widget/gtk/nsCUPSShim.cpp

   1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ex: set tabstop=8 softtabstop=4 shiftwidth=4 expandtab: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsDebug.h"
   8 #include "nsString.h"
   9 #include "nsCUPSShim.h"
  10 #include "mozilla/ArrayUtils.h"
  11 #include "prlink.h"
  12
  13
  14 // List of symbols to find in libcups. Must match symAddr[] defined in Init().
  15 // Making this an array of arrays instead of pointers allows storing the
  16 // whole thing in read-only memory.
  17 static const char gSymName[][sizeof("cupsPrintFile")] = {
  18     { "cupsAddOption" },
  19     { "cupsFreeDests" },
  20     { "cupsGetDest" },
  21     { "cupsGetDests" },
  22     { "cupsPrintFile" },
  23     { "cupsTempFd" },
  24 };
  25 static const int gSymNameCt = mozilla::ArrayLength(gSymName);
  26
  27
  28 bool
  29 nsCUPSShim::Init()
  30 {
  31     mCupsLib = PR_LoadLibrary("libcups.so.2");
  32     if (!mCupsLib)
  33         return false;
  34
  35     // List of symbol pointers. Must match gSymName[] defined above.
  36     void **symAddr[] = {
  37         (void **)&mCupsAddOption,
  38         (void **)&mCupsFreeDests,
  39         (void **)&mCupsGetDest,
  40         (void **)&mCupsGetDests,
  41         (void **)&mCupsPrintFile,
  42         (void **)&mCupsTempFd,
  43     };
  44
  45     for (int i = gSymNameCt; i--; ) {
  46         *(symAddr[i]) = PR_FindSymbol(mCupsLib, gSymName[i]);
  47         if (! *(symAddr[i])) {
  48 #ifdef DEBUG
  49             nsAutoCString msg(gSymName[i]);
  50             msg.AppendLiteral(" not found in CUPS library");
  51             NS_WARNING(msg.get());
  52 #endif
  53             PR_UnloadLibrary(mCupsLib);
  54             mCupsLib = nullptr;
  55             return false;
  56         }
  57     }
  58     return true;
  59 }