Rollup merge of rust-lang#60928 - TheSirC:fix/60229, r=eddyb

Changes the type `mir::Mir` into `mir::Body`

Fixes part 1 of rust-lang#60229 (previously attempted in rust-lang#60242).

I stumbled upon the issue and it seems that the previous attempt at solving it was not merged. This is a second try more up-to-date.

The commit should have changed comments as well.
At the time of writting, it passes the tidy and check tool.

src/librustc/mir/cache.rs

@@ -3,7 +3,7 @@ use rustc_data_structures::sync::{RwLock, MappedReadGuard, ReadGuard};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
                                            StableHasherResult};
 use crate::ich::StableHashingContext;
-use crate::mir::{Mir, BasicBlock};
+use crate::mir::{Body, BasicBlock};
 
 use crate::rustc_serialize as serialize;
 
@@ -47,7 +47,7 @@ impl Cache {
 
     pub fn predecessors(
         &self,
-        mir: &Mir<'_>
+        mir: &Body<'_>
     ) -> MappedReadGuard<'_, IndexVec<BasicBlock, Vec<BasicBlock>>> {
         if self.predecessors.borrow().is_none() {
             *self.predecessors.borrow_mut() = Some(calculate_predecessors(mir));
@@ -57,7 +57,7 @@ impl Cache {
     }
 }
 
-fn calculate_predecessors(mir: &Mir<'_>) -> IndexVec<BasicBlock, Vec<BasicBlock>> {
+fn calculate_predecessors(mir: &Body<'_>) -> IndexVec<BasicBlock, Vec<BasicBlock>> {
     let mut result = IndexVec::from_elem(vec![], mir.basic_blocks());
     for (bb, data) in mir.basic_blocks().iter_enumerated() {
         if let Some(ref term) = data.terminator {

src/librustc/mir/mod.rs

@@ -62,7 +62,7 @@ impl<'tcx> HasLocalDecls<'tcx> for LocalDecls<'tcx> {
     }
 }
 
-impl<'tcx> HasLocalDecls<'tcx> for Mir<'tcx> {
+impl<'tcx> HasLocalDecls<'tcx> for Body<'tcx> {
     fn local_decls(&self) -> &LocalDecls<'tcx> {
         &self.local_decls
     }
@@ -88,7 +88,7 @@ impl MirPhase {
 
 /// Lowered representation of a single function.
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
-pub struct Mir<'tcx> {
+pub struct Body<'tcx> {
     /// List of basic blocks. References to basic block use a newtyped index type `BasicBlock`
     /// that indexes into this vector.
     basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
@@ -109,15 +109,15 @@ pub struct Mir<'tcx> {
     pub source_scope_local_data: ClearCrossCrate<IndexVec<SourceScope, SourceScopeLocalData>>,
 
     /// Rvalues promoted from this function, such as borrows of constants.
-    /// Each of them is the Mir of a constant with the fn's type parameters
+    /// Each of them is the Body of a constant with the fn's type parameters
     /// in scope, but a separate set of locals.
-    pub promoted: IndexVec<Promoted, Mir<'tcx>>,
+    pub promoted: IndexVec<Promoted, Body<'tcx>>,
 
     /// Yields type of the function, if it is a generator.
     pub yield_ty: Option<Ty<'tcx>>,
 
     /// Generator drop glue
-    pub generator_drop: Option<Box<Mir<'tcx>>>,
+    pub generator_drop: Option<Box<Body<'tcx>>>,
 
     /// The layout of a generator. Produced by the state transformation.
     pub generator_layout: Option<GeneratorLayout<'tcx>>,
@@ -169,12 +169,12 @@ pub struct Mir<'tcx> {
     cache: cache::Cache,
 }
 
-impl<'tcx> Mir<'tcx> {
+impl<'tcx> Body<'tcx> {
     pub fn new(
         basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
         source_scopes: IndexVec<SourceScope, SourceScopeData>,
         source_scope_local_data: ClearCrossCrate<IndexVec<SourceScope, SourceScopeLocalData>>,
-        promoted: IndexVec<Promoted, Mir<'tcx>>,
+        promoted: IndexVec<Promoted, Body<'tcx>>,
         yield_ty: Option<Ty<'tcx>>,
         local_decls: LocalDecls<'tcx>,
         user_type_annotations: CanonicalUserTypeAnnotations<'tcx>,
@@ -191,7 +191,7 @@ impl<'tcx> Mir<'tcx> {
             local_decls.len()
         );
 
-        Mir {
+        Body {
             phase: MirPhase::Build,
             basic_blocks,
             source_scopes,
@@ -425,7 +425,7 @@ pub enum Safety {
     ExplicitUnsafe(hir::HirId),
 }
 
-impl_stable_hash_for!(struct Mir<'tcx> {
+impl_stable_hash_for!(struct Body<'tcx> {
     phase,
     basic_blocks,
     source_scopes,
@@ -444,7 +444,7 @@ impl_stable_hash_for!(struct Mir<'tcx> {
     cache
 });
 
-impl<'tcx> Index<BasicBlock> for Mir<'tcx> {
+impl<'tcx> Index<BasicBlock> for Body<'tcx> {
     type Output = BasicBlockData<'tcx>;
 
     #[inline]
@@ -453,7 +453,7 @@ impl<'tcx> Index<BasicBlock> for Mir<'tcx> {
     }
 }
 
-impl<'tcx> IndexMut<BasicBlock> for Mir<'tcx> {
+impl<'tcx> IndexMut<BasicBlock> for Body<'tcx> {
     #[inline]
     fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx> {
         &mut self.basic_blocks_mut()[index]
@@ -601,7 +601,7 @@ newtype_index! {
     }
 }
 
-/// Classifies locals into categories. See `Mir::local_kind`.
+/// Classifies locals into categories. See `Body::local_kind`.
 #[derive(PartialEq, Eq, Debug, HashStable)]
 pub enum LocalKind {
     /// User-declared variable binding
@@ -2890,23 +2890,23 @@ fn def_path_str(def_id: DefId) -> String {
     ty::tls::with(|tcx| tcx.def_path_str(def_id))
 }
 
-impl<'tcx> graph::DirectedGraph for Mir<'tcx> {
+impl<'tcx> graph::DirectedGraph for Body<'tcx> {
     type Node = BasicBlock;
 }
 
-impl<'tcx> graph::WithNumNodes for Mir<'tcx> {
+impl<'tcx> graph::WithNumNodes for Body<'tcx> {
     fn num_nodes(&self) -> usize {
         self.basic_blocks.len()
     }
 }
 
-impl<'tcx> graph::WithStartNode for Mir<'tcx> {
+impl<'tcx> graph::WithStartNode for Body<'tcx> {
     fn start_node(&self) -> Self::Node {
         START_BLOCK
     }
 }
 
-impl<'tcx> graph::WithPredecessors for Mir<'tcx> {
+impl<'tcx> graph::WithPredecessors for Body<'tcx> {
     fn predecessors<'graph>(
         &'graph self,
         node: Self::Node,
@@ -2915,7 +2915,7 @@ impl<'tcx> graph::WithPredecessors for Mir<'tcx> {
     }
 }
 
-impl<'tcx> graph::WithSuccessors for Mir<'tcx> {
+impl<'tcx> graph::WithSuccessors for Body<'tcx> {
     fn successors<'graph>(
         &'graph self,
         node: Self::Node,
@@ -2924,12 +2924,12 @@ impl<'tcx> graph::WithSuccessors for Mir<'tcx> {
     }
 }
 
-impl<'a, 'b> graph::GraphPredecessors<'b> for Mir<'a> {
+impl<'a, 'b> graph::GraphPredecessors<'b> for Body<'a> {
     type Item = BasicBlock;
     type Iter = IntoIter<BasicBlock>;
 }
 
-impl<'a, 'b> graph::GraphSuccessors<'b> for Mir<'a> {
+impl<'a, 'b> graph::GraphSuccessors<'b> for Body<'a> {
     type Item = BasicBlock;
     type Iter = iter::Cloned<Successors<'b>>;
 }
@@ -2968,7 +2968,7 @@ impl Location {
     }
 
     /// Returns `true` if `other` is earlier in the control flow graph than `self`.
-    pub fn is_predecessor_of<'tcx>(&self, other: Location, mir: &Mir<'tcx>) -> bool {
+    pub fn is_predecessor_of<'tcx>(&self, other: Location, mir: &Body<'tcx>) -> bool {
         // If we are in the same block as the other location and are an earlier statement
         // then we are a predecessor of `other`.
         if self.block == other.block && self.statement_index < other.statement_index {
@@ -3221,7 +3221,7 @@ CloneTypeFoldableAndLiftImpls! {
 }
 
 BraceStructTypeFoldableImpl! {
-    impl<'tcx> TypeFoldable<'tcx> for Mir<'tcx> {
+    impl<'tcx> TypeFoldable<'tcx> for Body<'tcx> {
         phase,
         basic_blocks,
         source_scopes,

src/librustc/mir/traversal.rs

@@ -21,14 +21,14 @@ use super::*;
 /// A preorder traversal of this graph is either `A B D C` or `A C D B`
 #[derive(Clone)]
 pub struct Preorder<'a, 'tcx: 'a> {
-    mir: &'a Mir<'tcx>,
+    mir: &'a Body<'tcx>,
     visited: BitSet<BasicBlock>,
     worklist: Vec<BasicBlock>,
     root_is_start_block: bool,
 }
 
 impl<'a, 'tcx> Preorder<'a, 'tcx> {
-    pub fn new(mir: &'a Mir<'tcx>, root: BasicBlock) -> Preorder<'a, 'tcx> {
+    pub fn new(mir: &'a Body<'tcx>, root: BasicBlock) -> Preorder<'a, 'tcx> {
         let worklist = vec![root];
 
         Preorder {
@@ -40,7 +40,7 @@ impl<'a, 'tcx> Preorder<'a, 'tcx> {
     }
 }
 
-pub fn preorder<'a, 'tcx>(mir: &'a Mir<'tcx>) -> Preorder<'a, 'tcx> {
+pub fn preorder<'a, 'tcx>(mir: &'a Body<'tcx>) -> Preorder<'a, 'tcx> {
     Preorder::new(mir, START_BLOCK)
 }
 
@@ -99,14 +99,14 @@ impl<'a, 'tcx> Iterator for Preorder<'a, 'tcx> {
 ///
 /// A Postorder traversal of this graph is `D B C A` or `D C B A`
 pub struct Postorder<'a, 'tcx: 'a> {
-    mir: &'a Mir<'tcx>,
+    mir: &'a Body<'tcx>,
     visited: BitSet<BasicBlock>,
     visit_stack: Vec<(BasicBlock, Successors<'a>)>,
     root_is_start_block: bool,
 }
 
 impl<'a, 'tcx> Postorder<'a, 'tcx> {
-    pub fn new(mir: &'a Mir<'tcx>, root: BasicBlock) -> Postorder<'a, 'tcx> {
+    pub fn new(mir: &'a Body<'tcx>, root: BasicBlock) -> Postorder<'a, 'tcx> {
         let mut po = Postorder {
             mir,
             visited: BitSet::new_empty(mir.basic_blocks().len()),
@@ -194,7 +194,7 @@ impl<'a, 'tcx> Postorder<'a, 'tcx> {
     }
 }
 
-pub fn postorder<'a, 'tcx>(mir: &'a Mir<'tcx>) -> Postorder<'a, 'tcx> {
+pub fn postorder<'a, 'tcx>(mir: &'a Body<'tcx>) -> Postorder<'a, 'tcx> {
     Postorder::new(mir, START_BLOCK)
 }
 
@@ -252,13 +252,13 @@ impl<'a, 'tcx> Iterator for Postorder<'a, 'tcx> {
 /// to re-use the traversal
 #[derive(Clone)]
 pub struct ReversePostorder<'a, 'tcx: 'a> {
-    mir: &'a Mir<'tcx>,
+    mir: &'a Body<'tcx>,
     blocks: Vec<BasicBlock>,
     idx: usize
 }
 
 impl<'a, 'tcx> ReversePostorder<'a, 'tcx> {
-    pub fn new(mir: &'a Mir<'tcx>, root: BasicBlock) -> ReversePostorder<'a, 'tcx> {
+    pub fn new(mir: &'a Body<'tcx>, root: BasicBlock) -> ReversePostorder<'a, 'tcx> {
         let blocks : Vec<_> = Postorder::new(mir, root).map(|(bb, _)| bb).collect();
 
         let len = blocks.len();
@@ -276,7 +276,7 @@ impl<'a, 'tcx> ReversePostorder<'a, 'tcx> {
 }
 
 
-pub fn reverse_postorder<'a, 'tcx>(mir: &'a Mir<'tcx>) -> ReversePostorder<'a, 'tcx> {
+pub fn reverse_postorder<'a, 'tcx>(mir: &'a Body<'tcx>) -> ReversePostorder<'a, 'tcx> {
     ReversePostorder::new(mir, START_BLOCK)
 }
 

src/librustc/mir/visit.rs

@@ -71,8 +71,8 @@ macro_rules! make_mir_visitor {
             // Override these, and call `self.super_xxx` to revert back to the
             // default behavior.
 
-            fn visit_mir(&mut self, mir: & $($mutability)? Mir<'tcx>) {
-                self.super_mir(mir);
+            fn visit_body(&mut self, mir: & $($mutability)? Body<'tcx>) {
+                self.super_body(mir);
             }
 
             fn visit_basic_block_data(&mut self,
@@ -251,8 +251,8 @@ macro_rules! make_mir_visitor {
             // The `super_xxx` methods comprise the default behavior and are
             // not meant to be overridden.
 
-            fn super_mir(&mut self,
-                         mir: & $($mutability)? Mir<'tcx>) {
+            fn super_body(&mut self,
+                         mir: & $($mutability)? Body<'tcx>) {
                 if let Some(yield_ty) = &$($mutability)? mir.yield_ty {
                     self.visit_ty(yield_ty, TyContext::YieldTy(SourceInfo {
                         span: mir.span,
@@ -825,7 +825,7 @@ macro_rules! make_mir_visitor {
 
             // Convenience methods
 
-            fn visit_location(&mut self, mir: & $($mutability)? Mir<'tcx>, location: Location) {
+            fn visit_location(&mut self, mir: & $($mutability)? Body<'tcx>, location: Location) {
                 let basic_block = & $($mutability)? mir[location.block];
                 if basic_block.statements.len() == location.statement_index {
                     if let Some(ref $($mutability)? terminator) = basic_block.terminator {

src/librustc/query/mod.rs

@@ -97,26 +97,26 @@ rustc_queries! {
 
         /// Fetch the MIR for a given `DefId` right after it's built - this includes
         /// unreachable code.
-        query mir_built(_: DefId) -> &'tcx Steal<mir::Mir<'tcx>> {}
+        query mir_built(_: DefId) -> &'tcx Steal<mir::Body<'tcx>> {}
 
         /// Fetch the MIR for a given `DefId` up till the point where it is
         /// ready for const evaluation.
         ///
         /// See the README for the `mir` module for details.
-        query mir_const(_: DefId) -> &'tcx Steal<mir::Mir<'tcx>> {
+        query mir_const(_: DefId) -> &'tcx Steal<mir::Body<'tcx>> {
             no_hash
         }
 
-        query mir_validated(_: DefId) -> &'tcx Steal<mir::Mir<'tcx>> {
+        query mir_validated(_: DefId) -> &'tcx Steal<mir::Body<'tcx>> {
             no_hash
         }
 
         /// MIR after our optimization passes have run. This is MIR that is ready
         /// for codegen. This is also the only query that can fetch non-local MIR, at present.
-        query optimized_mir(key: DefId) -> &'tcx mir::Mir<'tcx> {
+        query optimized_mir(key: DefId) -> &'tcx mir::Body<'tcx> {
             cache { key.is_local() }
             load_cached(tcx, id) {
-                let mir: Option<crate::mir::Mir<'tcx>> = tcx.queries.on_disk_cache
+                let mir: Option<crate::mir::Body<'tcx>> = tcx.queries.on_disk_cache
                                                             .try_load_query_result(tcx, id);
                 mir.map(|x| tcx.alloc_mir(x))
             }
@@ -456,7 +456,7 @@ rustc_queries! {
         /// in the case of closures, this will be redirected to the enclosing function.
         query region_scope_tree(_: DefId) -> &'tcx region::ScopeTree {}
 
-        query mir_shims(key: ty::InstanceDef<'tcx>) -> &'tcx mir::Mir<'tcx> {
+        query mir_shims(key: ty::InstanceDef<'tcx>) -> &'tcx mir::Body<'tcx> {
             no_force
             desc { |tcx| "generating MIR shim for `{}`", tcx.def_path_str(key.def_id()) }
         }

src/librustc/ty/context.rs

@@ -23,7 +23,7 @@ use crate::middle::cstore::EncodedMetadata;
 use crate::middle::lang_items;
 use crate::middle::resolve_lifetime::{self, ObjectLifetimeDefault};
 use crate::middle::stability;
-use crate::mir::{self, Mir, interpret, ProjectionKind};
+use crate::mir::{self, Body, interpret, ProjectionKind};
 use crate::mir::interpret::{ConstValue, Allocation};
 use crate::ty::subst::{Kind, InternalSubsts, SubstsRef, Subst};
 use crate::ty::ReprOptions;
@@ -103,8 +103,8 @@ pub struct GlobalArenas<'tcx> {
     generics: TypedArena<ty::Generics>,
     trait_def: TypedArena<ty::TraitDef>,
     adt_def: TypedArena<ty::AdtDef>,
-    steal_mir: TypedArena<Steal<Mir<'tcx>>>,
-    mir: TypedArena<Mir<'tcx>>,
+    steal_mir: TypedArena<Steal<Body<'tcx>>>,
+    mir: TypedArena<Body<'tcx>>,
     tables: TypedArena<ty::TypeckTables<'tcx>>,
     /// miri allocations
     const_allocs: TypedArena<interpret::Allocation>,
@@ -1151,11 +1151,11 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.global_arenas.generics.alloc(generics)
     }
 
-    pub fn alloc_steal_mir(self, mir: Mir<'gcx>) -> &'gcx Steal<Mir<'gcx>> {
+    pub fn alloc_steal_mir(self, mir: Body<'gcx>) -> &'gcx Steal<Body<'gcx>> {
         self.global_arenas.steal_mir.alloc(Steal::new(mir))
     }
 
-    pub fn alloc_mir(self, mir: Mir<'gcx>) -> &'gcx Mir<'gcx> {
+    pub fn alloc_mir(self, mir: Body<'gcx>) -> &'gcx Body<'gcx> {
         self.global_arenas.mir.alloc(mir)
     }
 

src/librustc/ty/mod.rs

@@ -19,7 +19,7 @@ use crate::ich::StableHashingContext;
 use crate::infer::canonical::Canonical;
 use crate::middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem, FnOnceTraitLangItem};
 use crate::middle::resolve_lifetime::ObjectLifetimeDefault;
-use crate::mir::Mir;
+use crate::mir::Body;
 use crate::mir::interpret::{GlobalId, ErrorHandled};
 use crate::mir::GeneratorLayout;
 use crate::session::CrateDisambiguator;
@@ -3002,7 +3002,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
     /// Returns the possibly-auto-generated MIR of a `(DefId, Subst)` pair.
     pub fn instance_mir(self, instance: ty::InstanceDef<'gcx>)
-                        -> &'gcx Mir<'gcx>
+                        -> &'gcx Body<'gcx>
     {
         match instance {
             ty::InstanceDef::Item(did) => {