Method ResolveRoot

Source/cmPathResolver.cxx:268–313

template <class Policy>
Control Impl<Policy>::ResolveRoot(Root root)
{
  if (root == Root::None) {
    return this->ResolveRelativePath();
  }

  // POSIX absolute paths always start with a '/'.
  std::string::size_type root_slash = 0;

#ifdef _WIN32
  if (root == Root::Drive) {
    if (P.size() == 2 || P[2] != '/') {
      return this->ResolveRootRelative();
    }

    if (Policy::ActualCase == Options::ActualCase::Yes) {
      // Normalize the drive letter to upper-case.
      P[0] = static_cast<char>(cmsysString_toupper(P[0]));
    }

    // The root is a drive letter.  The root '/' immediately follows.
    root_slash = 2;
  } else if (root == Root::Network) {
    // The root is a network name.  Find the root '/' after it.
    root_slash = P.find('/', 2);
    if (root_slash == std::string::npos) {
      root_slash = P.size();
      P.push_back('/');
    }
  }
#endif

  if (Policy::Existence == Options::Existence::Required
#ifdef _WIN32
      && root != Root::Network
#endif
  ) {
    std::string path = P.substr(0, root_slash + 1);
    if (!this->OS.PathExists(path)) {
      P = std::move(path);
      return Control::Error(cmsys::Status::POSIX(ENOENT));
    }
  }

  return Control::Continue(root_slash);
}

template <class Policy>
Control Impl<Policy>::ResolveComponent(Root root,