From 9f917d23b67b6f9e7de5040dfea64bbff6e53dbb Mon Sep 17 00:00:00 2001
From: Elias Castegren <elias.castegren@gmail.com>
Date: Wed, 10 Dec 2014 14:36:11 +0100
Subject: [PATCH] Assigning from this turns the alias into a normal active
 reference

Note that getting a future from a method called on the alias will cause
a deadlock!
---
 src/back/CodeGen/Expr.hs              | 14 ++++++++----
 src/tests/encore/basic/activeThis.enc | 33 +++++++++++++++++++++++++++
 src/tests/encore/basic/activeThis.out |  1 +
 3 files changed, 44 insertions(+), 4 deletions(-)
 create mode 100644 src/tests/encore/basic/activeThis.enc
 create mode 100644 src/tests/encore/basic/activeThis.out

diff --git a/src/back/CodeGen/Expr.hs b/src/back/CodeGen/Expr.hs
index 7d1ed2981..8b5ecaaa8 100644
--- a/src/back/CodeGen/Expr.hs
+++ b/src/back/CodeGen/Expr.hs
@@ -135,7 +135,9 @@ instance Translatable A.Expr (State Ctx.Context (CCode Lval, CCode Stat)) where
     return (last nes, Seq tes)
 
   translate (A.Assign {A.lhs, A.rhs}) = do
-    (nrhs, trhs) <- translate rhs
+    (nrhs, trhs) <- if A.isThisAccess rhs && (Ty.isActiveRefType $ A.getType rhs)
+                    then return (Deref (Var "this") `Dot` (Nam "aref"), Skip)
+                    else translate rhs
     lval <- mk_lval lhs
     return (unit, Seq [trhs, Assign lval nrhs])
         where
@@ -170,8 +172,10 @@ instance Translatable A.Expr (State Ctx.Context (CCode Lval, CCode Stat)) where
                        return (nbody, Seq $ tdecls ++ [tbody])
                      where
                        translate_decls [] = return []
-                       translate_decls ((name, expr):decls) = 
-                           do (ne, te) <- translate expr
+                       translate_decls ((name, expr):decls) =
+                           do (ne, te) <- if A.isThisAccess expr && (Ty.isActiveRefType $ A.getType expr)
+                                          then return (Deref (Var "this") `Dot` (Nam "aref"), Skip)
+                                          else translate expr
                               tmp <- Ctx.gen_sym
                               substitute_var name (Var tmp)
                               tdecls <- translate_decls decls
@@ -391,7 +395,9 @@ instance Translatable A.Expr (State Ctx.Context (CCode Lval, CCode Stat)) where
             | Ty.isRealType ty = AsExpr $ e `Dot` Nam "d"
             | otherwise        = AsExpr $ e `Dot` Nam "p"
         translateArgument arg = 
-            do (ntother, tother) <- translate arg
+            do (ntother, tother) <- if A.isThisAccess arg && (Ty.isActiveRefType $ A.getType arg)
+                                    then return (Deref (Var "this") `Dot` (Nam "aref"), Skip)
+                                    else translate arg
                return $ UnionInst (arg_member $ A.getType arg) (StatAsExpr ntother tother)
             where
               arg_member ty
diff --git a/src/tests/encore/basic/activeThis.enc b/src/tests/encore/basic/activeThis.enc
new file mode 100644
index 000000000..2ea614da5
--- /dev/null
+++ b/src/tests/encore/basic/activeThis.enc
@@ -0,0 +1,33 @@
+class Foo
+  def fr0b() : bool
+    true
+
+  def foo() : Fut bool
+    let that = this in{
+      that.fr0b();
+    }
+
+  def bar() : Fut bool
+    let that = null : Foo in{
+      that = this;
+      that.fr0b()
+    }
+
+  def baz() : Fut bool
+    let id = \ (x : a) -> x
+        that = id(this)
+    in
+      that.fr0b()
+
+class Main
+  def main() : void
+    let x = new Foo in{
+      assertTrue(get get x.foo());
+      assertTrue(get get x.bar());
+      assertTrue(get get x.baz());
+      print "Done!";
+    -- TODO: Find out why this is needed!
+    embed void
+      fflush(NULL);
+    end
+    }
\ No newline at end of file
diff --git a/src/tests/encore/basic/activeThis.out b/src/tests/encore/basic/activeThis.out
new file mode 100644
index 000000000..76f5a5a5a
--- /dev/null
+++ b/src/tests/encore/basic/activeThis.out
@@ -0,0 +1 @@
+Done!