Auto merge of #31010 - petrochenkov:def, r=arielb1

All structs and their constructors are defined as `DefStruct`.
`DefTy` is splitted into `DefEnum` and `DefTyAlias`.
Ad hoc flag `bool is_structure` is removed from `DefVariant`, it was required in one place in resolve and could be obtained by other means.
Flag `bool is_ctor` is removed from `DefFn`, it wasn't really used for constructors outside of metadata decoding.

Observable effects:
More specific error messages are selected in some cases.
Two name resolution bugs fixed (#30992 and FIXME in compile-fail/empty-struct-braces-expr.rs).

Fixes #30992
Closes #30361

src/librustc/middle/astconv_util.rs

@@ -14,7 +14,7 @@
  * Almost certainly this could (and should) be refactored out of existence.
  */
 
-use middle::def;
+use middle::def::Def;
 use middle::ty::{self, Ty};
 
 use syntax::codemap::Span;
@@ -72,7 +72,7 @@ pub fn ast_ty_to_prim_ty<'tcx>(tcx: &ty::ctxt<'tcx>, ast_ty: &ast::Ty)
             }
             Some(d) => d.full_def()
         };
-        if let def::DefPrimTy(nty) = def {
+        if let Def::PrimTy(nty) = def {
             Some(prim_ty_to_ty(tcx, &path.segments, nty))
         } else {
             None

src/librustc/middle/cfg/construct.rs

@@ -10,7 +10,7 @@
 
 use rustc_data_structures::graph;
 use middle::cfg::*;
-use middle::def;
+use middle::def::Def;
 use middle::pat_util;
 use middle::ty;
 use syntax::ast;
@@ -591,7 +591,7 @@ impl<'a, 'tcx> CFGBuilder<'a, 'tcx> {
         }
 
         match self.tcx.def_map.borrow().get(&expr.id).map(|d| d.full_def()) {
-            Some(def::DefLabel(loop_id)) => {
+            Some(Def::Label(loop_id)) => {
                 for l in &self.loop_scopes {
                     if l.loop_id == loop_id {
                         return *l;

src/librustc/middle/check_const.rs

@@ -29,7 +29,7 @@ use middle::ty::cast::{CastKind};
 use middle::const_eval::{self, ConstEvalErr};
 use middle::const_eval::ErrKind::IndexOpFeatureGated;
 use middle::const_eval::EvalHint::ExprTypeChecked;
-use middle::def;
+use middle::def::Def;
 use middle::def_id::DefId;
 use middle::expr_use_visitor as euv;
 use middle::infer;
@@ -610,21 +610,21 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
         hir::ExprPath(..) => {
             let def = v.tcx.def_map.borrow().get(&e.id).map(|d| d.full_def());
             match def {
-                Some(def::DefVariant(_, _, _)) => {
+                Some(Def::Variant(..)) => {
                     // Count the discriminator or function pointer.
                     v.add_qualif(ConstQualif::NON_ZERO_SIZED);
                 }
-                Some(def::DefStruct(_)) => {
+                Some(Def::Struct(..)) => {
                     if let ty::TyBareFn(..) = node_ty.sty {
                         // Count the function pointer.
                         v.add_qualif(ConstQualif::NON_ZERO_SIZED);
                     }
                 }
-                Some(def::DefFn(..)) | Some(def::DefMethod(..)) => {
+                Some(Def::Fn(..)) | Some(Def::Method(..)) => {
                     // Count the function pointer.
                     v.add_qualif(ConstQualif::NON_ZERO_SIZED);
                 }
-                Some(def::DefStatic(..)) => {
+                Some(Def::Static(..)) => {
                     match v.mode {
                         Mode::Static | Mode::StaticMut => {}
                         Mode::Const | Mode::ConstFn => {
@@ -635,16 +635,16 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
                         Mode::Var => v.add_qualif(ConstQualif::NOT_CONST)
                     }
                 }
-                Some(def::DefConst(did)) |
-                Some(def::DefAssociatedConst(did)) => {
+                Some(Def::Const(did)) |
+                Some(Def::AssociatedConst(did)) => {
                     if let Some(expr) = const_eval::lookup_const_by_id(v.tcx, did,
                                                                        Some(e.id),
                                                                        None) {
                         let inner = v.global_expr(Mode::Const, expr);
                         v.add_qualif(inner);
                     }
                 }
-                Some(def::DefLocal(..)) if v.mode == Mode::ConstFn => {
+                Some(Def::Local(..)) if v.mode == Mode::ConstFn => {
                     // Sadly, we can't determine whether the types are zero-sized.
                     v.add_qualif(ConstQualif::NOT_CONST | ConstQualif::NON_ZERO_SIZED);
                 }
@@ -672,16 +672,16 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
             }
             let def = v.tcx.def_map.borrow().get(&callee.id).map(|d| d.full_def());
             let is_const = match def {
-                Some(def::DefStruct(..)) => true,
-                Some(def::DefVariant(..)) => {
+                Some(Def::Struct(..)) => true,
+                Some(Def::Variant(..)) => {
                     // Count the discriminator.
                     v.add_qualif(ConstQualif::NON_ZERO_SIZED);
                     true
                 }
-                Some(def::DefFn(did, _)) => {
+                Some(Def::Fn(did)) => {
                     v.handle_const_fn_call(e, did, node_ty)
                 }
-                Some(def::DefMethod(did)) => {
+                Some(Def::Method(did)) => {
                     match v.tcx.impl_or_trait_item(did).container() {
                         ty::ImplContainer(_) => {
                             v.handle_const_fn_call(e, did, node_ty)

src/librustc/middle/check_match.rs

@@ -246,7 +246,7 @@ fn check_for_bindings_named_the_same_as_variants(cx: &MatchCheckCtxt, pat: &Pat)
                 let pat_ty = cx.tcx.pat_ty(p);
                 if let ty::TyEnum(edef, _) = pat_ty.sty {
                     let def = cx.tcx.def_map.borrow().get(&p.id).map(|d| d.full_def());
-                    if let Some(DefLocal(..)) = def {
+                    if let Some(Def::Local(..)) = def {
                         if edef.variants.iter().any(|variant|
                             variant.name == ident.node.unhygienic_name
                                 && variant.kind() == VariantKind::Unit
@@ -454,8 +454,8 @@ impl<'a, 'tcx> Folder for StaticInliner<'a, 'tcx> {
             hir::PatIdent(..) | hir::PatEnum(..) | hir::PatQPath(..) => {
                 let def = self.tcx.def_map.borrow().get(&pat.id).map(|d| d.full_def());
                 match def {
-                    Some(DefAssociatedConst(did)) |
-                    Some(DefConst(did)) => match lookup_const_by_id(self.tcx, did,
+                    Some(Def::AssociatedConst(did)) |
+                    Some(Def::Const(did)) => match lookup_const_by_id(self.tcx, did,
                                                                     Some(pat.id), None) {
                         Some(const_expr) => {
                             const_expr_to_pat(self.tcx, const_expr, pat.span).map(|new_pat| {
@@ -757,30 +757,30 @@ fn pat_constructors(cx: &MatchCheckCtxt, p: &Pat,
     match pat.node {
         hir::PatIdent(..) =>
             match cx.tcx.def_map.borrow().get(&pat.id).map(|d| d.full_def()) {
-                Some(DefConst(..)) | Some(DefAssociatedConst(..)) =>
+                Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) =>
                     cx.tcx.sess.span_bug(pat.span, "const pattern should've \
                                                     been rewritten"),
-                Some(DefStruct(_)) => vec!(Single),
-                Some(DefVariant(_, id, _)) => vec!(Variant(id)),
+                Some(Def::Struct(..)) => vec!(Single),
+                Some(Def::Variant(_, id)) => vec!(Variant(id)),
                 _ => vec!()
             },
         hir::PatEnum(..) =>
             match cx.tcx.def_map.borrow().get(&pat.id).map(|d| d.full_def()) {
-                Some(DefConst(..)) | Some(DefAssociatedConst(..)) =>
+                Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) =>
                     cx.tcx.sess.span_bug(pat.span, "const pattern should've \
                                                     been rewritten"),
-                Some(DefVariant(_, id, _)) => vec!(Variant(id)),
+                Some(Def::Variant(_, id)) => vec!(Variant(id)),
                 _ => vec!(Single)
             },
         hir::PatQPath(..) =>
             cx.tcx.sess.span_bug(pat.span, "const pattern should've \
                                             been rewritten"),
         hir::PatStruct(..) =>
             match cx.tcx.def_map.borrow().get(&pat.id).map(|d| d.full_def()) {
-                Some(DefConst(..)) | Some(DefAssociatedConst(..)) =>
+                Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) =>
                     cx.tcx.sess.span_bug(pat.span, "const pattern should've \
                                                     been rewritten"),
-                Some(DefVariant(_, id, _)) => vec!(Variant(id)),
+                Some(Def::Variant(_, id)) => vec!(Variant(id)),
                 _ => vec!(Single)
             },
         hir::PatLit(ref expr) =>
@@ -869,10 +869,10 @@ pub fn specialize<'a>(cx: &MatchCheckCtxt, r: &[&'a Pat],
         hir::PatIdent(_, _, _) => {
             let opt_def = cx.tcx.def_map.borrow().get(&pat_id).map(|d| d.full_def());
             match opt_def {
-                Some(DefConst(..)) | Some(DefAssociatedConst(..)) =>
+                Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) =>
                     cx.tcx.sess.span_bug(pat_span, "const pattern should've \
                                                     been rewritten"),
-                Some(DefVariant(_, id, _)) => if *constructor == Variant(id) {
+                Some(Def::Variant(_, id)) => if *constructor == Variant(id) {
                     Some(vec!())
                 } else {
                     None
@@ -884,11 +884,11 @@ pub fn specialize<'a>(cx: &MatchCheckCtxt, r: &[&'a Pat],
         hir::PatEnum(_, ref args) => {
             let def = cx.tcx.def_map.borrow().get(&pat_id).unwrap().full_def();
             match def {
-                DefConst(..) | DefAssociatedConst(..) =>
+                Def::Const(..) | Def::AssociatedConst(..) =>
                     cx.tcx.sess.span_bug(pat_span, "const pattern should've \
                                                     been rewritten"),
-                DefVariant(_, id, _) if *constructor != Variant(id) => None,
-                DefVariant(..) | DefStruct(..) => {
+                Def::Variant(_, id) if *constructor != Variant(id) => None,
+                Def::Variant(..) | Def::Struct(..) => {
                     Some(match args {
                         &Some(ref args) => args.iter().map(|p| &**p).collect(),
                         &None => vec![DUMMY_WILD_PAT; arity],

src/librustc/middle/check_static_recursion.rs

@@ -13,7 +13,7 @@
 
 use front::map as ast_map;
 use session::Session;
-use middle::def::{DefStatic, DefConst, DefAssociatedConst, DefVariant, DefMap};
+use middle::def::{Def, DefMap};
 use util::nodemap::NodeMap;
 
 use syntax::{ast};
@@ -238,9 +238,9 @@ impl<'a, 'ast: 'a> Visitor<'ast> for CheckItemRecursionVisitor<'a, 'ast> {
         match e.node {
             hir::ExprPath(..) => {
                 match self.def_map.get(&e.id).map(|d| d.base_def) {
-                    Some(DefStatic(def_id, _)) |
-                    Some(DefAssociatedConst(def_id)) |
-                    Some(DefConst(def_id)) => {
+                    Some(Def::Static(def_id, _)) |
+                    Some(Def::AssociatedConst(def_id)) |
+                    Some(Def::Const(def_id)) => {
                         if let Some(node_id) = self.ast_map.as_local_node_id(def_id) {
                             match self.ast_map.get(node_id) {
                                 ast_map::NodeItem(item) =>
@@ -263,7 +263,7 @@ impl<'a, 'ast: 'a> Visitor<'ast> for CheckItemRecursionVisitor<'a, 'ast> {
                     // affect the specific variant used, but we need to check
                     // the whole enum definition to see what expression that
                     // might be (if any).
-                    Some(DefVariant(enum_id, variant_id, false)) => {
+                    Some(Def::Variant(enum_id, variant_id)) => {
                         if let Some(enum_node_id) = self.ast_map.as_local_node_id(enum_id) {
                             if let hir::ItemEnum(ref enum_def, ref generics) =
                                 self.ast_map.expect_item(enum_node_id).node
@@ -276,7 +276,7 @@ impl<'a, 'ast: 'a> Visitor<'ast> for CheckItemRecursionVisitor<'a, 'ast> {
                             } else {
                                 self.sess.span_bug(e.span,
                                                    "`check_static_recursion` found \
-                                                    non-enum in DefVariant");
+                                                    non-enum in Def::Variant");
                             }
                         }
                     }

src/librustc/middle/const_eval.rs

@@ -17,7 +17,8 @@ use self::EvalHint::*;
 use front::map as ast_map;
 use front::map::blocks::FnLikeNode;
 use middle::cstore::{self, CrateStore, InlinedItem};
-use middle::{def, infer, subst, traits};
+use middle::{infer, subst, traits};
+use middle::def::Def;
 use middle::subst::Subst;
 use middle::def_id::DefId;
 use middle::pat_util::def_to_path;
@@ -331,9 +332,9 @@ pub fn const_expr_to_pat(tcx: &ty::ctxt, expr: &Expr, span: Span) -> P<hir::Pat>
                entry.insert(def);
             }
             let path = match def.full_def() {
-                def::DefStruct(def_id) => def_to_path(tcx, def_id),
-                def::DefVariant(_, variant_did, _) => def_to_path(tcx, variant_did),
-                def::DefFn(..) => return P(hir::Pat {
+                Def::Struct(def_id) => def_to_path(tcx, def_id),
+                Def::Variant(_, variant_did) => def_to_path(tcx, variant_did),
+                Def::Fn(..) => return P(hir::Pat {
                     id: expr.id,
                     node: hir::PatLit(P(expr.clone())),
                     span: span,
@@ -364,12 +365,12 @@ pub fn const_expr_to_pat(tcx: &ty::ctxt, expr: &Expr, span: Span) -> P<hir::Pat>
         hir::ExprPath(_, ref path) => {
             let opt_def = tcx.def_map.borrow().get(&expr.id).map(|d| d.full_def());
             match opt_def {
-                Some(def::DefStruct(..)) =>
+                Some(Def::Struct(..)) =>
                     hir::PatStruct(path.clone(), hir::HirVec::new(), false),
-                Some(def::DefVariant(..)) =>
+                Some(Def::Variant(..)) =>
                     hir::PatEnum(path.clone(), None),
-                Some(def::DefConst(def_id)) |
-                Some(def::DefAssociatedConst(def_id)) => {
+                Some(Def::Const(def_id)) |
+                Some(Def::AssociatedConst(def_id)) => {
                     let expr = lookup_const_by_id(tcx, def_id, Some(expr.id), None).unwrap();
                     return const_expr_to_pat(tcx, expr, span);
                 },
@@ -1002,7 +1003,7 @@ pub fn eval_const_expr_partial<'tcx>(tcx: &ty::ctxt<'tcx>,
               None
           };
           let (const_expr, const_ty) = match opt_def {
-              Some(def::DefConst(def_id)) => {
+              Some(Def::Const(def_id)) => {
                   if let Some(node_id) = tcx.map.as_local_node_id(def_id) {
                       match tcx.map.find(node_id) {
                           Some(ast_map::NodeItem(it)) => match it.node {
@@ -1017,7 +1018,7 @@ pub fn eval_const_expr_partial<'tcx>(tcx: &ty::ctxt<'tcx>,
                       (lookup_const_by_id(tcx, def_id, Some(e.id), None), None)
                   }
               }
-              Some(def::DefAssociatedConst(def_id)) => {
+              Some(Def::AssociatedConst(def_id)) => {
                   if let Some(node_id) = tcx.map.as_local_node_id(def_id) {
                       match tcx.impl_or_trait_item(def_id).container() {
                           ty::TraitContainer(trait_id) => match tcx.map.find(node_id) {
@@ -1052,21 +1053,21 @@ pub fn eval_const_expr_partial<'tcx>(tcx: &ty::ctxt<'tcx>,
                       (lookup_const_by_id(tcx, def_id, Some(e.id), None), None)
                   }
               }
-              Some(def::DefVariant(enum_def, variant_def, _)) => {
+              Some(Def::Variant(enum_def, variant_def)) => {
                   (lookup_variant_by_id(tcx, enum_def, variant_def), None)
               }
-              Some(def::DefStruct(_)) => {
+              Some(Def::Struct(..)) => {
                   return Ok(ConstVal::Struct(e.id))
               }
-              Some(def::DefLocal(_, id)) => {
-                  debug!("DefLocal({:?}): {:?}", id, fn_args);
+              Some(Def::Local(_, id)) => {
+                  debug!("Def::Local({:?}): {:?}", id, fn_args);
                   if let Some(val) = fn_args.and_then(|args| args.get(&id)) {
                       return Ok(val.clone());
                   } else {
                       (None, None)
                   }
               },
-              Some(def::DefMethod(id)) | Some(def::DefFn(id, _)) => return Ok(Function(id)),
+              Some(Def::Method(id)) | Some(Def::Fn(id)) => return Ok(Function(id)),
               _ => (None, None)
           };
           let const_expr = match const_expr {

src/librustc/middle/cstore.rs

@@ -24,9 +24,9 @@
 
 use back::svh::Svh;
 use front::map as hir_map;
-use middle::def;
+use middle::def::{self, Def};
 use middle::lang_items;
-use middle::ty::{self, Ty};
+use middle::ty::{self, Ty, VariantKind};
 use middle::def_id::{DefId, DefIndex};
 use mir::repr::Mir;
 use session::Session;
@@ -84,7 +84,7 @@ enum_from_u32! {
 // Something that a name can resolve to.
 #[derive(Copy, Clone, Debug)]
 pub enum DefLike {
-    DlDef(def::Def),
+    DlDef(Def),
     DlImpl(DefId),
     DlField
 }
@@ -211,6 +211,8 @@ pub trait CrateStore<'tcx> : Any {
 
     // resolve
     fn def_path(&self, def: DefId) -> hir_map::DefPath;
+    fn variant_kind(&self, def_id: DefId) -> Option<VariantKind>;
+    fn struct_ctor_def_id(&self, struct_def_id: DefId) -> Option<DefId>;
     fn tuple_struct_definition_if_ctor(&self, did: DefId) -> Option<DefId>;
     fn struct_field_names(&self, def: DefId) -> Vec<ast::Name>;
     fn item_children(&self, did: DefId) -> Vec<ChildItem>;
@@ -380,6 +382,9 @@ impl<'tcx> CrateStore<'tcx> for DummyCrateStore {
 
     // resolve
     fn def_path(&self, def: DefId) -> hir_map::DefPath { unimplemented!() }
+    fn variant_kind(&self, def_id: DefId) -> Option<VariantKind> { unimplemented!() }
+    fn struct_ctor_def_id(&self, struct_def_id: DefId) -> Option<DefId>
+        { unimplemented!() }
     fn tuple_struct_definition_if_ctor(&self, did: DefId) -> Option<DefId>
         { unimplemented!() }
     fn struct_field_names(&self, def: DefId) -> Vec<ast::Name> { unimplemented!() }

src/librustc/middle/dead.rs

@@ -17,7 +17,8 @@ use front::map as ast_map;
 use rustc_front::hir;
 use rustc_front::intravisit::{self, Visitor};
 
-use middle::{def, pat_util, privacy, ty};
+use middle::{pat_util, privacy, ty};
+use middle::def::Def;
 use middle::def_id::{DefId};
 use lint;
 
@@ -94,13 +95,13 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
 
         self.tcx.def_map.borrow().get(id).map(|def| {
             match def.full_def() {
-                def::DefConst(_) | def::DefAssociatedConst(..) => {
+                Def::Const(_) | Def::AssociatedConst(..) => {
                     self.check_def_id(def.def_id());
                 }
                 _ if self.ignore_non_const_paths => (),
-                def::DefPrimTy(_) => (),
-                def::DefSelfTy(..) => (),
-                def::DefVariant(enum_id, variant_id, _) => {
+                Def::PrimTy(_) => (),
+                Def::SelfTy(..) => (),
+                Def::Variant(enum_id, variant_id) => {
                     self.check_def_id(enum_id);
                     if !self.ignore_variant_stack.contains(&variant_id) {
                         self.check_def_id(variant_id);