Method FileCreateDir

source/script2.cpp:7961–8012

As of 2019-09-29, noinline reduces code size by over 20KB on VC++ 2019. Prior to merging Util_CreateDir with this, it wasn't inlined.

// As of 2019-09-29, noinline reduces code size by over 20KB on VC++ 2019.
// Prior to merging Util_CreateDir with this, it wasn't inlined.
DECLSPEC_NOINLINE
bool Line::FileCreateDir(LPTSTR aDirSpec, LPTSTR aCanModifyDirSpec)
{
	if (!aDirSpec || !*aDirSpec)
	{
		SetLastError(ERROR_INVALID_PARAMETER);
		return false;
	}

	DWORD attr = GetFileAttributes(aDirSpec);
	if (attr != 0xFFFFFFFF)  // aDirSpec already exists.
	{
		SetLastError(ERROR_ALREADY_EXISTS);
		return (attr & FILE_ATTRIBUTE_DIRECTORY) != 0; // Indicate success if it already exists as a dir.
	}

	// If it has a backslash, make sure all its parent directories exist before we attempt
	// to create this directory:
	LPTSTR last_backslash = _tcsrchr(aDirSpec, '\\');
	if (last_backslash > aDirSpec // v1.0.48.04: Changed "last_backslash" to "last_backslash > aDirSpec" so that an aDirSpec with a leading \ (but no other backslashes), such as \dir, is supported.
		&& last_backslash[-1] != ':') // v1.1.31.00: Don't attempt FileCreateDir("C:") since that's equivalent to either "C:\" or the working directory (which already exists), or FileCreateDir("\\?\C:") since it always fails.
	{
		LPTSTR parent_dir;
		if (aCanModifyDirSpec)
		{
			parent_dir = aDirSpec; // Caller provided a modifiable aDirSpec.
			*last_backslash = '\0'; // Temporarily terminate for parent directory.
		}
		else
		{
			// v1.1.31.00: Allocate a modifiable buffer to be used by all calls (supports long paths).
			parent_dir = (LPTSTR)_alloca((last_backslash - aDirSpec + 1) * sizeof(TCHAR));
			tcslcpy(parent_dir, aDirSpec, last_backslash - aDirSpec + 1); // Omits the last backslash.
		}
		bool exists = FileCreateDir(parent_dir, parent_dir); // Recursively create all needed ancestor directories.
		if (aCanModifyDirSpec)
			*last_backslash = '\\'; // Undo temporary termination.

		// v1.0.44: Fixed ErrorLevel being set to 1 when the specified directory ends in a backslash.  In such cases,
		// two calls were made to CreateDirectory for the same folder: the first without the backslash and then with
		// it.  Since the directory already existed on the second call, ErrorLevel was wrongly set to 1 even though
		// everything succeeded.  So now, when recursion finishes creating all the ancestors of this directory
		// our own layer here does not call CreateDirectory() when there's a trailing backslash because a previous
		// layer already did:
		if (!last_backslash[1] || !exists)
			return exists;
	}

	// The above has recursively created all parent directories of aDirSpec if needed.
	// Now we can create aDirSpec.
	return CreateDirectory(aDirSpec, NULL);
}