I am using boost generic image library and it requires libpng. I built libpng and obtained the files libpng.lib, zlib.lib and libpngd.lib. When I tried to compile my project, Visual Studio gives a fatal error
fatal error LNK1120: 21 unresolved externals
with a bunch of unresolved external symbols like _png_set_sig_bytes and _png_read_row. What's going on here and how to solve it?
From MSDN:
https://msdn.microsoft.com/en-us/library/ba1z7822.aspx?f=255&MSPPError=-2147217396
To add .lib files as linker input in the development environment
Open the project's Property Pages dialog box. For details, see Setting Visual C++ Project Properties.
Click the Linker folder.
Click the Input property page.
Modify the Additional Dependencies property.
You must do this; explicitly specifying "libpng.lib", "zlib.lib" and "libpngd.lib" in your .exe's link command.
So this is coming from a complete simple minded moron so maybe this'll be helpful....it took me a little while to grasp. Basically, you're downloading the source code. That means, that you have to be the one to compile the source code.
Windows can compile programs that are written in C in the command prompt. You have to build the program, and it spits out a .dll or a .lib file. That or those are the files that you link to visual studio application.
You set dependencies to the header files which is usually like the source codes root folder or wherever all those .h files are.
You then set the linker to link to the .dll or .lib file(s). In Boost C++'s case, you need to link to a 'lib' folder.
I think what you need is to go over and completely grasp the basics. Here's a link from Microsoft on how Windows can compile C programs from the command prompt:
https://learn.microsoft.com/en-us/cpp/build/walkthrough-compile-a-c-program-on-the-command-line?view=vs-2019
Related
I have problems building my code that is using static lib detours. I am trying to do an old basic CTF. For that I want to get into detours.
Whenever I try to build my .dll file I get an issue
LNK2019 unresolved external symbol _DetourTransactionBegin#0 referenced in function _DllMain#12
Now, I have built the detours library using 3 different version of the visual studio dev console.
I have tried firing 'vcvars32.bat' and then using nmake to build the library which was able to build it, but I get the above error during linking my .dll. I have also tried building it with 'vcvarsamd64_x86.bat' and then using nmake to build it which also was able to build the library, but I still get the same error as above during linking.
I have tried the usual stuff: the include folder for detours.h is added to C++/General/Additional Include Directories.
Under Linker/Additional Library Directories I added them as follows: "C:\temp\det_retry\lib.X64";"C:\temp\det_retry\lib.X86";%(AdditionalLibraryDirectories).
And also under Linker/Input/Additional Dependencies I have the following: detours.lib;%(AdditionalDependencies)
What am I missing here? This is a blocker for me for a couple of days and I am reiterating the same steps trying to figure out what's missing but I cannot see. I'd really appreciate the input.
I am sure I am using the newest version because I have downloaded (cloned) detours from the ms github page.
It appears your "Additional Library Directories" are setup incorrectly or contain invalid entries rather. They look like actual library file entries (i.e. pointing to some specific files) versus being only directories (e.g. "my/lib/path/for/my_project/"). Visual Studio's naming conventions are somewhat cryptic but they should be directory entries only. There should be an entry to whatever directory contains the detours.lib file (e.g. "MyProject/Libs/MSDetour" ... where MSDetour is a folder with the "detours.lib" in it) and then Visual Studio should find the library and link everything correctly.
As a side note, if you are using the Visual Studio developer console for building your project/solution you might want to look into CMake ... it is, in my opinion, significantly easier to work with (less "settings" digging) and maintain in the long-run.
I have been referring to https://learnopengl.com/. In those tutorials, many libraries were used for performing different tasks. I have worked on those tutorials on Windows 7 in Visual Studio 2013, linking all the .lib files and .dll files correctly for that project inside Visual Studio 2013.
But now the issue is that I want to run the program from command line. But I can't run, since none of the libraries and header files are linked and I get various errors saying Couldn't locate filename and unresolved name in function.
Any ideas how do I link the libraries and header files so that I can run the program from command line?
I know this can be marked as an open ended and not clear question, but I am stuck and all the answers which I have gone through did not describe clearly about linking the .lib files?
As #Michael Chourdakis suggested, msbuild was the thing I was looking for.
Some back story: I am trying to get the bolt-lmm software to compile on a Windows machine, because it would be a nice addition to the research group I am in. The developers of the software have only made a linux static executeable, but made the source code available. I am used to programming in R or python, and this is my first ever encounter with C++.
I have solved a fair bit of problems, but for some reason I have not been able to get visual studio to link properly with Nlopt-2.4.2.
I downloaded it
and followed the steps given there on how to install it.
I can tell I have done the same to link the Nlopt library to the project as is described in How to add additional libraries to Visual Studio project?
I still get errors like:
Error LNK2019 unresolved external symbol __imp__nlopt_create referenced in function "public: __thiscall nlopt::opt::opt(enum nlopt::algorithm,unsigned int)" (??0opt#nlopt##QAE#W4algorithm#1#I#Z) boltCompiler C:\Users\au483192\source\repos\boltCompiled\boltCompiler\NonlinearOptMulti.obj 1
(there are a total of 12 of this type of error, and an error link 1120, which just tells me there are 12 unresolved eternals.)
I hope this is enough information to provide a hint of what is going wrong.
I did some more digging, and it seems the linker needed more than just the folder for the .lib file.
This post sums it up:
Linking a static library to my project on Visual Studio 2010
Essentially you just need to tell the linker the placement of the lib and the actual name of the .lib file.
Hopefully this will help others who forgot/did not know that added library names manually could be needed for some libraries.
TL;DR:
open configuration properties for the project > linker > general
Then add the path to the .lib file in the "addition library directories" line
Then (still in configuration properties) go to linker > input
add the .lib file name to the "addition dependencies" line, e.g. libnlopt-0.lib (don't forget to separate with ";")
I've been trying to compile tulip using cmake to generate visual studio 2012 project files. It's giving me lots of trouble. I don't know how to get this to build. I've been trying to get visual studio to build this for 4 days now, and I'm extremely frustrated. Essentially, I follow the steps here, and then set the variables CMAKE_LIBRARY_PATH AND CMAKE_INCLUDE_PATH according to these instructions.
To get to where I'm at, all you have to do is download tulip, and:
Unzip it, create a separate build directory outside of this source directory
Open CMake-gui to the source and build directories
Hit configure. Check use qt5, tell it where qmake is (make sure it's qt5)
You need some dependencies as described in The Independent CMake tutorial. Grab all those dependencies
As you continue to hit configure, specify each of the directories that it asks for as it errors out. It should ask for freetype, glew, zlib and sphinx. It shouldn't ask for where libxml or libpng, or libjpeg are. I don't know why it doesn't ask for those.
Generate, and then browse to the ALL_BUILD that you've generated. Open it with visual studio
try to build it with visual studio.
In those instructions and in the process of getting CMake to generate the visual studio build files, it specifically asks for freetype's location. But in my build, it doesn't have a clue how to link the freetype library.
Here are the errors that I get
Here is my CMakeCached.txt
I know that many people aren't going to want to exactly try and go about replicating the build environment, so I've uploaded my build directory to dropbox. You can pull the entire thing down, and then open it in cmake gui and open the visual studio files in there too.
https://www.dropbox.com/sh/qsvukh9t5gb6bvt/tOfOBxWgd0
The linker errors you point to (mostly "unresolved external" errors) indicate that there are missing libraries on the link command line.
That is most likely happening because target_link_libraries calls in the tulip project are either being skipped or being called with library names that do not match the library names on disk.
Open up the solution in Visual Studio and right click the project and choose "Properties" -- look at the "Linker > Input" panel at the "Additional Dependencies" field. That should list all the libraries it wants to link to. Is there a freetype library listed there? Does that library exist in the referenced location on your disk?
There could be a mistake in the tulip project, or there could just be something wrong with your build/install of freetype...
UPDATE AFTER SOME CHAT:
Or it may be that you have some libraries built for x86 and some for x64... or maybe some for Debug and some for Release... or maybe even some with the MinGW compiler and some with the Visual Studio compiler. If that's the case, start over, from a clean slate, and build everything with a consistent compiler, configuration type and architecture. Then report back again with an update and see if the problems still remain.
I do with Dave,
You should try to fix your error 1 by 1.
The first error seems to be a link error:
Error 1 error LNK2019: unresolved external symbol gzread referenced in function "public: virtual int __cdecl gzstreambuf::underflow(void)" (?underflow#gzstreambuf##UEAAHXZ) C:\Users\kenne_000\tulip-build\tulip-build-debug\thirdparty\gzstream\gzstream.obj gzstream
gzstream is a third party lib included with tulip source in:
thirdparty\gzstream
from
thirdparty\gzstream\CMakeLists.txt
you can see that the missing symbols should be coming from ZLIB.
However your CMakeCache.txt indicate that
ZLIB_LIBRARY:FILEPATH=C:/Users/kenne_000/dependencies/zlib128-dll/lib/zdll.lib
is found.
So the question may be, was this dependency compiled with the same compiler?
Don't you have compiler-specific name mangling issue ?
Running visual studio 2010 writing an openGL program in C++
I'm getting this error, and can't for the life of me figure out why
fatal error LNK1104: cannot open file 'Image_Loading/nvImage.lib'
The file is in the correct place, and nvImage.lib is present in the additional dependencies of the linker, any ideas??
The folder "Image_Loading" is probably not in your library search path. Include files has a different search path, so even if its find the includes, the folder might be missing from the libary search path.
you should either add the folder to the LIB enviromental variable, or add /LIBPATH:folder to the command line of the linker.