rustc: turn mir::LocalDecl's syntactic_scope into a SourceInfo.

Author: eddyb

src/librustc/ich/impls_mir.rs

@@ -26,8 +26,8 @@ impl_stable_hash_for!(struct mir::LocalDecl<'tcx> {
     ty,
     name,
     source_info,
+    syntactic_source_info,
     internal,
-    syntactic_scope,
     is_user_variable
 });
 impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, by_ref, mutability });

src/librustc/mir/mod.rs

@@ -506,7 +506,7 @@ pub struct LocalDecl<'tcx> {
     pub name: Option<Name>,
 
     /// Source info of the local. The `SourceScope` is the *visibility* one,
-    /// not the the *syntactic* one (see `syntactic_scope` for more details).
+    /// not the the *syntactic* one (see `syntactic_source_info` for more details).
     pub source_info: SourceInfo,
 
     /// The *syntactic* (i.e. not visibility) source scope the local is defined
@@ -560,9 +560,9 @@ pub struct LocalDecl<'tcx> {
     /// `drop(x)`, we want it to refer to `x: u32`.
     ///
     /// To allow both uses to work, we need to have more than a single scope
-    /// for a local. We have the `syntactic_scope` represent the
+    /// for a local. We have the `syntactic_source_info.scope` represent the
     /// "syntactic" lint scope (with a variable being under its let
-    /// block) while the source-info scope represents the "local variable"
+    /// block) while the `source_info.scope` represents the "local variable"
     /// scope (where the "rest" of a block is under all prior let-statements).
     ///
     /// The end result looks like this:
@@ -574,10 +574,10 @@ pub struct LocalDecl<'tcx> {
     ///  │ │{ #[allow(unused_mut] } // this is actually split into 2 scopes
     ///  │ │                        // in practice because I'm lazy.
     ///  │ │
-    ///  │ │← x.syntactic_scope
+    ///  │ │← x.syntactic_source_info.scope
     ///  │ │← `x.parse().unwrap()`
     ///  │ │
-    ///  │ │ │← y.syntactic_scope
+    ///  │ │ │← y.syntactic_source_info.scope
     ///  │ │
     ///  │ │ │{ let y: u32 }
     ///  │ │ │
@@ -588,7 +588,7 @@ pub struct LocalDecl<'tcx> {
     ///  │ │← x.source_info.scope
     ///  │ │← `drop(x)` // this accesses `x: u32`
     /// ```
-    pub syntactic_scope: SourceScope,
+    pub syntactic_source_info: SourceInfo,
 }
 
 impl<'tcx> LocalDecl<'tcx> {
@@ -603,7 +603,10 @@ impl<'tcx> LocalDecl<'tcx> {
                 span,
                 scope: OUTERMOST_SOURCE_SCOPE
             },
-            syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+            syntactic_source_info: SourceInfo {
+                span,
+                scope: OUTERMOST_SOURCE_SCOPE
+            },
             internal: false,
             is_user_variable: false
         }
@@ -620,7 +623,10 @@ impl<'tcx> LocalDecl<'tcx> {
                 span,
                 scope: OUTERMOST_SOURCE_SCOPE
             },
-            syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+            syntactic_source_info: SourceInfo {
+                span,
+                scope: OUTERMOST_SOURCE_SCOPE
+            },
             internal: true,
             is_user_variable: false
         }
@@ -638,7 +644,10 @@ impl<'tcx> LocalDecl<'tcx> {
                 span,
                 scope: OUTERMOST_SOURCE_SCOPE
             },
-            syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+            syntactic_source_info: SourceInfo {
+                span,
+                scope: OUTERMOST_SOURCE_SCOPE
+            },
             internal: false,
             name: None,     // FIXME maybe we do want some name here?
             is_user_variable: false
@@ -2192,7 +2201,7 @@ BraceStructTypeFoldableImpl! {
         ty,
         name,
         source_info,
-        syntactic_scope,
+        syntactic_source_info,
     }
 }
 

src/librustc/mir/visit.rs

@@ -716,16 +716,16 @@ macro_rules! make_mir_visitor {
                     name: _,
                     ref $($mutability)* source_info,
                     internal: _,
-                    ref $($mutability)* syntactic_scope,
+                    ref $($mutability)* syntactic_source_info,
                     is_user_variable: _,
                 } = *local_decl;
 
                 self.visit_ty(ty, TyContext::LocalDecl {
                     local,
                     source_info: *source_info,
                 });
+                self.visit_source_info(syntactic_source_info);
                 self.visit_source_info(source_info);
-                self.visit_source_scope(syntactic_scope);
             }
 
             fn super_source_scope(&mut self,

src/librustc_mir/borrow_check/mod.rs

@@ -311,7 +311,7 @@ fn do_mir_borrowck<'a, 'gcx, 'tcx>(
 
             tcx.struct_span_lint_node(
                 UNUSED_MUT,
-                vsi[local_decl.syntactic_scope].lint_root,
+                vsi[local_decl.syntactic_source_info.scope].lint_root,
                 source_info.span,
                 "variable does not need to be mutable"
             )

src/librustc_mir/build/expr/into.rs

@@ -247,7 +247,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                         ty: ptr_ty,
                         name: None,
                         source_info,
-                        syntactic_scope: source_info.scope,
+                        syntactic_source_info: source_info,
                         internal: true,
                         is_user_variable: false
                     });

src/librustc_mir/build/matches/mod.rs

@@ -314,7 +314,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                                                            None));
                 // If we have lints, create a new source scope
                 // that marks the lints for the locals. See the comment
-                // on the `syntactic_scope` field for why this is needed.
+                // on the `syntactic_source_info` field for why this is needed.
                 if lint_level.is_explicit() {
                     syntactic_scope =
                         this.new_source_scope(scope_span, lint_level, None);
@@ -324,7 +324,11 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 span,
                 scope: var_scope.unwrap()
             };
-            this.declare_binding(source_info, syntactic_scope, mutability, name, var,
+            let syntactic_source_info = SourceInfo {
+                span,
+                scope: syntactic_scope,
+            };
+            this.declare_binding(source_info, syntactic_source_info, mutability, name, var,
                                  ty, has_guard);
         });
         var_scope
@@ -1114,24 +1118,24 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
     /// in the arm body, which will have type `T`.
     fn declare_binding(&mut self,
                        source_info: SourceInfo,
-                       syntactic_scope: SourceScope,
+                       syntactic_source_info: SourceInfo,
                        mutability: Mutability,
                        name: Name,
                        var_id: NodeId,
                        var_ty: Ty<'tcx>,
                        has_guard: ArmHasGuard)
     {
         debug!("declare_binding(var_id={:?}, name={:?}, var_ty={:?}, source_info={:?}, \
-                syntactic_scope={:?})",
-               var_id, name, var_ty, source_info, syntactic_scope);
+                syntactic_source_info={:?})",
+               var_id, name, var_ty, source_info, syntactic_source_info);
 
         let tcx = self.hir.tcx();
         let local = LocalDecl::<'tcx> {
             mutability,
             ty: var_ty.clone(),
             name: Some(name),
             source_info,
-            syntactic_scope,
+            syntactic_source_info,
             internal: false,
             is_user_variable: true,
         };
@@ -1143,7 +1147,7 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 ty: tcx.mk_imm_ref(tcx.types.re_empty, var_ty),
                 name: Some(name),
                 source_info,
-                syntactic_scope,
+                syntactic_source_info,
                 internal: false,
                 is_user_variable: true,
             });

src/librustc_mir/build/mod.rs

@@ -657,14 +657,15 @@ impl<'a, 'gcx, 'tcx> Builder<'a, 'gcx, 'tcx> {
                 }
             }
 
+            let source_info = SourceInfo {
+                scope: OUTERMOST_SOURCE_SCOPE,
+                span: pattern.map_or(self.fn_span, |pat| pat.span)
+            };
             self.local_decls.push(LocalDecl {
                 mutability: Mutability::Mut,
                 ty,
-                source_info: SourceInfo {
-                    scope: OUTERMOST_SOURCE_SCOPE,
-                    span: pattern.map_or(self.fn_span, |pat| pat.span)
-                },
-                syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+                source_info,
+                syntactic_source_info: source_info,
                 name,
                 internal: false,
                 is_user_variable: false,

src/librustc_mir/shim.rs

@@ -138,10 +138,11 @@ enum CallKind {
 }
 
 fn temp_decl(mutability: Mutability, ty: Ty, span: Span) -> LocalDecl {
+    let source_info = SourceInfo { scope: OUTERMOST_SOURCE_SCOPE, span };
     LocalDecl {
         mutability, ty, name: None,
-        source_info: SourceInfo { scope: OUTERMOST_SOURCE_SCOPE, span },
-        syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+        source_info,
+        syntactic_source_info: source_info,
         internal: false,
         is_user_variable: false
     }

src/librustc_mir/transform/generator.rs

@@ -295,12 +295,13 @@ fn make_generator_state_argument_indirect<'a, 'tcx>(
 
 fn replace_result_variable<'tcx>(ret_ty: Ty<'tcx>,
                             mir: &mut Mir<'tcx>) -> Local {
+    let source_info = source_info(mir);
     let new_ret = LocalDecl {
         mutability: Mutability::Mut,
         ty: ret_ty,
         name: None,
-        source_info: source_info(mir),
-        syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+        source_info,
+        syntactic_source_info: source_info,
         internal: false,
         is_user_variable: false,
     };
@@ -641,7 +642,7 @@ fn create_generator_drop_shim<'a, 'tcx>(
         ty: tcx.mk_nil(),
         name: None,
         source_info,
-        syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+        syntactic_source_info: source_info,
         internal: false,
         is_user_variable: false,
     };
@@ -657,7 +658,7 @@ fn create_generator_drop_shim<'a, 'tcx>(
         }),
         name: None,
         source_info,
-        syntactic_scope: OUTERMOST_SOURCE_SCOPE,
+        syntactic_source_info: source_info,
         internal: false,
         is_user_variable: false,
     };

src/librustc_mir/transform/inline.rs

@@ -400,6 +400,9 @@ impl<'a, 'tcx> Inliner<'a, 'tcx> {
 
                     local.source_info.scope = scope_map[local.source_info.scope];
                     local.source_info.span = callsite.location.span;
+                    local.syntactic_source_info.scope =
+                        scope_map[local.syntactic_source_info.scope];
+                    local.syntactic_source_info.span = callsite.location.span;
 
                     let idx = caller_mir.local_decls.push(local);
                     local_map.push(idx);