From 586bc5d1da55e776b39601ad06f00c7cae0a0f5e Mon Sep 17 00:00:00 2001
From: Scott Olson <scott@solson.me>
Date: Mon, 7 Mar 2016 04:48:12 -0600
Subject: [PATCH] Reimplement 'if' conditions.

---
 src/interpreter.rs | 16 +++++++---------
 test/new_values.rs | 16 ++++++++--------
 2 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/src/interpreter.rs b/src/interpreter.rs
index 3abc4231edd7..6e01f8e7944f 100644
--- a/src/interpreter.rs
+++ b/src/interpreter.rs
@@ -162,8 +162,15 @@ impl<'a, 'tcx> Interpreter<'a, 'tcx> {
             use rustc::mir::repr::Terminator::*;
             match *block_data.terminator() {
                 Return => break,
+
                 Goto { target } => block = target,
 
+                If { ref cond, targets: (then_target, else_target) } => {
+                    let cond_ptr = try!(self.operand_to_ptr(cond));
+                    let cond = try!(self.memory.read_bool(&cond_ptr));
+                    block = if cond { then_target } else { else_target }
+                }
+
                 // Call { ref func, ref args, ref destination, .. } => {
                 //     let ptr = destination.as_ref().map(|&(ref lv, _)| self.lvalue_to_ptr(lv));
                 //     let func_val = self.operand_to_ptr(func);
@@ -192,15 +199,6 @@ impl<'a, 'tcx> Interpreter<'a, 'tcx> {
                 //     }
                 // }
 
-                // If { ref cond, targets: (then_target, else_target) } => {
-                //     let cond_ptr = try!(self.operand_to_ptr(cond));
-                //     match self.operand_to_ptr(cond) {
-                //         Value::Bool(true) => block = then_target,
-                //         Value::Bool(false) => block = else_target,
-                //         cond_val => panic!("Non-boolean `if` condition value: {:?}", cond_val),
-                //     }
-                // }
-
                 // SwitchInt { ref discr, ref values, ref targets, .. } => {
                 //     let discr_val = self.read_lvalue(discr);
 
diff --git a/test/new_values.rs b/test/new_values.rs
index b4a506a9fb46..880ac71abc30 100644
--- a/test/new_values.rs
+++ b/test/new_values.rs
@@ -51,15 +51,15 @@ fn boolean() -> bool {
     true
 }
 
-// #[miri_run(expected = "Int(0)")]
-// fn if_false() -> i32 {
-//     if false { 1 } else { 0 }
-// }
+#[miri_run]
+fn if_false() -> i32 {
+    if false { 1 } else { 0 }
+}
 
-// #[miri_run(expected = "Int(1)")]
-// fn if_true() -> i32 {
-//     if true { 1 } else { 0 }
-// }
+#[miri_run]
+fn if_true() -> i32 {
+    if true { 1 } else { 0 }
+}
 
 // #[miri_run(expected = "Int(2)")]
 // fn call() -> i32 {