Package de.fraunhofer.aisec.cpg.passes

Class EvaluationOrderGraphPass

  • All Implemented Interfaces:
    java.util.function.Consumer<TranslationResult>
    public class EvaluationOrderGraphPass
extends Pass
    Creates an Evaluation Order Graph (EOG) based on AST.

    EOG is similar to the CFG ControlFlowGraphPass, but its nodes are not limited to *executable* statements but also include (some) *evaluated* expressions and CompoundStatements. This leads to subtle differences:

    • For methods without explicit return statement, EOF will have an edge to a virtual return node with line number -1 which does not exist in the original code. In CFG, the last reachable statement(s) will not have any further nextCFG edges.
    • For IF statements, EOG treats the "if" keyword and the condition as separate nodes. CFG treats this as one "if" statement.
    • EOG considers an opening blocking ("CompoundStatement", indicated by a "{") as a separate node. CFG will rather use the first actual executable statement within the block.
    • EOG considers a method header as a node. CFG will consider the first executable statement of the methods as a node.

    • Constructor Detail

      • EvaluationOrderGraphPass

        public EvaluationOrderGraphPass()

    • Method Detail

      • cleanup

        public void cleanup()
        Specified by:
        cleanup in class Pass

      • pushToEOG

        public <T extends Node> void pushToEOG​(@NonNull T node)

      • getCurrentEOG

        public java.util.List<Node> getCurrentEOG()

      • setCurrentEOG

        public void setCurrentEOG​(java.util.List<Node> currentEOG)

      • setCurrentEOG

        public void setCurrentEOG​(Node node)

      • setCurrentEOGs

        public <T extends Node> void setCurrentEOGs​(java.util.List<T> nodes)

      • addToCurrentEOG

        public void addToCurrentEOG​(java.util.List<Node> nodes)

      • exitLoop

        public void exitLoop​(@NonNull Statement loopStatement,
                     @NonNull LoopScope loopScope)
        Connects the current EOG leaf nodes to the last stacked node, e.g. loop head, and removes the nodes.
        Parameters:
        loopStatement - the loop statement
        loopScope - the loop scope

      • connectCurrentToLoopStart

        public void connectCurrentToLoopStart()
        Connects current EOG nodes to the previously saved loop start to mimic control flow of loops

      • addEOGEdge

        public void addEOGEdge​(Node prev,
                       Node next)
        Builds an EOG edge from prev to next. 'eogDirection' defines how the node instances save the references constituting the edge. 'FORWARD': only the nodes nextEOG member contains references, an points to the next nodes. 'BACKWARD': only the nodes prevEOG member contains references and points to the previous nodes. 'BIDIRECTIONAL': nextEOG and prevEOG contain references and point to the previous and the next nodes.
        Parameters:
        prev - the previous node
        next - the next node

      • addMultipleIncomingEOGEdges

        public void addMultipleIncomingEOGEdges​(java.util.List<Node> prevs,
                                        Node next)