Get the type of a local from local_decls in schedule_drop

Passing around a separate type is unnecessary and error-prone.

Author: matthewjasper

src/librustc_mir/build/expr/as_rvalue.rs

@@ -128,7 +128,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         expr_span,
                         scope,
                         result,
-                        expr.ty,
                     );
                 }
 
@@ -569,7 +568,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 upvar_span,
                 temp_lifetime,
                 temp,
-                upvar_ty,
             );
         }
 

src/librustc_mir/build/expr/as_temp.rs

@@ -103,7 +103,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         expr_span,
                         temp_lifetime,
                         temp,
-                        expr_ty,
                         DropKind::Storage,
                     );
                 }
@@ -117,7 +116,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 expr_span,
                 temp_lifetime,
                 temp,
-                expr_ty,
                 DropKind::Value,
             );
         }

src/librustc_mir/build/matches/mod.rs

@@ -535,21 +535,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 kind: StatementKind::StorageLive(local_id),
             },
         );
-        let var_ty = self.local_decls[local_id].ty;
         let region_scope = self.hir.region_scope_tree.var_scope(var.local_id);
-        self.schedule_drop(span, region_scope, local_id, var_ty, DropKind::Storage);
+        self.schedule_drop(span, region_scope, local_id, DropKind::Storage);
         Place::from(local_id)
     }
 
     pub fn schedule_drop_for_binding(&mut self, var: HirId, span: Span, for_guard: ForGuard) {
         let local_id = self.var_local_id(var, for_guard);
-        let var_ty = self.local_decls[local_id].ty;
         let region_scope = self.hir.region_scope_tree.var_scope(var.local_id);
         self.schedule_drop(
             span,
             region_scope,
             local_id,
-            var_ty,
             DropKind::Value,
         );
     }

src/librustc_mir/build/mod.rs

@@ -812,12 +812,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             // Function arguments always get the first Local indices after the return place
             let local = Local::new(index + 1);
             let place = Place::from(local);
-            let &ArgInfo(ty, opt_ty_info, arg_opt, ref self_binding) = arg_info;
+            let &ArgInfo(_, opt_ty_info, arg_opt, ref self_binding) = arg_info;
 
             // Make sure we drop (parts of) the argument even when not matched on.
             self.schedule_drop(
                 arg_opt.as_ref().map_or(ast_body.span, |arg| arg.pat.span),
-                argument_scope, local, ty, DropKind::Value,
+                argument_scope, local, DropKind::Value,
             );
 
             if let Some(arg) = arg_opt {

src/librustc_mir/build/scope.rs

@@ -85,7 +85,6 @@ should go to.
 use crate::build::{BlockAnd, BlockAndExtension, BlockFrame, Builder, CFG};
 use crate::hair::{ExprRef, LintLevel};
 use rustc::middle::region;
-use rustc::ty::Ty;
 use rustc::hir;
 use rustc::mir::*;
 use syntax_pos::{DUMMY_SP, Span};
@@ -483,10 +482,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         span: Span,
         region_scope: region::Scope,
         local: Local,
-        place_ty: Ty<'tcx>,
     ) {
-        self.schedule_drop(span, region_scope, local, place_ty, DropKind::Storage);
-        self.schedule_drop(span, region_scope, local, place_ty, DropKind::Value);
+        self.schedule_drop(span, region_scope, local, DropKind::Storage);
+        self.schedule_drop(span, region_scope, local, DropKind::Value);
     }
 
     // Other

src/librustc_mir/build/scope/stack.rs

@@ -4,7 +4,6 @@ use crate::hair::Expr;
 use rustc::middle::region;
 use rustc::mir::{BasicBlock, Local, Operand, Place, PlaceBase, SourceScope};
 use rustc::mir::{SourceInfo, Statement, StatementKind, START_BLOCK, TerminatorKind};
-use rustc::ty::Ty;
 use syntax_pos::Span;
 use rustc_data_structures::fx::FxHashMap;
 use std::mem;
@@ -301,11 +300,10 @@ impl<'tcx> Builder<'_, 'tcx> {
         span: Span,
         region_scope: region::Scope,
         local: Local,
-        place_ty: Ty<'tcx>,
         drop_kind: DropKind,
     ) {
         match drop_kind {
-            DropKind::Value => if !self.hir.needs_drop(place_ty) { return },
+            DropKind::Value => if !self.hir.needs_drop(self.local_decls[local].ty) { return },
             DropKind::Storage => {
                 if local.index() <= self.arg_count {
                     span_bug!(