Examples with ASTUsesAndDefs soot.dava.toolkits.base.AST.traversals.ASTUsesAndDefs used on opensource projects

Example 1 with ASTUsesAndDefs

use of soot.dava.toolkits.base.AST.traversals.ASTUsesAndDefs in project soot by Sable.

the class SuperFirstStmtHandler method addDefsToLiveVariables.

/*
	 * newASTPreInitMethod at time of invocation just contains body X find all
	 * defs for this body
	 */
private List<Local> addDefsToLiveVariables() {
    // get all defs within x
    AllDefinitionsFinder finder = new AllDefinitionsFinder();
    newASTPreInitMethod.apply(finder);
    List<DefinitionStmt> allDefs = finder.getAllDefs();
    List<Local> uniqueLocals = new ArrayList<Local>();
    List<DefinitionStmt> uniqueLocalDefs = new ArrayList<DefinitionStmt>();
    // remove any defs for fields, and any which are done multiple times
    Iterator<DefinitionStmt> it = allDefs.iterator();
    while (it.hasNext()) {
        DefinitionStmt s = it.next();
        Value left = s.getLeftOp();
        if (left instanceof Local) {
            if (uniqueLocals.contains(left)) {
                // a def for this local already encountered
                int index = uniqueLocals.indexOf(left);
                uniqueLocals.remove(index);
                uniqueLocalDefs.remove(index);
            } else {
                // no def for this local yet
                uniqueLocals.add((Local) left);
                uniqueLocalDefs.add(s);
            }
        }
    }
    // at this point unique locals contains all locals defined and
    // uniqueLocaldef list has a list of the corresponding definitions
    // Now remove those unique locals and localdefs whose stmtseq node does
    // not have the ASTMEthodNode as a parent
    // This is a conservative step!!
    ASTParentNodeFinder parentFinder = new ASTParentNodeFinder();
    newASTPreInitMethod.apply(parentFinder);
    List<DefinitionStmt> toRemoveDefs = new ArrayList<DefinitionStmt>();
    it = uniqueLocalDefs.iterator();
    while (it.hasNext()) {
        DefinitionStmt s = it.next();
        Object parent = parentFinder.getParentOf(s);
        if (parent == null || (!(parent instanceof ASTStatementSequenceNode))) {
            // shouldnt happen but if it does add this s to toRemove list
            toRemoveDefs.add(s);
        }
        // parent is an ASTStatementsequence node. check that its parent is
        // the ASTMethodNode
        Object grandParent = parentFinder.getParentOf(parent);
        if (grandParent == null || (!(grandParent instanceof ASTMethodNode))) {
            // can happen if obfuscators are really smart. add s to toRemove
            // list
            toRemoveDefs.add(s);
        }
    }
    // remove any defs and corresponding locals if present in the
    // toRemoveDefs list
    it = toRemoveDefs.iterator();
    while (it.hasNext()) {
        DefinitionStmt s = it.next();
        int index = uniqueLocalDefs.indexOf(s);
        uniqueLocals.remove(index);
        uniqueLocalDefs.remove(index);
    }
    // the uniqueLocalDefs contains all those definitions to unique locals
    // which are not deeply nested in the X body
    // find all the uses of these definitions in the original method body
    toRemoveDefs = new ArrayList<DefinitionStmt>();
    ASTUsesAndDefs uDdU = new ASTUsesAndDefs(originalASTMethod);
    originalASTMethod.apply(uDdU);
    it = uniqueLocalDefs.iterator();
    while (it.hasNext()) {
        DefinitionStmt s = it.next();
        Object temp = uDdU.getDUChain(s);
        if (temp == null) {
            // couldnt find uses
            toRemoveDefs.add(s);
            continue;
        }
        ArrayList uses = (ArrayList) temp;
        // check if uses is non-empty
        if (uses.size() == 0) {
            toRemoveDefs.add(s);
        }
        // check for all the non zero uses
        Iterator useIt = uses.iterator();
        boolean onlyInConstructorUnit = true;
        while (useIt.hasNext()) {
            // a use is either a statement or a node(condition, synch,
            // switch , for etc)
            Object tempUse = useIt.next();
            if (tempUse != originalConstructorUnit) {
                onlyInConstructorUnit = false;
            }
        }
        if (onlyInConstructorUnit) {
            // mark it to be removed
            toRemoveDefs.add(s);
        }
    }
    // remove any defs and corresponding locals if present in the
    // toRemoveDefs list
    it = toRemoveDefs.iterator();
    while (it.hasNext()) {
        DefinitionStmt s = it.next();
        int index = uniqueLocalDefs.indexOf(s);
        uniqueLocals.remove(index);
        uniqueLocalDefs.remove(index);
    }
    // the remaining uniquelocals are the ones which are needed for body Y
    return uniqueLocals;
}