NullnessHint analyzeReturnType()

in jar-infer/jar-infer-lib/src/main/java/com/uber/nullaway/jarinfer/DefinitelyDerefedParams.java [239:269]

29 lines of code
11 McCabe index (conditional complexity)


  NullnessHint analyzeReturnType() {
    if (method.getReturnType().isPrimitiveType()) {
      LOG(DEBUG, "DEBUG", "Skipping method with primitive return type: " + method.getSignature());
      return NullnessHint.UNKNOWN;
    }
    LOG(DEBUG, "DEBUG", "@ Return type analysis for: " + method.getSignature());
    // Get ExceptionPrunedCFG
    if (prunedCFG == null) {
      prunedCFG = ExceptionPrunedCFG.make(cfg);
    }
    // In case the only control flows are exceptional, simply return.
    if (prunedCFG.getNumberOfNodes() == 2
        && prunedCFG.containsNode(cfg.entry())
        && prunedCFG.containsNode(cfg.exit())
        && GraphUtil.countEdges(prunedCFG) == 0) {
      return NullnessHint.UNKNOWN;
    }
    for (ISSABasicBlock bb : prunedCFG.getNormalPredecessors(prunedCFG.exit())) {
      for (int i = bb.getFirstInstructionIndex(); i <= bb.getLastInstructionIndex(); i++) {
        SSAInstruction instr = ir.getInstructions()[i];
        if (instr instanceof SSAReturnInstruction) {
          SSAReturnInstruction retInstr = (SSAReturnInstruction) instr;
          if (ir.getSymbolTable().isNullConstant(retInstr.getResult())) {
            LOG(DEBUG, "DEBUG", "Nullable return in method: " + method.getSignature());
            return NullnessHint.NULLABLE;
          }
        }
      }
    }
    return NullnessHint.UNKNOWN;
  }