beginnings of type unification code

[org.ibex.classgen.git] / src / org / ibex / classgen / JSSA.java

diff --git a/src/org/ibex/classgen/JSSA.java b/src/org/ibex/classgen/JSSA.java
index f29c57f..d14efef 100644 (file)
--- a/src/org/ibex/classgen/JSSA.java
+++ b/src/org/ibex/classgen/JSSA.java
@@ -321,7 +321,11 @@ public class JSSA extends MethodGen implements CGConst {
     public class Return extends Op {
         final Expr e;
         public Return() { this(VOID_EXPR); }
-        public Return(Expr e) { this.e = e; }
+        public Return(Expr e) {
+            this.e = e; 
+            if(Type.unify(method.getReturnType(),e.getType()) != method.getReturnType())
+               throw new IllegalArgumentException("type mismatch");
+        }
         public String toString() { return e.getType() == Type.VOID ? "return" : ("return "+e.toString()); }
     }
 
@@ -425,8 +429,9 @@ public class JSSA extends MethodGen implements CGConst {
         private final Object o;
         public Constant(int i) { this(new Integer(i)); }
         public Constant(Object o) { this.o = o; }
-        public String _toString() { return o instanceof String ? "\"" + o + "\"" : o.toString(); }
+        public String _toString() { return o == null ? "null" : o instanceof String ? "\"" + o + "\"" : o.toString(); }
         public Type getType() {
+            if (o == null) return Type.NULL;
             if (o instanceof Byte) return Type.BYTE;
             if (o instanceof Short) return Type.SHORT;
             if (o instanceof Character) return Type.CHAR;
@@ -465,8 +470,8 @@ public class JSSA extends MethodGen implements CGConst {
 
                 // Stack manipulations //////////////////////////////////////////////////////////////////////////////
 
-            case ACONST_NULL:                                                      return stack[sp++] = new Constant(null);
-            case ICONST_M1:                                                        return stack[sp++] = new Constant(-1);
+            case ACONST_NULL:                                                      push(new Constant(null)); return null;
+            case ICONST_M1:                                                        push(new Constant(-1)); return null;
             case ICONST_0: case LCONST_0: case FCONST_0: case DCONST_0:            push(new Constant(0)); return null;
             case ICONST_1: case LCONST_1: case FCONST_1: case DCONST_1:            push(new Constant(1)); return null;
             case ICONST_2: case FCONST_2:                                          push(new Constant(2)); return null;