public Expression getIncrVal() {
if (incr instanceof StmtExpr) {
StmtExpr se = (StmtExpr) incr;
if (se.getExpression() instanceof ExprUnary) {
ExprUnary eu = (ExprUnary) se.getExpression();
int op = eu.getOp();
if (op == ExprUnary.UNOP_POSTINC || op == ExprUnary.UNOP_PREINC) {
return ExprConstInt.one;
}
if (op == ExprUnary.UNOP_POSTDEC || op == ExprUnary.UNOP_PREDEC) {
return ExprConstInt.minusone;
}
}
}
if (incr instanceof StmtAssign) {
StmtAssign sa = (StmtAssign) incr;
if (sa.getOp() == 0) {
if (sa.getRHS() instanceof ExprBinary) {
ExprBinary eb = (ExprBinary) sa.getRHS();
if (eb.getLeft().equals(sa.getLHS())) {
return eb.getRight();
}
if (eb.getRight().equals(sa.getLHS())) {
return eb.getLeft();
}
}
}
if (sa.getOp() == ExprBinary.BINOP_ADD) {
return sa.getRHS();
}
if (sa.getOp() == ExprBinary.BINOP_SUB) {
return new ExprUnary("-", sa.getRHS());
}
}
return null;
}
