private static void markBranchReachable(
ConditionalGotoInstruction instruction, boolean isTrueBranch) {
if (isTrueBranch ^ instruction.isNegated()) {
instruction.setTrueReachable();
} else {
instruction.setFalseReachable();
}
}
public DfaInstructionState[] visitConditionalGoto(
ConditionalGotoInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
DfaValue cond = memState.pop();
DfaValue condTrue;
DfaValue condFalse;
if (instruction.isNegated()) {
condFalse = cond;
condTrue = cond.createNegated();
} else {
condTrue = cond;
condFalse = cond.createNegated();
}
if (condTrue == runner.getFactory().getConstFactory().getTrue()) {
markBranchReachable(instruction, true);
return new DfaInstructionState[] {
new DfaInstructionState(runner.getInstruction(instruction.getOffset()), memState)
};
}
if (condFalse == runner.getFactory().getConstFactory().getTrue()) {
markBranchReachable(instruction, false);
return nextInstruction(instruction, runner, memState);
}
ArrayList<DfaInstructionState> result = new ArrayList<DfaInstructionState>();
DfaMemoryState thenState = memState.createCopy();
DfaMemoryState elseState = memState.createCopy();
if (thenState.applyCondition(condTrue)) {
result.add(
new DfaInstructionState(runner.getInstruction(instruction.getOffset()), thenState));
markBranchReachable(instruction, true);
}
if (elseState.applyCondition(condFalse)) {
result.add(
new DfaInstructionState(runner.getInstruction(instruction.getIndex() + 1), elseState));
markBranchReachable(instruction, false);
}
return result.toArray(new DfaInstructionState[result.size()]);
}