/CLRSUPPORTLASTERROR (Preserve Last Error Code for PInvoke Calls)

/CLRSUPPORTLASTERROR, which is on by default, preserves the last error code of functions called through the P/Invoke mechanism, which allows you to call native functions in DLLS, from code compiled with /clr.

Syntax

/CLRSUPPORTLASTERROR{:NO | SYSTEMDLL}

Remarks

Preserving the last error code implies a decrease in performance. If you do not want to incur the performance impact of preserving the last error code, link with /CLRSUPPORTLASTERROR:NO.

You can minimize the performance impact by linking with /CLRSUPPORTLASTERROR:SYSTEMDLL, which only preserves the last error code for functions in system DLLs. A system DLL is defined as one of the following:

ACLUI.DLL ACTIVEDS.DLL ADPTIF.DLL ADVAPI32.DLL
ASYCFILT.DLL AUTHZ.DLL AVICAP32.DLL AVIFIL32.DLL
CABINET.DLL CLUSAPI.DLL COMCTL32.DLL COMDLG32.DLL
COMSVCS.DLL CREDUI.DLL CRYPT32.DLL CRYPTNET.DLL
CRYPTUI.DLL D3D8THK.DLL DBGENG.DLL DBGHELP.DLL
DCIMAN32.DLL DNSAPI.DLL DSPROP.DLL DSUIEXT.DLL
GDI32.DLL GLU32.DLL HLINK.DLL ICM32.DLL
IMAGEHLP.DLL IMM32.DLL IPHLPAPI.DLL IPROP.DLL
KERNEL32.DLL KSUSER.DLL LOADPERF.DLL LZ32.DLL
MAPI32.DLL MGMTAPI.DLL MOBSYNC.DLL MPR.DLL
MPRAPI.DLL MQRT.DLL MSACM32.DLL MSCMS.DLL
MSI.DLL MSIMG32.DLL MSRATING.DLL MSTASK.DLL
MSVFW32.DLL MSWSOCK.DLL MTXEX.DLL NDDEAPI.DLL
NETAPI32.DLL NPPTOOLS.DLL NTDSAPI.DLL NTDSBCLI.DLL
NTMSAPI.DLL ODBC32.DLL ODBCBCP.DLL OLE32.DLL
OLEACC.DLL OLEAUT32.DLL OLEDLG.DLL OPENGL32.DLL
PDH.DLL POWRPROF.DLL QOSNAME.DLL QUERY.DLL
RASAPI32.DLL RASDLG.DLL RASSAPI.DLL RESUTILS.DLL
RICHED20.DLL RPCNS4.DLL RPCRT4.DLL RTM.DLL
RTUTILS.DLL SCARDDLG.DLL SECUR32.DLL SENSAPI.DLL
SETUPAPI.DLL SFC.DLL SHELL32.DLL SHFOLDER.DLL
SHLWAPI.DLL SISBKUP.DLL SNMPAPI.DLL SRCLIENT.DLL
STI.DLL TAPI32.DLL TRAFFIC.DLL URL.DLL
URLMON.DLL USER32.DLL USERENV.DLL USP10.DLL
UXTHEME.DLL VDMDBG.DLL VERSION.DLL WINFAX.DLL
WINHTTP.DLL WININET.DLL WINMM.DLL WINSCARD.DLL
WINTRUST.DLL WLDAP32.DLL WOW32.DLL WS2_32.DLL
WSNMP32.DLL WSOCK32.DLL WTSAPI32.DLL XOLEHLP.DLL

Note

Preserving the last error is not supported for unmanaged functions that are consumed by CLR code, in the same module.

To set this linker option in the Visual Studio development environment

  1. Open the project's Property Pages dialog box. For details, see Set C++ compiler and build properties in Visual Studio.

  2. Click the Linker folder.

  3. Click the Command Line property page.

  4. Type the option into the Additional Options box.

To set this linker option programmatically

Example

The following sample defines a native DLL with one exported function that modifies last error.

// CLRSUPPORTLASTERROR_dll.cpp
// compile with: /LD
#include <windows.h>
#include <math.h>

#pragma unmanaged
__declspec(dllexport) double MySqrt(__int64 n) {
   SetLastError(DWORD(-1));
   return sqrt(double(n));
}

Example

The following sample consumes the DLL, demonstrating how to use /CLRSUPPORTLASTERROR.

// CLRSUPPORTLASTERROR_client.cpp
// compile with: /clr CLRSUPPORTLASTERROR_dll.lib /link /clrsupportlasterror:systemdll
// processor: x86
#include <windows.h>
#include <wininet.h>
#include <stdio.h>
#include <math.h>

#pragma comment(lib, "wininet.lib")

double MySqrt(__int64 n);

#pragma managed
int main() {
   double   d = 0.0;
   __int64 n = 65;
   HANDLE  hGroup = NULL;
   GROUPID groupID;
   DWORD   dwSet = 127, dwGet = 37;

   SetLastError(dwSet);
   d = MySqrt(n);
   dwGet = GetLastError();

   if (dwGet == DWORD(-1))
      printf_s("GetLastError for application call succeeded (%d).\n",
             dwGet);
   else
      printf_s("GetLastError for application call failed (%d).\n",
             dwGet);

   hGroup = FindFirstUrlCacheGroup(0, CACHEGROUP_SEARCH_ALL,
                           0, 0, &groupID, 0);
   dwGet = GetLastError();
   if (dwGet == 183)
      printf_s("GetLastError for system call succeeded (%d).\n",
             dwGet);
   else
      printf_s("GetLastError for system call failed (%d).\n",
             dwGet);
}
GetLastError for application call failed (127).
GetLastError for system call succeeded (183).

See also

MSVC linker reference
MSVC Linker Options