MATLAB: How to specify the own print and error handling functions using the MCC Command when generating a standalone executable using MATLAB Compiler 4.10 (R2009a)

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I am creating a standalone executable from my MATLAB function called "myfunc.m" using the MCC command using MATLAB Compiler 4.10 (R2009a). I would like to use my own custom printing and error handling routines in my application.

In order to do this, it appears that I have to modify the C wrapper files that are generated and re-build them to create the executable.

I would like to be able to specify my custom print and error handling routines using an option switch in the MCC command.

Best Answer

The ability to specify custom print and error handling routines using options switches for the MCC command is not is not available in MATLAB Compiler.

To work around this issue, you would have to generate the wrapper files, modify them and then re-compile them into an executable. The steps below indicate how you can do this.These steps assume that you are attempting to create a standalone from the MATLAB function "myfunc.m".

1. Generate the C wrapper files for the function myfunc.m using the commands below:

mcc -W main foo.m -C

This generates three C-files called "myfunc_main.c", "myfunc_delay_load.c" and "myfunc_mcc_component.c". Do not embed the CTF as once it is embedded it will be deleted.

2. Open the file "myfunc_main.c". This file contains the following line of code

LIB_myfunc_C_API 
bool MW_CALL_CONV myfuncInitialize(void)
{
    return myfuncInitializeWithHandlers(mclDefaultErrorHandler, mclDefaultPrintHandler);
}

where "mclDefaultErrorHandler" and "mclDefaultPrintHandler" are the default routines.

3. Add the C-code for your custom print and error handling functions in the file "myfunc_main.c". Let these functions be called "myPrintHandler" and "myErrorHandler" respectively. If these functions are defined in another source file, please be sure to include the header file containing the function prototype in the file "myfunc.c".

4. Please modify the the code specified above to the following:

LIB_myfunc_C_API 
bool MW_CALL_CONV myfuncInitialize(void)
{
    return myfuncInitializeWithHandlers(myErrorHandler, myPrintHandler);
}

5. Compile the C-source files using the MBUILD command as shown below:

mbuild myfunc_delay_load.c myfunc_main.c myfunc_mcc_component_data.c -output foo

If the print and error handlers are present in another source file, please include that file also as an input to MBUILD.

Related Solutions

MATLAB: What is the difference between functions like mclmcrInitialize and mclInitializeApplication

mclmcrInitialize and mclInitializeApplication are MATLAB Compiler Runtime (MCR) functions which are typically used in driver applications for shared libraries.

mclInitializeApplication: This function should be called once at the beginning of your driver application. You must make this call before calling any other MathWorks functions.

mclmcrInitialize: Loads three main libraries (libmex,libmat.libmclmcr) and sets runtime environment for running MATLAB functions.

If the driver application has a main() method, you need to use mclInitializeApplication in the main() method. This in turn calls mclmcrInitialize to load all the libraries.

For example, refer to the following C shared library example:

https://in.mathworks.com/help/compiler_sdk/cxx/c-shared-library-target.html?s_tid=srchtitle

If the driver application has a main() as well as an additional method which uses the mclRunMain function, you must first call mclmcrInitialize. Then inside the function called from mclRunMain, you can call mclInitializeApplication to complete the MCR initialization procedure. mclRunMain is an additional MCR function which handles platform specific threading issues.

For example, refer to the following C++ shared library example:

https://in.mathworks.com/help/compiler_sdk/cxx/c-shared-library-target-1.html?s_tid=srchtitle

In this example, run_main() is the additional method which is called by the mclRunMain function.

MATLAB: How to use custom error and print handlers in the compiled C++ shared libraries

C++ shared libraries compiled using MATLAB support the use of custom print and error handlers. To replace the default handlers, the library needs to be initialized using the following syntax in the driver code (i.e the code calling the DLL functions)

/* Initialize the library liberrorH with custom error and print handlers */
liberrorHInitializeWithHandlers((mclOutputHandlerFcn) myErrorHandler,(mclOutputHandlerFcn) myPrintHandler))

Both these handlers should adhere to the following templates:

static int myPrintHandler(const char *s){
      //Please use the mclWrite function for R2006a  and later
      //mclWrite(1 /* stdout */,"*Print handler called with ",sizeof(char)*strlen("*Print handler called with "));
      //mclWrite(1 /* stdout */, s, sizeof(char)*strlen(s));
      //Please comment the above two lines and use the one below for R14SP3
      std::cout<<"*Print handler called with "<<s<<std::endl;    
      return 5;
}

See the attached files for a complete example.

Description of the files:

testerrorhandling.m: Source MATLAB file being compiled. Has a numeric input based on which it creates various calls to the print and error handlers.
cmds.txt: Commands used to generate the DLL file (test with Microsoft Visual C/C++ 6.0)
errhndlrDriver.cpp: C++ driver code to call the testerrorhandling from the compiled DLL, creates custom print and error handlers.
errmsgchk.m: MATLAB file to run the created executable with different arguments
Outputs.txt: Expected output

Best Answer

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MATLAB: What is the difference between functions like mclmcrInitialize and mclInitial​izeApplica​tion

MATLAB: How to use custom error and print handlers in the compiled C++ shared libraries

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MATLAB: What is the difference between functions like mclmcrInitialize and mclInitializeApplication