Getting linker errors when including JSBSim library

[ilyapetrovMO]

Hello! I want to learn about JSBSim by using it as a library from a c++ program paired with raylib for visualizations.
I am on windows, and I'm using VS2022.

I've downloaded and installed JSBSim with the provided release executable JSBSim-1.2.1-1348-setup.exe, configured my VS2022 project to use AppData\Local\JSBSim\include and AppData\Local\JSBSim\lib directories for the headers and their implementations.

I have a very basic main file:

#include "raylib-cpp.hpp"
#include "FGFDMExec.h"

int main() {
    constexpr int screenWidth = 800;
    constexpr int screenHeight = 450;

    raylib::Window window(screenWidth, screenHeight, "raylib-cpp - basic window");

    SetTargetFPS(60);

    auto FDMExec = new JSBSim::FGFDMExec();

    while (!window.ShouldClose())
    {
        BeginDrawing();

        window.ClearBackground(RAYWHITE);

        DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);

        EndDrawing();
    }

    return 0;
}

I first successfully compiled, linked, and executed the program with code only referencing the raylib library and its cpp wrapper. After that, I've included FGFDMExec.h and added the line auto FDMExec = new JSBSim::FGFDMExec(); to check if the JSBSim library is also configured correctly. This is where I've encountered linker errors:

1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl JSBSim::FGFDMExec::FGFDMExec(class JSBSim::FGPropertyManager *,class std::shared_ptr<unsigned int>)" (__imp_??0FGFDMExec@JSBSim@@QEAA@PEAVFGPropertyManager@1@V?$shared_ptr@I@std@@@Z) referenced in function main
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __cdecl JSBSim::FGFDMExec::~FGFDMExec(void)" (__imp_??1FGFDMExec@JSBSim@@UEAA@XZ) referenced in function "public: virtual void * __cdecl JSBSim::FGFDMExec::`scalar deleting destructor'(unsigned int)" (??_GFGFDMExec@JSBSim@@UEAAPEAXI@Z)
1>C:\Users\user\source\repos\JSBSimRaylib\x64\Debug\JSBSimRaylib.exe : fatal error LNK1120: 2 unresolved externals

These are the compiler flags VS2022 generates from my project configuration:

CL.exe /c /I"C:\Users\user\Documents\CPPLibs\raylib-cpp-5.5.0\include" /IC:\Users\user\AppData\Local\JSBSim\include /I"C:\Program Files\vcpkg-master\installed\x64-windows\include" /ZI /JMC /nologo /W3 /WX- /diagnostics:column /sdl /Od /D _DEBUG /D _CONSOLE /D _UNICODE /D UNICODE /Gm- /EHsc /RTC1 /MTd /GS /fp:precise /Zc:wchar_t /Zc:forScope /Zc:inline /std:c++17 /permissive- /Fo"x64\Debug\\" /Fd"x64\Debug\vc143.pdb" /external:W3 /Gd /TP /FC /errorReport:prompt main.cpp

These are the linker flags:

link.exe /ERRORREPORT:PROMPT /OUT:"C:\Users\user\source\repos\JSBSimRaylib\x64\Debug\JSBSimRaylib.exe" /VERBOSE:Lib /INCREMENTAL /ILK:"x64\Debug\JSBSimRaylib.ilk" /NOLOGO /LIBPATH:"C:\Users\user\Documents\CPPLibs\raylib-5.5_win64_msvc16\lib" /LIBPATH:C:\Users\user\AppData\Local\JSBSim\lib /LIBPATH:"C:\Program Files\vcpkg-master\installed\x64-windows\debug\lib" /LIBPATH:"C:\Program Files\vcpkg-master\installed\x64-windows\debug\lib\manual-link" kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib raylib.lib JSBSim.lib "C:\Program Files\vcpkg-master\installed\x64-windows\debug\lib\*.lib" /MANIFEST /MANIFESTUAC:"level='asInvoker' uiAccess='false'" /manifest:embed /DEBUG /PDB:"C:\Users\user\source\repos\JSBSimRaylib\x64\Debug\JSBSimRaylib.pdb" /SUBSYSTEM:CONSOLE /TLBID:1 /DYNAMICBASE /NXCOMPAT /IMPLIB:"C:\Users\user\source\repos\JSBSimRaylib\x64\Debug\JSBSimRaylib.lib" /MACHINE:X64 x64\Debug\main.obj

I've tried compiling the .lib from source, but no luck. Also checked the paths, and spelling.
I am unable to tell if this is simply a VS2022 project configuration error, or something more involved. Maybe I'm misunderstanding how c++ libraries work or how to include them. I've seen a discussion kind of similar to mine, but it was seemingly resolved, and the person had problems with the self compiled library, and not the distributed version.
If anyone has the time and expertise, I would greatly appreciate it if you could help me understand the cause of this error.

[ilyapetrovMO]

How I've managed to get this project to link:

I've added a BUILD_SHARED_LIBS=1 option in CMake and compiled the JSBSim project. This yielded me both .lib and .dll files, which I placed in my project root. So this is showing my lack of understanding of what the .lib file is in AppData. I was under the impression that it is a static library file, and it was the only thing I needed to make JSBSim to work in my project. I'm guessing the JSBSim installer placed this .dll file somewhere on my system, but VS2022 is not configured to use that path?

Don't know if this is the correct way of doing things, so I'm not yet marking this question as answered.

[alphamikeuniform]

It seems that the provided JSBSim setup package contains the static lib version of jsbsim.lib.
To link against this static lib you have to define JSBSIM_STATIC_LINK, either in the visual studio project settings (C/C++->Preprocessor->Preprocessor Definitions) or by putting "#define JSBSIM_STATIC_LINK" in your code files before you include the JSBSim header files.
At least that's my understandig after I had a look at JSBSim_API.h. I think this info is missing in the JSBSim docu, or I haven't found it.

EDIT: Ok, I found it in the docu. The jsbsim.lib contained in the setup package is meant to be used to build the JSBSim Matlab S-Function and not to build general c++ applications.

[Warning39]

So in terms of .lib files remember there are 2 types. Static .lib files which contain compiled code implementing the functionality of the library and import .lib files which contain just enough information for resolving references for your code to call into a DLL version of the library.

An import library (.lib) file contains information that the linker needs in order to resolve external references to exported DLL functions, so that the system can locate the specified DLL and exported DLL functions at run-time. You can create an import library for your DLL when you build your DLL.

So when building JSBSim you need to configure the build to either generate a static library or to generate a dynamic library (DLL) with an associated import lib.

And when you build your application to make use of JSBSim you need to configure your build to specify whether you're wanting to make use of the JSBSim static library or the dynamic library (DLL).

error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl JSBSim::FGFDMExec:

From your initial error message you can tell based on the mention of __declspec(dllimport) that you had configured the build of your application to try and link against the dynamic/import library, but the actual .lib file you pointed it to was the static lib.