Auto merge of #30555 - Manishearth:rollup, r=Manishearth

- Successful merges: #30485, #30490, #30513, #30518, #30528, #30545, #30551, #30552
- Failed merges:

src/doc/book/syntax-index.md

@@ -41,6 +41,7 @@
 
 * `!` (`ident!(…)`, `ident!{…}`, `ident![…]`): denotes macro expansion.  See [Macros].
 * `!` (`!expr`): bitwise or logical complement.  Overloadable (`Not`).
+* `!=` (`var != expr`): nonequality comparison.  Overloadable (`PartialEq`).
 * `%` (`expr % expr`): arithmetic remainder.  Overloadable (`Rem`).
 * `%=` (`var %= expr`): arithmetic remainder & assignment.
 * `&` (`expr & expr`): bitwise and.  Overloadable (`BitAnd`).
@@ -75,13 +76,13 @@
 * `;` (`[…; len]`): part of fixed-size array syntax.  See [Primitive Types (Arrays)].
 * `<<` (`expr << expr`): left-shift.  Overloadable (`Shl`).
 * `<<=` (`var <<= expr`): left-shift & assignment.
-* `<` (`expr < expr`): less-than comparison.  Overloadable (`Cmp`, `PartialCmp`).
-* `<=` (`var <= expr`): less-than or equal-to comparison.  Overloadable (`Cmp`, `PartialCmp`).
+* `<` (`expr < expr`): less-than comparison.  Overloadable (`PartialOrd`).
+* `<=` (`var <= expr`): less-than or equal-to comparison.  Overloadable (`PartialOrd`).
 * `=` (`var = expr`, `ident = type`): assignment/equivalence.  See [Variable Bindings], [`type` Aliases], generic parameter defaults.
-* `==` (`var == expr`): comparison.  Overloadable (`Eq`, `PartialEq`).
+* `==` (`var == expr`): equality comparison.  Overloadable (`PartialEq`).
 * `=>` (`pat => expr`): part of match arm syntax.  See [Match].
-* `>` (`expr > expr`): greater-than comparison.  Overloadable (`Cmp`, `PartialCmp`).
-* `>=` (`var >= expr`): greater-than or equal-to comparison.  Overloadable (`Cmp`, `PartialCmp`).
+* `>` (`expr > expr`): greater-than comparison.  Overloadable (`PartialOrd`).
+* `>=` (`var >= expr`): greater-than or equal-to comparison.  Overloadable (`PartialOrd`).
 * `>>` (`expr >> expr`): right-shift.  Overloadable (`Shr`).
 * `>>=` (`var >>= expr`): right-shift & assignment.
 * `@` (`ident @ pat`): pattern binding.  See [Patterns (Bindings)].

src/grammar/parser-lalr.y

@@ -1822,8 +1822,8 @@ unpaired_token
 | LIT_FLOAT                  { $$ = mk_atom(yytext); }
 | LIT_STR                    { $$ = mk_atom(yytext); }
 | LIT_STR_RAW                { $$ = mk_atom(yytext); }
-| LIT_BYTE_STR                 { $$ = mk_atom(yytext); }
-| LIT_BYTE_STR_RAW             { $$ = mk_atom(yytext); }
+| LIT_BYTE_STR               { $$ = mk_atom(yytext); }
+| LIT_BYTE_STR_RAW           { $$ = mk_atom(yytext); }
 | IDENT                      { $$ = mk_atom(yytext); }
 | UNDERSCORE                 { $$ = mk_atom(yytext); }
 | LIFETIME                   { $$ = mk_atom(yytext); }

src/librustc/front/map/mod.rs

@@ -839,11 +839,10 @@ pub fn map_crate<'ast>(forest: &'ast mut Forest) -> Map<'ast> {
 }
 
 /// Used for items loaded from external crate that are being inlined into this
-/// crate.  The `path` should be the path to the item but should not include
-/// the item itself.
+/// crate.
 pub fn map_decoded_item<'ast, F: FoldOps>(map: &Map<'ast>,
-                                          path: Vec<PathElem>,
-                                          def_path: DefPath,
+                                          parent_path: Vec<PathElem>,
+                                          parent_def_path: DefPath,
                                           ii: InlinedItem,
                                           fold_ops: F)
                                           -> &'ast InlinedItem {
@@ -862,7 +861,7 @@ pub fn map_decoded_item<'ast, F: FoldOps>(map: &Map<'ast>,
     };
 
     let ii_parent = map.forest.inlined_items.alloc(InlinedParent {
-        path: path,
+        path: parent_path,
         ii: ii
     });
 
@@ -872,7 +871,7 @@ pub fn map_decoded_item<'ast, F: FoldOps>(map: &Map<'ast>,
             map.krate(),
             ii_parent,
             ii_parent_id,
-            def_path,
+            parent_def_path,
             mem::replace(&mut *map.map.borrow_mut(), vec![]),
             mem::replace(&mut *map.definitions.borrow_mut(), Definitions::new()));
     ii_parent.ii.visit(&mut collector);

src/librustc/mir/repr.rs

@@ -701,9 +701,9 @@ pub struct Constant<'tcx> {
 #[derive(Clone, Copy, Debug, PartialEq, RustcEncodable, RustcDecodable)]
 pub enum ItemKind {
     Constant,
+    /// This is any sort of callable (usually those that have a type of `fn(…) -> …`). This
+    /// includes functions, constructors, but not methods which have their own ItemKind.
     Function,
-    Struct,
-    Variant,
     Method,
 }
 

src/librustc_metadata/astencode.rs

@@ -124,20 +124,20 @@ impl<'a, 'b, 'c, 'tcx> ast_map::FoldOps for &'a DecodeContext<'b, 'c, 'tcx> {
 /// ast-map.
 pub fn decode_inlined_item<'tcx>(cdata: &cstore::crate_metadata,
                                  tcx: &ty::ctxt<'tcx>,
-                                 path: Vec<ast_map::PathElem>,
-                                 def_path: ast_map::DefPath,
+                                 parent_path: Vec<ast_map::PathElem>,
+                                 parent_def_path: ast_map::DefPath,
                                  par_doc: rbml::Doc,
                                  orig_did: DefId)
                                  -> Result<&'tcx InlinedItem, (Vec<ast_map::PathElem>,
                                                                ast_map::DefPath)> {
     match par_doc.opt_child(c::tag_ast) {
-      None => Err((path, def_path)),
+      None => Err((parent_path, parent_def_path)),
       Some(ast_doc) => {
         let mut path_as_str = None;
         debug!("> Decoding inlined fn: {:?}::?",
         {
             // Do an Option dance to use the path after it is moved below.
-            let s = ast_map::path_to_string(path.iter().cloned());
+            let s = ast_map::path_to_string(parent_path.iter().cloned());
             path_as_str = Some(s);
             path_as_str.as_ref().map(|x| &x[..])
         });
@@ -152,8 +152,11 @@ pub fn decode_inlined_item<'tcx>(cdata: &cstore::crate_metadata,
             last_filemap_index: Cell::new(0)
         };
         let raw_ii = decode_ast(ast_doc);
-        let ii = ast_map::map_decoded_item(&dcx.tcx.map, path, def_path, raw_ii, dcx);
-
+        let ii = ast_map::map_decoded_item(&dcx.tcx.map,
+                                           parent_path,
+                                           parent_def_path,
+                                           raw_ii,
+                                           dcx);
         let name = match *ii {
             InlinedItem::Item(ref i) => i.name,
             InlinedItem::Foreign(ref i) => i.name,

src/librustc_metadata/decoder.rs

@@ -763,29 +763,54 @@ pub fn get_item_name(intr: &IdentInterner, cdata: Cmd, id: DefIndex) -> ast::Nam
 pub type DecodeInlinedItem<'a> =
     Box<for<'tcx> FnMut(Cmd,
                         &ty::ctxt<'tcx>,
-                        Vec<hir_map::PathElem>,
-                        hir_map::DefPath,
+                        Vec<hir_map::PathElem>, // parent_path
+                        hir_map::DefPath,       // parent_def_path
                         rbml::Doc,
                         DefId)
                         -> Result<&'tcx InlinedItem, (Vec<hir_map::PathElem>,
                                                       hir_map::DefPath)> + 'a>;
 
-pub fn maybe_get_item_ast<'tcx>(cdata: Cmd, tcx: &ty::ctxt<'tcx>, id: DefIndex,
+pub fn maybe_get_item_ast<'tcx>(cdata: Cmd,
+                                tcx: &ty::ctxt<'tcx>,
+                                id: DefIndex,
                                 mut decode_inlined_item: DecodeInlinedItem)
                                 -> FoundAst<'tcx> {
     debug!("Looking up item: {:?}", id);
     let item_doc = cdata.lookup_item(id);
     let item_did = item_def_id(item_doc, cdata);
-    let path = item_path(item_doc).split_last().unwrap().1.to_vec();
-    let def_path = def_path(cdata, id);
-    match decode_inlined_item(cdata, tcx, path, def_path, item_doc, item_did) {
+    let parent_path = {
+        let mut path = item_path(item_doc);
+        path.pop();
+        path
+    };
+    let parent_def_path = {
+        let mut def_path = def_path(cdata, id);
+        def_path.pop();
+        def_path
+    };
+    match decode_inlined_item(cdata,
+                              tcx,
+                              parent_path,
+                              parent_def_path,
+                              item_doc,
+                              item_did) {
         Ok(ii) => FoundAst::Found(ii),
-        Err((path, def_path)) => {
+        Err((mut parent_path, mut parent_def_path)) => {
             match item_parent_item(cdata, item_doc) {
-                Some(did) => {
-                    let parent_item = cdata.lookup_item(did.index);
-                    match decode_inlined_item(cdata, tcx, path, def_path, parent_item, did) {
-                        Ok(ii) => FoundAst::FoundParent(did, ii),
+                Some(parent_did) => {
+                    // Remove the last element from the paths, since we are now
+                    // trying to inline the parent.
+                    parent_path.pop();
+                    parent_def_path.pop();
+
+                    let parent_item = cdata.lookup_item(parent_did.index);
+                    match decode_inlined_item(cdata,
+                                              tcx,
+                                              parent_path,
+                                              parent_def_path,
+                                              parent_item,
+                                              parent_did) {
+                        Ok(ii) => FoundAst::FoundParent(parent_did, ii),
                         Err(_) => FoundAst::NotFound
                     }
                 }

src/librustc_mir/hair/cx/expr.rs

@@ -519,51 +519,51 @@ fn convert_path_expr<'a, 'tcx: 'a>(cx: &mut Cx<'a, 'tcx>, expr: &'tcx hir::Expr)
     let substs = cx.tcx.mk_substs(cx.tcx.node_id_item_substs(expr.id).substs);
     // Otherwise there may be def_map borrow conflicts
     let def = cx.tcx.def_map.borrow()[&expr.id].full_def();
-    match def {
-        def::DefVariant(_, def_id, false) |
-        def::DefStruct(def_id) |
-        def::DefFn(def_id, _) |
-        def::DefMethod(def_id) => {
-            let kind = match def {
-                def::DefVariant(..) => ItemKind::Variant,
-                def::DefStruct(..) => ItemKind::Struct,
-                def::DefFn(..) => ItemKind::Function,
-                def::DefMethod(..) => ItemKind::Method,
-                _ => panic!()
-            };
-            ExprKind::Literal {
-                literal: Literal::Item { def_id: def_id, kind: kind, substs: substs }
+    let (def_id, kind) = match def {
+        // A variant constructor.
+        def::DefVariant(_, def_id, false) => (def_id, ItemKind::Function),
+        // A regular function.
+        def::DefFn(def_id, _) => (def_id, ItemKind::Function),
+        def::DefMethod(def_id) => (def_id, ItemKind::Method),
+        def::DefStruct(def_id) => {
+            match cx.tcx.node_id_to_type(expr.id).sty {
+                // A tuple-struct constructor.
+                ty::TyBareFn(..) => (def_id, ItemKind::Function),
+                // This is a special case: a unit struct which is used as a value. We return a
+                // completely different ExprKind here to account for this special case.
+                ty::TyStruct(adt_def, substs) => return ExprKind::Adt {
+                    adt_def: adt_def,
+                    variant_index: 0,
+                    substs: substs,
+                    fields: vec![],
+                    base: None
+                },
+                ref sty => panic!("unexpected sty: {:?}", sty)
             }
         },
         def::DefConst(def_id) |
         def::DefAssociatedConst(def_id) => {
             if let Some(v) = cx.try_const_eval_literal(expr) {
-                ExprKind::Literal { literal: v }
+                return ExprKind::Literal { literal: v };
             } else {
-                ExprKind::Literal {
-                    literal: Literal::Item {
-                        def_id: def_id,
-                        kind: ItemKind::Constant,
-                        substs: substs
-                    }
-                }
+                (def_id, ItemKind::Constant)
             }
         }
 
-
-        def::DefStatic(node_id, _) =>
-            ExprKind::StaticRef {
-                id: node_id,
-            },
+        def::DefStatic(node_id, _) => return ExprKind::StaticRef {
+            id: node_id,
+        },
 
         def @ def::DefLocal(..) |
-        def @ def::DefUpvar(..) =>
-            convert_var(cx, expr, def),
+        def @ def::DefUpvar(..) => return convert_var(cx, expr, def),
 
         def =>
             cx.tcx.sess.span_bug(
                 expr.span,
                 &format!("def `{:?}` not yet implemented", def)),
+    };
+    ExprKind::Literal {
+        literal: Literal::Item { def_id: def_id, kind: kind, substs: substs }
     }
 }
 

src/librustc_trans/trans/mir/did.rs

@@ -39,9 +39,7 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
                           did: DefId)
                           -> OperandRef<'tcx> {
         match kind {
-            ItemKind::Function |
-            ItemKind::Struct |
-            ItemKind::Variant => self.trans_fn_ref(bcx, ty, substs, did),
+            ItemKind::Function => self.trans_fn_ref(bcx, ty, substs, did),
             ItemKind::Method => match bcx.tcx().impl_or_trait_item(did).container() {
                 ty::ImplContainer(_) => self.trans_fn_ref(bcx, ty, substs, did),
                 ty::TraitContainer(tdid) => self.trans_static_method(bcx, ty, did, tdid, substs)

src/librustc_trans/trans/mir/rvalue.rs

@@ -19,28 +19,30 @@ use trans::common::{self, Block, Result};
 use trans::debuginfo::DebugLoc;
 use trans::declare;
 use trans::expr;
+use trans::adt;
 use trans::machine;
 use trans::type_::Type;
 use trans::type_of;
 use trans::tvec;
 
 use super::MirContext;
 use super::operand::{OperandRef, OperandValue};
+use super::lvalue::LvalueRef;
 
 impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
     pub fn trans_rvalue(&mut self,
                         bcx: Block<'bcx, 'tcx>,
-                        lldest: ValueRef,
+                        dest: LvalueRef<'tcx>,
                         rvalue: &mir::Rvalue<'tcx>)
                         -> Block<'bcx, 'tcx>
     {
-        debug!("trans_rvalue(lldest={}, rvalue={:?})",
-               bcx.val_to_string(lldest),
+        debug!("trans_rvalue(dest.llval={}, rvalue={:?})",
+               bcx.val_to_string(dest.llval),
                rvalue);
 
         match *rvalue {
             mir::Rvalue::Use(ref operand) => {
-                self.trans_operand_into(bcx, lldest, operand);
+                self.trans_operand_into(bcx, dest.llval, operand);
                 bcx
             }
 
@@ -49,7 +51,7 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
                     // into-coerce of a thin pointer to a fat pointer - just
                     // use the operand path.
                     let (bcx, temp) = self.trans_rvalue_operand(bcx, rvalue);
-                    self.store_operand(bcx, lldest, temp);
+                    self.store_operand(bcx, dest.llval, temp);
                     return bcx;
                 }
 
@@ -72,12 +74,12 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
                         base::store_ty(bcx, llval, lltemp, operand.ty);
                         base::coerce_unsized_into(bcx,
                                                   lltemp, operand.ty,
-                                                  lldest, cast_ty);
+                                                  dest.llval, cast_ty);
                     }
                     OperandValue::Ref(llref) => {
                         base::coerce_unsized_into(bcx,
                                                   llref, operand.ty,
-                                                  lldest, cast_ty);
+                                                  dest.llval, cast_ty);
                     }
                 }
                 bcx
@@ -86,20 +88,31 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
             mir::Rvalue::Repeat(ref elem, ref count) => {
                 let elem = self.trans_operand(bcx, elem);
                 let size = self.trans_constant(bcx, count).immediate();
-                let base = expr::get_dataptr(bcx, lldest);
+                let base = expr::get_dataptr(bcx, dest.llval);
                 tvec::iter_vec_raw(bcx, base, elem.ty, size, |bcx, llslot, _| {
                     self.store_operand(bcx, llslot, elem);
                     bcx
                 })
             }
 
-            mir::Rvalue::Aggregate(_, ref operands) => {
-                for (i, operand) in operands.iter().enumerate() {
-                    // Note: perhaps this should be StructGep, but
-                    // note that in some cases the values here will
-                    // not be structs but arrays.
-                    let lldest_i = build::GEPi(bcx, lldest, &[0, i]);
-                    self.trans_operand_into(bcx, lldest_i, operand);
+            mir::Rvalue::Aggregate(ref kind, ref operands) => {
+                match *kind {
+                    // Unit struct, which is translated very differently compared to any other
+                    // aggregate
+                    mir::AggregateKind::Adt(adt_def, 0, _)
+                    if adt_def.struct_variant().kind() == ty::VariantKind::Unit => {
+                        let repr = adt::represent_type(bcx.ccx(), dest.ty.to_ty(bcx.tcx()));
+                        adt::trans_set_discr(bcx, &*repr, dest.llval, 0);
+                    },
+                    _ => {
+                        for (i, operand) in operands.iter().enumerate() {
+                            // Note: perhaps this should be StructGep, but
+                            // note that in some cases the values here will
+                            // not be structs but arrays.
+                            let lldest_i = build::GEPi(bcx, dest.llval, &[0, i]);
+                            self.trans_operand_into(bcx, lldest_i, operand);
+                        }
+                    }
                 }
                 bcx
             }
@@ -113,9 +126,9 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
                 let llbase1 = build::GEPi(bcx, llbase, &[from_start]);
                 let adj = common::C_uint(ccx, from_start + from_end);
                 let lllen1 = build::Sub(bcx, lllen, adj, DebugLoc::None);
-                let lladdrdest = expr::get_dataptr(bcx, lldest);
+                let lladdrdest = expr::get_dataptr(bcx, dest.llval);
                 build::Store(bcx, llbase1, lladdrdest);
-                let llmetadest = expr::get_meta(bcx, lldest);
+                let llmetadest = expr::get_meta(bcx, dest.llval);
                 build::Store(bcx, lllen1, llmetadest);
                 bcx
             }
@@ -127,7 +140,7 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
             _ => {
                 assert!(rvalue_creates_operand(rvalue));
                 let (bcx, temp) = self.trans_rvalue_operand(bcx, rvalue);
-                self.store_operand(bcx, lldest, temp);
+                self.store_operand(bcx, dest.llval, temp);
                 bcx
             }
         }