More tests for anonymous objects. Issues #702, #703.

Author: lkuper

src/test/compile-fail/anon-obj-overloading-wrong-type.rs

@@ -0,0 +1,29 @@
+//xfail-stage0
+//xfail-stage1
+//xfail-stage2
+use std;
+
+fn main() {
+
+    obj a() {
+        fn foo() -> int {
+            ret 2;
+        }
+        fn bar() -> int {
+            ret self.foo();
+        }
+    }
+
+    auto my_a = a();
+
+    // This compiles and shouldn't.  You should only be able to
+    // overload a method with one of the same type.  Issue #703.
+    auto my_b = obj() {
+        fn foo() -> str {
+            ret "hello";
+        }
+        with my_a
+    };
+
+    log_err my_b.foo();
+}

src/test/run-pass/anon-obj-backwarding.rs

@@ -0,0 +1,65 @@
+//xfail-stage0
+//xfail-stage1
+//xfail-stage2
+use std;
+
+fn main() {
+
+    obj inner() {
+        fn a() -> int {
+            ret 2;
+        }
+        fn m() -> uint {
+            ret 3u;
+        }
+        fn z() -> uint {
+            ret self.m();
+        }
+    }
+
+    auto my_inner = inner();
+
+    auto my_outer = obj() {
+        fn b() -> uint {
+            ret 5u;
+        }
+        fn n() -> str {
+            ret "world!";
+        }
+        with my_inner
+    };
+
+    log_err my_inner.z();
+    assert (my_inner.z() == 3u);
+    log_err my_outer.z();
+    assert (my_outer.z() == 3u);
+}
+
+/*
+   Here, when we make the self-call to self.m() in inner, we're going
+   back through the outer "self".  That outer "self" has 5 methods in
+   its vtable: a, b, m, n, z.  But the method z has already been
+   compiled, and at the time it was compiled, it expected "self" to
+   only have three methods in its vtable: a, m, and z.  So, the method
+   z thinks that "self.m()" means "look up method #1 (indexing from 0)
+   in my vtable and call it".  That means that it'll call method #1 on
+   the larger vtable that it thinks is "self", and method #1 at that
+   point is b.
+
+   So, when we call my_inner.z(), we get 3, which is what we'd
+   expect.  When we call my_outer.z(), we should also get 3, because
+   at no point is z being overridden.
+
+   To fix this bug, we need to add a second level of forwarding
+   functions (let's call them "backwarding functions") on the inner
+   object.  Every time an object is extended with another object, we
+   have to rewrite the inner object's vtable to account for the fact
+   that future self-calls will get a larger object.  The inner
+   object's vtable will need to have five slots, too.  The ones for b
+   and n will point right back at the outer object.  (These are the
+   "backwarding" ones.)  And the ones for a, m, and z will point at
+   the original, real vtable for inner.
+
+   Adding support for this is issue #702.
+
+*/

src/test/run-pass/anon-obj-overloading-reduced.rs

@@ -0,0 +1,24 @@
+//xfail-stage0
+//xfail-stage1
+//xfail-stage2
+
+// Reduced test case for issue #543.
+fn main() {
+
+    obj a() {
+        fn foo() -> int {
+            ret 2;
+        }
+    }
+
+    auto my_a = a();
+
+    auto my_b = obj() {
+        fn foo() -> int {
+            ret 3;
+        }
+        with my_a
+    };
+
+    assert (my_b.foo() == 3);
+}