unresolved external symbol, but dumpbin says it's ok

Question

I downloaded Crypto++ 5.62 and built it with default project settings. In my project I set up the path to cryptopp.lib and defined its name in \"Ad

Answer 1

Try adding CRYPTOPP_IMPORTS to your project defines.

From config.h:

#ifdef CRYPTOPP_EXPORTS
# define CRYPTOPP_IS_DLL
# define CRYPTOPP_DLL __declspec(dllexport)
#elif defined(CRYPTOPP_IMPORTS)
# define CRYPTOPP_IS_DLL
# define CRYPTOPP_DLL __declspec(dllimport)
#else
# define CRYPTOPP_DLL
#endif

Or include Crypto++'s dll.h. It sets CRYPTOPP_IMPORTS:

#if !defined(CRYPTOPP_IMPORTS) && !defined(CRYPTOPP_EXPORTS) && !defined(CRYPTOPP_DEFAULT_NO_DLL)
# ifdef CRYPTOPP_CONFIG_H
#  error To use the DLL version of Crypto++, this file must be included before any other Crypto++ header files.
# endif
# define CRYPTOPP_IMPORTS
#endif

---

If that does not work...

g_pAssignIntToInteger is from algparams.cpp:

$ grep -R g_pAssignIntToInteger *
algparam.cpp:PAssignIntToInteger g_pAssignIntToInteger = NULL;
algparam.h:CRYPTOPP_DLL extern PAssignIntToInteger g_pAssignIntToInteger;
algparam.h:     if (!(g_pAssignIntToInteger != NULL && typeid(T) == typeid(int) && g_pAssignIntToInteger(valueType, pValue, &m_value)))
integer.cpp:    if (!g_pAssignIntToInteger)
integer.cpp:        g_pAssignIntToInteger = AssignIntToInteger;

Looking at the declaration in algparam.h:

// to allow the linker to discard Integer code if not needed.
typedef bool (CRYPTOPP_API * PAssignIntToInteger)(const std::type_info &valueType, void *pInteger, const void *pInt);
CRYPTOPP_DLL extern PAssignIntToInteger g_pAssignIntToInteger;

And the implementation in algparam.cpp:

#ifndef CRYPTOPP_IMPORTS
...

NAMESPACE_BEGIN(CryptoPP)    
PAssignIntToInteger g_pAssignIntToInteger = NULL;
...

So you might need to change the implementation to ensure the code uses g_pAssignIntToInteger (to keep it from being discarded). Unfortunately, nothing comes to mind at the moment.

---

DEFAULT_CHANNEL is declared in cryptlib.h and has storage allocated in cryptolib.cpp:

$ grep -R DEFAULT_CHANNEL *
...
cryptlib.cpp:const std::string DEFAULT_CHANNEL;
...
cryptlib.h:extern CRYPTOPP_DLL const std::string DEFAULT_CHANNEL;
...

This might be a different problem since I'm not used to seeing issues with DEFAULT_CHANNEL. See how CRYPTOPP_IMPORTS works for you, and then ask a different question since this might be a different problem.