rename type_moves_by_default to type_is_copy_modulo_regions

Author: nikomatsakis

src/librustc/infer/mod.rs

@@ -1400,18 +1400,19 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             .verify_generic_bound(origin, kind, a, bound);
     }
 
-    pub fn type_moves_by_default(
+    pub fn type_is_copy_modulo_regions(
         &self,
         param_env: ty::ParamEnv<'tcx>,
         ty: Ty<'tcx>,
         span: Span,
     ) -> bool {
         let ty = self.resolve_type_vars_if_possible(&ty);
+
         // Even if the type may have no inference variables, during
         // type-checking closure types are in local tables only.
         if !self.in_progress_tables.is_some() || !ty.has_closure_types() {
             if let Some((param_env, ty)) = self.tcx.lift_to_global(&(param_env, ty)) {
-                return ty.moves_by_default(self.tcx.global_tcx(), param_env, span);
+                return ty.is_copy_modulo_regions(self.tcx.global_tcx(), param_env, span);
             }
         }
 
@@ -1421,7 +1422,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         // rightly refuses to work with inference variables, but
         // moves_by_default has a cache, which we want to use in other
         // cases.
-        !traits::type_known_to_meet_bound_modulo_regions(self, param_env, ty, copy_def_id, span)
+        traits::type_known_to_meet_bound_modulo_regions(self, param_env, ty, copy_def_id, span)
     }
 
     /// Obtains the latest type of the given closure; this may be a

src/librustc/middle/expr_use_visitor.rs

@@ -976,7 +976,7 @@ fn copy_or_move<'a, 'gcx, 'tcx>(mc: &mc::MemCategorizationContext<'a, 'gcx, 'tcx
                                 move_reason: MoveReason)
                                 -> ConsumeMode
 {
-    if mc.type_moves_by_default(param_env, cmt.ty, cmt.span) {
+    if !mc.type_is_copy_modulo_regions(param_env, cmt.ty, cmt.span) {
         Move(move_reason)
     } else {
         Copy

src/librustc/middle/mem_categorization.rs

@@ -443,15 +443,16 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
         }
     }
 
-    pub fn type_moves_by_default(&self,
-                                 param_env: ty::ParamEnv<'tcx>,
-                                 ty: Ty<'tcx>,
-                                 span: Span)
-                                 -> bool {
-        self.infcx.map(|infcx| infcx.type_moves_by_default(param_env, ty, span))
+    pub fn type_is_copy_modulo_regions(
+        &self,
+        param_env: ty::ParamEnv<'tcx>,
+        ty: Ty<'tcx>,
+        span: Span,
+    ) -> bool {
+        self.infcx.map(|infcx| infcx.type_is_copy_modulo_regions(param_env, ty, span))
             .or_else(|| {
                 self.tcx.lift_to_global(&(param_env, ty)).map(|(param_env, ty)| {
-                    ty.moves_by_default(self.tcx.global_tcx(), param_env, span)
+                    ty.is_copy_modulo_regions(self.tcx.global_tcx(), param_env, span)
                 })
             })
             .unwrap_or(true)

src/librustc/ty/query/mod.rs

@@ -382,7 +382,7 @@ define_queries! { <'tcx>
         /// might want to use `reveal_all()` method to change modes.
         [] fn param_env: ParamEnv(DefId) -> ty::ParamEnv<'tcx>,
 
-        /// Trait selection queries. These are best used by invoking `ty.moves_by_default()`,
+        /// Trait selection queries. These are best used by invoking `ty.is_copy_modulo_regions()`,
         /// `ty.is_copy()`, etc, since that will prune the environment where possible.
         [] fn is_copy_raw: is_copy_dep_node(ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool,
         [] fn is_sized_raw: is_sized_dep_node(ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool,

src/librustc/ty/util.rs

@@ -203,7 +203,7 @@ impl<'tcx> ty::ParamEnv<'tcx> {
                     let cause = ObligationCause { span, ..ObligationCause::dummy() };
                     let ctx = traits::FulfillmentContext::new();
                     match traits::fully_normalize(&infcx, ctx, cause, self, &ty) {
-                        Ok(ty) => if infcx.type_moves_by_default(self, ty, span) {
+                        Ok(ty) => if !infcx.type_is_copy_modulo_regions(self, ty, span) {
                             infringing.push(field);
                         }
                         Err(errors) => {
@@ -628,12 +628,12 @@ impl<'a, 'tcx> ty::TyS<'tcx> {
     /// does copies even when the type actually doesn't satisfy the
     /// full requirements for the `Copy` trait (cc #29149) -- this
     /// winds up being reported as an error during NLL borrow check.
-    pub fn moves_by_default(&'tcx self,
-                            tcx: TyCtxt<'a, 'tcx, 'tcx>,
-                            param_env: ty::ParamEnv<'tcx>,
-                            span: Span)
-                            -> bool {
-        !tcx.at(span).is_copy_raw(param_env.and(self))
+    pub fn is_copy_modulo_regions(&'tcx self,
+                                  tcx: TyCtxt<'a, 'tcx, 'tcx>,
+                                  param_env: ty::ParamEnv<'tcx>,
+                                  span: Span)
+                                  -> bool {
+        tcx.at(span).is_copy_raw(param_env.and(self))
     }
 
     /// Checks whether values of this type `T` have a size known at
@@ -947,11 +947,11 @@ fn needs_drop_raw<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         // `ManuallyDrop` doesn't have a destructor regardless of field types.
         ty::Adt(def, _) if Some(def.did) == tcx.lang_items().manually_drop() => false,
 
-        // Issue #22536: We first query type_moves_by_default.  It sees a
+        // Issue #22536: We first query `is_copy_modulo_regions`.  It sees a
         // normalized version of the type, and therefore will definitely
         // know whether the type implements Copy (and thus needs no
         // cleanup/drop/zeroing) ...
-        _ if !ty.moves_by_default(tcx, param_env, DUMMY_SP) => false,
+        _ if ty.is_copy_modulo_regions(tcx, param_env, DUMMY_SP) => false,
 
         // ... (issue #22536 continued) but as an optimization, still use
         // prior logic of asking for the structural "may drop".

src/librustc_lint/builtin.rs

@@ -540,7 +540,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingCopyImplementations {
             return;
         }
         let param_env = ty::ParamEnv::empty();
-        if !ty.moves_by_default(cx.tcx, param_env, item.span) {
+        if ty.is_copy_modulo_regions(cx.tcx, param_env, item.span) {
             return;
         }
         if param_env.can_type_implement_copy(cx.tcx, ty).is_ok() {

src/librustc_mir/borrow_check/nll/type_check/mod.rs

@@ -503,13 +503,17 @@ impl<'a, 'b, 'gcx, 'tcx> TypeVerifier<'a, 'b, 'gcx, 'tcx> {
                 substs: tcx.mk_substs_trait(place_ty.to_ty(tcx), &[]),
             };
 
-            // In order to have a Copy operand, the type T of the value must be Copy. Note that we
-            // prove that T: Copy, rather than using the type_moves_by_default test. This is
-            // important because type_moves_by_default ignores the resulting region obligations and
-            // assumes they pass. This can result in bounds from Copy impls being unsoundly ignored
-            // (e.g., #29149). Note that we decide to use Copy before knowing whether the bounds
-            // fully apply: in effect, the rule is that if a value of some type could implement
-            // Copy, then it must.
+            // In order to have a Copy operand, the type T of the
+            // value must be Copy. Note that we prove that T: Copy,
+            // rather than using the `is_copy_modulo_regions`
+            // test. This is important because
+            // `is_copy_modulo_regions` ignores the resulting region
+            // obligations and assumes they pass. This can result in
+            // bounds from Copy impls being unsoundly ignored (e.g.,
+            // #29149). Note that we decide to use Copy before knowing
+            // whether the bounds fully apply: in effect, the rule is
+            // that if a value of some type could implement Copy, then
+            // it must.
             self.cx.prove_trait_ref(
                 trait_ref,
                 location.to_locations(),

src/librustc_mir/build/misc.rs

@@ -71,7 +71,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     pub fn consume_by_copy_or_move(&self, place: Place<'tcx>) -> Operand<'tcx> {
         let tcx = self.hir.tcx();
         let ty = place.ty(&self.local_decls, tcx).to_ty(tcx);
-        if self.hir.type_moves_by_default(ty, DUMMY_SP) {
+        if !self.hir.type_is_copy_modulo_regions(ty, DUMMY_SP) {
             Operand::Move(place)
         } else {
             Operand::Copy(place)

src/librustc_mir/hair/cx/mod.rs

@@ -223,8 +223,8 @@ impl<'a, 'gcx, 'tcx> Cx<'a, 'gcx, 'tcx> {
         self.check_overflow
     }
 
-    pub fn type_moves_by_default(&self, ty: Ty<'tcx>, span: Span) -> bool {
-        self.infcx.type_moves_by_default(self.param_env, ty, span)
+    pub fn type_is_copy_modulo_regions(&self, ty: Ty<'tcx>, span: Span) -> bool {
+        self.infcx.type_is_copy_modulo_regions(self.param_env, ty, span)
     }
 }
 

src/librustc_mir/hair/pattern/check_match.rs

@@ -545,7 +545,7 @@ fn check_legality_of_move_bindings(cx: &MatchVisitor,
                     match bm {
                         ty::BindByValue(..) => {
                             let pat_ty = cx.tables.node_id_to_type(p.hir_id);
-                            if pat_ty.moves_by_default(cx.tcx, cx.param_env, pat.span) {
+                            if !pat_ty.is_copy_modulo_regions(cx.tcx, cx.param_env, pat.span) {
                                 check_move(p, sub.as_ref().map(|p| &**p), span_vec);
                             }
                         }

src/librustc_mir/shim.rs

@@ -310,7 +310,7 @@ fn build_clone_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     debug!("build_clone_shim(def_id={:?})", def_id);
 
     let mut builder = CloneShimBuilder::new(tcx, def_id, self_ty);
-    let is_copy = !self_ty.moves_by_default(tcx, tcx.param_env(def_id), builder.span);
+    let is_copy = self_ty.is_copy_modulo_regions(tcx, tcx.param_env(def_id), builder.span);
 
     let dest = Place::Local(RETURN_PLACE);
     let src = Place::Local(Local::new(1+0)).deref();

src/librustc_mir/transform/check_unsafety.rs

@@ -224,8 +224,11 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
                                         "non-field projection {:?} from union?",
                                         place)
                                 };
-                                if elem_ty.moves_by_default(self.tcx, self.param_env,
-                                                            self.source_info.span) {
+                                if !elem_ty.is_copy_modulo_regions(
+                                    self.tcx,
+                                    self.param_env,
+                                    self.source_info.span,
+                                ) {
                                     self.require_unsafe(
                                         "assignment to non-`Copy` union field",
                                         "the previous content of the field will be dropped, which \

src/librustc_typeck/check/demand.rs

@@ -353,9 +353,9 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 
                         // Maybe add `*`? Only if `T: Copy`.
                         _ => {
-                            if !self.infcx.type_moves_by_default(self.param_env,
-                                                                checked,
-                                                                sp) {
+                            if self.infcx.type_is_copy_modulo_regions(self.param_env,
+                                                                      checked,
+                                                                      sp) {
                                 // do not suggest if the span comes from a macro (#52783)
                                 if let (Ok(code),
                                         true) = (cm.span_to_snippet(sp), sp == expr.span) {

src/librustc_typeck/check/op.rs

@@ -262,9 +262,9 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                             let mut suggested_deref = false;
                             if let Ref(_, mut rty, _) = lhs_ty.sty {
                                 if {
-                                    !self.infcx.type_moves_by_default(self.param_env,
-                                                                        rty,
-                                                                        lhs_expr.span) &&
+                                    self.infcx.type_is_copy_modulo_regions(self.param_env,
+                                                                           rty,
+                                                                           lhs_expr.span) &&
                                         self.lookup_op_method(rty,
                                                               &[rhs_ty],
                                                               Op::Binary(op, is_assign))
@@ -334,9 +334,9 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                             let mut suggested_deref = false;
                             if let Ref(_, mut rty, _) = lhs_ty.sty {
                                 if {
-                                    !self.infcx.type_moves_by_default(self.param_env,
-                                                                      rty,
-                                                                      lhs_expr.span) &&
+                                    self.infcx.type_is_copy_modulo_regions(self.param_env,
+                                                                           rty,
+                                                                           lhs_expr.span) &&
                                         self.lookup_op_method(rty,
                                                               &[rhs_ty],
                                                               Op::Binary(op, is_assign))

src/test/ui/coherence/coherence-subtyping.stderr

@@ -7,7 +7,7 @@ LL | impl TheTrait for for<'a,'b> fn(&'a u8, &'b u8) -> &'a u8 {
 LL | impl TheTrait for for<'a> fn(&'a u8, &'a u8) -> &'a u8 {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `for<'a, 'b> fn(&'a u8, &'b u8) -> &'a u8`
    |
-   = note: this behavior recently changed as a result of a bug fix; see #XXX for details
+   = note: this behavior recently changed as a result of a bug fix; see rust-lang/rust#56105 for details
 
 error: aborting due to previous error