INTERIOR));
                         // Even if the value inside may not need dropping,

src/librustc_mir/transform/type_check.rs

@@ -83,9 +83,8 @@ impl<'a, 'b, 'gcx, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'gcx, 'tcx> {
 
     fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) {
         self.super_rvalue(rvalue, location);
-        if let Some(ty) = rvalue.ty(self.mir, self.tcx()) {
-            self.sanitize_type(rvalue, ty);
-        }
+        let rval_ty = rvalue.ty(self.mir, self.tcx());
+        self.sanitize_type(rvalue, rval_ty);
     }
 
     fn visit_mir(&mut self, mir: &Mir<'tcx>) {
@@ -356,14 +355,10 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
             StatementKind::Assign(ref lv, ref rv) => {
                 let lv_ty = lv.ty(mir, tcx).to_ty(tcx);
                 let rv_ty = rv.ty(mir, tcx);
-                if let Some(rv_ty) = rv_ty {
-                    if let Err(terr) = self.sub_types(rv_ty, lv_ty) {
-                        span_mirbug!(self, stmt, "bad assignment ({:?} = {:?}): {:?}",
-                                     lv_ty, rv_ty, terr);
-                    }
+                if let Err(terr) = self.sub_types(rv_ty, lv_ty) {
+                    span_mirbug!(self, stmt, "bad assignment ({:?} = {:?}): {:?}",
+                                 lv_ty, rv_ty, terr);
                 }
-                // FIXME: rvalue with undeterminable type - e.g. AggregateKind::Array branch that
-                // returns `None`.
             }
             StatementKind::SetDiscriminant{ ref lvalue, variant_index } => {
                 let lvalue_type = lvalue.ty(mir, tcx).to_ty(tcx);