Revert "Remove rule requiring non-nil block-style statements to be semi-terminated"

This reverts commit 0f5eaef5fb2443acd3ea67250c953839c3d04d38.

8 files changed, 18 insertions, 5 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 6c0b5a2e8b1..9419b9f647e 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -243,7 +243,12 @@ type stmt = spanned<stmt_>;
 #[auto_serialize]
 enum stmt_ {
     stmt_decl(@decl, node_id),
+
+    // expr without trailing semi-colon (must have unit type):
     stmt_expr(@expr, node_id),
+
+    // expr with trailing semi-colon (may have any type):
+    stmt_semi(@expr, node_id),
 }
 
 #[auto_serialize]
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 568f00b0dfb..c6fb9349ad5 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -38,6 +38,7 @@ pure fn stmt_id(s: stmt) -> node_id {
     alt s.node {
       stmt_decl(_, id) { id }
       stmt_expr(_, id) { id }
+      stmt_semi(_, id) { id }
     }
 }
 
diff --git a/src/libsyntax/ext/auto_serialize.rs b/src/libsyntax/ext/auto_serialize.rs
index 8685bce4c1b..d2d685f8f7d 100644
--- a/src/libsyntax/ext/auto_serialize.rs
+++ b/src/libsyntax/ext/auto_serialize.rs
@@ -206,7 +206,7 @@ impl helpers for ext_ctxt {
     }
 
     fn stmt(expr: @ast::expr) -> @ast::stmt {
-        @{node: ast::stmt_expr(expr, self.next_id()),
+        @{node: ast::stmt_semi(expr, self.next_id()),
           span: expr.span}
     }
 
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index fd17403b695..c949c2e17aa 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -315,6 +315,7 @@ fn noop_fold_stmt(s: stmt_, fld: ast_fold) -> stmt_ {
     ret alt s {
       stmt_decl(d, nid) { stmt_decl(fld.fold_decl(d), fld.new_id(nid)) }
       stmt_expr(e, nid) { stmt_expr(fld.fold_expr(e), fld.new_id(nid)) }
+      stmt_semi(e, nid) { stmt_semi(fld.fold_expr(e), fld.new_id(nid)) }
     };
 }
 
diff --git a/src/libsyntax/parse/classify.rs b/src/libsyntax/parse/classify.rs
index 4fcb761fa06..9b36b77407e 100644
--- a/src/libsyntax/parse/classify.rs
+++ b/src/libsyntax/parse/classify.rs
@@ -27,6 +27,9 @@ fn stmt_ends_with_semi(stmt: ast::stmt) -> bool {
       ast::stmt_expr(e, _) {
         ret expr_requires_semi_to_be_stmt(e);
       }
+      ast::stmt_semi(e, _) {
+        ret false;
+      }
     }
 }
 
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 97185b6dfb9..747ca07bee5 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -1848,7 +1848,7 @@ class parser {
                       token::SEMI {
                         self.bump();
                         push(stmts,
-                             @{node: stmt_expr(e, stmt_id) with *stmt});
+                             @{node: stmt_semi(e, stmt_id) with *stmt});
                       }
                       token::RBRACE {
                         expr = some(e);
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 171ad240635..5f2aada9fc6 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -682,9 +682,11 @@ fn print_stmt(s: ps, st: ast::stmt) {
       ast::stmt_expr(expr, _) {
         space_if_not_bol(s);
         print_expr(s, expr);
-        if expr_requires_semi_to_be_stmt(expr) {
-            word(s.s, ";");
-        }
+      }
+      ast::stmt_semi(expr, _) {
+        space_if_not_bol(s);
+        print_expr(s, expr);
+        word(s.s, ";");
       }
     }
     if parse::classify::stmt_ends_with_semi(st) { word(s.s, ";"); }
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index d2e5b1d1f21..48f2e57de1c 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -320,6 +320,7 @@ fn visit_stmt<E>(s: @stmt, e: E, v: vt<E>) {
     alt s.node {
       stmt_decl(d, _) { v.visit_decl(d, e, v); }
       stmt_expr(ex, _) { v.visit_expr(ex, e, v); }
+      stmt_semi(ex, _) { v.visit_expr(ex, e, v); }
     }
 }