I would like to integrate Lua into my current C++ application I build with VisualStudio 2015 (x64 mode).
I grabbed a simple Lua wrapper from here, and the Lua binaries for windows x64 from here (the lua-5.1.5_Win32_dll14_lib.zip one).
Next, I added the include and library path to the project preferences. Works so far in the IDE. However, when I try to compile the code it throws 24 errors (like these first two):
1>LuaScript.obj : error LNK2019: unresolved external symbol "lua_close" referenced in function ""public: __cdecl LuaScript::~LuaScript(void)" (??1LuaScript##QEAA#XZ)".
1>LuaScript.obj : error LNK2019: unresolved external symbol "lua_gettop" referenced in function ""public: void __cdecl LuaScript::clean(void)" (?clean#LuaScript##QEAAXXZ)".
which tells me next to nothing. Seems that the linker is unable to find the library but the includes are working and the path to library is set, too. Any suggestions what I might have missed or should look into? Any hint would be appreciated!
Related
Attempting to link in libyaml (0.2.5) using Visual Studio 2019 Enterprise and CMake, as I have a cross-platform (Linux/Windows) project that uses this library. According to the documentation, this library should work in Windows 10. It links in just fine on Linux (64-bit machine).
I'm compiling it as a static lib, and it has no issue generating the .lib file. I've copied it to the appropriate location that I'm linking in from my CMakelists.txt, as well as the header.
When I link it in from my project on Windows:
ts.lib(yamlparser.cxx.obj) : error LNK2019: unresolved external symbol __imp_yaml_parser_initialize referenced in function "public: bool __cdecl YAMLParser::parse_cfg(void)" (?parse_cfg#YAMLParser##QEAA_NXZ)
ts.lib(yamlparser.cxx.obj) : error LNK2019: unresolved external symbol __imp_yaml_parser_set_input_file referenced in function "public: bool __cdecl YAMLParser::parse_cfg(void)" (?parse_cfg#YAMLParser##QEAA_NXZ)
ts.lib(yamlparser.cxx.obj) : error LNK2019: unresolved external symbol __imp_yaml_parser_scan referenced in function "public: bool __cdecl YAMLParser::parse_cfg(void)" (?parse_cfg#YAMLParser##QEAA_NXZ)
This is what I'm doing on the CMake side - the very same thing I'm doing to link in my GoogleTest libraries on both Linux and Windows:
if (UNIX)
...
...
else()
set (MY_LIB_DIR "C:/mylib/lib")
set (MY_INCLUDE "C:/mylib/include")
set (YAML_LIB "${MY_LIB_DIR}/yaml.lib")
set (VCPKG_LIBRARY_LINKAGE static)
endif()
include_directories(${MY_INCLUDE})
add_library(ts
...
...
)
add_executable(myexec main.cxx)
target_link_libraries(myexec ts ${YAML_LIB})
VS isn't giving me many clues here except that there's a linkage problem that I can't quite figure out.
Any advice on how I can debug this or what the problem may be?
The __imp was the clue that my code was trying to include the library dynamically... Opening up yaml.h, I noticed that it tries to export from DLL unless YAML_DECLARE_STATIC is defined. Defined this in CMake and my issue is resolved.
I'm getting LNK 2019 when trying to link in the OpenSSL libraries for a project I'm working on. I compiled the OpenSSL libraries and ran the test and all of them passed. I played with openssl.exe and got it to correctly create and MD5 hash. When I try to use the functions provided by the API though, it just won't recognize them. I even used dumpbin -headers on the .lib files to make sure that the ones I was using contained the correct references for the functions I was using.
I made sure to include the correct files and paths (I also included the header which isn't pictured here).
Here are the actual files and their paths
Here's the actual errors.
error LNK2019: unresolved external symbol _EVP_MD_CTX_create referenced in function _main
error LNK2019: unresolved external symbol _EVP_DigestInit_ex referenced in function _main
error LNK2019: unresolved external symbol _OpenSSL_add_all_digests
referenced in function _main error LNK2019: unresolved external symbol
_EVP_get_digestbyname referenced in function _main error LNK1120: 4 unresolved externals
How do I fix this? Did I put the files in the right place or did I forget an include? I've spent a few days trying to fix this already, this is my last resort :/
Im using Microsoft Visual Studio 2012
This can be problem with calling conventions.
Please check the project setting regarding calling convention.
OpenSSL compiles with /Gd option that means function will be of __cdecl calling convention.
You can either change your calling convention to /Gd or prefix OpenSSL function signatures which you are using with __cdecl.
I believe that this might help. This link explains how to change calling convention.
Please confirm if this can help you.
I was building for x86 when I should have been building with x64. As the x64 option did not show up in the menu, I thought it was unavailable to me. I realized that I had to add it under the project properties and now everything works fine.
Thanks for all the help.
I'm trying to use an external DLL (provided by AutoItX) with Visual C++ 2010. AutoItX provides a DLL, but for some reason not a LIB, so I generated one with Visual Studio.
The problem is that the linker seems to have trouble linking against the library. I added AutoItX3.lib as an additional dependency under Properties->Linker -> Inputs, and added the directory to Properties -> Linker -> General -> Additional Library Directories. No matter what I do, I still get these errors:
1>main.obj : error LNK2019: unresolved external symbol _AU3_Send#8 referenced in function _WinMain#16
1>main.obj : error LNK2019: unresolved external symbol _AU3_WinWaitActive#12 referenced in function _WinMain#16
1>main.obj : error LNK2019: unresolved external symbol _AU3_Run#12 referenced in function _WinMain#16
1>main.obj : error LNK2019: unresolved external symbol _AU3_Sleep#4 referenced in function _WinMain#16
AU3_Send, AU3_WinWaitActive, AU3_Run, and AU3_Sleep are functions called by the program, main.cpp. I'm really out of ideas, because these functions clearly exist in the DLL. Any help would be appreciated.
It is very common to provide only DLLs as a mean of interfaces. Many software providers do that. Doing this has following impacts (consequences):
the client applications can only dynamically link to the library provided (hence the name Dynamic-Link Library). The binding between the provider (the library) and the consumer (the App or any other Library) is made dynamically.
the client must use LoadLibray and GetProcAddress in order to bind the library and retrieve the Symbols (functions) desired
the interface (contract) between the Library and the consumer should be documented via a Header file - see AutoIt3.h for example - (or any other documentation like a help file, ..)
No LIB is provided (since it is not needed), since the Linking takes place at runtime, not at compiler/linker time
To resolve your problem you just need to remove the static dependency (the LIB) you put in the Visual Studio configuration and set the dependency at runtime using LoadLibrary and GetProcAddress
I just tried to build Qt for WinCE7.0 using VS2008 after lots of code modification I successfully compiled main libraries.
While Compiling the QtScript library I received the following linker errors:
1>Linking...
1> Creating library ..\..\lib\QtScript4.lib and object ..\..\lib\QtScript4.exp
1>BytecodeGenerator.obj : error LNK2019: unresolved external symbol __imp__Inf referenced in function "public: static double __cdecl QTWTF::FloatHashTraits<double>::emptyValue(void)" (?emptyValue#?$FloatHashTraits#N#QTWTF##SANXZ)
1>Executable.obj : error LNK2001: unresolved external symbol __imp__Inf
1>MathObject.obj : error LNK2001: unresolved external symbol __imp__Inf
1>DateMath.obj : error LNK2019: unresolved external symbol __imp__Nan referenced in function "double __cdecl QTWTF::parseDateFromNullTerminatedCharacters(char const *,bool &,int &)" (?parseDateFromNullTerminatedCharacters#QTWTF##YANPBDAA_NAAH#Z)
1>JSValue.obj : error LNK2001: unresolved external symbol __imp__Nan
1>..\..\lib\QtScript4.dll : fatal error LNK1120: 2 unresolved externals
I have absolutely no idea which libraries I missed to link with!
Thanks
If you're using Windows, I'll assume you're building in MSVS. I often start projects WITHOUT default libs and if I happen to touch "out of reach" terriotry from another lib, I add what I need as I go along.
Fortunately, MSVS is great at helping me with this. Just turn VERBOSE compiling status and see what libs it's trying to access, then just add them:
right click the project, linker, show progress -> select VERBOSE
Another method is when I check MSDN for Microsoft functions and see the lib they are declared in and add it (since VERBOSE can be overkill on my poor output window). I don't know if Qt has a detailed reference documentation (also stating the libs) but it's worth a shot.
When all else fails, just add all libs Qt could possibly want (make sure IGNORE STANDARD LIBS is disabled) then check VERBOSE and only keep those in the list.
Assuming you have all the libraries in the project, another problem is mismatched dependencies (right click the solution, startup project -> select the one you need, [project dependencies -> map each dependency for the specified libs).
Also make sure when you import an extern the lib is defined in Linker->Input.
However, if you modified the source (either adding new functions/global or static vars or you modified function signatures), the unresolved external reference means a function/var definition has no associated body. Either implement one or add { } in the definition; so if that's the case, check the functions/vars from the error message.
We use Lua (www.lua.org) script to let users to customize our server software written in C++.
At the moment we are porting the 32 bits Windows version of our project to Visual Studio 2010.
Once everything works fine with VS 2008, we thought that we would have no problem on upgrade process.
Unfortunately whenever we tried to link the lualib (as dll) to our project in VS 2010, the lua functions could not be found by the linker (the error messages are displayed below).
It seems that some calling convention is wrong on 2010, like the application may be looking for the lua functions with a prefix '_'.
To access lua functions (written in C) from our project modules (C++) we use this:
extern "C" {
#include "lua/src/lua.h"
#include "lua/src/lualib.h"
#include "lua/src/lauxlib.h"
}
The same project compiles and links with lualib successfully on VS 2008 and Linux (g++).
Could anybody help me with this ?
1>dscscript.obj : error LNK2019: unresolved external symbol __imp__luaL_openlibs referenced in function "public: int __thiscall DsCScriptEngine::Init(void)" (?Init#DsCScriptEngine##QAEHXZ)
1>dscscript.obj : error LNK2019: unresolved external symbol __imp__luaL_newstate referenced in function "public: int __thiscall DsCScriptEngine::Init(void)" (?Init#DsCScriptEngine##QAEHXZ)
1>dscscript.obj : error LNK2019: unresolved external symbol __imp__lua_close referenced in function "public: void __thiscall DsCScriptEngine::Shutdown(void)" (?Shutdown#DsCScriptEngine##QAEXXZ)
1>dscscript.obj : error LNK2019: unresolved external symbol __imp__lua_pcall referenced in function "public: long __thiscall DsCScriptEngine::Execute(char const *)" (?Execute#DsCScriptEngine##QAEJPBD#Z)
etc.
The reported missing names are correct, this not a compile problem. You must be linking the wrong .lib. The name you use sounds wrong, it isn't "lualib", the current version of the import library is named lua5.1.lib (or lua51.lib, not sure what the difference is). Download it from here.