From a22b3cdceecb85bf55a21e15959d639d98f6da5e Mon Sep 17 00:00:00 2001
From: llogiq <bogusandre@gmail.com>
Date: Fri, 21 Aug 2015 12:26:03 +0200
Subject: [PATCH] const folding for eq_op

---
 src/eq_op.rs                | 5 +++--
 tests/compile-fail/eq_op.rs | 4 ++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/eq_op.rs b/src/eq_op.rs
index 6202dcc3670..ebc6aa17100 100644
--- a/src/eq_op.rs
+++ b/src/eq_op.rs
@@ -33,7 +33,7 @@ impl LintPass for EqOp {
 }
 
 pub fn is_exp_equal(cx: &Context, left : &Expr, right : &Expr) -> bool {
-    match (&left.node, &right.node) {
+    if match (&left.node, &right.node) {
         (&ExprBinary(ref lop, ref ll, ref lr),
                 &ExprBinary(ref rop, ref rl, ref rr)) =>
             lop.node == rop.node &&
@@ -66,7 +66,8 @@ pub fn is_exp_equal(cx: &Context, left : &Expr, right : &Expr) -> bool {
             lunop == runop && is_exp_equal(cx, l, r),
         (&ExprVec(ref l), &ExprVec(ref r)) => is_exps_equal(cx, l, r),
         _ => false
-    } || match (constant(cx, left), constant(cx, right)) {
+    } { return true; }
+    match (constant(cx, left), constant(cx, right)) {
         (Some(l), Some(r)) => l == r,
         _ => false
     }
diff --git a/tests/compile-fail/eq_op.rs b/tests/compile-fail/eq_op.rs
index 8f61a11aa08..a1183629344 100755
--- a/tests/compile-fail/eq_op.rs
+++ b/tests/compile-fail/eq_op.rs
@@ -34,4 +34,8 @@ fn main() {
     ((1, 2) != (1, 2)); //~ERROR equal expressions
     [1].len() == [1].len(); //~ERROR equal expressions
     vec![1, 2, 3] == vec![1, 2, 3]; //no error yet, as we don't match macros
+
+    // const folding
+    1 + 1 == 2; //~ERROR equal expressions
+    1 - 1 == 0; //~ERROR equal expressions
 }