Function HandleExprCommand

Source/cmMathCommand.cxx:36–119

namespace {
bool HandleExprCommand(std::vector<std::string> const& args,
                       cmExecutionStatus& status)
{
  if ((args.size() != 3) && (args.size() != 5)) {
    status.SetError("EXPR called with incorrect arguments.");
    return false;
  }

  enum class NumericFormat
  {
    UNINITIALIZED,
    DECIMAL,
    HEXADECIMAL,
  };

  std::string const& outputVariable = args[1];
  std::string const& expression = args[2];
  size_t argumentIndex = 3;
  NumericFormat outputFormat = NumericFormat::UNINITIALIZED;

  status.GetMakefile().AddDefinition(outputVariable, "ERROR");

  if (argumentIndex < args.size()) {
    std::string const messageHint = "sub-command EXPR ";
    std::string const& option = args[argumentIndex++];
    if (option == "OUTPUT_FORMAT") {
      if (argumentIndex < args.size()) {
        std::string const& argument = args[argumentIndex++];
        if (argument == "DECIMAL") {
          outputFormat = NumericFormat::DECIMAL;
        } else if (argument == "HEXADECIMAL") {
          outputFormat = NumericFormat::HEXADECIMAL;
        } else {
          std::string error = messageHint + "value \"" + argument +
            "\" for option \"" + option + "\" is invalid.";
          status.SetError(error);
          return false;
        }
      } else {
        std::string error =
          messageHint + "missing argument for option \"" + option + "\".";
        status.SetError(error);
        return false;
      }
    } else {
      std::string error =
        messageHint + "option \"" + option + "\" is unknown.";
      status.SetError(error);
      return false;
    }
  }

  if (outputFormat == NumericFormat::UNINITIALIZED) {
    outputFormat = NumericFormat::DECIMAL;
  }

  cmExprParserHelper helper;
  if (!helper.ParseString(expression.c_str(), 0)) {