Fix type encoding/decoding for unions

Fix union debuginfo test on lldb

Author: petrochenkov

src/librustc_metadata/decoder.rs

@@ -291,7 +291,7 @@ fn maybe_item_name(item: rbml::Doc) -> Option<ast::Name> {
 
 fn family_to_variant_kind<'tcx>(family: Family) -> Option<ty::VariantKind> {
     match family {
-        Struct(VariantKind::Struct) | Variant(VariantKind::Struct) =>
+        Struct(VariantKind::Struct) | Variant(VariantKind::Struct) | Union =>
             Some(ty::VariantKind::Struct),
         Struct(VariantKind::Tuple) | Variant(VariantKind::Tuple) =>
             Some(ty::VariantKind::Tuple),

src/librustc_metadata/tydecode.rs

@@ -472,6 +472,14 @@ impl<'a,'tcx> TyDecoder<'a,'tcx> {
                 let def = self.tcx.lookup_adt_def(did);
                 return self.tcx.mk_struct(def, substs);
             }
+            'U' => {
+                assert_eq!(self.next(), '[');
+                let did = self.parse_def();
+                let substs = self.parse_substs();
+                assert_eq!(self.next(), ']');
+                let def = self.tcx.lookup_adt_def(did);
+                return self.tcx.mk_union(def, substs);
+            }
             'k' => {
                 assert_eq!(self.next(), '[');
                 let did = self.parse_def();

src/librustc_metadata/tyencode.rs

@@ -171,7 +171,7 @@ pub fn enc_ty<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>, t: Ty<'tcx
             write!(w, "]");
         }
         ty::TyUnion(def, substs) => {
-            write!(w, "u[{}|", (cx.ds)(cx.tcx, def.did));
+            write!(w, "U[{}|", (cx.ds)(cx.tcx, def.did));
             enc_substs(w, cx, substs);
             write!(w, "]");
         }

src/test/debuginfo/union-smoke.rs

@@ -23,10 +23,10 @@
 // === LLDB TESTS ==================================================================================
 
 // lldb-command:run
-// lldb-command:print a
-// lldb-check:[...]$0 = {a = {__0 = 2 '\002', __1 = 2 '\002'}, b = 514}
+// lldb-command:print u
+// lldb-check:[...]$0 = { a = ('\x02', '\x02') b = 514 }
 // lldb-command:print union_smoke::SU
-// lldb-check:[...]$1 = {a = {__0 = 1 '\001', __1 = 1 '\001'}, b = 257}
+// lldb-check:[...]$1 = 257
 
 #![allow(unused)]
 #![feature(omit_gdb_pretty_printer_section)]

src/test/run-pass/union/auxiliary/union.rs

@@ -12,5 +12,5 @@
 
 pub union U {
     pub a: u8,
-    b: u16,
+    pub b: u16,
 }

src/test/run-pass/union/union-basic.rs

@@ -8,47 +8,51 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// aux-build:union.rs
+
 #![feature(untagged_unions)]
 
+extern crate union;
 use std::mem::{size_of, align_of, zeroed};
 
 union U {
     a: u8,
+    b: u16
 }
 
-union U64 {
-    a: u64,
-}
+fn local() {
+    assert_eq!(size_of::<U>(), 2);
+    assert_eq!(align_of::<U>(), 2);
 
-union W {
-    a: u8,
-    b: u64,
-}
+    let u = U { a: 10 };
+    unsafe {
+        assert_eq!(u.a, 10);
+        let U { a } = u;
+        assert_eq!(a, 10);
+    }
 
-#[repr(C)]
-union Y {
-    f1: u16,
-    f2: [u8; 4],
+    let mut w = U { b: 0 };
+    unsafe {
+        assert_eq!(w.a, 0);
+        assert_eq!(w.b, 0);
+        w.a = 1;
+        assert_eq!(w.a, 1);
+        assert_eq!(w.b, 1);
+    }
 }
 
-fn main() {
-    assert_eq!(size_of::<U>(), 1);
-    assert_eq!(size_of::<U64>(), 8);
-    assert_eq!(size_of::<W>(), 8);
-    assert_eq!(align_of::<U>(), 1);
-    assert_eq!(align_of::<U64>(), align_of::<u64>());
-    assert_eq!(align_of::<W>(), align_of::<u64>());
-    assert_eq!(size_of::<Y>(), 4);
-    assert_eq!(align_of::<Y>(), 2);
+fn xcrate() {
+    assert_eq!(size_of::<union::U>(), 2);
+    assert_eq!(align_of::<union::U>(), 2);
 
-    let u = U { a: 10 };
+    let u = union::U { a: 10 };
     unsafe {
         assert_eq!(u.a, 10);
-        let U { a } = u;
+        let union::U { a } = u;
         assert_eq!(a, 10);
     }
 
-    let mut w = W { b: 0 };
+    let mut w = union::U { b: 0 };
     unsafe {
         assert_eq!(w.a, 0);
         assert_eq!(w.b, 0);
@@ -57,3 +61,8 @@ fn main() {
         assert_eq!(w.b, 1);
     }
 }
+
+fn main() {
+    local();
+    xcrate();
+}