librustc: Remove the unused stmt_map from the borrow checker

Author: pcwalton

src/librustc/middle/borrowck/gather_loans/mod.rs

@@ -85,7 +85,7 @@ impl<'a> visit::Visitor<()> for GatherLoanCtxt<'a> {
         gather_loans_in_fn(self, fk, fd, b, s, n);
     }
     fn visit_stmt(&mut self, s:@Stmt, _:()) {
-        add_stmt_to_map(self, s);
+        visit::walk_stmt(self, s, ());
     }
     fn visit_pat(&mut self, p:&Pat, _:()) {
         add_pat_to_id_range(self, p);
@@ -824,15 +824,3 @@ impl<'a> GatherLoanCtxt<'a> {
     }
 }
 
-// Setting up info that preserve needs.
-// This is just the most convenient place to do it.
-fn add_stmt_to_map(this: &mut GatherLoanCtxt,
-                   stmt: @ast::Stmt) {
-    match stmt.node {
-        ast::StmtExpr(_, id) | ast::StmtSemi(_, id) => {
-            this.bccx.stmt_map.insert(id);
-        }
-        _ => ()
-    }
-    visit::walk_stmt(this, stmt, ());
-}

src/librustc/middle/borrowck/mod.rs

@@ -17,7 +17,6 @@ use middle::typeck;
 use middle::moves;
 use middle::dataflow::DataFlowContext;
 use middle::dataflow::DataFlowOperator;
-use util::common::stmt_set;
 use util::ppaux::{note_and_explain_region, Repr, UserString};
 
 use std::cell::RefCell;
@@ -85,7 +84,6 @@ pub fn check_crate(
         root_map: root_map(),
         loan_map: @mut HashMap::new(),
         write_guard_map: @mut HashSet::new(),
-        stmt_map: @mut HashSet::new(),
         stats: @mut BorrowStats {
             loaned_paths_same: 0,
             loaned_paths_imm: 0,
@@ -177,7 +175,6 @@ pub struct BorrowckCtxt {
     root_map: root_map,
     loan_map: LoanMap,
     write_guard_map: write_guard_map,
-    stmt_map: stmt_set,
 
     // Statistics:
     stats: @mut BorrowStats

src/librustc/util/common.rs

@@ -14,7 +14,6 @@ use syntax::codemap::{Span};
 use syntax::visit;
 use syntax::visit::Visitor;
 
-use std::hashmap::HashSet;
 use std::local_data;
 use extra;
 
@@ -132,5 +131,3 @@ pub fn pluralize(n: uint, s: ~str) -> ~str {
     else { format!("{}s", s) }
 }
 
-// A set of node IDs (used to keep track of which node IDs are for statements)
-pub type stmt_set = @mut HashSet<ast::NodeId>;