Split TyBareFn into TyFnDef and TyFnPtr.

There's a lot of stuff wrong with the representation of these types:
TyFnDef doesn't actually uniquely identify a function, TyFnPtr is used to
represent method calls, TyFnDef in the sub-expression of a cast isn't
correctly reified, and probably some other stuff I haven't discovered yet.
Splitting them seems like the right first step, though.

Author: eefriedman

src/librustc/metadata/decoder.rs

@@ -719,7 +719,7 @@ pub fn get_enum_variants<'tcx>(intr: Rc<IdentInterner>, cdata: Cmd, id: ast::Nod
                                 item, tcx, cdata);
         let name = item_name(&*intr, item);
         let (ctor_ty, arg_tys, arg_names) = match ctor_ty.sty {
-            ty::TyBareFn(_, ref f) =>
+            ty::TyFnDef(_, ref f) =>
                 (Some(ctor_ty), f.sig.0.inputs.clone(), None),
             _ => { // Nullary or struct enum variant.
                 let mut arg_names = Vec::new();

src/librustc/metadata/tyencode.rs

@@ -123,12 +123,12 @@ pub fn enc_ty<'a, 'tcx>(w: &mut Encoder, cx: &ctxt<'a, 'tcx>, t: Ty<'tcx>) {
         ty::TyStr => {
             mywrite!(w, "v");
         }
-        ty::TyBareFn(Some(def_id), f) => {
+        ty::TyFnDef(def_id, f) => {
             mywrite!(w, "F");
             mywrite!(w, "{}|", (cx.ds)(def_id));
             enc_bare_fn_ty(w, cx, f);
         }
-        ty::TyBareFn(None, f) => {
+        ty::TyFnPtr(f) => {
             mywrite!(w, "G");
             enc_bare_fn_ty(w, cx, f);
         }

src/librustc/middle/cast.rs

@@ -70,7 +70,9 @@ impl<'tcx> CastTy<'tcx> {
                 tcx, t) => Some(CastTy::Int(IntTy::CEnum)),
             ty::TyRawPtr(ref mt) => Some(CastTy::Ptr(mt)),
             ty::TyRef(_, ref mt) => Some(CastTy::RPtr(mt)),
-            ty::TyBareFn(..) => Some(CastTy::FnPtr),
+            // FIXME: Treating TyFnDef as a pointer here is a bit dubious;
+            // we should be coercing the operand to an actual pointer.
+            ty::TyFnDef(..) | ty::TyFnPtr(..) => Some(CastTy::FnPtr),
             _ => None,
         }
     }

src/librustc/middle/check_const.rs

@@ -612,7 +612,7 @@ fn check_expr<'a, 'tcx>(v: &mut CheckCrateVisitor<'a, 'tcx>,
                     v.add_qualif(ConstQualif::NON_ZERO_SIZED);
                 }
                 Some(def::DefStruct(_)) => {
-                    if let ty::TyBareFn(..) = node_ty.sty {
+                    if let ty::TyFnDef(..) = node_ty.sty {
                         // Count the function pointer.
                         v.add_qualif(ConstQualif::NON_ZERO_SIZED);
                     }

src/librustc/middle/effect.rs

@@ -31,7 +31,8 @@ enum UnsafeContext {
 
 fn type_is_unsafe_function(ty: Ty) -> bool {
     match ty.sty {
-        ty::TyBareFn(_, ref f) => f.unsafety == ast::Unsafety::Unsafe,
+        ty::TyFnDef(_, ref f) |
+        ty::TyFnPtr(ref f) => f.unsafety == ast::Unsafety::Unsafe,
         _ => false,
     }
 }

src/librustc/middle/expr_use_visitor.rs

@@ -622,7 +622,7 @@ impl<'d,'t,'tcx,TYPER:mc::Typer<'tcx>> ExprUseVisitor<'d,'t,'tcx,TYPER> {
                callee.repr(self.tcx()), callee_ty.repr(self.tcx()));
         let call_scope = region::CodeExtent::from_node_id(call.id);
         match callee_ty.sty {
-            ty::TyBareFn(..) => {
+            ty::TyFnDef(..) | ty::TyFnPtr(_) => {
                 self.consume_expr(callee);
             }
             ty::TyError => { }

src/librustc/middle/fast_reject.rs

@@ -80,7 +80,7 @@ pub fn simplify_type(tcx: &ty::ctxt,
         ty::TyTuple(ref tys) => {
             Some(TupleSimplifiedType(tys.len()))
         }
-        ty::TyBareFn(_, ref f) => {
+        ty::TyFnDef(_, ref f) | ty::TyFnPtr(ref f) => {
             Some(FunctionSimplifiedType(f.sig.0.inputs.len()))
         }
         ty::TyProjection(_) => {

src/librustc/middle/implicator.rs

@@ -93,7 +93,8 @@ impl<'a, 'tcx> Implicator<'a, 'tcx> {
             ty::TyInt(..) |
             ty::TyUint(..) |
             ty::TyFloat(..) |
-            ty::TyBareFn(..) |
+            ty::TyFnDef(..) |
+            ty::TyFnPtr(..) |
             ty::TyError |
             ty::TyStr => {
                 // No borrowed content reachable here.

src/librustc/middle/infer/freshen.rs

@@ -162,7 +162,8 @@ impl<'a, 'tcx> TypeFolder<'tcx> for TypeFreshener<'a, 'tcx> {
             ty::TySlice(..) |
             ty::TyRawPtr(..) |
             ty::TyRef(..) |
-            ty::TyBareFn(..) |
+            ty::TyFnDef(..) |
+            ty::TyFnPtr(_) |
             ty::TyTrait(..) |
             ty::TyStruct(..) |
             ty::TyClosure(..) |

src/librustc/middle/intrinsicck.rs

@@ -12,7 +12,7 @@ use ast_map::NodeForeignItem;
 use metadata::csearch;
 use middle::def::DefFn;
 use middle::subst::{Subst, Substs, EnumeratedItems};
-use middle::ty::{TransmuteRestriction, ctxt, TyBareFn};
+use middle::ty::{TransmuteRestriction, ctxt};
 use middle::ty::{self, Ty};
 use util::ppaux::Repr;
 
@@ -54,7 +54,7 @@ struct IntrinsicCheckingVisitor<'a, 'tcx: 'a> {
 impl<'a, 'tcx> IntrinsicCheckingVisitor<'a, 'tcx> {
     fn def_id_is_transmute(&self, def_id: DefId) -> bool {
         let intrinsic = match ty::lookup_item_type(self.tcx, def_id).ty.sty {
-            ty::TyBareFn(_, ref bfty) => bfty.abi == RustIntrinsic,
+            ty::TyFnDef(_, ref bfty) => bfty.abi == RustIntrinsic,
             _ => return false
         };
         if def_id.krate == ast::LOCAL_CRATE {
@@ -256,7 +256,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for IntrinsicCheckingVisitor<'a, 'tcx> {
                 DefFn(did, _) if self.def_id_is_transmute(did) => {
                     let typ = ty::node_id_to_type(self.tcx, expr.id);
                     match typ.sty {
-                        TyBareFn(_, ref bare_fn_ty) if bare_fn_ty.abi == RustIntrinsic => {
+                        ty::TyFnDef(_, ref bare_fn_ty) if bare_fn_ty.abi == RustIntrinsic => {
                             if let ty::FnConverging(to) = bare_fn_ty.sig.0.output {
                                 let from = bare_fn_ty.sig.0.inputs[0];
                                 self.check_transmute(expr.span, from, to, expr.id);