windows-nt/Source/XPSP1/NT/shell/ext/msident/dllload.cpp
2020-09-26 16:20:57 +08:00

168 lines
6.6 KiB
C++

//----------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1997
//
// File:
//
// Contents:
//
// Classes:
//
// Functions:
//
// History:
//
//----------------------------------------------------------------------------
#include "private.h"
#include <winsock.h>
#pragma warning(disable:4229) // No warnings when modifiers used on data
//----------------------------------------------------------------------------
// Delay loading mechanism. [Stolen from shdocvw.]
//
// This allows you to write code as if you are
// calling implicitly linked APIs, and yet have these APIs really be
// explicitly linked. You can reduce the initial number of DLLs that
// are loaded (load on demand) using this technique.
//
// Use the following macros to indicate which APIs/DLLs are delay-linked
// and -loaded.
//
// DELAY_LOAD
// DELAY_LOAD_HRESULT
// DELAY_LOAD_SAFEARRAY
// DELAY_LOAD_UINT
// DELAY_LOAD_INT
// DELAY_LOAD_VOID
//
// Use these macros for APIs that are exported by ordinal only.
//
// DELAY_LOAD_ORD
// DELAY_LOAD_ORD_VOID
//
// Use these macros for APIs that only exist on the integrated-shell
// installations (i.e., a new shell32 is on the system).
//
// DELAY_LOAD_SHELL
// DELAY_LOAD_SHELL_HRESULT
// DELAY_LOAD_SHELL_VOID
//
//----------------------------------------------------------------------------
#define ENSURE_LOADED(_hinst, _dll, pszfn) (_hinst ? TRUE : NULL!=(_hinst = LoadLibrary(TEXT(#_dll))))
#define DELAY_LOAD_ERR(_hinst, _dll, _ret, _fn, _args, _nargs, _err) \
static _ret (* __stdcall _pfn##_fn) _args = NULL; \
_ret __stdcall _fn _args \
{ \
if (!ENSURE_LOADED(_hinst, _dll, #_fn)) \
{ \
ASSERT_MSGA(_hinst!=NULL, "LoadLibrary failed on " ## #_dll); \
return (_ret)_err; \
} \
if (_pfn##_fn == NULL) \
{ \
*(FARPROC*)&(_pfn##_fn) = GetProcAddress(_hinst, #_fn); \
ASSERT_MSGA(_pfn##_fn!=NULL, "GetProcAddress failed on " ## #_fn); \
if (_pfn##_fn == NULL) \
return (_ret)_err; \
} \
return _pfn##_fn _nargs; \
}
#define DELAY_LOAD_VOID(_hinst, _dll, _fn, _args, _nargs) \
void __stdcall _fn _args \
{ \
static void (* __stdcall _pfn##_fn) _args = NULL; \
if (!ENSURE_LOADED(_hinst, _dll, #_fn)) \
{ \
AssertMsg(_hinst!=NULL, "LoadLibrary failed on " ## #_dll); \
return; \
} \
if (_pfn##_fn == NULL) \
{ \
*(FARPROC*)&(_pfn##_fn) = GetProcAddress(_hinst, #_fn); \
ASSERT_MSGA(_pfn##_fn!=NULL, "GetProcAddress failed on " ## #_fn); \
if (_pfn##_fn == NULL) \
return; \
} \
_pfn##_fn _nargs; \
}
#define DELAY_LOAD(_hinst, _dll, _ret, _fn, _args, _nargs) DELAY_LOAD_ERR(_hinst, _dll, _ret, _fn, _args, _nargs, 0)
#define DELAY_LOAD_HRESULT(_hinst, _dll, _fn, _args, _nargs) DELAY_LOAD_ERR(_hinst, _dll, HRESULT, _fn, _args, _nargs, E_FAIL)
#define DELAY_LOAD_SAFEARRAY(_hinst, _dll, _fn, _args, _nargs) DELAY_LOAD_ERR(_hinst, _dll, SAFEARRAY *, _fn, _args, _nargs, NULL)
#define DELAY_LOAD_DWORD(_hinst, _dll, _fn, _args, _nargs) DELAY_LOAD_ERR(_hinst, _dll, DWORD, _fn, _args, _nargs, 0)
#define DELAY_LOAD_UINT(_hinst, _dll, _fn, _args, _nargs) DELAY_LOAD_ERR(_hinst, _dll, UINT, _fn, _args, _nargs, 0)
#define DELAY_LOAD_INT(_hinst, _dll, _fn, _args, _nargs) DELAY_LOAD_ERR(_hinst, _dll, INT, _fn, _args, _nargs, 0)
#define DELAY_LOAD_ORD_ERR(_hinst, _dll, _ret, _fn, _ord, _args, _nargs, _err) \
_ret __stdcall _fn _args \
{ \
static _ret (* __stdcall _pfn##_fn) _args = NULL; \
if (!ENSURE_LOADED(_hinst, _dll, "(ordinal " ## #_ord ## ")")) \
{ \
TraceMsg(TF_ERROR, "LoadLibrary failed on " ## #_dll); \
return (_ret)_err; \
} \
if (_pfn##_fn == NULL) \
{ \
*(FARPROC*)&(_pfn##_fn) = GetProcAddress(_hinst, (LPSTR) _ord); \
\
/* GetProcAddress always returns non-NULL, even for bad ordinals. \
But do the check anyways... */ \
\
if (_pfn##_fn == NULL) \
return (_ret)_err; \
} \
return _pfn##_fn _nargs; \
}
#define DELAY_LOAD_ORD_VOID(_hinst, _dll, _fn, _ord, _args, _nargs) \
void __stdcall _fn _args \
{ \
static void (* __stdcall _pfn##_fn) _args = NULL; \
if (!ENSURE_LOADED(_hinst, _dll, "(ordinal " ## #_ord ## ")")) \
{ \
TraceMsg(TF_ERROR, "LoadLibrary failed on " ## #_dll); \
return; \
} \
if (_pfn##_fn == NULL) \
{ \
*(FARPROC*)&(_pfn##_fn) = GetProcAddress(_hinst, (LPSTR) _ord); \
\
/* GetProcAddress always returns non-NULL, even for bad ordinals. \
But do the check anyways... */ \
\
if (_pfn##_fn == NULL) \
return; \
} \
_pfn##_fn _nargs; \
}
#define DELAY_LOAD_ORD(_hinst, _dll, _ret, _fn, _ord, _args, _nargs) DELAY_LOAD_ORD_ERR(_hinst, _dll, _ret, _fn, _ord, _args, _nargs, 0)
//
// And now the DLLs which are delay loaded
//
// --------- PSTOREC.DLL ---------------
HINSTANCE g_hinstPSTOREC = NULL;
DELAY_LOAD_ERR(g_hinstPSTOREC, PSTOREC.DLL, HRESULT, PStoreCreateInstance,
(IPStore ** ppProvider, PST_PROVIDERID *pProviderID, void *pReserved, DWORD dwFlags),
(ppProvider, pProviderID, pReserved, dwFlags),
E_FAIL);
void UnloadPStore()
{
if (g_hinstPSTOREC)
FreeLibrary(g_hinstPSTOREC);
g_hinstPSTOREC = NULL;
}
#pragma warning(default:4229)