rustc: don't store a lifetime in hir::TyKind::CVarArgs.

Author: eddyb

src/librustc/hir/intravisit.rs

@@ -633,9 +633,7 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
         TyKind::Typeof(ref expression) => {
             visitor.visit_anon_const(expression)
         }
-        TyKind::CVarArgs(ref lt) => {
-            visitor.visit_lifetime(lt)
-        }
+        TyKind::CVarArgs |
         TyKind::Infer | TyKind::Err => {}
     }
 }

src/librustc/hir/lowering.rs

@@ -1336,12 +1336,7 @@ impl<'a> LoweringContext<'a> {
                 }
             }
             TyKind::Mac(_) => bug!("`TyMac` should have been expanded by now"),
-            TyKind::CVarArgs => {
-                // Create the implicit lifetime of the "spoofed" `VaListImpl`.
-                let span = self.sess.source_map().next_point(t.span.shrink_to_lo());
-                let lt = self.new_implicit_lifetime(span);
-                hir::TyKind::CVarArgs(lt)
-            },
+            TyKind::CVarArgs => hir::TyKind::CVarArgs,
         };
 
         hir::Ty {

src/librustc/hir/mod.rs

@@ -2029,7 +2029,7 @@ pub enum TyKind {
     Err,
     /// Placeholder for C-variadic arguments. We "spoof" the `VaListImpl` created
     /// from the variadic arguments. This type is only valid up to typeck.
-    CVarArgs(Lifetime),
+    CVarArgs,
 }
 
 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)]

src/librustc/hir/print.rs

@@ -361,7 +361,7 @@ impl<'a> State<'a> {
                 self.s.word("/*ERROR*/");
                 self.pclose();
             }
-            hir::TyKind::CVarArgs(_) => {
+            hir::TyKind::CVarArgs => {
                 self.s.word("...");
             }
         }

src/librustc/middle/resolve_lifetime.rs

@@ -764,13 +764,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                     });
                 }
             }
-            hir::TyKind::CVarArgs(ref lt) => {
-                // Resolve the generated lifetime for the C-variadic arguments.
-                // The lifetime is generated in AST -> HIR lowering.
-                if lt.name.is_elided() {
-                    self.resolve_elided_lifetimes(vec![lt])
-                }
-            }
             _ => intravisit::walk_ty(self, ty),
         }
     }
@@ -2378,7 +2371,6 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                             self.visit_lifetime(lifetime);
                         }
                     }
-                    hir::TyKind::CVarArgs(_) => {}
                     _ => {
                         intravisit::walk_ty(self, ty);
                     }

src/librustc_typeck/astconv.rs

@@ -2151,13 +2151,16 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 // handled specially and will not descend into this routine.
                 self.ty_infer(None, ast_ty.span)
             }
-            hir::TyKind::CVarArgs(lt) => {
+            hir::TyKind::CVarArgs => {
                 let va_list_did = match tcx.lang_items().va_list() {
                     Some(did) => did,
                     None => span_bug!(ast_ty.span,
                                       "`va_list` lang item required for variadics"),
                 };
-                let region = self.ast_region_to_region(&lt, None);
+                // FIXME(eddyb) compute this in the body and don't let it reach the signature.
+                // HACK(eddyb) the `123` anon index is only temporary, to keep tests passing.
+                // Ideally this would use `ReScope` or similar.
+                let region = tcx.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BrAnon(123)));
                 tcx.type_of(va_list_did).subst(tcx, &[region.into()])
             }
             hir::TyKind::Err => {

src/librustdoc/clean/mod.rs

@@ -3032,7 +3032,7 @@ impl Clean<Type> for hir::Ty {
             TyKind::BareFn(ref barefn) => BareFunction(box barefn.clean(cx)),
             TyKind::Infer | TyKind::Err => Infer,
             TyKind::Typeof(..) => panic!("unimplemented type {:?}", self.kind),
-            TyKind::CVarArgs(_) => CVarArgs,
+            TyKind::CVarArgs => CVarArgs,
         }
     }
 }

src/test/ui/c-variadic/variadic-ffi-4.stderr

@@ -47,7 +47,7 @@ LL |     *ap0 = ap1;
    |
    = note: expected type `core::ffi::VaListImpl<'_>`
               found type `core::ffi::VaListImpl<'_>`
-note: the anonymous lifetime #3 defined on the function body at 19:1...
+note: the anonymous lifetime #124 defined on the function body at 19:1...
   --> $DIR/variadic-ffi-4.rs:19:1
    |
 LL | / pub unsafe extern "C" fn no_escape3(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) {
@@ -80,7 +80,7 @@ LL | |     *ap0 = ap1;
 LL | |
 LL | | }
    | |_^
-note: ...does not necessarily outlive the anonymous lifetime #3 defined on the function body at 19:1
+note: ...does not necessarily outlive the anonymous lifetime #124 defined on the function body at 19:1
   --> $DIR/variadic-ffi-4.rs:19:1
    |
 LL | / pub unsafe extern "C" fn no_escape3(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) {
@@ -106,7 +106,7 @@ LL | |
 LL | |
 LL | | }
    | |_^
-note: but the borrow lasts for the anonymous lifetime #3 defined on the function body at 24:1
+note: but the borrow lasts for the anonymous lifetime #124 defined on the function body at 24:1
   --> $DIR/variadic-ffi-4.rs:24:1
    |
 LL | / pub unsafe extern "C" fn no_escape4(_: usize, ap0: &mut VaListImpl, mut ap1: ...) {
@@ -126,7 +126,7 @@ LL |     ap0 = &mut ap1;
    |
    = note: expected type `&mut core::ffi::VaListImpl<'_>`
               found type `&mut core::ffi::VaListImpl<'_>`
-note: the anonymous lifetime #3 defined on the function body at 24:1...
+note: the anonymous lifetime #124 defined on the function body at 24:1...
   --> $DIR/variadic-ffi-4.rs:24:1
    |
 LL | / pub unsafe extern "C" fn no_escape4(_: usize, ap0: &mut VaListImpl, mut ap1: ...) {
@@ -168,7 +168,7 @@ LL | |
 LL | |
 LL | | }
    | |_^
-note: ...does not necessarily outlive the anonymous lifetime #3 defined on the function body at 24:1
+note: ...does not necessarily outlive the anonymous lifetime #124 defined on the function body at 24:1
   --> $DIR/variadic-ffi-4.rs:24:1
    |
 LL | / pub unsafe extern "C" fn no_escape4(_: usize, ap0: &mut VaListImpl, mut ap1: ...) {
@@ -186,7 +186,7 @@ error[E0495]: cannot infer an appropriate lifetime for borrow expression due to
 LL |     ap0 = &mut ap1;
    |           ^^^^^^^^
    |
-note: first, the lifetime cannot outlive the anonymous lifetime #3 defined on the function body at 24:1...
+note: first, the lifetime cannot outlive the anonymous lifetime #124 defined on the function body at 24:1...
   --> $DIR/variadic-ffi-4.rs:24:1
    |
 LL | / pub unsafe extern "C" fn no_escape4(_: usize, ap0: &mut VaListImpl, mut ap1: ...) {
@@ -227,7 +227,7 @@ LL |     *ap0 = ap1.clone();
    |
    = note: expected type `core::ffi::VaListImpl<'_>`
               found type `core::ffi::VaListImpl<'_>`
-note: the anonymous lifetime #3 defined on the function body at 32:1...
+note: the anonymous lifetime #124 defined on the function body at 32:1...
   --> $DIR/variadic-ffi-4.rs:32:1
    |
 LL | / pub unsafe extern "C" fn no_escape5(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) {
@@ -260,7 +260,7 @@ LL | |     *ap0 = ap1.clone();
 LL | |
 LL | | }
    | |_^
-note: ...does not necessarily outlive the anonymous lifetime #3 defined on the function body at 32:1
+note: ...does not necessarily outlive the anonymous lifetime #124 defined on the function body at 32:1
   --> $DIR/variadic-ffi-4.rs:32:1
    |
 LL | / pub unsafe extern "C" fn no_escape5(_: usize, mut ap0: &mut VaListImpl, mut ap1: ...) {