---

yaml
---
r: 193374
b: refs/heads/beta
c: 280dea7
h: refs/heads/master
v: v3

Author: Aatch

[refs]

@@ -31,7 +31,7 @@ refs/heads/automation-fail: 1bf06495443584539b958873e04cc2f864ab10e4
 refs/heads/issue-18208-method-dispatch-3-quick-reject: 2009f85b9f99dedcec4404418eda9ddba90258a2
 refs/heads/batch: b7fd822592a4fb577552d93010c4a4e14f314346
 refs/heads/building: 126db549b038c84269a1e4fe46f051b2c15d6970
-refs/heads/beta: 1246d4067fdc034d064dfb78f88c2c3c079c3f4f
+refs/heads/beta: 280dea743b5227d0d162217cbb89db881242c94e
 refs/heads/windistfix: 7608dbad651f02e837ed05eef3d74a6662a6e928
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: de8a23bbc3a7b9cbd7574b5b91a34af59bf030e6

branches/beta/src/librustc/session/config.rs

@@ -348,7 +348,8 @@ macro_rules! options {
     #[allow(non_upper_case_globals, dead_code)]
     mod $mod_desc {
         pub const parse_bool: Option<&'static str> = None;
-        pub const parse_opt_bool: Option<&'static str> = None;
+        pub const parse_opt_bool: Option<&'static str> =
+            Some("one of: `y`, `yes`, `on`, `n`, `no`, or `off`");
         pub const parse_string: Option<&'static str> = Some("a string");
         pub const parse_opt_string: Option<&'static str> = Some("a string");
         pub const parse_list: Option<&'static str> = Some("a space-separated list of strings");
@@ -379,7 +380,19 @@ macro_rules! options {
 
         fn parse_opt_bool(slot: &mut Option<bool>, v: Option<&str>) -> bool {
             match v {
-                Some(..) => false,
+                Some(s) => {
+                    match s {
+                        "n" | "no" | "off" => {
+                            *slot = Some(false);
+                        }
+                        "y" | "yes" | "on" => {
+                            *slot = Some(true);
+                        }
+                        _ => { return false; }
+                    }
+
+                    true
+                },
                 None => { *slot = Some(true); true }
             }
         }