My goal is to compile existing C++ classes (legacy code, stored in a set of *.h files) into a DLL so that it can be further integrated into a C# application.
For that purpose, it seems best to use MS Visual Studio. I have no experience with this environment, so I tried the naive approach found on MSDN and other SO answers:
File | New | Project from existing code
selected Visual C++
selected file location that is base for include references used in those .h files
specified a project name
let the wizard find and add all C++ files below the directory
selected "Use Visual Studio" for build, with project type "Dynamically Linked Library (DLL) project"
checked none of the checkboxes below (ATL, MFC, CLR)
specified . dir in the "Include search paths (/I)" in Debug settings
checked "Same as Debug configuration" in "Release settings"
clicked Finish button
This creates couple of VS files in the directory:
mylibrary.sln
mylibrary.vcxproj
mylibrary.vcxproj.filters
mylibrary.vcxproj.user
With a project created this way, I press F6 or select Build | Rebuild solution from the menu.
Then I expect the build to produce the .dll file somewhere, but it does not appear. Only these files appear:
.vs/mylibrary/v15/.suo
.vs/mylibrary/v15/Browse.VC.db
.vs/mylibrary/v15/Browse.VC.opendb
.vs/mylibrary/v15/ipch/AutoPCH/efad7c74cd39331b/EXAMPLE.ipch
Debug/mylibrary.log
Debug/mylibrary.tlog/mylibrary.lastbuildstate
Next, I decided to try creating a fresh new library project, just to observe the differences to get some hints, but that did not help - there were too many differences, even in the file structure...
My questions are:
is my choice of MS Visual C++ a good one for given purpose?
if so, what am I doing wrong here?
I think your steps are probably correct and I think that the right approach to use the code from a C# application. You definitely can call a C++ library from C# by importing the methods.
You missed only to export the methods that you want to use from your library. try using __declspec(dllexport) with these methods. please check this link:
https://msdn.microsoft.com/en-us/library/a90k134d.aspx.
Also, the output should be at the build folder, not the source code folder
Compiling .h files into libraries is ok, the compiler does not care - however, the UI does.
Still, you can tweak this by directly editing the .vcxproj file.
While doing so, make sure that the <ClCompile> sections contain:
<RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
Note that you can use commandline for building the DLL project:
"%ProgramFiles(x86)%\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\MSBuild.exe" -target:Clean,Build
(this assumes that your current directory is the one with your .vcxproj)
Related
I have been successfully testing an image processing library (https://github.com/libvips/libvips) in a C++ project in VS2017. I am new to C/C++ and I have been following the documentation here which describes the C way of using the library. There are features I would like to try in the C++ API, but the C++ API needs to be built with the same compiler as my project. According to the author:
It's slightly awkward to set up under Windows. The problem is that C++
does not have a ABI, so you must use exactly the same C++ compiler for
your whole project. This means the libvips C++ win binary (built with
g++) won't work with MSVC C++.
You need to copy the libvips C++ API source code into your own project
and build it with your own code. It's just a few files and pretty
simple to incorporate:
https://github.com/libvips/libvips/tree/master/cplusplus
I have made several attempts to build the minimal set of files but I have not had any success.
My steps so far:
Create a C++ console app in VS2017, set to Debug and x64
Extract the 'vips-dev-8.10' folder from vips-dev-w64-all-8.10.6.zip to where the project file is (this contains all the built .dll files, .lib files, .h files etc.)
Extract 'cplusplus' folder from 'libvips-master.zip' to where the project file is (this has all the project source files including the cplusplus folder which is the part I have to build per the above explanation)
Add the following folders to Project > Properties > C/C++->General > Additional Include Directories
C:\Projects\ConsoleApplicationVIPS3\ConsoleApplicationVIPS3\cplusplus\include\vips
C:\Projects\ConsoleApplicationVIPS3\ConsoleApplicationVIPS3\vips-dev-8.10\include
C:\Projects\ConsoleApplicationVIPS\ConsoleApplicationVIPS\vips-dev-8.10\lib\glib-2.0\include
C:\Projects\ConsoleApplicationVIPS\ConsoleApplicationVIPS\vips-dev-8.10\include\glib-2.0
Add the 5 .cpp files from the cplusplus folder into the project Source Files folder and Add them in the project tree.
Build the project.
As a result I get the following errors:
I haven't written any code yet. I thought I should just be able to point to the .h include files and compile the required C++ files. It's not clear to me what else I might need to add, but it definitely seems like I don't understand the correct procedure to build the project. I watched some videos on C++ compilation like this one but I cant see where I went wrong.
Any thoughts would be much appreciated.
EDITS 3-Jun-21
I have made some changes. I have instead extracted the exact version of the library according to the suggestion by #Frank, and I also discovered the usefulness of the compiler output window, thanks #Alan Birtles.
I am still getting errors, but I am not clear why. The first error is:
E0020 identifier "VImage" is undefined
Which is odd because I have added the folders to Project > Properties > C/C++->General > Additional Include Directories, and one of them is ..\cplusplus\include\vips which contains VImage8.h
And the Output window shows
Any further advice would be appreciated!
I have recently switched my IDE to Visual Studio 2019 for C++ projects. I easily followed a tutorial into setting up a new library like SFML into visual studio, and tell it where the additional include and library directories are.
But there is something else that is required for it to work, which are the .dll files. Every page I followed, even the Documentation by the SFML website, it says that they have to be in the same directory as my project. That means I need to copy-paste the 7-8 files into my project directory. This really makes the folder look untidy. I would like to create a new folder and tell Visual Studio where those files are. I tried going doing this
Project -> Properties -> Linker -> Input -> Additional dependencies
Usually, the lines that would work are
sfml-system-d.lib
sfml-window-d.lib
...
I tried doing $(ProjectDir)valid path\ sfml-files.lib but this gives me the linker error, saying that It could not find the file.
If I simply move the .dlls into a folder without doing anything, the code would compile and link fine. But when it runs, Windows gives me a pop-up box with the same error message.
Here is how it currently looks
Looks really messy, I just want to be able to move them into dependencies like how src contains the source files.
How can I achieve this?
As it is now, it works perfectly fine. The issue only occurs when I try to create a new folder.
I hope I have covered the important information required for a good answer, If not please let me know what more I should add
Microsoft Visual Studio 2019
Currently running 64-bit platform with Debug configuration. Hence the -d suffix
You could create a path environment for your specified directory, which is like drescherjm’s suggestion. The steps:
Right-click “This PC” -> “Properties”-> “Advance System settings”
Click “Environment Variables”
In the System Variables group, edit “Path”
Add your directory, for example: ”D:\ SFML-2.5.1\bin”
Restart your visual studio and re-open your project
The easier solution might be to put them in the x64 subdirectory. This allows you to have various builds side by side (x86/x64, debug/release).
Since this x64 directory is where the EXE is located, it is the first directory searched for DLL's. It will take precedence over the Path solution suggested in the other answer. The Path directories are searched last of all.
My friend has given me a visual studio project , with lots of files.
I know for sure that it is C++ application.
But I want to verify that if it is an MFC application or not.
The issue is since this project has been developed on a higher version (VS 2013) than mine (VS 2010), it is not opening in VS 2010.
So I thought I will make a new project and then gradually add these files.
But When I try to make a new project , I have many options to choose , such as MFC, win32 etc.
I guess it is an MFC application. But to be sure I want to verify that this project is indeed an MFC application. How do I do this ? Especially by just looking at the project files!
Look into your source files and check if afx.h or afxwin.h is included any where.
Project Settings are secondary. Only if such a Header file is used in the Project the MFC libraries are included in the link phase.
You would probably be better off checking the source files, not the project file. For sure, the MFC library need to be present in the project file, but that option could have been left on accidentally.
You could search the source files for CWinApp, which is the class MFC applications need to be derived from. Also, you could try this page on MSDN, which will give you some idea about source and header files typically found in an MFC project.
VS2010 and VS2013 uses XML for .sln/.vcxproj files. Just create a minimal solution in VS2010. Then use a good text editor or even a file comparer to adjust settings inside the .vcxproj.
Great syntax changes occurred between VS2008 and VS2010. But since then most XML tags were kept unchanged between VS2010 and VS2013.
I've been trying for weeks to get Microsoft Visual Studio 2010 to create a DLL for me with SWIG. If you have already gone through this process, would you be so kind as to give a thoughtful step-by-step process explanation? I've looked everywhere online and have spent many many hours trying to do this; but all of the tutorials that I have found are outdated or badly explained.
I have succeeded in going through this process with cygwin; but as some of you know, a cygwin DLL is not very practical.
As a result, I have .i, .cpp, and .h files that I know can create a DLL together. I just need to know how to do this with Visual Studio C++ 2010. The language that I am targeting is Python.
Step-by-step instructions. This assumes you have the source and are building a single DLL extension that links the source directly into it. I didn't go back through it after creating a working project, so I may have missed something. Comment on this post if you get stuck on a step. If you have an existing DLL and want to create a Python extension DLL that wraps it, this steps are slightly different. If you need help with that comment on this post and I will extend it.
Edit 8/19/2012: If starting with a C example, don't use -c++ in step 13 and use .c instead of .cxx for the wrap file extension in steps 14 and 19.
Start Visual Studio 2010
File, New, Project from Existing Code...
Select "Visual C++" project type and click Next.
Enter project file location where the .cpp/.h/.i files are.
For Project Name, choose the name used in %module statement in your .i file (case matters).
Select project type "Dynamically linked library (DLL) project" and click Next.
Add to Include search paths the path to the Python.h file, usually something like "C:\Python27\include" and click Next.
Click Finish.
Right-click the Project in Solution Explorer, Add, Existing Item..., and select your .i file.
Right-click the .i file, Properties, and select Configuration "All Configurations".
Change Item Type to "Custom Build Tool" and click Apply.
Select "Custom Build Tool" in Properties (it will appear after Apply above).
Enter Command Line of "swig -c++ -python -outdir $(Outdir) %(Identity)" (this assumes SWIG is in your path and redirects the generated .py file to the Debug or Release directory as needed).
In Outputs enter "%(Filename)_wrap.cxx;$(Outdir)%(Filename).py".
Click OK.
Right-click the .i file, and select Compile.
Right-click the project, Add, New Filter, name it "Generated Files".
Right-click "Generated Files", click Properties, and set "SCC Files" to "False" (if you use source-control, this prevents VS2010 trying to check in the generated files in this filter).
Right-click "Generated Files", Add, Exiting Item and select the _wrap.cxx file that was generated by the compile.
Right-click the project, Properties.
Select Configuration "All Configurations".
Select Configuration Properties, Linker, General, Additional Library Directories and add the path to the python libraries, typically "C:\Python27\libs".
Select Configuration Properties, General and set TargetName to "_$(ProjectName)".
Set Target Extension to ".pyd".
Build the "Release" version of the project. You can't build the Debug version unless you build a debug version of Python itself.
Open a console, go to the Release directory of the project, run python, import your module, and call a function!
I have a project in a c++ solution. For that project, I have some config files that I would like to manage from within the project and when I build the project, have those config files added to the executable build path in the proper directory structure.
Example:
test.exe references config/myconfig.txt
Is there a way to setup myconfig.txt and my project so when I build test.exe, I get
/
as well as
//config/config.txt
so when I run test, all paths stay in the proper order without me having to go in and manually create those directories.
I'm not sure I'm making sense here, but maybe one of you will understand where I'm going.
You could use pre-build events to create the directories and copy the files.
In Visual Studio's Solution Explorer, you can right-click on the non-code files, select "Properties" and set the "Copy To Output Directory" property.
This creates a rule in the build file to (1) include the file, and (2) to copy that file as part of the build process. In other words, it's possible to get this behavior without Visual Studio, but a little more work.