VC调用MatLab生成的动态链接库

Technical Solutions

Solution Number: 1-18CBI

Date Last Modified: 18 Oct 2004 Product:   MATLAB® Compiler Reported in Release:   R12 Fixed in Release:     Platform:   Windows Operating System:   Windows Any

 

Subject:

How do I create a C - shared library with MATLAB Compiler 3.0 which can be used in other projects?

Problem Description

I am using MATLAB Compiler 3.0 or earlier and am interested in creating a C-shared library for use in an IDE such as Microsoft Visual Studio 6.

How do I create a shared library?

How do I hand initialize code without invoking the main( ) in my MSVC (or other IDE) project?
How do I generate the C-files which do not contain the main( ) function?

The objective is to convert the M-file to a C file to be used with MSVC (or other IDE) projects.

Solution:

This solution explains how to generate a C-shared library with MATLAB Compiler 3.0 and how to use it in general in an integrated development environment (IDE) using Microsoft Visual Studio 6 as an example.


Here are the steps to create a C - shared library:

1. Compile your M-files into a DLL (on Windows):



mcc -t -L C -W lib:mylib -T link:lib -h libmmfile.mlib



The -t option tells the MATLAB Compiler to translate the M code to the target language.
The -L option specifies the target language, which is chosen to be C.
The -W option tells the MATLAB Compiler to build a wrapper for libraries with the name specified after "lib:".
The -T option tellls the compiler what stage should be reached and for what intentions. Here we want to link our application together to build a shared library (i.e. DLL on a PC).
Specifying libmmfile.mlib tells the MATLAB Compiler to link against the MATLAB M-file Math routines that have already been precompiled into shared libraries when necessary.

This step will produce mylib.dll, mylib.lib, and mylib.h. You can add the
-g switch to produce a DLL suitable for debugging in MSVC (or your own IDE).

2. Add mylib.lib to your MSVC (or your own IDE) project

3. Make sure to call the initialization and termination routines from your
code before calling any of the M-Files that are compiled. You need to call:



mylibInitialize();



Afterwards, you should call the termination routine:



mylibTerminate();



All of the symbols in mylib.dll will also appear in mylib.h.

4. You can call the functions compiled from the M-code by invoking mlfFoo(...), from your C code.

For example:

In MATLAB,

1. Write a M-file function named foo and saved as foo.m that contains the following code:



function y = foo(x)
y = x+1;



2. Use the MATLAB Compiler to compile foo.m into C code that can be included in a C shared library:



mcc -t -L C -W lib:foolib -T link:lib foo.m libmmfile.mlib



This will generate the following files:

foo.c
foo.h
foolib.c
foolib.h
foolib.exports
foolib.dll
foolib.exp
foolib.lib
foolib.mlib

In Microsoft Visual C/C++ 6.0

1. Start up the Microsoft Visual C/C++ 6.0 IDE

2. Go to FILE and NEW. Click on Projects Tab. Select Win32 Console Application. In the Project Name field type "test". "Create new workspace" should be filled in. In the "Platforms" field, "Win32" should also be checked. Click OK.

3. Select the File View tab and double click on test files. Select Source Files, select Project menu option, select Add to Project and then click on New. In the Files tab select C++ Source file, check Add to project and type "foowrap.c" in the File name field.

4. Enter the following code in the foowrap.c file:



#include "foolib.h"
#include "matlab.h"
#include

void main(void)
{
mxArray *x_ptr;
mxArray *y_ptr;
double *y;
double ret;

/* Create an mxArray to input into mlfFoo */
x_ptr = mxCreateDoubleScalar(1);

/* Call the library initialization function */
foolibInitialize();

/* Call the implementation function */
y_ptr = mlfFoo(x_ptr);

/* Call the library termination function */
foolibTerminate();

/* The return value from mlfFoo is an mxArray so we must extract the data from it */
y = mxGetPr(y_ptr);
ret = *y;

/* Print a double precision number*/
printf("The output of foo is %f/n",ret);

mxDestroyArray(x_ptr);
mxDestroyArray(y_ptr);
}



5. Right click on test files and select Add Files to Project. Select:

foolib.lib

and the following files located in $MATLAB/extern/lib/win32/microsoft/msvc60:

libmatlb.lib
libmmfile.lib
libmx.lib

6. Highlight test files and right click. Select Settings. Click on the C/C++ Tab. In the Category listbox select Code Generation. In the Use Runtime library listbox select Multithreaded DLL. Change the Category listbox to Preprocessor. Add to the Preprocessor definitions MSVC, MSWIND, IBMPC so:

WIN32,_DEBUG,_CONSOLE,_MBCS

changes to:

WIN32,_DEBUG,_CONSOLE,_MBCS,MSVC,MSWIND,IBMPC

Add to the Additional include directories field:

$MATLAB/extern/include/cpp;$MATLAB/extern/include

where $MATLAB is the MATLAB installation directory such as d:/matlabR12.

Also add to the Additional include directories field the directory in which foolib.h is located.
Click OK

7. Go to Build and Rebuild All.

8. You should now have built test.exe.

9. You may also need to place foolib.dll in the same location as test.exe.

For information on how to call a MATLAB Compiler generated DLL from a Visual C++ environment, see the following: