Rollup merge of rust-lang#59232 - saleemjaffer:mir_place_refactor, r=…

…oli-obk

Merge `Promoted` and `Static` in `mir::Place`

fixes rust-lang#53848

src/librustc/mir/mod.rs

@@ -1913,22 +1913,24 @@ pub enum PlaceBase<'tcx> {
 
     /// static or static mut variable
     Static(Box<Static<'tcx>>),
-
-    /// Constant code promoted to an injected static
-    Promoted(Box<(Promoted, Ty<'tcx>)>),
 }
 
-/// The `DefId` of a static, along with its normalized type (which is
-/// stored to avoid requiring normalization when reading MIR).
+/// We store the normalized type to avoid requiring normalization when reading MIR
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)]
 pub struct Static<'tcx> {
-    pub def_id: DefId,
     pub ty: Ty<'tcx>,
+    pub kind: StaticKind,
+}
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable, RustcEncodable, RustcDecodable)]
+pub enum StaticKind {
+    Promoted(Promoted),
+    Static(DefId),
 }
 
 impl_stable_hash_for!(struct Static<'tcx> {
-    def_id,
-    ty
+    ty,
+    kind
 });
 
 /// The `Projection` data structure defines things of the form `B.x`
@@ -2048,7 +2050,7 @@ impl<'tcx> Place<'tcx> {
         match self {
             Place::Base(PlaceBase::Local(local)) => Some(*local),
             Place::Projection(box Projection { base, elem: _ }) => base.base_local(),
-            Place::Base(PlaceBase::Promoted(..)) | Place::Base(PlaceBase::Static(..)) => None,
+            Place::Base(PlaceBase::Static(..)) => None,
         }
     }
 }
@@ -2059,18 +2061,24 @@ impl<'tcx> Debug for Place<'tcx> {
 
         match *self {
             Base(PlaceBase::Local(id)) => write!(fmt, "{:?}", id),
-            Base(PlaceBase::Static(box self::Static { def_id, ty })) => write!(
-                fmt,
-                "({}: {:?})",
-                ty::tls::with(|tcx| tcx.def_path_str(def_id)),
-                ty
-            ),
-            Base(PlaceBase::Promoted(ref promoted)) => write!(
-                fmt,
-                "({:?}: {:?})",
-                promoted.0,
-                promoted.1
-            ),
+            Base(PlaceBase::Static(box self::Static { ty, kind: StaticKind::Static(def_id) })) => {
+                write!(
+                    fmt,
+                    "({}: {:?})",
+                    ty::tls::with(|tcx| tcx.def_path_str(def_id)),
+                    ty
+                )
+            },
+            Base(PlaceBase::Static(
+                box self::Static { ty, kind: StaticKind::Promoted(promoted) })
+            ) => {
+                write!(
+                    fmt,
+                    "({:?}: {:?})",
+                    promoted,
+                    ty
+                )
+            },
             Projection(ref data) => match data.elem {
                 ProjectionElem::Downcast(ref adt_def, index) => {
                     write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].ident)

src/librustc/mir/tcx.rs

@@ -160,7 +160,6 @@ impl<'tcx> Place<'tcx> {
         match *self {
             Place::Base(PlaceBase::Local(index)) =>
                 PlaceTy::Ty { ty: local_decls.local_decls()[index].ty },
-            Place::Base(PlaceBase::Promoted(ref data)) => PlaceTy::Ty { ty: data.1 },
             Place::Base(PlaceBase::Static(ref data)) =>
                 PlaceTy::Ty { ty: data.ty },
             Place::Projection(ref proj) =>

src/librustc/mir/visit.rs

@@ -156,13 +156,6 @@ macro_rules! make_mir_visitor {
                 self.super_place(place, context, location);
             }
 
-            fn visit_static(&mut self,
-                            static_: & $($mutability)? Static<'tcx>,
-                            context: PlaceContext<'tcx>,
-                            location: Location) {
-                self.super_static(static_, context, location);
-            }
-
             fn visit_projection(&mut self,
                                 place: & $($mutability)? PlaceProjection<'tcx>,
                                 context: PlaceContext<'tcx>,
@@ -736,27 +729,18 @@ macro_rules! make_mir_visitor {
                     Place::Base(PlaceBase::Local(local)) => {
                         self.visit_local(local, context, location);
                     }
-                    Place::Base(PlaceBase::Static(static_)) => {
-                        self.visit_static(static_, context, location);
+                    Place::Base(PlaceBase::Static(box Static { kind, ty })) => {
+                        if let StaticKind::Static(def_id) = kind {
+                            self.visit_def_id(& $($mutability)? *def_id, location)
+                        }
+                        self.visit_ty(& $($mutability)? *ty, TyContext::Location(location));
                     }
-                    Place::Base(PlaceBase::Promoted(promoted)) => {
-                        self.visit_ty(& $($mutability)? promoted.1, TyContext::Location(location));
-                    },
                     Place::Projection(proj) => {
                         self.visit_projection(proj, context, location);
                     }
                 }
             }
 
-            fn super_static(&mut self,
-                            static_: & $($mutability)? Static<'tcx>,
-                            _context: PlaceContext<'tcx>,
-                            location: Location) {
-                let Static { def_id, ty } = static_;
-                self.visit_def_id(def_id, location);
-                self.visit_ty(ty, TyContext::Location(location));
-            }
-
             fn super_projection(&mut self,
                                 proj: & $($mutability)? PlaceProjection<'tcx>,
                                 context: PlaceContext<'tcx>,

src/librustc_codegen_ssa/mir/block.rs

@@ -1,7 +1,7 @@
 use rustc::middle::lang_items;
 use rustc::ty::{self, Ty, TypeFoldable};
 use rustc::ty::layout::{self, LayoutOf, HasTyCtxt};
-use rustc::mir;
+use rustc::mir::{self, Place, PlaceBase, Static, StaticKind};
 use rustc::mir::interpret::EvalErrorKind;
 use rustc_target::abi::call::{ArgType, FnType, PassMode, IgnoreMode};
 use rustc_target::spec::abi::Abi;
@@ -621,15 +621,23 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         // but specified directly in the code. This means it gets promoted
                         // and we can then extract the value by evaluating the promoted.
                         mir::Operand::Copy(
-                            mir::Place::Base(mir::PlaceBase::Promoted(box(index, ty)))
+                            Place::Base(
+                                PlaceBase::Static(
+                                    box Static { kind: StaticKind::Promoted(promoted), ty }
+                                )
+                            )
                         ) |
                         mir::Operand::Move(
-                            mir::Place::Base(mir::PlaceBase::Promoted(box(index, ty)))
+                            Place::Base(
+                                PlaceBase::Static(
+                                    box Static { kind: StaticKind::Promoted(promoted), ty }
+                                )
+                            )
                         ) => {
                             let param_env = ty::ParamEnv::reveal_all();
                             let cid = mir::interpret::GlobalId {
                                 instance: self.instance,
-                                promoted: Some(index),
+                                promoted: Some(promoted),
                             };
                             let c = bx.tcx().const_eval(param_env.and(cid));
                             let (llval, ty) = self.simd_shuffle_indices(

src/librustc_codegen_ssa/mir/place.rs

@@ -408,11 +408,15 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         let result = match *place {
             mir::Place::Base(mir::PlaceBase::Local(_)) => bug!(), // handled above
-            mir::Place::Base(mir::PlaceBase::Promoted(box (index, ty))) => {
+            mir::Place::Base(
+                mir::PlaceBase::Static(
+                    box mir::Static { ty, kind: mir::StaticKind::Promoted(promoted) }
+                )
+            ) => {
                 let param_env = ty::ParamEnv::reveal_all();
                 let cid = mir::interpret::GlobalId {
                     instance: self.instance,
-                    promoted: Some(index),
+                    promoted: Some(promoted),
                 };
                 let layout = cx.layout_of(self.monomorphize(&ty));
                 match bx.tcx().const_eval(param_env.and(cid)) {
@@ -435,7 +439,11 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     }
                 }
             }
-            mir::Place::Base(mir::PlaceBase::Static(box mir::Static { def_id, ty })) => {
+            mir::Place::Base(
+                mir::PlaceBase::Static(
+                    box mir::Static { ty, kind: mir::StaticKind::Static(def_id) }
+                )
+            ) => {
                 // NB: The layout of a static may be unsized as is the case when working
                 // with a static that is an extern_type.
                 let layout = cx.layout_of(self.monomorphize(&ty));

src/librustc_mir/borrow_check/error_reporting.rs

@@ -10,7 +10,7 @@ use rustc::mir::{
     self, AggregateKind, BindingForm, BorrowKind, ClearCrossCrate, Constant,
     ConstraintCategory, Field, Local, LocalDecl, LocalKind, Location, Operand,
     Place, PlaceBase, PlaceProjection, ProjectionElem, Rvalue, Statement, StatementKind,
-    TerminatorKind, VarBindingForm,
+    Static, StaticKind, TerminatorKind, VarBindingForm,
 };
 use rustc::ty::{self, DefIdTree};
 use rustc::ty::print::Print;
@@ -1598,14 +1598,14 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         including_downcast: &IncludingDowncast,
     ) -> Result<(), ()> {
         match *place {
-            Place::Base(PlaceBase::Promoted(_)) => {
-                buf.push_str("promoted");
-            }
             Place::Base(PlaceBase::Local(local)) => {
                 self.append_local_to_string(local, buf)?;
             }
-            Place::Base(PlaceBase::Static(ref static_)) => {
-                buf.push_str(&self.infcx.tcx.item_name(static_.def_id).to_string());
+            Place::Base(PlaceBase::Static(box Static{ kind: StaticKind::Promoted(_), .. })) => {
+                buf.push_str("promoted");
+            }
+            Place::Base(PlaceBase::Static(box Static{ kind: StaticKind::Static(def_id), .. })) => {
+                buf.push_str(&self.infcx.tcx.item_name(def_id).to_string());
             }
             Place::Projection(ref proj) => {
                 match proj.elem {
@@ -1744,8 +1744,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                 let local = &self.mir.local_decls[local];
                 self.describe_field_from_ty(&local.ty, field)
             }
-            Place::Base(PlaceBase::Promoted(ref prom)) =>
-                self.describe_field_from_ty(&prom.1, field),
             Place::Base(PlaceBase::Static(ref static_)) =>
                 self.describe_field_from_ty(&static_.ty, field),
             Place::Projection(ref proj) => match proj.elem {
@@ -1809,8 +1807,10 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
 
     /// Checks if a place is a thread-local static.
     pub fn is_place_thread_local(&self, place: &Place<'tcx>) -> bool {
-        if let Place::Base(PlaceBase::Static(statik)) = place {
-            let attrs = self.infcx.tcx.get_attrs(statik.def_id);
+        if let Place::Base(
+            PlaceBase::Static(box Static{ kind: StaticKind::Static(def_id), .. })
+        ) = place {
+            let attrs = self.infcx.tcx.get_attrs(*def_id);
             let is_thread_local = attrs.iter().any(|attr| attr.check_name("thread_local"));
 
             debug!(
@@ -1828,8 +1828,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         let tcx = self.infcx.tcx;
         match place {
             Place::Base(PlaceBase::Local(_)) |
-            Place::Base(PlaceBase::Static(_)) |
-            Place::Base(PlaceBase::Promoted(_)) => {
+            Place::Base(PlaceBase::Static(_)) => {
                 StorageDeadOrDrop::LocalStorageDead
             }
             Place::Projection(box PlaceProjection { base, elem }) => {

src/librustc_mir/borrow_check/mod.rs

@@ -8,7 +8,9 @@ use rustc::infer::InferCtxt;
 use rustc::lint::builtin::UNUSED_MUT;
 use rustc::middle::borrowck::SignalledError;
 use rustc::mir::{AggregateKind, BasicBlock, BorrowCheckResult, BorrowKind};
-use rustc::mir::{ClearCrossCrate, Local, Location, Mir, Mutability, Operand, Place, PlaceBase};
+use rustc::mir::{
+    ClearCrossCrate, Local, Location, Mir, Mutability, Operand, Place, PlaceBase, Static, StaticKind
+};
 use rustc::mir::{Field, Projection, ProjectionElem, Rvalue, Statement, StatementKind};
 use rustc::mir::{Terminator, TerminatorKind};
 use rustc::ty::query::Providers;
@@ -1226,8 +1228,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                                 }
                                 Operand::Move(Place::Base(PlaceBase::Static(..)))
                                 | Operand::Copy(Place::Base(PlaceBase::Static(..)))
-                                | Operand::Move(Place::Base(PlaceBase::Promoted(..)))
-                                | Operand::Copy(Place::Base(PlaceBase::Promoted(..)))
                                 | Operand::Constant(..) => {}
                             }
                         }
@@ -1310,12 +1310,13 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         //
         // FIXME: allow thread-locals to borrow other thread locals?
         let (might_be_alive, will_be_dropped) = match root_place {
-            Place::Base(PlaceBase::Promoted(_)) => (true, false),
-            Place::Base(PlaceBase::Static(_)) => {
+            Place::Base(PlaceBase::Static(box Static{ kind: StaticKind::Promoted(_), .. })) => {
+                (true, false)
+            }
+            Place::Base(PlaceBase::Static(box Static{ kind: StaticKind::Static(_), .. })) => {
                 // Thread-locals might be dropped after the function exits, but
                 // "true" statics will never be.
-                let is_thread_local = self.is_place_thread_local(&root_place);
-                (true, is_thread_local)
+                (true, self.is_place_thread_local(&root_place))
             }
             Place::Base(PlaceBase::Local(_)) => {
                 // Locals are always dropped at function exit, and if they
@@ -1578,7 +1579,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         match *last_prefix {
             Place::Base(PlaceBase::Local(_)) => panic!("should have move path for every Local"),
             Place::Projection(_) => panic!("PrefixSet::All meant don't stop for Projection"),
-            Place::Base(PlaceBase::Promoted(_)) |
             Place::Base(PlaceBase::Static(_)) => Err(NoMovePathFound::ReachedStatic),
         }
     }
@@ -1605,7 +1605,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
         let mut place = place;
         loop {
             match *place {
-                Place::Base(PlaceBase::Promoted(_)) |
                 Place::Base(PlaceBase::Local(_)) | Place::Base(PlaceBase::Static(_)) => {
                     // assigning to `x` does not require `x` be initialized.
                     break;
@@ -1953,10 +1952,6 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                     self.used_mut_upvars.push(field);
                 }
             }
-            RootPlace {
-                place: Place::Base(PlaceBase::Promoted(..)),
-                is_local_mutation_allowed: _,
-            } => {}
             RootPlace {
                 place: Place::Base(PlaceBase::Static(..)),
                 is_local_mutation_allowed: _,
@@ -1994,12 +1989,13 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             }
             // The rules for promotion are made by `qualify_consts`, there wouldn't even be a
             // `Place::Promoted` if the promotion weren't 100% legal. So we just forward this
-            Place::Base(PlaceBase::Promoted(_)) => Ok(RootPlace {
-                place,
-                is_local_mutation_allowed,
-            }),
-            Place::Base(PlaceBase::Static(ref static_)) => {
-                if self.infcx.tcx.is_static(static_.def_id) != Some(hir::Mutability::MutMutable) {
+            Place::Base(PlaceBase::Static(box Static{kind: StaticKind::Promoted(_), ..})) =>
+                Ok(RootPlace {
+                    place,
+                    is_local_mutation_allowed,
+                }),
+            Place::Base(PlaceBase::Static(box Static{ kind: StaticKind::Static(def_id), .. })) => {
+                if self.infcx.tcx.is_static(def_id) != Some(hir::Mutability::MutMutable) {
                     Err(place)
                 } else {
                     Ok(RootPlace {

src/librustc_mir/borrow_check/mutability_errors.rs

@@ -1,7 +1,9 @@
 use rustc::hir;
 use rustc::hir::Node;
 use rustc::mir::{self, BindingForm, Constant, ClearCrossCrate, Local, Location, Mir};
-use rustc::mir::{Mutability, Operand, Place, PlaceBase, Projection, ProjectionElem, Static};
+use rustc::mir::{
+    Mutability, Operand, Place, PlaceBase, Projection, ProjectionElem, Static, StaticKind,
+};
 use rustc::mir::{Terminator, TerminatorKind};
 use rustc::ty::{self, Const, DefIdTree, TyS, TyKind, TyCtxt};
 use rustc_data_structures::indexed_vec::Idx;
@@ -129,9 +131,10 @@ impl<'a, 'gcx, 'tcx> MirBorrowckCtxt<'a, 'gcx, 'tcx> {
                 }
             }
 
-            Place::Base(PlaceBase::Promoted(_)) => unreachable!(),
+            Place::Base(PlaceBase::Static(box Static { kind: StaticKind::Promoted(_), .. })) =>
+                unreachable!(),
 
-            Place::Base(PlaceBase::Static(box Static { def_id, ty: _ })) => {
+            Place::Base(PlaceBase::Static(box Static { kind: StaticKind::Static(def_id), .. })) => {
                 if let Place::Base(PlaceBase::Static(_)) = access_place {
                     item_msg = format!("immutable static item `{}`", access_place_desc.unwrap());
                     reason = String::new();