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Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically embedded into Java applications to provide scripting to end users.

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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package jscover.mozilla.javascript;

import jscover.mozilla.javascript.ast.Comment;
import jscover.mozilla.javascript.ast.FunctionNode;
import jscover.mozilla.javascript.ast.Jump;
import jscover.mozilla.javascript.ast.Name;
import jscover.mozilla.javascript.ast.NumberLiteral;
import jscover.mozilla.javascript.ast.Scope;
import jscover.mozilla.javascript.ast.ScriptNode;

import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * This class implements the root of the intermediate representation.
 *
 * @author Norris Boyd
 * @author Mike McCabe
 */
public class Node implements Iterable
{
    public static final int
        FUNCTION_PROP      =  1,
        LOCAL_PROP         =  2,
        LOCAL_BLOCK_PROP   =  3,
        REGEXP_PROP        =  4,
        CASEARRAY_PROP     =  5,

    //  the following properties are defined and manipulated by the
    //  optimizer -
    //  TARGETBLOCK_PROP - the block referenced by a branch node
    //  VARIABLE_PROP - the variable referenced by a BIND or NAME node
    //  ISNUMBER_PROP - this node generates code on Number children and
    //                  delivers a Number result (as opposed to Objects)
    //  DIRECTCALL_PROP - this call node should emit code to test the function
    //                    object against the known class and call direct if it
    //                    matches.

        TARGETBLOCK_PROP     =  6,
        VARIABLE_PROP        =  7,
        ISNUMBER_PROP        =  8,
        DIRECTCALL_PROP      =  9,
        SPECIALCALL_PROP     = 10,
        SKIP_INDEXES_PROP    = 11, // array of skipped indexes of array literal
        OBJECT_IDS_PROP      = 12, // array of properties for object literal
        INCRDECR_PROP        = 13, // pre or post type of increment/decrement
        CATCH_SCOPE_PROP     = 14, // index of catch scope block in catch
        LABEL_ID_PROP        = 15, // label id: code generation uses it
        MEMBER_TYPE_PROP     = 16, // type of element access operation
        NAME_PROP            = 17, // property name
        CONTROL_BLOCK_PROP   = 18, // flags a control block that can drop off
        PARENTHESIZED_PROP   = 19, // expression is parenthesized
        GENERATOR_END_PROP   = 20,
        DESTRUCTURING_ARRAY_LENGTH = 21,
        DESTRUCTURING_NAMES  = 22,
        DESTRUCTURING_PARAMS = 23,
        JSDOC_PROP           = 24,
        EXPRESSION_CLOSURE_PROP = 25, // JS 1.8 expression closure pseudo-return
        DESTRUCTURING_SHORTHAND = 26, // JS 1.8 destructuring shorthand
        LAST_PROP            = 26;

    // values of ISNUMBER_PROP to specify
    // which of the children are Number types
    public static final int
        BOTH = 0,
        LEFT = 1,
        RIGHT = 2;

    public static final int    // values for SPECIALCALL_PROP
        NON_SPECIALCALL  = 0,
        SPECIALCALL_EVAL = 1,
        SPECIALCALL_WITH = 2;

    public static final int   // flags for INCRDECR_PROP
        DECR_FLAG = 0x1,
        POST_FLAG = 0x2;

    public static final int   // flags for MEMBER_TYPE_PROP
        PROPERTY_FLAG    = 0x1, // property access: element is valid name
        ATTRIBUTE_FLAG   = 0x2, // x.@y or x..@y
        DESCENDANTS_FLAG = 0x4; // x..y or x..@i

    private static class PropListItem
    {
        PropListItem next;
        int type;
        int intValue;
        Object objectValue;
    }

    public Node(int nodeType) {
        type = nodeType;
    }

    public Node(int nodeType, Node child) {
        type = nodeType;
        first = last = child;
        child.next = null;
    }

    public Node(int nodeType, Node left, Node right) {
        type = nodeType;
        first = left;
        last = right;
        left.next = right;
        right.next = null;
    }

    public Node(int nodeType, Node left, Node mid, Node right) {
        type = nodeType;
        first = left;
        last = right;
        left.next = mid;
        mid.next = right;
        right.next = null;
    }

    public Node(int nodeType, int line) {
        type = nodeType;
        lineno = line;
    }

    public Node(int nodeType, Node child, int line) {
        this(nodeType, child);
        lineno = line;
    }

    public Node(int nodeType, Node left, Node right, int line) {
        this(nodeType, left, right);
        lineno = line;
    }

    public Node(int nodeType, Node left, Node mid, Node right, int line) {
        this(nodeType, left, mid, right);
        lineno = line;
    }

    public static Node newNumber(double number) {
        NumberLiteral n = new NumberLiteral();
        n.setNumber(number);
        return n;
    }

    public static Node newString(String str) {
        return newString(Token.STRING, str);
    }

    public static Node newString(int type, String str) {
        Name name = new Name();
        name.setIdentifier(str);
        name.setType(type);
        return name;
    }

    public int getType() {
        return type;
    }

    /**
     * Sets the node type and returns this node.
     */
    public Node setType(int type) {
        this.type = type;
        return this;
    }

    /**
     * Gets the JsDoc comment string attached to this node.
     * @return the comment string or {@code null} if no JsDoc is attached to
     *     this node
     */
    public String getJsDoc() {
        Comment comment = getJsDocNode();
        if (comment != null) {
          return comment.getValue();
        }
        return null;
    }

    /**
     * Gets the JsDoc Comment object attached to this node.
     * @return the Comment or {@code null} if no JsDoc is attached to
     *     this node
     */
    public Comment getJsDocNode() {
        return (Comment) getProp(JSDOC_PROP);
    }

    /**
     * Sets the JsDoc comment string attached to this node.
     */
    public void setJsDocNode(Comment jsdocNode) {
        putProp(JSDOC_PROP, jsdocNode);
    }

    public boolean hasChildren() {
        return first != null;
    }

    public Node getFirstChild() {
        return first;
    }

    public Node getLastChild() {
        return last;
    }

    public Node getNext() {
        return next;
    }

    public Node getChildBefore(Node child) {
        if (child == first)
            return null;
        Node n = first;
        while (n.next != child) {
            n = n.next;
            if (n == null)
                throw new RuntimeException("node is not a child");
        }
        return n;
    }

    public Node getLastSibling() {
        Node n = this;
        while (n.next != null) {
            n = n.next;
        }
        return n;
    }

    public void addChildToFront(Node child) {
        child.next = first;
        first = child;
        if (last == null) {
            last = child;
        }
    }

    public void addChildToBack(Node child) {
        child.next = null;
        if (last == null) {
            first = last = child;
            return;
        }
        last.next = child;
        last = child;
    }

    public void addChildrenToFront(Node children) {
        Node lastSib = children.getLastSibling();
        lastSib.next = first;
        first = children;
        if (last == null) {
            last = lastSib;
        }
    }

    public void addChildrenToBack(Node children) {
        if (last != null) {
            last.next = children;
        }
        last = children.getLastSibling();
        if (first == null) {
            first = children;
        }
    }

    /**
     * Add 'child' before 'node'.
     */
    public void addChildBefore(Node newChild, Node node) {
        if (newChild.next != null)
            throw new RuntimeException(
                      "newChild had siblings in addChildBefore");
        if (first == node) {
            newChild.next = first;
            first = newChild;
            return;
        }
        Node prev = getChildBefore(node);
        addChildAfter(newChild, prev);
    }

    /**
     * Add 'child' after 'node'.
     */
    public void addChildAfter(Node newChild, Node node) {
        if (newChild.next != null)
            throw new RuntimeException(
                      "newChild had siblings in addChildAfter");
        newChild.next = node.next;
        node.next = newChild;
        if (last == node)
            last = newChild;
    }

    public void removeChild(Node child) {
        Node prev = getChildBefore(child);
        if (prev == null)
            first = first.next;
        else
            prev.next = child.next;
        if (child == last) last = prev;
        child.next = null;
    }

    public void replaceChild(Node child, Node newChild) {
        newChild.next = child.next;
        if (child == first) {
            first = newChild;
        } else {
            Node prev = getChildBefore(child);
            prev.next = newChild;
        }
        if (child == last)
            last = newChild;
        child.next = null;
    }

    public void replaceChildAfter(Node prevChild, Node newChild) {
        Node child = prevChild.next;
        newChild.next = child.next;
        prevChild.next = newChild;
        if (child == last)
            last = newChild;
        child.next = null;
    }

    public void removeChildren() {
        first = last = null;
    }

    private static final Node NOT_SET = new Node(Token.ERROR);

    /**
     * Iterates over the children of this Node.  Supports child removal.  Not
     * thread-safe.  If anyone changes the child list before the iterator
     * finishes, the results are undefined and probably bad.
     */
    public class NodeIterator implements Iterator {
        private Node cursor;  // points to node to be returned next
        private Node prev = NOT_SET;
        private Node prev2;
        private boolean removed = false;

        public NodeIterator() {
            cursor = Node.this.first;
        }

        public boolean hasNext() {
            return cursor != null;
        }

        public Node next() {
            if (cursor == null) {
                throw new NoSuchElementException();
            }
            removed = false;
            prev2 = prev;
            prev = cursor;
            cursor = cursor.next;
            return prev;
        }

        public void remove() {
            if (prev == NOT_SET) {
                throw new IllegalStateException("next() has not been called");
            }
            if (removed) {
                throw new IllegalStateException(
                    "remove() already called for current element");
            }
            if (prev == first) {
                first = prev.next;
            } else if (prev == last) {
                prev2.next = null;
                last = prev2;
            } else {
                prev2.next = cursor;
            }
        }
    }

    /**
     * Returns an {@link java.util.Iterator} over the node's children.
     */
    public Iterator iterator() {
        return new NodeIterator();
    }

    private static final String propToString(int propType)
    {
        if (Token.printTrees) {
            // If Context.printTrees is false, the compiler
            // can remove all these strings.
            switch (propType) {
                case FUNCTION_PROP:        return "function";
                case LOCAL_PROP:           return "local";
                case LOCAL_BLOCK_PROP:     return "local_block";
                case REGEXP_PROP:          return "regexp";
                case CASEARRAY_PROP:       return "casearray";

                case TARGETBLOCK_PROP:     return "targetblock";
                case VARIABLE_PROP:        return "variable";
                case ISNUMBER_PROP:        return "isnumber";
                case DIRECTCALL_PROP:      return "directcall";

                case SPECIALCALL_PROP:     return "specialcall";
                case SKIP_INDEXES_PROP:    return "skip_indexes";
                case OBJECT_IDS_PROP:      return "object_ids_prop";
                case INCRDECR_PROP:        return "incrdecr_prop";
                case CATCH_SCOPE_PROP:     return "catch_scope_prop";
                case LABEL_ID_PROP:        return "label_id_prop";
                case MEMBER_TYPE_PROP:     return "member_type_prop";
                case NAME_PROP:            return "name_prop";
                case CONTROL_BLOCK_PROP:   return "control_block_prop";
                case PARENTHESIZED_PROP:   return "parenthesized_prop";
                case GENERATOR_END_PROP:   return "generator_end";
                case DESTRUCTURING_ARRAY_LENGTH:
                                           return "destructuring_array_length";
                case DESTRUCTURING_NAMES:  return "destructuring_names";
                case DESTRUCTURING_PARAMS: return "destructuring_params";

                default: Kit.codeBug();
            }
        }
        return null;
    }

    private PropListItem lookupProperty(int propType)
    {
        PropListItem x = propListHead;
        while (x != null && propType != x.type) {
            x = x.next;
        }
        return x;
    }

    private PropListItem ensureProperty(int propType)
    {
        PropListItem item = lookupProperty(propType);
        if (item == null) {
            item = new PropListItem();
            item.type = propType;
            item.next = propListHead;
            propListHead = item;
        }
        return item;
    }

    public void removeProp(int propType)
    {
        PropListItem x = propListHead;
        if (x != null) {
            PropListItem prev = null;
            while (x.type != propType) {
                prev = x;
                x = x.next;
                if (x == null) { return; }
            }
            if (prev == null) {
                propListHead = x.next;
            } else {
                prev.next = x.next;
            }
        }
    }

    public Object getProp(int propType)
    {
        PropListItem item = lookupProperty(propType);
        if (item == null) { return null; }
        return item.objectValue;
    }

    public int getIntProp(int propType, int defaultValue)
    {
        PropListItem item = lookupProperty(propType);
        if (item == null) { return defaultValue; }
        return item.intValue;
    }

    public int getExistingIntProp(int propType)
    {
        PropListItem item = lookupProperty(propType);
        if (item == null) { Kit.codeBug(); }
        return item.intValue;
    }

    public void putProp(int propType, Object prop)
    {
        if (prop == null) {
            removeProp(propType);
        } else {
            PropListItem item = ensureProperty(propType);
            item.objectValue = prop;
        }
    }

    public void putIntProp(int propType, int prop)
    {
        PropListItem item = ensureProperty(propType);
        item.intValue = prop;
    }

    /**
     * Return the line number recorded for this node.
     * @return the line number
     */
    public int getLineno() {
        return lineno;
    }

    public void setLineno(int lineno) {
        this.lineno = lineno;
    }

    /** Can only be called when getType() == Token.NUMBER */
    public final double getDouble() {
        return ((NumberLiteral)this).getNumber();
    }

    public final void setDouble(double number) {
        ((NumberLiteral)this).setNumber(number);
    }

    /** Can only be called when node has String context. */
    public final String getString() {
        return ((Name)this).getIdentifier();
    }

    /** Can only be called when node has String context. */
    public final void setString(String s) {
        if (s == null) Kit.codeBug();
        ((Name)this).setIdentifier(s);
    }

    /** Can only be called when node has String context. */
    public Scope getScope() {
        return ((Name)this).getScope();
    }

    /** Can only be called when node has String context. */
    public void setScope(Scope s) {
        if (s == null) Kit.codeBug();
        if (!(this instanceof Name)) {
            throw Kit.codeBug();
        }
        ((Name)this).setScope(s);
    }

    public static Node newTarget()
    {
        return new Node(Token.TARGET);
    }

    public final int labelId()
    {
        if (type != Token.TARGET && type != Token.YIELD) Kit.codeBug();
        return getIntProp(LABEL_ID_PROP, -1);
    }

    public void labelId(int labelId)
    {
        if (type != Token.TARGET  && type != Token.YIELD) Kit.codeBug();
        putIntProp(LABEL_ID_PROP, labelId);
    }


    /**
     * Does consistent-return analysis on the function body when strict mode is
     * enabled.
     *
     *   function (x) { return (x+1) }
     * is ok, but
     *   function (x) { if (x < 0) return (x+1); }
     * is not becuase the function can potentially return a value when the
     * condition is satisfied and if not, the function does not explicitly
     * return value.
     *
     * This extends to checking mismatches such as "return" and "return "
     * used in the same function. Warnings are not emitted if inconsistent
     * returns exist in code that can be statically shown to be unreachable.
     * Ex.
     * 
function (x) { while (true) { ... if (..) { return value } ... } }
     * 
* emits no warning. However if the loop had a break statement, then a * warning would be emitted. * * The consistency analysis looks at control structures such as loops, ifs, * switch, try-catch-finally blocks, examines the reachable code paths and * warns the user about an inconsistent set of termination possibilities. * * Caveat: Since the parser flattens many control structures into almost * straight-line code with gotos, it makes such analysis hard. Hence this * analyser is written to taken advantage of patterns of code generated by * the parser (for loops, try blocks and such) and does not do a full * control flow analysis of the gotos and break/continue statements. * Future changes to the parser will affect this analysis. */ /** * These flags enumerate the possible ways a statement/function can * terminate. These flags are used by endCheck() and by the Parser to * detect inconsistent return usage. * * END_UNREACHED is reserved for code paths that are assumed to always be * able to execute (example: throw, continue) * * END_DROPS_OFF indicates if the statement can transfer control to the * next one. Statement such as return dont. A compound statement may have * some branch that drops off control to the next statement. * * END_RETURNS indicates that the statement can return (without arguments) * END_RETURNS_VALUE indicates that the statement can return a value. * * A compound statement such as * if (condition) { * return value; * } * Will be detected as (END_DROPS_OFF | END_RETURN_VALUE) by endCheck() */ public static final int END_UNREACHED = 0; public static final int END_DROPS_OFF = 1; public static final int END_RETURNS = 2; public static final int END_RETURNS_VALUE = 4; public static final int END_YIELDS = 8; /** * Checks that every return usage in a function body is consistent with the * requirements of strict-mode. * @return true if the function satisfies strict mode requirement. */ public boolean hasConsistentReturnUsage() { int n = endCheck(); return (n & END_RETURNS_VALUE) == 0 || (n & (END_DROPS_OFF|END_RETURNS|END_YIELDS)) == 0; } /** * Returns in the then and else blocks must be consistent with each other. * If there is no else block, then the return statement can fall through. * @return logical OR of END_* flags */ private int endCheckIf() { Node th, el; int rv = END_UNREACHED; th = next; el = ((Jump)this).target; rv = th.endCheck(); if (el != null) rv |= el.endCheck(); else rv |= END_DROPS_OFF; return rv; } /** * Consistency of return statements is checked between the case statements. * If there is no default, then the switch can fall through. If there is a * default,we check to see if all code paths in the default return or if * there is a code path that can fall through. * @return logical OR of END_* flags */ private int endCheckSwitch() { int rv = END_UNREACHED; // examine the cases // for (n = first.next; n != null; n = n.next) // { // if (n.type == Token.CASE) { // rv |= ((Jump)n).target.endCheck(); // } else // break; // } // // we don't care how the cases drop into each other // rv &= ~END_DROPS_OFF; // // examine the default // n = ((Jump)this).getDefault(); // if (n != null) // rv |= n.endCheck(); // else // rv |= END_DROPS_OFF; // // remove the switch block // rv |= getIntProp(CONTROL_BLOCK_PROP, END_UNREACHED); return rv; } /** * If the block has a finally, return consistency is checked in the * finally block. If all code paths in the finally returns, then the * returns in the try-catch blocks don't matter. If there is a code path * that does not return or if there is no finally block, the returns * of the try and catch blocks are checked for mismatch. * @return logical OR of END_* flags */ private int endCheckTry() { int rv = END_UNREACHED; // a TryStatement isn't a jump - needs rewriting // check the finally if it exists // n = ((Jump)this).getFinally(); // if(n != null) { // rv = n.next.first.endCheck(); // } else { // rv = END_DROPS_OFF; // } // // if the finally block always returns, then none of the returns // // in the try or catch blocks matter // if ((rv & END_DROPS_OFF) != 0) { // rv &= ~END_DROPS_OFF; // // examine the try block // rv |= first.endCheck(); // // check each catch block // n = ((Jump)this).target; // if (n != null) // { // // point to the first catch_scope // for (n = n.next.first; n != null; n = n.next.next) // { // // check the block of user code in the catch_scope // rv |= n.next.first.next.first.endCheck(); // } // } // } return rv; } /** * Return statement in the loop body must be consistent. The default * assumption for any kind of a loop is that it will eventually terminate. * The only exception is a loop with a constant true condition. Code that * follows such a loop is examined only if one can statically determine * that there is a break out of the loop. *
     *  for(<> ; <>; <>) {}
     *  for(<> in <> ) {}
     *  while(<>) { }
     *  do { } while(<>)
     * 
* @return logical OR of END_* flags */ private int endCheckLoop() { Node n; int rv = END_UNREACHED; // To find the loop body, we look at the second to last node of the // loop node, which should be the predicate that the loop should // satisfy. // The target of the predicate is the loop-body for all 4 kinds of // loops. for (n = first; n.next != last; n = n.next) { /* skip */ } if (n.type != Token.IFEQ) return END_DROPS_OFF; // The target's next is the loop body block rv = ((Jump)n).target.next.endCheck(); // check to see if the loop condition is true if (n.first.type == Token.TRUE) rv &= ~END_DROPS_OFF; // look for effect of breaks rv |= getIntProp(CONTROL_BLOCK_PROP, END_UNREACHED); return rv; } /** * A general block of code is examined statement by statement. If any * statement (even compound ones) returns in all branches, then subsequent * statements are not examined. * @return logical OR of END_* flags */ private int endCheckBlock() { Node n; int rv = END_DROPS_OFF; // check each statment and if the statement can continue onto the next // one, then check the next statement for (n=first; ((rv & END_DROPS_OFF) != 0) && n != null; n = n.next) { rv &= ~END_DROPS_OFF; rv |= n.endCheck(); } return rv; } /** * A labelled statement implies that there maybe a break to the label. The * function processes the labelled statement and then checks the * CONTROL_BLOCK_PROP property to see if there is ever a break to the * particular label. * @return logical OR of END_* flags */ private int endCheckLabel() { int rv = END_UNREACHED; rv = next.endCheck(); rv |= getIntProp(CONTROL_BLOCK_PROP, END_UNREACHED); return rv; } /** * When a break is encountered annotate the statement being broken * out of by setting its CONTROL_BLOCK_PROP property. * @return logical OR of END_* flags */ private int endCheckBreak() { Node n = ((Jump) this).getJumpStatement(); n.putIntProp(CONTROL_BLOCK_PROP, END_DROPS_OFF); return END_UNREACHED; } /** * endCheck() examines the body of a function, doing a basic reachability * analysis and returns a combination of flags END_* flags that indicate * how the function execution can terminate. These constitute only the * pessimistic set of termination conditions. It is possible that at * runtime certain code paths will never be actually taken. Hence this * analysis will flag errors in cases where there may not be errors. * @return logical OR of END_* flags */ private int endCheck() { switch(type) { case Token.BREAK: return endCheckBreak(); case Token.EXPR_VOID: if (this.first != null) return first.endCheck(); return END_DROPS_OFF; case Token.YIELD: return END_YIELDS; case Token.CONTINUE: case Token.THROW: return END_UNREACHED; case Token.RETURN: if (this.first != null) return END_RETURNS_VALUE; else return END_RETURNS; case Token.TARGET: if (next != null) return next.endCheck(); else return END_DROPS_OFF; case Token.LOOP: return endCheckLoop(); case Token.LOCAL_BLOCK: case Token.BLOCK: // there are several special kinds of blocks if (first == null) return END_DROPS_OFF; switch(first.type) { case Token.LABEL: return first.endCheckLabel(); case Token.IFNE: return first.endCheckIf(); case Token.SWITCH: return first.endCheckSwitch(); case Token.TRY: return first.endCheckTry(); default: return endCheckBlock(); } default: return END_DROPS_OFF; } } public boolean hasSideEffects() { switch (type) { case Token.EXPR_VOID: case Token.COMMA: if (last != null) return last.hasSideEffects(); else return true; case Token.HOOK: if (first == null || first.next == null || first.next.next == null) Kit.codeBug(); return first.next.hasSideEffects() && first.next.next.hasSideEffects(); case Token.AND: case Token.OR: if (first == null || last == null) Kit.codeBug(); return first.hasSideEffects() || last.hasSideEffects(); case Token.ERROR: // Avoid cascaded error messages case Token.EXPR_RESULT: case Token.ASSIGN: case Token.ASSIGN_ADD: case Token.ASSIGN_SUB: case Token.ASSIGN_MUL: case Token.ASSIGN_DIV: case Token.ASSIGN_MOD: case Token.ASSIGN_BITOR: case Token.ASSIGN_BITXOR: case Token.ASSIGN_BITAND: case Token.ASSIGN_LSH: case Token.ASSIGN_RSH: case Token.ASSIGN_URSH: case Token.ENTERWITH: case Token.LEAVEWITH: case Token.RETURN: case Token.GOTO: case Token.IFEQ: case Token.IFNE: case Token.NEW: case Token.DELPROP: case Token.SETNAME: case Token.SETPROP: case Token.SETELEM: case Token.CALL: case Token.THROW: case Token.RETHROW: case Token.SETVAR: case Token.CATCH_SCOPE: case Token.RETURN_RESULT: case Token.SET_REF: case Token.DEL_REF: case Token.REF_CALL: case Token.TRY: case Token.SEMI: case Token.INC: case Token.DEC: case Token.IF: case Token.ELSE: case Token.SWITCH: case Token.WHILE: case Token.DO: case Token.FOR: case Token.BREAK: case Token.CONTINUE: case Token.VAR: case Token.CONST: case Token.LET: case Token.LETEXPR: case Token.WITH: case Token.WITHEXPR: case Token.CATCH: case Token.FINALLY: case Token.BLOCK: case Token.LABEL: case Token.TARGET: case Token.LOOP: case Token.JSR: case Token.SETPROP_OP: case Token.SETELEM_OP: case Token.LOCAL_BLOCK: case Token.SET_REF_OP: case Token.YIELD: return true; default: return false; } } /** * Recursively unlabel every TARGET or YIELD node in the tree. * * This is used and should only be used for inlining finally blocks where * jsr instructions used to be. It is somewhat hackish, but implementing * a clone() operation would take much, much more effort. * * This solution works for inlining finally blocks because you should never * be writing any given block to the class file simultaneously. Therefore, * an unlabeling will never occur in the middle of a block. */ public void resetTargets() { if (type == Token.FINALLY) { resetTargets_r(); } else { Kit.codeBug(); } } private void resetTargets_r() { if (type == Token.TARGET || type == Token.YIELD) { labelId(-1); } Node child = first; while (child != null) { child.resetTargets_r(); child = child.next; } } @Override public String toString() { if (Token.printTrees) { StringBuffer sb = new StringBuffer(); toString(new ObjToIntMap(), sb); return sb.toString(); } return String.valueOf(type); } private void toString(ObjToIntMap printIds, StringBuffer sb) { if (Token.printTrees) { sb.append(Token.name(type)); if (this instanceof Name) { sb.append(' '); sb.append(getString()); Scope scope = getScope(); if (scope != null) { sb.append("[scope: "); appendPrintId(scope, printIds, sb); sb.append("]"); } } else if (this instanceof Scope) { if (this instanceof ScriptNode) { ScriptNode sof = (ScriptNode)this; if (this instanceof FunctionNode) { FunctionNode fn = (FunctionNode)this; sb.append(' '); sb.append(fn.getName()); } sb.append(" [source name: "); sb.append(sof.getSourceName()); sb.append("] [encoded source length: "); sb.append(sof.getEncodedSourceEnd() - sof.getEncodedSourceStart()); sb.append("] [base line: "); sb.append(sof.getBaseLineno()); sb.append("] [end line: "); sb.append(sof.getEndLineno()); sb.append(']'); } if (((Scope)this).getSymbolTable() != null) { sb.append(" [scope "); appendPrintId(this, printIds, sb); sb.append(": "); Iterator iter = ((Scope) this).getSymbolTable().keySet().iterator(); while (iter.hasNext()) { sb.append(iter.next()); sb.append(" "); } sb.append("]"); } } else if (this instanceof Jump) { Jump jump = (Jump)this; if (type == Token.BREAK || type == Token.CONTINUE) { sb.append(" [label: "); appendPrintId(jump.getJumpStatement(), printIds, sb); sb.append(']'); } else if (type == Token.TRY) { Node catchNode = jump.target; Node finallyTarget = jump.getFinally(); if (catchNode != null) { sb.append(" [catch: "); appendPrintId(catchNode, printIds, sb); sb.append(']'); } if (finallyTarget != null) { sb.append(" [finally: "); appendPrintId(finallyTarget, printIds, sb); sb.append(']'); } } else if (type == Token.LABEL || type == Token.LOOP || type == Token.SWITCH) { sb.append(" [break: "); appendPrintId(jump.target, printIds, sb); sb.append(']'); if (type == Token.LOOP) { sb.append(" [continue: "); appendPrintId(jump.getContinue(), printIds, sb); sb.append(']'); } } else { sb.append(" [target: "); appendPrintId(jump.target, printIds, sb); sb.append(']'); } } else if (type == Token.NUMBER) { sb.append(' '); sb.append(getDouble()); } else if (type == Token.TARGET) { sb.append(' '); appendPrintId(this, printIds, sb); } if (lineno != -1) { sb.append(' '); sb.append(lineno); } for (PropListItem x = propListHead; x != null; x = x.next) { int type = x.type; sb.append(" ["); sb.append(propToString(type)); sb.append(": "); String value; switch (type) { case TARGETBLOCK_PROP : // can't add this as it recurses value = "target block property"; break; case LOCAL_BLOCK_PROP : // can't add this as it is dull value = "last local block"; break; case ISNUMBER_PROP: switch (x.intValue) { case BOTH: value = "both"; break; case RIGHT: value = "right"; break; case LEFT: value = "left"; break; default: throw Kit.codeBug(); } break; case SPECIALCALL_PROP: switch (x.intValue) { case SPECIALCALL_EVAL: value = "eval"; break; case SPECIALCALL_WITH: value = "with"; break; default: // NON_SPECIALCALL should not be stored throw Kit.codeBug(); } break; case OBJECT_IDS_PROP: { Object[] a = (Object[]) x.objectValue; value = "["; for (int i=0; i < a.length; i++) { value += a[i].toString(); if (i+1 < a.length) value += ", "; } value += "]"; break; } default : Object obj = x.objectValue; if (obj != null) { value = obj.toString(); } else { value = String.valueOf(x.intValue); } break; } sb.append(value); sb.append(']'); } } } public String toStringTree(ScriptNode treeTop) { if (Token.printTrees) { StringBuffer sb = new StringBuffer(); toStringTreeHelper(treeTop, this, null, 0, sb); return sb.toString(); } return null; } private static void toStringTreeHelper(ScriptNode treeTop, Node n, ObjToIntMap printIds, int level, StringBuffer sb) { if (Token.printTrees) { if (printIds == null) { printIds = new ObjToIntMap(); generatePrintIds(treeTop, printIds); } for (int i = 0; i != level; ++i) { sb.append(" "); } n.toString(printIds, sb); sb.append('\n'); for (Node cursor = n.getFirstChild(); cursor != null; cursor = cursor.getNext()) { if (cursor.getType() == Token.FUNCTION) { int fnIndex = cursor.getExistingIntProp(Node.FUNCTION_PROP); FunctionNode fn = treeTop.getFunctionNode(fnIndex); toStringTreeHelper(fn, fn, null, level + 1, sb); } else { toStringTreeHelper(treeTop, cursor, printIds, level+1, sb); } } } } private static void generatePrintIds(Node n, ObjToIntMap map) { if (Token.printTrees) { map.put(n, map.size()); for (Node cursor = n.getFirstChild(); cursor != null; cursor = cursor.getNext()) { generatePrintIds(cursor, map); } } } private static void appendPrintId(Node n, ObjToIntMap printIds, StringBuffer sb) { if (Token.printTrees) { if (n != null) { int id = printIds.get(n, -1); sb.append('#'); if (id != -1) { sb.append(id + 1); } else { sb.append(""); } } } } protected int type = Token.ERROR; // type of the node, e.g. Token.NAME protected Node next; // next sibling protected Node first; // first element of a linked list of children protected Node last; // last element of a linked list of children protected int lineno = -1; /** * Linked list of properties. Since vast majority of nodes would have * no more then 2 properties, linked list saves memory and provides * fast lookup. If this does not holds, propListHead can be replaced * by UintMap. */ protected PropListItem propListHead; }




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