rustc: move mir::SourceScopeLocalData to a field of SourceScopeData.

Author: eddyb

src/librustc/mir/mod.rs

@@ -104,10 +104,6 @@ pub struct Body<'tcx> {
     /// and used for debuginfo. Indexed by a `SourceScope`.
     pub source_scopes: IndexVec<SourceScope, SourceScopeData>,
 
-    /// Crate-local information for each source scope, that can't (and
-    /// needn't) be tracked across crates.
-    pub source_scope_local_data: IndexVec<SourceScope, ClearCrossCrate<SourceScopeLocalData>>,
-
     /// The yield type of the function, if it is a generator.
     pub yield_ty: Option<Ty<'tcx>>,
 
@@ -167,7 +163,6 @@ impl<'tcx> Body<'tcx> {
     pub fn new(
         basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
         source_scopes: IndexVec<SourceScope, SourceScopeData>,
-        source_scope_local_data: IndexVec<SourceScope, ClearCrossCrate<SourceScopeLocalData>>,
         local_decls: LocalDecls<'tcx>,
         user_type_annotations: CanonicalUserTypeAnnotations<'tcx>,
         arg_count: usize,
@@ -188,7 +183,6 @@ impl<'tcx> Body<'tcx> {
             phase: MirPhase::Build,
             basic_blocks,
             source_scopes,
-            source_scope_local_data,
             yield_ty: None,
             generator_drop: None,
             generator_layout: None,
@@ -2034,6 +2028,10 @@ rustc_index::newtype_index! {
 pub struct SourceScopeData {
     pub span: Span,
     pub parent_scope: Option<SourceScope>,
+
+    /// Crate-local information for this source scope, that can't (and
+    /// needn't) be tracked across crates.
+    pub local_data: ClearCrossCrate<SourceScopeLocalData>,
 }
 
 #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)]

src/librustc/mir/visit.rs

@@ -317,6 +317,7 @@ macro_rules! make_mir_visitor {
                 let SourceScopeData {
                     span,
                     parent_scope,
+                    local_data: _,
                 } = scope_data;
 
                 self.visit_span(span);

src/librustc_mir/borrow_check/mod.rs

@@ -301,7 +301,7 @@ fn do_mir_borrowck<'a, 'tcx>(
             mbcx.report_conflicting_borrow(location, (&place, span), bk, &borrow);
 
         let scope = mbcx.body.source_info(location).scope;
-        let lint_root = match &mbcx.body.source_scope_local_data[scope] {
+        let lint_root = match &mbcx.body.source_scopes[scope].local_data {
             ClearCrossCrate::Set(data) => data.lint_root,
             _ => id,
         };
@@ -338,7 +338,7 @@ fn do_mir_borrowck<'a, 'tcx>(
     let used_mut = mbcx.used_mut;
     for local in mbcx.body.mut_vars_and_args_iter().filter(|local| !used_mut.contains(local)) {
         let local_decl = &mbcx.body.local_decls[local];
-        let lint_root = match &mbcx.body.source_scope_local_data[local_decl.source_info.scope] {
+        let lint_root = match &mbcx.body.source_scopes[local_decl.source_info.scope].local_data {
             ClearCrossCrate::Set(data) => data.lint_root,
             _ => continue,
         };

src/librustc_mir/build/mod.rs

@@ -309,7 +309,6 @@ struct Builder<'a, 'tcx> {
     /// The vector of all scopes that we have created thus far;
     /// we track this for debuginfo later.
     source_scopes: IndexVec<SourceScope, SourceScopeData>,
-    source_scope_local_data: IndexVec<SourceScope, ClearCrossCrate<SourceScopeLocalData>>,
     source_scope: SourceScope,
 
     /// The guard-context: each time we build the guard expression for
@@ -704,7 +703,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             block_context: BlockContext::new(),
             source_scopes: IndexVec::new(),
             source_scope: OUTERMOST_SOURCE_SCOPE,
-            source_scope_local_data: IndexVec::new(),
             guard_context: vec![],
             push_unsafe_count: 0,
             unpushed_unsafe: safety,
@@ -741,7 +739,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         Body::new(
             self.cfg.basic_blocks,
             self.source_scopes,
-            self.source_scope_local_data,
             self.local_decls,
             self.canonical_user_type_annotations,
             self.arg_count,
@@ -942,7 +939,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             self.hir.root_lint_level
         );
         let parent_root = tcx.maybe_lint_level_root_bounded(
-            self.source_scope_local_data[original_source_scope]
+            self.source_scopes[original_source_scope]
+                .local_data
                 .as_ref()
                 .assert_crate_local()
                 .lint_root,

src/librustc_mir/build/scope.rs

@@ -436,7 +436,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             // We estimate the true lint roots here to avoid creating a lot of source scopes.
 
             let parent_root = tcx.maybe_lint_level_root_bounded(
-                self.source_scope_local_data[source_scope]
+                self.source_scopes[source_scope]
+                    .local_data
                     .as_ref()
                     .assert_crate_local()
                     .lint_root,
@@ -657,23 +658,22 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         let parent = self.source_scope;
         debug!("new_source_scope({:?}, {:?}, {:?}) - parent({:?})={:?}",
                span, lint_level, safety,
-               parent, self.source_scope_local_data.get(parent));
-        let scope = self.source_scopes.push(SourceScopeData {
-            span,
-            parent_scope: Some(parent),
-        });
+               parent, self.source_scopes.get(parent));
         let scope_local_data = SourceScopeLocalData {
             lint_root: if let LintLevel::Explicit(lint_root) = lint_level {
                 lint_root
             } else {
-                self.source_scope_local_data[parent].as_ref().assert_crate_local().lint_root
+                self.source_scopes[parent].local_data.as_ref().assert_crate_local().lint_root
             },
             safety: safety.unwrap_or_else(|| {
-                self.source_scope_local_data[parent].as_ref().assert_crate_local().safety
+                self.source_scopes[parent].local_data.as_ref().assert_crate_local().safety
             })
         };
-        self.source_scope_local_data.push(ClearCrossCrate::Set(scope_local_data));
-        scope
+        self.source_scopes.push(SourceScopeData {
+            span,
+            parent_scope: Some(parent),
+            local_data: ClearCrossCrate::Set(scope_local_data),
+        })
     }
 
     /// Given a span and the current source scope, make a SourceInfo.

src/librustc_mir/interpret/eval_context.rs

@@ -849,7 +849,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 } else {
                     block.terminator().source_info
                 };
-                match &body.source_scope_local_data[source_info.scope] {
+                match &body.source_scopes[source_info.scope].local_data {
                     mir::ClearCrossCrate::Set(data) => Some(data.lint_root),
                     mir::ClearCrossCrate::Clear => None,
                 }

src/librustc_mir/shim.rs

@@ -248,10 +248,8 @@ fn new_body<'tcx>(
     Body::new(
         basic_blocks,
         IndexVec::from_elem_n(
-            SourceScopeData { span, parent_scope: None }, 1
-        ),
-        IndexVec::from_elem_n(
-            ClearCrossCrate::Clear, 1
+            SourceScopeData { span, parent_scope: None, local_data: ClearCrossCrate::Clear },
+            1,
         ),
         local_decls,
         IndexVec::new(),

src/librustc_mir/transform/check_unsafety.rs

@@ -214,7 +214,8 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
             if context.is_borrow() {
                 if util::is_disaligned(self.tcx, self.body, self.param_env, place) {
                     let source_info = self.source_info;
-                    let lint_root = self.body.source_scope_local_data[source_info.scope]
+                    let lint_root = self.body.source_scopes[source_info.scope]
+                        .local_data
                         .as_ref()
                         .assert_crate_local()
                         .lint_root;
@@ -343,7 +344,8 @@ impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
     fn register_violations(&mut self,
                            violations: &[UnsafetyViolation],
                            unsafe_blocks: &[(hir::HirId, bool)]) {
-        let safety = self.body.source_scope_local_data[self.source_info.scope]
+        let safety = self.body.source_scopes[self.source_info.scope]
+            .local_data
             .as_ref()
             .assert_crate_local()
             .safety;

src/librustc_mir/transform/const_prop.rs

@@ -9,7 +9,7 @@ use rustc::hir::def_id::DefId;
 use rustc::mir::{
     AggregateKind, Constant, Location, Place, PlaceBase, Body, Operand, Rvalue, Local, UnOp,
     StatementKind, Statement, LocalKind, TerminatorKind, Terminator,  ClearCrossCrate, SourceInfo,
-    BinOp, SourceScope, SourceScopeLocalData, LocalDecl, BasicBlock, RETURN_PLACE,
+    BinOp, SourceScope, SourceScopeData, LocalDecl, BasicBlock, RETURN_PLACE,
 };
 use rustc::mir::visit::{
     Visitor, PlaceContext, MutatingUseContext, MutVisitor, NonMutatingUseContext,
@@ -77,8 +77,7 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
         let dummy_body =
             &Body::new(
                 body.basic_blocks().clone(),
-                Default::default(),
-                body.source_scope_local_data.clone(),
+                body.source_scopes.clone(),
                 body.local_decls.clone(),
                 Default::default(),
                 body.arg_count,
@@ -254,7 +253,7 @@ struct ConstPropagator<'mir, 'tcx> {
     param_env: ParamEnv<'tcx>,
     // FIXME(eddyb) avoid cloning these two fields more than once,
     // by accessing them through `ecx` instead.
-    source_scope_local_data: IndexVec<SourceScope, ClearCrossCrate<SourceScopeLocalData>>,
+    source_scopes: IndexVec<SourceScope, SourceScopeData>,
     local_decls: IndexVec<Local, LocalDecl<'tcx>>,
     ret: Option<OpTy<'tcx, ()>>,
 }
@@ -325,7 +324,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             can_const_prop,
             // FIXME(eddyb) avoid cloning these two fields more than once,
             // by accessing them through `ecx` instead.
-            source_scope_local_data: body.source_scope_local_data.clone(),
+            source_scopes: body.source_scopes.clone(),
             //FIXME(wesleywiser) we can't steal this because `Visitor::super_visit_body()` needs it
             local_decls: body.local_decls.clone(),
             ret: ret.map(Into::into),
@@ -362,9 +361,9 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
     {
         self.ecx.tcx.span = source_info.span;
         // FIXME(eddyb) move this to the `Panic(_)` error case, so that
-        // `f(self)` is always called, and that the only difference when
-        // `source_scope_local_data` is missing, is that the lint isn't emitted.
-        let lint_root = match &self.source_scope_local_data[source_info.scope] {
+        // `f(self)` is always called, and that the only difference when the
+        // scope's `local_data` is missing, is that the lint isn't emitted.
+        let lint_root = match &self.source_scopes[source_info.scope].local_data {
             ClearCrossCrate::Set(data) => data.lint_root,
             ClearCrossCrate::Clear => return None,
         };
@@ -489,7 +488,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
                     let right_size = r.layout.size;
                     let r_bits = r.to_scalar().and_then(|r| r.to_bits(right_size));
                     if r_bits.ok().map_or(false, |b| b >= left_bits as u128) {
-                        let lint_root = match &self.source_scope_local_data[source_info.scope] {
+                        let lint_root = match &self.source_scopes[source_info.scope].local_data {
                             ClearCrossCrate::Set(data) => data.lint_root,
                             ClearCrossCrate::Clear => return None,
                         };

src/librustc_mir/transform/inline.rs

@@ -388,8 +388,7 @@ impl Inliner<'tcx> {
                 let mut local_map = IndexVec::with_capacity(callee_body.local_decls.len());
                 let mut scope_map = IndexVec::with_capacity(callee_body.source_scopes.len());
 
-                for (callee_idx, scope) in callee_body.source_scopes.iter_enumerated() {
-                    let mut scope = scope.clone();
+                for mut scope in callee_body.source_scopes.iter().cloned() {
                     if scope.parent_scope.is_none() {
                         scope.parent_scope = Some(callsite.location.scope);
                         // FIXME(eddyb) is this really needed?
@@ -404,9 +403,6 @@ impl Inliner<'tcx> {
 
                     let idx = caller_body.source_scopes.push(scope);
                     scope_map.push(idx);
-
-                    let local_data = callee_body.source_scope_local_data[callee_idx].clone();
-                    assert_eq!(idx, caller_body.source_scope_local_data.push(local_data));
                 }
 
                 for loc in callee_body.vars_and_temps_iter() {

src/librustc_mir/transform/promote_consts.rs

@@ -1081,7 +1081,6 @@ pub fn promote_candidates<'tcx>(
                 // FIXME: maybe try to filter this to avoid blowing up
                 // memory usage?
                 body.source_scopes.clone(),
-                body.source_scope_local_data.clone(),
                 initial_locals,
                 IndexVec::new(),
                 0,