I am converting a MATLAB written function into C by "Matlab coder". After I get the converted files , the converted function always have first input argument as const emlrtStack *sp. Now when I am trying to test it on VC++ 2013, IntelliSense is giving mentioned above error.
I manually tried to locate this identifier in emlrt.h file but no such thing is present there. I tried to convert a simple multiply function with two input arguments[like, c=mul(a,b)] but still the converted function has this extra argument inside the function in addition to a and b.
(which means this argument is not function specific).
If someone has a solution to this or have experienced a problem like this, please share or help.
Moreover If someone know how to simply test these converted functions, it would be a much appreciated additional help .
It is likely that the code that was generated for a MEX function rather than a standalone target. MEX functions are binaries written C, C++ or Fortran that can be called like a normal MATLAB function. Generating code to produce a MEX function allows two things. First, you can test your generated code in MATLAB because you can call the MEX function from MATLAB like any other function. Look for a file named mul_mex.mex* after you do code generation and try to call it: mul_mex(1,2). The other use for generating a MEX function is that it can often be faster than the MATLAB code from which it was generated. MEX functions are only used in the context of MATLAB.
The parameter emlrtStack* that you saw appears in MEX generated code to aid in runtime error reporting. It is not present in standalone code that is designed to be run outside of MATLAB.
If you want to use the generated code in Visual Studio, or outside of MATLAB you should choose one of the standalone targets, LIB, DLL, or EXE. This page shows how to change the output type. To summarize, if using the command line you could say:
cfg = coder.config('lib'); %or 'dll' or 'exe'
codegen mul -config cfg -args {1,2}
If using the project interface, you click on the Build tab and choose static library or shared library in the "Output type" dropdown menu.
I would recommend reading this example that demonstrates how to use a generated DLL in Visual Studio.
Related
I am writing a c++/CUDA code with Visual Studio 2015 to generate a mex file to integrate with MATLAB.
When I run the mex file through the MATLAB console and then try to compile it again on VS I get this error:
LINK : fatal error LNK1168: cannot open filename.mexw64 for writing
Closing the MATLAB and opening the programme again solves the problem.
Does anyone know any solution which not involves closing the MATLAB?
MEX-files are DLLs (on Windows, shared objects on other systems). When first run, MATLAB links to them, but doesn't unlink unless explicitly told to (or quitting MATLAB of course).
Typing
clear mex
in MATLAB will unlink all MEX-files. See the relevant documentation.
But note that your MEX-file can call mxLock, which will cause it to be locked in memory and then it will not be cleared by clear mex. If you use this function in your MEX-file, you need to include a facility to have your MEX-file call mxUnlock. I usually add a syntax such as mymexfile --unlock: the MEX-file checks to see if it is called with one argument, and that argument is a string, and the string matches "--unlock", then it calls mxUnlock.
I was able to temporarily get some legacy Fortran code running (I was able to step through it with the debugger) in Visual Studio 2017 with the Intel Fortran compiler, until it stopped working apparently for no reason.
At the very start I was getting the error below when trying to get the code to run.
error #6633: The type of the actual argument differs from the type of the dummy argument.
That error went away after a post-installation reboot and I was able to test the code for a few weeks, but now it's back.
I don't think I've changed any of the code.
You're using Intel Fortran and it has a feature called "Generated Interface Checking". The way this works is when you compile a source that declares a subroutine or function that isn't in a module, it generates an INTERFACE block and saves a compiled module for it. Then when you compile a source that calls a routine for which you have not provided an explicit interface, it looks to see if there's a generated one and compares it. If you have an argument type mismatch you'll get an error such as this.
However, to work properly the called routine must be compiled before the caller. If this doesn't happen, the interface can't be checked and you'll not get an error. The error is still there, and you may be able to see it if you do a rebuild of the project. Pay attention to the message and fix the problem it describes. A mismatched argument type is a common cause of run-time errors that come and go.
Good afternoon,
I'm trying to work with some C++ dll files with Matlab, and I'm trying to implement a simple test case to understand the procedure. The dll file I'm using is copied verbatim from here:
https://msdn.microsoft.com/en-us/library/ms235636.aspx
I only implement up to step 5, since my hope is to call the dll file through Matlab. After completing step 5, I copy MathLibrary.h and MathLibrary.dll to the directory I'm using for my Matlab code, and then run
[notfound,warnings]=loadlibrary('MathLibrary.dll','MathLibrary.h');
Upon running this I get the warning
>Warning: No functions found in library.
>
>In C:\Program Files\MATLAB\R2014b\toolbox\matlab\general\loadlibrary.p>loadlibrary at 431
The cell array notfound is empty and warnings is an array with warnings = MathLibrary.h
If I try using one of the functions from the dll, I execute the following code:
calllib('MathLibrary','Add',5,3)
which throws the following error
>Error using calllib
>
>Method was not found.
I've tried Googling solutions to similar problems, but have not found solutions where I've looked (at least ones I've understood). My C++ is weak, which may be hindering my understanding of the problem and solution. I'm hoping to incorporate dll files from a much larger project soon, so understanding this would be a great help. Thanks so much!
Working on a C++ based application, it takes user input and generates a C++ function and compile it to create a .so file and links the function to the main application. Currently had to call an external command "g++" to do it. Wonder if it's possible to call some kind of function, say, "compile" which takes as input an code snippet and produces an .so. More precisely, I need a function that has the following syntax:
sizeOfObjBuf = compile(codeBuf, objBuf);
First parameter is a null terminated string containing a code snippet, the second parameter is the output buffer that hold the compiled code and it returns the size of size of compiled code.
The whole idea is to get rid of dependency on an external program (g++) so the application can run on any Linux system (even when it doesn't have g++ installed).
Thanks.
I'm afraid the answer is "no".
You could implement that function by executing G++ (or some other compiler) in a separate process and waiting for it to finish, but that still requires the user to have a compiler installed.
You can't compile C++ code without a C++ compiler.
I am not going to do the research to figure out how it is done, but I believe the LLVM C++ compiler can be used in this way. All of the parts of LLVM are designed to run as a library, in theory.
OK, a tiny bit of research and I found this: http://clang.llvm.org/docs/LibTooling.html
I built Qt from source (dlls) and am trying to build an application that uses the Qt dlls. I don't have a lot of experience with C++ so I'm running into what I'm sure is a very basic issue.
My builds are failing on the includes with errors like so:
Fatal error: QNetworkProxy: No such file or directory
Here is the g++ command I am using (I also used -L to add the correct folder to the lib path, but that also didn't work):
g++ -l..\..\wkqt\bin\QtCore4.dll -l..\..\wkqt\bin\QtNetwork4.dll -l..\..\wkqt\bin\QtWebKit4.dll -I..\include -Ishared -Ipdf -Ilib -Iimage -o ..\bin\wkhtmltopdf.exe pdf\*.cc lib\*.cc image\*.cc shared\*.cc
I tried in Visual Studio as well (assuming it wouldn't build, but I wanted to see if I could at least include the Qt dlls from there properly) and I am getting the same errors. Am I doing something wrong with the way I am compiling with g++? If I am linking with the Dlls properly then what is the proper way to use Qt functions from my code?
To clarify, I am not looking for how to properly use Qt. My question is: what is the proper way to use functions defined in any Dll from native C++ code? I apologize if this is a very basic question, but I'm unable to find a clear answer on Google and I don't have any experience with C++ and including third party libraries for use from C++ code.
DLLs can be used by dynamicly loading them and calling their used functions.
to call the exposed functions first define their syntax in the begining
suppose function is syntax is
BOOL MyFunction(int a,char* pszString)
then define syntax
#typedef BOOL (WINAPI *PMYFUNCTION)(int a,char* pszString)
then make object
PMYFUNCTION pfnMyFunction;
and get valid pointer by calling GetProcaddress after loadlibrarycall
HMODULE hlib= Loadlibrary("c:\\Mylib.dll");
if(hlib)
{ pfnMyFunction = (PMYFUNCTION)Getprocaddress(hlib,"MyFunction"); }
Hope this helps...