DLL exporting function names - aliases

[FrankieH]

Hi,

my problem is, that I have to compile a few programs with VS2005 and other programs with Watcom (OpenWatcom to be exact). A lot of DLLs, most of them with stdcall calling convention.

Watcom is exporting all functions twice, as the dependency walker shows:

Function               EntryPoint
_grafixLibFileInfo@4   0x000010A7
grafixLibFileInfo      0x000010A7

Visual Studio is exporting the functions only once

Function               EntryPoint
_grafixLibFileInfo@4   0x00011267

I'm using

#define	DLL_EXPORT	__declspec(dllexport) __stdcall
long  DLL_EXPORT grafikLibFileInfo(struct GRAFLIBFILE *gLibFile)
{
...
}

no def file

Is there any chance, to export the functions like Watcom does?

Otherwise I have to change all the GetProcAddress calls from e.g.
grafixLibFileInfo to _grafixLibFileInfo@4

Thanks in advance

[Alex F]

What about exporting functions once, but without C++ name mangling, grafixLibFileInfo and not _grafixLibFileInfo@4 ?
This can be done by using extern "C":

http://msdn.microsoft.com/en-us/libr...3s(VS.80).aspx

[FrankieH]

What about exporting functions once, but without C++ name mangling, grafixLibFileInfo and not _grafixLibFileInfo@4 ?
This can be done by using extern "C"

it's plain C - the DLL I'm talking about at least.

This name decoration with underscore is an old 16 bit thing - afaik.
Add the @4 is showing the bytecount of the parameters. If two long would be passed, there would be a @8 - it's not a C++ function name.

But thanks nevertheless for your reply.

[Igor Vartanov]

What about exporting functions once, but without C++ name mangling, grafixLibFileInfo and not _grafixLibFileInfo@4 ?
This can be done by using extern "C":

http://msdn.microsoft.com/en-us/libr...3s(VS.80).aspx

_grafixLibFileInfo@4 already is extern "C".

[Igor Vartanov]

Is there any chance, to export the functions like Watcom does?

Sure, just build it with Watcom.

Now getting serious. VC++ mangles the function this way, and there is no other way to change the behavior, except one of explicit specifications:

• .def file or
• #pragma comment(linker, "/export:grafixLibFileInfo=_grafixLibFileInfo@4")

[FrankieH]

Sure, just build it with Watcom.

I'm quite a Watcom-fan :-) the debugger is really great - just missing the possibility to code in teh debugger like in VS and changing from debugging to coding.

• .def file or
• #pragma comment(linker, "/export:grafixLibFileInfo=_grafixLibFileInfo@4")

Thanks for responding. I'll give the pragma a try ... curious whether that'll work.

[Igor Vartanov]

I'll give the pragma a try ... curious whether that'll work.

I'll be surprized if that won't.

// 17.cpp
extern "C" __declspec(dllexport) 
int __stdcall foo(int a) { return 0; }

#pragma comment(linker, "/export:foo=_foo@4")

D:\Temp\17>cl 17.cpp /link /dll /out:17.dll
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 14.00.50727.762 for 80x86
Copyright (C) Microsoft Corporation.  All rights reserved.

17.cpp
Microsoft (R) Incremental Linker Version 8.00.50727.762
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:17.exe
/dll
/out:17.dll
17.obj
   Creating library 17.lib and object 17.exp

D:\Temp\17>exports 17.dll
ModuleType:
  PE executable (DLL)
Subsystem:
  Win32 GUI
ModuleName:
  17.dll
Exported Info: BaseOfOrdinals    = 1
               NumberOfNames     = 2
               NumberOfFunctions = 2

  RelVirtAddr  Ord  Hint   ExportedFuncName

  0x00001000     1     0   _foo@4
  0x00001000     2     1   foo

[FrankieH]

thanks again - it's working fine ....