gecko-dev/widget/nsCUPSShim.cpp

62 строки
2.0 KiB
C++

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ex: set tabstop=8 softtabstop=4 shiftwidth=4 expandtab: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsDebug.h"
#include "nsString.h"
#include "nsCUPSShim.h"
#include "mozilla/ArrayUtils.h"
#include "prlink.h"
#ifdef XP_MACOSX
// TODO: On OS X we are guaranteed to have CUPS, so it would be nice to just
// assign the members from the header directly instead of dlopen'ing.
// Alternatively, we could just do some #define's on OS X, but we don't use
// CUPS all that much, so there really isn't too much overhead in storing this
// table of functions even on OS X.
static const char gCUPSLibraryName[] = "libcups.2.dylib";
#else
static const char gCUPSLibraryName[] = "libcups.so.2";
#endif
template <typename FuncT>
static bool LoadCupsFunc(PRLibrary*& lib, FuncT*& dest,
const char* const name) {
dest = (FuncT*)PR_FindSymbol(lib, name);
if (MOZ_UNLIKELY(!dest)) {
#ifdef DEBUG
nsAutoCString msg(name);
msg.AppendLiteral(" not found in CUPS library");
NS_WARNING(msg.get());
#endif
#ifndef MOZ_TSAN
// With TSan, we cannot unload libcups once we have loaded it because
// TSan does not support unloading libraries that are matched from its
// suppression list. Hence we just keep the library loaded in TSan builds.
PR_UnloadLibrary(lib);
#endif
lib = nullptr;
return false;
}
return true;
}
bool nsCUPSShim::Init() {
MOZ_ASSERT(!mInited);
mCupsLib = PR_LoadLibrary(gCUPSLibraryName);
if (!mCupsLib) {
return false;
}
// This is a macro so that it could also load from libcups if we are configured
// to use it as a compile-time dependency.
#define CUPS_SHIM_LOAD(NAME) \
if (!LoadCupsFunc(mCupsLib, NAME, #NAME)) return false;
CUPS_SHIM_ALL_FUNCS(CUPS_SHIM_LOAD)
#undef CUPS_SHIM_LOAD
mInited = true;
return true;
}