Add missing unused variable warnings for for loop bindings

src/librustc/middle/liveness.rs

@@ -131,8 +131,8 @@ enum LoopKind<'a> {
  LoopLoop,
  /// A `while` loop, with the given expression as condition.
  WhileLoop(&'a Expr),
- /// A `for` loop.
- ForLoop,
+ /// A `for` loop, with the given pattern to bind.
+ ForLoop(&'a Pat),
 }
 
 #[deriving(PartialEq)]
@@ -1024,8 +1024,8 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
  self.propagate_through_loop(expr, WhileLoop(&**cond), &**blk, succ)
  }
 
- ExprForLoop(_, ref head, ref blk, _) => {
- let ln = self.propagate_through_loop(expr, ForLoop, &**blk, succ);
+ ExprForLoop(ref pat, ref head, ref blk, _) => {
+ let ln = self.propagate_through_loop(expr, ForLoop(&**pat), &**blk, succ);
  self.propagate_through_expr(&**head, ln)
  }
 
@@ -1355,7 +1355,8 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
  expr.id, block_to_string(body));
 
  let cond_ln = match kind {
- LoopLoop | ForLoop => ln,
+ LoopLoop => ln,
+ ForLoop(ref pat) => self.define_bindings_in_pat(*pat, ln),
  WhileLoop(ref cond) => self.propagate_through_expr(&**cond, ln),
  };
  let body_ln = self.with_loop_nodes(expr.id, succ, ln, |this| {
@@ -1367,7 +1368,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
  first_merge = false;
 
  let new_cond_ln = match kind {
- LoopLoop | ForLoop => ln,
+ LoopLoop => ln,
+ ForLoop(ref pat) => {
+ self.define_bindings_in_pat(*pat, ln)
+ }
  WhileLoop(ref cond) => {
  self.propagate_through_expr(&**cond, ln)
  }
@@ -1453,6 +1457,12 @@ fn check_expr(this: &mut Liveness, expr: &Expr) {
  visit::walk_expr(this, expr);
  }
 
+ ExprForLoop(ref pat, _, _, _) => {
+ this.pat_bindings(&**pat, |this, ln, var, sp, id| {
+ this.warn_about_unused(sp, id, ln, var);
+ });
+ }
+
  // no correctness conditions related to liveness
  ExprCall(..) | ExprMethodCall(..) | ExprIf(..) | ExprMatch(..) |
  ExprWhile(..) | ExprLoop(..) | ExprIndex(..) | ExprField(..) |
@@ -1461,7 +1471,7 @@ fn check_expr(this: &mut Liveness, expr: &Expr) {
  ExprAgain(..) | ExprLit(_) | ExprBlock(..) |
  ExprMac(..) | ExprAddrOf(..) | ExprStruct(..) | ExprRepeat(..) |
  ExprParen(..) | ExprFnBlock(..) | ExprProc(..) | ExprUnboxedFn(..) |
- ExprPath(..) | ExprBox(..) | ExprForLoop(..) => {
+ ExprPath(..) | ExprBox(..) => {
  visit::walk_expr(this, expr);
  }
  }

src/librustc/middle/trans/_match.rs

@@ -557,7 +557,7 @@ fn get_branches<'a, 'p, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
  let tcx = bcx.tcx();
 
  let mut found: Vec<Opt> = vec![];
- for (i, br) in m.iter().enumerate() {
+ for br in m.iter() {
  let cur = *br.pats.get(col);
  let opt = match cur.node {
  ast::PatLit(ref l) => ConstantValue(ConstantExpr(&**l)),

src/test/compile-fail/liveness-unused.rs

@@ -82,5 +82,23 @@ fn f4b() -> int {
  }
 }
 
+fn f5a() {
+ for x in range(1i, 10) { }
+ //~^ ERROR unused variable: `x`
+}
+
+fn f5b() {
+ for (x, _) in [1i, 2, 3].iter().enumerate() { }
+ //~^ ERROR unused variable: `x`
+}
+
+fn f5c() {
+ for (_, x) in [1i, 2, 3].iter().enumerate() {
+ //~^ ERROR unused variable: `x`
+ continue;
+ std::os::set_exit_status(*x); //~ WARNING unreachable statement
+ }
+}
+
 fn main() {
 }