windows-nt/Source/XPSP1/NT/shell/ext/mlang/dllload.cpp

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2020-09-26 03:20:57 -05:00
//----------------------------------------------------------------------------
//
// 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 ? _hinst : (_hinst = LoadLibrary(#_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)) \
{ \
AssertMsg(_hinst != NULL, "LoadLibrary failed on " ## #_dll); \
return (_ret)_err; \
} \
if (_pfn##_fn == NULL) \
{ \
*(FARPROC*)&(_pfn##_fn) = GetProcAddress(_hinst, #_fn); \
AssertMsg(_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); \
AssertMsg(_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
//
// --------- OLEAUT32.DLL ---------------
HINSTANCE g_hinstOLEAUT32 = NULL;
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, RegisterTypeLib,
(ITypeLib *ptlib, OLECHAR *szFullPath, OLECHAR *szHelpDir), (ptlib, szFullPath, szHelpDir));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, LoadTypeLib,
(const OLECHAR *szFile, ITypeLib **pptlib), (szFile, pptlib));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, CreateErrorInfo,
(ICreateErrorInfo **pperrinfo), (pperrinfo));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, SetErrorInfo,
(unsigned long dwReserved, IErrorInfo*perrinfo), (dwReserved, perrinfo));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, LoadRegTypeLib,
(REFGUID rguid, WORD wVerMajor, WORD wVerMinor, LCID lcid, ITypeLib **pptlib),
(rguid, wVerMajor, wVerMinor, lcid, pptlib));
DELAY_LOAD(g_hinstOLEAUT32, OLEAUT32.DLL, BSTR, SysAllocString, (const OLECHAR*pch), (pch));
DELAY_LOAD(g_hinstOLEAUT32, OLEAUT32.DLL, BSTR, SysAllocStringLen,
(const OLECHAR*pch, unsigned int i), (pch, i));
DELAY_LOAD(g_hinstOLEAUT32, OLEAUT32.DLL, BSTR, SysAllocStringByteLen,
(LPCSTR psz, UINT i), (psz, i));
DELAY_LOAD_UINT(g_hinstOLEAUT32, OLEAUT32.DLL, SysStringLen, (BSTR bstr), (bstr));
DELAY_LOAD_UINT(g_hinstOLEAUT32, OLEAUT32.DLL, SysStringByteLen, (BSTR bstr), (bstr));
DELAY_LOAD_VOID(g_hinstOLEAUT32, OLEAUT32.DLL, SysFreeString, (BSTR bs), (bs));
DELAY_LOAD_VOID(g_hinstOLEAUT32, OLEAUT32.DLL, VariantInit, (VARIANTARG *pvarg), (pvarg));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, VariantCopy,
(VARIANTARG *pvargDest, VARIANTARG *pvargSrc), (pvargDest, pvargSrc));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, VariantChangeType,
(VARIANTARG *pvargDest, VARIANTARG *pvargSrc, unsigned short wFlags, VARTYPE vt),
(pvargDest, pvargSrc, wFlags, vt));
DELAY_LOAD_HRESULT(g_hinstOLEAUT32, OLEAUT32.DLL, VariantClear, (VARIANTARG *pvarg), (pvarg));
#pragma warning(default:4229)