modules/fdbworkers/src/flash/tools/debugger/expression/AS3DebuggerBURM.jbg

package flash.tools.debugger.expression;

header
{
	/*
    
      Licensed to the Apache Software Foundation (ASF) under one or more
      contributor license agreements.  See the NOTICE file distributed with
      this work for additional information regarding copyright ownership.
      The ASF licenses this file to You under the Apache License, Version 2.0
      (the "License"); you may not use this file except in compliance with
      the License.  You may obtain a copy of the License at
    
          http://www.apache.org/licenses/LICENSE-2.0
    
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.

		AS3DebuggerBURM.java is a Bottom-Up Rewrite Machine for ActionScript 3.0.

		A BURM recognizes patterns of nodes within an tree (in this case, an
		abstract syntax tree for AS 3.0 expressions) and performs rule-based reduction
		on them (in this case producing DebuggerValues).

		AS3DebuggerBURM.java is generated from AS3DebuggerBURM.jbg using JBurg, an open-source
		Java implementation of a Bottom-Up Rewrite Generator.

		The most important entry point of this class is burm(),
		which is called by the code generator.
	*/

    import static com.adobe.flash.abc3.ABCConstants.*;
    import static com.adobe.flash.compiler.tree.ASTNodeID.*;

    import com.adobe.flash.compiler.constants.IASLanguageConstants;
    import com.adobe.flash.compiler.exceptions.BURMAbortException;
    import com.adobe.flash.compiler.problems.*;
    import com.adobe.flash.compiler.internal.semantics.AS3SemanticUtils;
    import com.adobe.flash.compiler.tree.ASTNodeID;
    import com.adobe.flash.compiler.tree.as.IASNode;
    import com.adobe.flash.compiler.tree.as.ITryNode;
}

INodeType IASNode;
OpcodeType ASTNodeID;

/*
 *  The I-node type is IASNode, and it has its own adapter.
 */
INodeAdapter com.adobe.flash.compiler.internal.codegen.as.IASNodeAdapter;

//  Generate Java output.
Language java;

// Return type of all the reductions
ReturnType Object;

/**
 *  This is a name to use in an expression context.
 *
 *  TODO: What type should this be?
 */
ReturnType name = Object;

ReturnType decl_name = Object;

/**
 *  Qualified name - this acts the same as a name above, but is built a little differently.
 */
ReturnType qualifiedName = Object;
ReturnType qualifiedNamePart = Object;

/**
 *  This is a name used in a type annotation context, such as 'Foo' in:
 *      var x : Foo;
 *  It is a Binding, as type annotations must always be resolved.
 *  A type_name also allows '*', which can't happen in a general expression context.
 */
ReturnType type_name = Object;

/**
 *  This is a name used in a new context, such as 'Foo' in:
 *      new Foo();
 *  We can do additional analysis when the new expression resolves to a Type, which
 *  is why we have a special name for the new expression.
 */
ReturnType new_type_name = Object;

ReturnType dottedNamePart = String;

ReturnType non_resolving_identifier = String;

ReturnType runtime_name_expression = Object;
ReturnType multinameL = Object;
ReturnType e4x_literal = String;

ReturnType integer_constant = Integer;
ReturnType uint_constant = Long;
ReturnType double_constant = Double;
ReturnType string_constant = String;
ReturnType boolean_constant = Boolean;
ReturnType float_constant = Float;

ReturnType numeric_constant = Number;

ReturnType constant_value = Object;

/**
 * Value to use to indicate a cost that is not feasible
 */
JBurg.Constant ERROR_TRAP = 268435456;

{
    final static boolean NEED_VALUE = true;
    final static boolean DISCARD_VALUE = false;


    /**
     *  The reducer has all the implementation
     *  logic for the rewrite; the BURM constructed
     *  by this specification drives that logic.
     */
    AS3DebuggerReducer reducer;


    /*
     *  **  Cost functions  **
     * Cost functions are Java code that returns an int value.
     * The value is used to compute the cost of a particular
     * candidate reduction. The BURM searches for the lowest
     * total cost sequence of reductions to transform the input
     * AST into a value, so low values mean "good cost," higher
     * values mean "less desirable."   The total cost of a reduction
     * is always strictly less than Integer.MAX_VALUE; a cost of
     * Integer.MAX_VALUE tells the pattern matcher that the
     * reduction is not feasible.
     */


    /**
     *  @return "feasible" if the reducer can reduce this to a dotted name.
     */
    int isDottedName(IASNode iNode)
    {
       return reducer.isDottedName(iNode);
    }

    /**
     *  @return "feasible" if the reducer can reduce this to a package name.
     */
    int isPackageName(IASNode iNode)
    {
       return reducer.isPackageName(iNode);
    }

    /**
     *  @return "feasible" if this node's qualifier is a compile-time constant.
     */
    int qualifierIsCompileTimeConstant(IASNode iNode)
    {
       return reducer.qualifierIsCompileTimeConstant(iNode);
    }

    /**
     *  @return "feasible" if this node can be resolved to a compile-time constant.
     */
    int isCompileTimeConstant(IASNode iNode)
    {
       return reducer.isCompileTimeConstant(iNode);
    }

    /**
     *  @return "feasible" if this function call node can be resolved to a compile-time constant function.
     */
    int isCompileTimeConstantFunction(IASNode iNode)
    {
       return reducer.isCompileTimeConstantFunction(iNode);
    }

    /**
     *  @return "feasible" if this binary node has at least one expression that is
     *          of type "float".
     */
    int isFloatBinOp(IASNode iNode)
    {
       return reducer.isFloatBinOp(iNode);
    }

    /**
     *  @return "feasible" if this node is for 'new Array()'.
     */
    int isEmptyArrayConstructor(IASNode iNode)
    {
        return reducer.isEmptyArrayConstructor(iNode);
    }

    /**
     *  @return "feasible" if this node is for 'new Object()'.
     */
    int isEmptyObjectConstructor(IASNode iNode)
    {
        return reducer.isEmptyObjectConstructor(iNode);
    }

    /**
     * @return "feasible" if this node resolves to a type definition.
     */
    int isKnownType(IASNode iNode)
    {
        return reducer.isKnownType(iNode);
    }

    /**
     * @return "feasible" if the type parameter resolves to a type definition.
     */
    int parameterTypeIsConstant(IASNode iNode)
    {
        return reducer.parameterTypeIsConstant(iNode);
    }

    /**
     *  recordError is a convenience method for error reductions;
     *  it adds a problem to the current set of problems and
     */
    Object recordError(ICompilerProblem problem)
    {
        return new Object();
    }

    int isIntLiteral(IASNode iNode)
    {
        return reducer.isIntLiteral(iNode);
    }

    int isUintLiteral(IASNode iNode)
    {
        return reducer.isUintLiteral(iNode);
    }

    int isDoubleLiteral(IASNode iNode)
    {
        return reducer.isDoubleLiteral(iNode);
    }

    int isFloatLiteral(IASNode iNode)
    {
        return reducer.isDoubleLiteral(iNode);
    }

}

/*
 *  Error recovery routine: deduce what we can from the problem
 *  tree, then abort this BURM with an exception that the caller
 *  can catch and ignore.
 */
DefaultErrorHandler
{
    BURMAbortException.abort();
}

/*
 *  Patterns and rules are stored in their own, shareable file.
 */
JBurg.include "../../compiler/com.adobe.flash.compiler/src/com/adobe/flash/compiler/internal/codegen/as3/AS3Patterns.jbg"
JBurg.include "AS3DebuggerRules.jbg"