Make vectors of enums work as constants

Author: jld

src/librustc/middle/trans/consts.rs

@@ -73,9 +73,15 @@ pub fn const_vec(cx: @crate_ctxt, e: @ast::expr, es: &[@ast::expr])
         let vec_ty = ty::expr_ty(cx.tcx, e);
         let unit_ty = ty::sequence_element_type(cx.tcx, vec_ty);
         let llunitty = type_of::type_of(cx, unit_ty);
-        let v = C_array(llunitty, es.map(|e| const_expr(cx, *e)));
         let unit_sz = machine::llsize_of(cx, llunitty);
         let sz = llvm::LLVMConstMul(C_uint(cx, es.len()), unit_sz);
+        let vs = es.map(|e| const_expr(cx, *e));
+        // If the vector contains enums, an LLVM array won't work.
+        let v = if vs.any(|vi| val_ty(*vi) != llunitty) {
+            C_struct(vs)
+        } else {
+            C_array(llunitty, vs)
+        };
         return (v, sz, llunitty);
     }
 }

src/test/run-pass/const-enum-vector.rs

@@ -0,0 +1,23 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+enum E { V1(int), V0 }
+const C: [E * 3] = [V0, V1(0xDEADBEE), V0];
+
+fn main() {
+    match C[1] {
+        V1(n) => assert(n == 0xDEADBEE),
+        _ => die!()
+    }
+    match C[2] { 
+        V0 => (),
+        _ => die!()
+    }
+}