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forked from 0ad/0ad
0ad/source/ps/DllLoader.h
leper 53ea269af0 Add the ability to specify a log level when using dlopen and change it to normal for Atlas.
This way we do not have two error messages when starting Atlas, but the
dynamic Atlas lib is not available.
Patch by Gallaecio. Fixes #1540.

This was SVN commit r15301.
2014-06-05 17:07:04 +00:00

98 lines
2.9 KiB
C++

/* Copyright (C) 2014 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef INCLUDED_DLLLOADER
#define INCLUDED_DLLLOADER
#include "ps/Errors.h"
#include "ps/CLogger.h"
ERROR_GROUP(DllLoader);
ERROR_TYPE(DllLoader, DllNotLoaded);
ERROR_TYPE(DllLoader, SymbolNotFound);
class DllLoader
{
public:
/**
* Prepare the DLL loader. Does no actual work.
*
* @param name base name of the library (from which we'll derive
* "name.dll", "libname_dbg.so", etc). Pointer must remain valid for
* this object's lifetime (which is fine if you just use a string literal).
* @param loadErrorLogMethod Allows to set the CLogger log level that is
* used when the DllLoader reports loading errors.
*/
DllLoader(const char* name, CLogger::ELogMethod loadErrorLogMethod = CLogger::Error);
~DllLoader();
/**
* Attempt to load and initialise the library, if not already. Can be harmlessly
* called multiple times. Returns false if unsuccessful.
*/
bool LoadDLL();
/**
* Check whether the library has been loaded successfully. Returns false
* before {@link #LoadDLL} has been called; otherwise returns the same as
* LoadDLL did.
*/
bool IsLoaded() const;
/**
* Unload the library, if it has been loaded already. (Usually not needed,
* since the destructor will unload it.)
*/
void Unload();
/**
* Attempt to load a named symbol from the library. If {@link #IsLoaded} is
* false, throws PSERROR_DllLoader_DllNotLoaded. If it cannot load the
* symbol, throws PSERROR_DllLoader_SymbolNotFound. In both cases, sets fptr
* to NULL. Otherwise, fptr is set to point to the loaded function.
*
* @throws PSERROR_DllLoader
*/
template <typename T>
void LoadSymbol(const char* name, T& fptr) const;
/**
* Override the build-time setting of the directory to search for libraries.
*/
static void OverrideLibdir(const char* libdir);
private:
// Typeless version - the public LoadSymbol hides the slightly ugly
// casting from users.
void LoadSymbolInternal(const char* name, void** fptr) const;
void LogLoadError(const char* errors);
const char* m_Name;
void* m_Handle;
CLogger::ELogMethod m_LoadErrorLogMethod;
};
template <typename T>
void DllLoader::LoadSymbol(const char* name, T& fptr) const
{
LoadSymbolInternal(name, (void**)&fptr);
}
#endif // INCLUDED_DLLLOADER