dataflowCfgFilter.h

#pragma once

// DQ (10/5/2014): This is more strict now that we include rose_config.h in the sage3basic.h.
// #include "rose.h"
// rose.h and sage3basic.h should not be included in librose header files. [Robb P. Matzke 2014-10-15]
// #include "sage3basic.h"

namespace ssa_private
{

    struct DataflowCfgFilter
    {

        bool operator() (CFGNode cfgn) const
        {
            SgNode *node = cfgn.getNode();

            switch (node->variantT())
            {
                    //For function calls, we only keep the last node. The function is actually called after all its parameters
                    //are evaluated.
                case V_SgFunctionCallExp:
                    return (cfgn == node->cfgForEnd());

                    //For basic blocks and other "container" nodes, keep the node that appears before the contents are executed
                case V_SgBasicBlock:
                case V_SgExprStatement:
                case V_SgCommaOpExp:
                    return (cfgn == node->cfgForBeginning());

                    //Keep the last index for initialized names. This way the def of the variable doesn't propagate to its assign
                    //initializer.
                case V_SgInitializedName:
                    return (cfgn == node->cfgForEnd());

                case V_SgTryStmt:
                    return (cfgn == node->cfgForBeginning());

                    //We only want the middle appearance of the teritatry operator - after its conditional expression
                    //and before the true and false bodies. This makes it behave as an if statement for data flow
                    //purposes
                case V_SgConditionalExp:
                    return (cfgn.getIndex() == 1);

                    //Make these binary operators appear after their operands, because they are evaluated after their operands
                case V_SgAndOp:
                case V_SgOrOp:
                    return (cfgn == node->cfgForEnd());

                default:
                    return cfgn.isInteresting();
            }
        }
    };
}