Method chooseRandomConcreteSignature

bolt/expression/fuzzer/ExpressionFuzzer.cpp:1155–1183

}

const CallableSignature* ExpressionFuzzer::chooseRandomConcreteSignature(
    const TypePtr& returnType,
    const std::string& functionName) {
  if (expressionToSignature_.find(functionName) ==
      expressionToSignature_.end()) {
    return nullptr;
  }
  auto baseType = typeToBaseName(returnType);
  auto itr = expressionToSignature_[functionName].find(baseType);
  if (itr == expressionToSignature_[functionName].end()) {
    return nullptr;
  }
  // Only function signatures whose return type equals to returnType are
  // eligible. There may be ineligible signatures in signaturesMap_ because
  // the map keys only differentiate top-level type kinds.
  std::vector<const CallableSignature*> eligible;
  for (auto signature : itr->second) {
    if (signature->returnType->equivalent(*returnType)) {
      eligible.push_back(signature);
    }
  }
  if (eligible.empty()) {
    return nullptr;
  }

  // Randomly pick a function that can return `returnType`.
  size_t idx = rand32(0, eligible.size() - 1);
  return eligible[idx];
}

const CallableSignature* ExpressionFuzzer::findConcreteSignature(
    const std::vector<TypePtr>& argTypes,