Function format

rocclr/device/devhcprintf.cpp:168–228

\brief Process a printf message using the system printf function. * \param begin Start of the uint64_t array containing the message. * \param end One past the last element in the array. * \return An integer that satisfies the POSIX return value for printf. * * The message has the following format: * - uint64_t version, required to be zero. * - Format string padded to an 8 byte boundary.

 * - %n specifier is ignored and the corresponding argument is skipped.
 */
static int format(FILE* stream, const uint64_t* begin, const uint64_t* end) {
  const char convSpecifiers[] = "diouxXfFeEgGaAcspn";
  auto ptr = begin;

  const std::string fmt(reinterpret_cast<const char*>(ptr));
  ptr += (fmt.length() + 7 + 1) / 8;  // the extra '1' is for the null

  int outCount = 0;
  size_t point = 0;
  while (true) {
    // Each segment of the format string delineated by [mark,
    // point) is handled seprately.
    auto mark = point;
    point = fmt.find('%', point);

    // Two different cases where a literal segment is printed out.
    // 1. When the point reaches the end of the format string.
    // 2. When the point is at the start of a format specifier.
    if (point == std::string::npos) {
      checkPrintf(stream, &outCount, "%s", &fmt[mark]);
      return outCount;
    }
    checkPrintf(stream, &outCount, "%.*s", (int)(point - mark), &fmt[mark]);
    if (outCount < 0) {
      return outCount;
    }

    mark = point;
    ++point;

    // Handle the simplest specifier, '%%'.
    if (fmt[point] == '%') {
      checkPrintf(stream, &outCount, "%%");
      if (outCount < 0) {
        return outCount;
      }
      ++point;
      continue;
    }

    // Before processing the specifier, check if we have run out
    // of arguments.
    if (ptr == end) {
      return outCount;
    }

    // Undefined behaviour if we don't see a conversion specifier.
    point = fmt.find_first_of(convSpecifiers, point);
    if (point == std::string::npos) {
      return outCount;
    }
    ++point;

    // [mark,point) now contains a complete specifier.
    const std::string spec(fmt, mark, point - mark);
    ptr = processSpec(stream, &outCount, spec, ptr, end);
    if (outCount < 0) {
      return outCount;