Examples with ASTCondition soot.dava.internal.AST.ASTCondition used on opensource projects

Example 11 with ASTCondition

use of soot.dava.internal.AST.ASTCondition in project soot by Sable.

the class SimplifyConditions method fixedPoint.

public void fixedPoint(ASTControlFlowNode node) {
    ASTCondition returned;
    do {
        if (DEBUG)
            System.out.println("Invoking simplify");
        changed = false;
        ASTCondition cond = node.get_Condition();
        returned = simplifyTheCondition(cond);
        if (returned != null)
            node.set_Condition(returned);
    } while (changed);
}

Example 12 with ASTCondition

use of soot.dava.internal.AST.ASTCondition in project soot by Sable.

the class SimplifyConditions method simplifyIfAtleastOneConstant.

/*
     * When this method is invoked we are sure that there are no occurences of !true or !false since
     * this is AFTER doing depth first of the children so the unaryCondition must have simplified the above
     * 
     * Return Null if no change else return changed condition
     */
public ASTCondition simplifyIfAtleastOneConstant(ASTAggregatedCondition aggCond) {
    ASTCondition left = aggCond.getLeftOp();
    ASTCondition right = aggCond.getRightOp();
    Boolean leftBool = null;
    Boolean rightBool = null;
    if (left instanceof ASTUnaryCondition)
        leftBool = isBooleanConstant(((ASTUnaryCondition) left).getValue());
    if (right instanceof ASTUnaryCondition)
        rightBool = isBooleanConstant(((ASTUnaryCondition) right).getValue());
    /*
		 *  a && b NOCHANGE    DONE
		 *  b && a NOCHANGE	 DONE
		 *              
		 *  a || b NOCHANGE DONE 
		 *  b || a NOCHANGE DONE
		 *  
		 */
    if (leftBool == null && rightBool == null) {
        // meaning both are not constants
        return null;
    }
    if (aggCond instanceof ASTAndCondition) {
        if (leftBool != null && rightBool != null) {
            // meaning both are constants
            if (leftBool.booleanValue() && rightBool.booleanValue()) {
                // both are true
                return new ASTUnaryCondition(DIntConstant.v(1, BooleanType.v()));
            } else {
                // atleast one of the two is false
                return new ASTUnaryCondition(DIntConstant.v(0, BooleanType.v()));
            }
        }
        if (leftBool != null) {
            // condition passed
            if (leftBool.booleanValue()) {
                // condition.......just return the right condition
                return right;
            } else {
                // return a unary false
                return new ASTUnaryCondition(DIntConstant.v(0, BooleanType.v()));
            }
        }
        if (rightBool != null) {
            // implicityly means that the leftBool is null
            if (rightBool.booleanValue()) {
                // rightBool is true so it all depends on left
                return left;
            } else {
                // remove the leftBool since there might be side effects
                return aggCond;
            }
        }
    } else if (aggCond instanceof ASTOrCondition) {
        /*
			 * 
			 * true || false ---> true    DONE 
			 * true || true --> true      DONE
			 * false || true --> true     DONE
			 * false || false ---> false  DONE
			 * 
			 * 
			 * true || b ----> true DONE
			 * false || b -----> b   DONE
			 *   
			 * b || true ---> b || true .... although we know the condition is true we have to evaluate b because of possible side effects   DONE 
			 * b || false ---> b     DONE
			 * 
			 */
        if (leftBool != null && rightBool != null) {
            // meaning both are constants
            if (!leftBool.booleanValue() && !rightBool.booleanValue()) {
                // both are false
                return new ASTUnaryCondition(DIntConstant.v(0, BooleanType.v()));
            } else {
                // atleast one of the two is true
                return new ASTUnaryCondition(DIntConstant.v(1, BooleanType.v()));
            }
        }
        if (leftBool != null) {
            // condition passed
            if (leftBool.booleanValue()) {
                // left bool is true that means we will stop evaluation of condition, just return true
                return new ASTUnaryCondition(DIntConstant.v(1, BooleanType.v()));
            } else {
                // left bool is false so we have to continue evaluating right
                return right;
            }
        }
        if (rightBool != null) {
            // implicityly means that the leftBool is null
            if (rightBool.booleanValue()) {
                // rightBool is true but leftBool must be evaluated beforehand
                return aggCond;
            } else {
                // rightBool is false so everything depends on left
                return left;
            }
        }
    } else
        throw new RuntimeException("Found unknown aggregated condition");
    return null;
}

Example 13 with ASTCondition

use of soot.dava.internal.AST.ASTCondition in project soot by Sable.

the class SimplifyConditions method simplifyTheCondition.

/*
	 * In a loop keep simplifying the condition as much as possible
	 * 
	 */
public ASTCondition simplifyTheCondition(ASTCondition cond) {
    if (cond instanceof ASTAggregatedCondition) {
        ASTAggregatedCondition aggCond = (ASTAggregatedCondition) cond;
        ASTCondition leftCond = simplifyTheCondition(aggCond.getLeftOp());
        ASTCondition rightCond = simplifyTheCondition(aggCond.getRightOp());
        // if returned values are non null then set leftop /rightop to new condition
        if (leftCond != null) {
            aggCond.setLeftOp(leftCond);
        }
        if (rightCond != null) {
            aggCond.setRightOp(rightCond);
        }
        ASTCondition returned = simplifyIfAtleastOneConstant(aggCond);
        if (returned != null) {
            changed = true;
            return returned;
        }
        returned = applyDeMorgans(aggCond);
        if (returned != null) {
            changed = true;
            return returned;
        }
        return aggCond;
    } else if (cond instanceof ASTUnaryCondition) {
        // dont do anything with unary conditions
        ASTUnaryCondition unary = (ASTUnaryCondition) cond;
        /*
			 * if unary is a noted constant simplify it
			 * !true to be converted to false
			 * !false to be converted to true
			 */
        Value unaryVal = unary.getValue();
        if (unaryVal instanceof DNotExpr) {
            if (DEBUG)
                System.out.println("Found NotExpr in unary COndition" + unaryVal);
            DNotExpr notted = (DNotExpr) unaryVal;
            Value internal = notted.getOp();
            Boolean isIt = isBooleanConstant(internal);
            if (isIt != null) {
                // convert !true to false
                if (isIt.booleanValue()) {
                    // true
                    if (DEBUG)
                        System.out.println("CONVERTED !true to false");
                    changed = true;
                    return new ASTUnaryCondition(DIntConstant.v(0, BooleanType.v()));
                } else if (!isIt.booleanValue()) {
                    // false
                    if (DEBUG)
                        System.out.println("CONVERTED !false to true");
                    changed = true;
                    return new ASTUnaryCondition(DIntConstant.v(1, BooleanType.v()));
                } else
                    throw new RuntimeException("BooleanType found with value different than 0 or 1");
            } else {
                if (DEBUG)
                    System.out.println("Not boolean type");
            }
        }
        return unary;
    } else if (cond instanceof ASTBinaryCondition) {
        ASTBinaryCondition binary = (ASTBinaryCondition) cond;
        ConditionExpr expr = binary.getConditionExpr();
        // returns null if no change
        ASTUnaryCondition temp = evaluateBinaryCondition(expr);
        if (DEBUG)
            System.out.println("changed binary condition " + cond + " to" + temp);
        if (temp != null)
            changed = true;
        return temp;
    } else {
        throw new RuntimeException("Method getUseList in ASTUsesAndDefs encountered unknown condition type");
    }
}