4 files changed, 14 insertions, 9 deletions
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 440e11e385f..a294706ef2c 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -32,7 +32,6 @@ pub use self::LitIntType::*;
 pub use self::LocalSource::*;
 pub use self::Mac_::*;
 pub use self::MacStmtStyle::*;
-pub use self::MatchSource::*;
 pub use self::MetaItem_::*;
 pub use self::Method_::*;
 pub use self::Mutability::*;
@@ -760,9 +759,9 @@ pub struct QPath {
 
 #[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
 pub enum MatchSource {
-    MatchNormal,
-    MatchIfLetDesugar,
-    MatchWhileLetDesugar,
+    Normal,
+    IfLetDesugar { contains_else_clause: bool },
+    WhileLetDesugar,
 }
 
 #[deriving(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Show)]
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index d35091f8ab0..9d4992f7453 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -868,7 +868,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     }
 
     fn expr_match(&self, span: Span, arg: P<ast::Expr>, arms: Vec<ast::Arm>) -> P<Expr> {
-        self.expr(span, ast::ExprMatch(arg, arms, ast::MatchNormal))
+        self.expr(span, ast::ExprMatch(arg, arms, ast::MatchSource::Normal))
     }
 
     fn expr_if(&self, span: Span, cond: P<ast::Expr>,
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 20c8ff20b71..bf19eecbf65 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -97,7 +97,7 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
             // `match <expr> { ... }`
             let arms = vec![pat_arm, break_arm];
             let match_expr = fld.cx.expr(span,
-                                         ast::ExprMatch(expr, arms, ast::MatchWhileLetDesugar));
+                                    ast::ExprMatch(expr, arms, ast::MatchSource::WhileLetDesugar));
 
             // `[opt_ident]: loop { ... }`
             let loop_block = fld.cx.block_expr(match_expr);
@@ -158,6 +158,8 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
                 arms
             };
 
+            let contains_else_clause = elseopt.is_some();
+
             // `_ => [<elseopt> | ()]`
             let else_arm = {
                 let pat_under = fld.cx.pat_wild(span);
@@ -170,7 +172,11 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
             arms.extend(else_if_arms.into_iter());
             arms.push(else_arm);
 
-            let match_expr = fld.cx.expr(span, ast::ExprMatch(expr, arms, ast::MatchIfLetDesugar));
+            let match_expr = fld.cx.expr(span,
+                                         ast::ExprMatch(expr, arms,
+                                                ast::MatchSource::IfLetDesugar {
+                                                    contains_else_clause: contains_else_clause,
+                                                }));
             fld.fold_expr(match_expr)
         }
 
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index f8b47e0405f..52aa609aeaf 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -41,7 +41,7 @@ use ast::{LifetimeDef, Lit, Lit_};
 use ast::{LitBool, LitChar, LitByte, LitBinary};
 use ast::{LitStr, LitInt, Local, LocalLet};
 use ast::{MacStmtWithBraces, MacStmtWithSemicolon, MacStmtWithoutBraces};
-use ast::{MutImmutable, MutMutable, Mac_, MacInvocTT, MatchNormal};
+use ast::{MutImmutable, MutMutable, Mac_, MacInvocTT, MatchSource};
 use ast::{Method, MutTy, BiMul, Mutability};
 use ast::{MethodImplItem, NamedField, UnNeg, NoReturn, NodeId, UnNot};
 use ast::{Pat, PatEnum, PatIdent, PatLit, PatRange, PatRegion, PatStruct};
@@ -3111,7 +3111,7 @@ impl<'a> Parser<'a> {
         }
         let hi = self.span.hi;
         self.bump();
-        return self.mk_expr(lo, hi, ExprMatch(discriminant, arms, MatchNormal));
+        return self.mk_expr(lo, hi, ExprMatch(discriminant, arms, MatchSource::Normal));
     }
 
     pub fn parse_arm(&mut self) -> Arm {