tools/source/misc/pathutils.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <sal/config.h>
  21
  22 #if defined(_WIN32)
  23
  24 #define WIN32_LEAN_AND_MEAN
  25 #include <windows.h>
  26
  27 #include <o3tl/safeint.hxx>
  28 #include <sal/types.h>
  29 #include <tools/pathutils.hxx>
  30
  31 namespace tools {
  32
  33 WCHAR * filename(WCHAR * path) {
  34     WCHAR * f = path;
  35     for (WCHAR * p = path;;) {
  36         switch (*p++) {
  37         case L'\0':
  38             return f;
  39         case L'\\':
  40             f = p;
  41             break;
  42         }
  43     }
  44 }
  45
  46 WCHAR * buildPath(
  47     WCHAR * path, WCHAR const * frontBegin, WCHAR const * frontEnd,
  48     WCHAR const * backBegin, std::size_t backLength)
  49 {
  50     // Remove leading ".." segments in the second path together with matching
  51     // segments in the first path that are neither empty nor "." nor ".." nor
  52     // end in ":" (which is not foolproof, as it can erroneously erase the start
  53     // of a UNC path, but only if the input is bad data):
  54     while (backLength >= 2 && backBegin[0] == L'.' && backBegin[1] == L'.' &&
  55            (backLength == 2 || backBegin[2] == L'\\'))
  56     {
  57         if (frontEnd - frontBegin < 2 || frontEnd[-1] != L'\\' ||
  58             frontEnd[-2] == L'\\' || frontEnd[-2] == L':' ||
  59             (frontEnd[-2] == L'.' &&
  60              (frontEnd - frontBegin < 3 || frontEnd[-3] == L'\\' ||
  61               (frontEnd[-3] == L'.' &&
  62                (frontEnd - frontBegin < 4 || frontEnd[-4] == L'\\')))))
  63         {
  64             break;
  65         }
  66         WCHAR const * p = frontEnd - 1;
  67         while (p != frontBegin && p[-1] != L'\\') {
  68             --p;
  69         }
  70         if (p == frontBegin) {
  71             break;
  72         }
  73         frontEnd = p;
  74         if (backLength == 2) {
  75             backBegin += 2;
  76             backLength -= 2;
  77         } else {
  78             backBegin += 3;
  79             backLength -= 3;
  80         }
  81     }
  82     if (backLength <
  83         o3tl::make_unsigned(MAX_PATH - (frontEnd - frontBegin)))
  84     {
  85         WCHAR * p;
  86         if (frontBegin == path) {
  87             p = const_cast< WCHAR * >(frontEnd);
  88         } else {
  89             p = path;
  90             while (frontBegin != frontEnd) {
  91                 *p++ = *frontBegin++;
  92             }
  93         }
  94         for (; backLength > 0; --backLength) {
  95             *p++ = *backBegin++;
  96         }
  97         *p = L'\0';
  98         return p;
  99     } else {
 100         SetLastError(ERROR_FILENAME_EXCED_RANGE);
 101         return nullptr;
 102     }
 103 }
 104
 105 }
 106
 107 #endif
 108
 109 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */