irfactory.java

這是一個javascript 的 interpreter是了解 web browser的好材料

    {
        setRequiresActivation();
        Node result = new Node(Token.BLOCK, lineno);
        result.addChildToBack(new Node(Token.ENTERWITH, obj));
        Node bodyNode = new Node(Token.WITH, body, lineno);
        result.addChildrenToBack(bodyNode);
        result.addChildToBack(new Node(Token.LEAVEWITH));
        return result;
    }

    /**
     * DOTQUERY
     */
    public Node createDotQuery (Node obj, Node body, int lineno)
    {
        setRequiresActivation();
        Node result = new Node(Token.DOTQUERY, obj, body, lineno);
        return result;
    }

    Node createArrayLiteral(ObjArray elems, int skipCount, int destructuringLen)
    {
        int length = elems.size();
        int[] skipIndexes = null;
        if (skipCount != 0) {
            skipIndexes = new int[skipCount];
        }
        Node array = new Node(Token.ARRAYLIT);
        for (int i = 0, j = 0; i != length; ++i) {
            Node elem = (Node)elems.get(i);
            if (elem != null) {
                array.addChildToBack(elem);
            } else {
                skipIndexes[j] = i;
                ++j;
            }
        }
        if (skipCount != 0) {
            array.putProp(Node.SKIP_INDEXES_PROP, skipIndexes);
        }
        array.putIntProp(Node.DESTRUCTURING_ARRAY_LENGTH, destructuringLen);
        return array;
    }

    /**
     * Object Literals
     * <BR> createObjectLiteral rewrites its argument as object
     * creation plus object property entries, so later compiler
     * stages don't need to know about object literals.
     */
    Node createObjectLiteral(ObjArray elems)
    {
        int size = elems.size() / 2;
        Node object = new Node(Token.OBJECTLIT);
        Object[] properties;
        if (size == 0) {
            properties = ScriptRuntime.emptyArgs;
        } else {
            properties = new Object[size];
            for (int i = 0; i != size; ++i) {
                properties[i] = elems.get(2 * i);
                Node value = (Node)elems.get(2 * i + 1);
                object.addChildToBack(value);
            }
        }
        object.putProp(Node.OBJECT_IDS_PROP, properties);
        return object;
    }

    /**
     * Regular expressions
     */
    Node createRegExp(int regexpIndex)
    {
        Node n = new Node(Token.REGEXP);
        n.putIntProp(Node.REGEXP_PROP, regexpIndex);
        return n;
    }

    /**
     * If statement
     */
    Node createIf(Node cond, Node ifTrue, Node ifFalse, int lineno)
    {
        int condStatus = isAlwaysDefinedBoolean(cond);
        if (condStatus == ALWAYS_TRUE_BOOLEAN) {
            return ifTrue;
        } else if (condStatus == ALWAYS_FALSE_BOOLEAN) {
            if (ifFalse != null) {
                return ifFalse;
            }
            // Replace if (false) xxx by empty block
            return new Node(Token.BLOCK, lineno);
        }

        Node result = new Node(Token.BLOCK, lineno);
        Node ifNotTarget = Node.newTarget();
        Node.Jump IFNE = new Node.Jump(Token.IFNE, cond);
        IFNE.target = ifNotTarget;

        result.addChildToBack(IFNE);
        result.addChildrenToBack(ifTrue);

        if (ifFalse != null) {
            Node endTarget = Node.newTarget();
            result.addChildToBack(makeJump(Token.GOTO, endTarget));
            result.addChildToBack(ifNotTarget);
            result.addChildrenToBack(ifFalse);
            result.addChildToBack(endTarget);
        } else {
            result.addChildToBack(ifNotTarget);
        }

        return result;
    }

    Node createCondExpr(Node cond, Node ifTrue, Node ifFalse)
    {
        int condStatus = isAlwaysDefinedBoolean(cond);
        if (condStatus == ALWAYS_TRUE_BOOLEAN) {
            return ifTrue;
        } else if (condStatus == ALWAYS_FALSE_BOOLEAN) {
            return ifFalse;
        }
        return new Node(Token.HOOK, cond, ifTrue, ifFalse);
    }

    /**
     * Unary
     */
    Node createUnary(int nodeType, Node child)
    {
        int childType = child.getType();
        switch (nodeType) {
          case Token.DELPROP: {
            Node n;
            if (childType == Token.NAME) {
                // Transform Delete(Name "a")
                //  to Delete(Bind("a"), String("a"))
                child.setType(Token.BINDNAME);
                Node left = child;
                Node right = Node.newString(child.getString());
                n = new Node(nodeType, left, right);
            } else if (childType == Token.GETPROP ||
                       childType == Token.GETELEM)
            {
                Node left = child.getFirstChild();
                Node right = child.getLastChild();
                child.removeChild(left);
                child.removeChild(right);
                n = new Node(nodeType, left, right);
            } else if (childType == Token.GET_REF) {
                Node ref = child.getFirstChild();
                child.removeChild(ref);
                n = new Node(Token.DEL_REF, ref);
            } else {
                n = new Node(Token.TRUE);
            }
            return n;
          }
          case Token.TYPEOF:
            if (childType == Token.NAME) {
                child.setType(Token.TYPEOFNAME);
                return child;
            }
            break;
          case Token.BITNOT:
            if (childType == Token.NUMBER) {
                int value = ScriptRuntime.toInt32(child.getDouble());
                child.setDouble(~value);
                return child;
            }
            break;
          case Token.NEG:
            if (childType == Token.NUMBER) {
                child.setDouble(-child.getDouble());
                return child;
            }
            break;
          case Token.NOT: {
            int status = isAlwaysDefinedBoolean(child);
            if (status != 0) {
                int type;
                if (status == ALWAYS_TRUE_BOOLEAN) {
                    type = Token.FALSE;
                } else {
                    type = Token.TRUE;
                }
                if (childType == Token.TRUE || childType == Token.FALSE) {
                    child.setType(type);
                    return child;
                }
                return new Node(type);
            }
            break;
          }
        }
        return new Node(nodeType, child);
    }

    Node createYield(Node child, int lineno)
    {
      if (!parser.insideFunction()) {
        parser.reportError("msg.bad.yield");
      }
      setRequiresActivation();
      setIsGenerator();
      if (child != null)
        return new Node(Token.YIELD, child, lineno);
      else
        return new Node(Token.YIELD, lineno);
    }

    Node createCallOrNew(int nodeType, Node child)
    {
        int type = Node.NON_SPECIALCALL;
        if (child.getType() == Token.NAME) {
            String name = child.getString();
            if (name.equals("eval")) {
                type = Node.SPECIALCALL_EVAL;
            } else if (name.equals("With")) {
                type = Node.SPECIALCALL_WITH;
            }
        } else if (child.getType() == Token.GETPROP) {
            String name = child.getLastChild().getString();
            if (name.equals("eval")) {
                type = Node.SPECIALCALL_EVAL;
            }
        }
        Node node = new Node(nodeType, child);
        if (type != Node.NON_SPECIALCALL) {
            // Calls to these functions require activation objects.
            setRequiresActivation();
            node.putIntProp(Node.SPECIALCALL_PROP, type);
        }
        return node;
    }

    Node createIncDec(int nodeType, boolean post, Node child)
    {
        child = makeReference(child);
        if (child == null) {
            String msg;
            if (nodeType == Token.DEC) {
                msg = "msg.bad.decr";
            } else {
                msg = "msg.bad.incr";
            }
            parser.reportError(msg);
            return null;
        }

        int childType = child.getType();

        switch (childType) {
          case Token.NAME:
          case Token.GETPROP:
          case Token.GETELEM:
          case Token.GET_REF: {
            Node n = new Node(nodeType, child);
            int incrDecrMask = 0;
            if (nodeType == Token.DEC) {
                incrDecrMask |= Node.DECR_FLAG;
            }
            if (post) {
                incrDecrMask |= Node.POST_FLAG;
            }
            n.putIntProp(Node.INCRDECR_PROP, incrDecrMask);
            return n;
          }
        }
        throw Kit.codeBug();
    }

    Node createPropertyGet(Node target, String namespace, String name,
                           int memberTypeFlags)
    {
        if (namespace == null && memberTypeFlags == 0) {
            if (target == null) {
                return createName(name);
            }
            checkActivationName(name, Token.GETPROP);
            if (ScriptRuntime.isSpecialProperty(name)) {
                Node ref = new Node(Token.REF_SPECIAL, target);
                ref.putProp(Node.NAME_PROP, name);
                return new Node(Token.GET_REF, ref);
            }
            return new Node(Token.GETPROP, target, createString(name));
        }
        Node elem = createString(name);
        memberTypeFlags |= Node.PROPERTY_FLAG;
        return createMemberRefGet(target, namespace, elem, memberTypeFlags);
    }

    Node createElementGet(Node target, String namespace, Node elem,
                          int memberTypeFlags)
    {
        // OPT: could optimize to createPropertyGet
        // iff elem is string that can not be number
        if (namespace == null && memberTypeFlags == 0) {
            // stand-alone [aaa] as primary expression is array literal
            // declaration and should not come here!
            if (target == null) throw Kit.codeBug();
            return new Node(Token.GETELEM, target, elem);
        }
        return createMemberRefGet(target, namespace, elem, memberTypeFlags);
    }

    private Node createMemberRefGet(Node target, String namespace, Node elem,
                                    int memberTypeFlags)
    {
        Node nsNode = null;
        if (namespace != null) {
            // See 11.1.2 in ECMA 357
            if (namespace.equals("*")) {
                nsNode = new Node(Token.NULL);
            } else {
                nsNode = createName(namespace);
            }
        }
        Node ref;
        if (target == null) {
            if (namespace == null) {
                ref = new Node(Token.REF_NAME, elem);
            } else {
                ref = new Node(Token.REF_NS_NAME, nsNode, elem);
            }
        } else {
            if (namespace == null) {
                ref = new Node(Token.REF_MEMBER, target, elem);
            } else {
                ref = new Node(Token.REF_NS_MEMBER, target, nsNode, elem);
            }
        }
        if (memberTypeFlags != 0) {
            ref.putIntProp(Node.MEMBER_TYPE_PROP, memberTypeFlags);
        }
        return new Node(Token.GET_REF, ref);
    }

    /**
     * Binary
     */
    Node createBinary(int nodeType, Node left, Node right)
    {
        switch (nodeType) {

          case Token.ADD:
            // numerical addition and string concatenation
            if (left.type == Token.STRING) {
                String s2;
                if (right.type == Token.STRING) {
                    s2 = right.getString();
                } else if (right.type == Token.NUMBER) {
                    s2 = ScriptRuntime.numberToString(right.getDouble(), 10);
                } else {
                    break;
                }
                String s1 = left.getString();
                left.setString(s1.concat(s2));
                return left;
            } else if (left.type == Token.NUMBER) {
                if (right.type == Token.NUMBER) {
                    left.setDouble(left.getDouble() + right.getDouble());
                    return left;
                } else if (right.type == Token.STRING) {
                    String s1, s2;
                    s1 = ScriptRuntime.numberToString(left.getDouble(), 10);
                    s2 = right.getString();
                    right.setString(s1.concat(s2));
                    return right;
                }
            }
            // can't do anything if we don't know  both types - since
            // 0 + object is supposed to call toString on the object and do
            // string concantenation rather than addition
            break;

          case Token.SUB:
            // numerical subtraction
            if (left.type == Token.NUMBER) {
                double ld = left.getDouble();
                if (right.type == Token.NUMBER) {
                    //both numbers
                    left.setDouble(ld - right.getDouble());
                    return left;
                } else if (ld == 0.0) {
                    // first 0: 0-x -> -x
                    return new Node(Token.NEG, right);
                }
            } else if (right.type == Token.NUMBER) {
                if (right.getDouble() == 0.0) {
                    //second 0: x - 0 -> +x
                    // can not make simply x because x - 0 must be number
                    return new Node(Token.POS, left);
                }
            }
            break;

          case Token.MUL:
            // numerical multiplication
            if (left.type == Token.NUMBER) {