Documentation

Generating Code Files

Source (.c or .cpp) and header (.h) files are created by calling LibCreateSourceFile, as in the following excerpts:

%assign cFile = LibCreateSourceFile("Source", "Custom", "timestwo")
...
%assign hFile = LibCreateSourceFile("Header", "Custom", "timestwo")

Subsequent code refers to the files by the file reference returned from LibCreateSourceFile.

File Sections and Buffers

The code template API lets you partition the code generated to each file into sections, tagged as Definitions, Includes, Functions, Banner, and so on. You can append code to each section as many times as required. This technique gives you a great deal of flexibility in the formatting of your custom code files.

Subsections Defined for Built-In Sections describes the available file sections and their order in the generated file.

For each section of a generated file, use %openfile and %closefile to store the text for that section in temporary buffers. Then, to write (append) the buffer contents to a file section, call LibSetSourceFileSection, passing in the desired section tag and file reference. For example, the following code uses two buffers (typesBuf and tmpBuf) to generate two sections (tagged "Includes" and "Functions") of the source file timestwo.c or .cpp (referenced as cFile):

%openfile typesBuf

#include "rtwtypes.h"

%closefile typesBuf

%<LibSetSourceFileSection(cFile,"Includes",typesBuf)>

 %openfile tmpBuf

 /* Times two function */
 real_T timestwofcn(real_T input) {
   return (input * 2.0);
}

%closefile tmpBuf

%<LibSetSourceFileSection(cFile,"Functions",tmpBuf)>

These two sections generate the entire timestwo.c or .cpp file:

#include "rtwtypes.h"

/* Times two function */
FLOAT64 timestwofcn(FLOAT64 input)
{
  return (input * 2.0);
}

Adding Code to Standard Generated Files

The timestwo.c or .cpp file generated in the previous example was independent of the standard code files generated from a model (for example, model.c or .cpp, model.h, and so on). You can use similar techniques to generate custom code within the model files. The code template API includes functions to obtain the names of the standard models files and other model-related information. The following excerpt calls LibGetMdlPubHdrBaseName to obtain the name for the model.h file. It then obtains a file reference and generates a definition in the Defines section of model.h:

%% Add a #define to the model's public header file model.h

%assign pubName = LibGetMdlPubHdrBaseName()
%assign modelH  = LibCreateSourceFile("Header", "Simulink", pubName)

%openfile tmpBuf

 #define ACCELERATION 9.81

 %closefile tmpBuf

%<LibSetSourceFileSection(modelH,"Defines",tmpBuf)>

Examine the generated rtwdemo_udt.h file to see the generated #define directive.

Customizing Main Program Module Generation

Normally, the ERT target determines whether and how to generate an ert_main.c or .cpp module based on the settings of the Generate an example main program and Target operating system options on the Templates pane of the Configuration Parameters dialog box. You can use a CFP template to override the normal behavior and generate a main program module customized for your target environment.

To support generation of main program modules, two TLC files are provided:

In the example CFP template file matlabroot/toolbox/rtw/targets/ecoder/example_file_process.tlc, the following code generates either a single- or multitasking ert_main.c or .cpp module. The logic depends on information obtained from the code template API calls LibIsSingleRateModel and LibIsSingleTasking:

%% Create a simple main.  Files are located in MATLAB/rtw/c/tlc/mw.

 %if LibIsSingleRateModel() || LibIsSingleTasking()
   %include "bareboard_srmain.tlc"
   %<FcnSingleTaskingMain()>
 %else
   %include "bareboard_mrmain.tlc"
   %<FcnMultiTaskingMain()>
 %endif

Note that bareboard_srmain.tlc and bareboard_mrmain.tlc use the code template API to generate ert_main.c or .cpp.

When generating your own main program module, you disable the default generation of ert_main.c or .cpp. The TLC variable GenerateSampleERTMain controls generation of ert_main.c or .cpp. You can directly force this variable to TLC_FALSE. The examples bareboard_mrmain.tlc and bareboard_srmain.tlc use this technique, as shown in the following excerpt from bareboard_srmain.tlc.

%if GenerateSampleERTMain
    %assign CompiledModel.GenerateSampleERTMain = TLC_FALSE
    %warning Overriding example ert_main.c!
%endif

Alternatively, you can implement a SelectCallback function for your target. A SelectCallback function is a MATLAB function that is triggered when you:

Your SelectCallback function should deselect and disable the Generate an example main program option. This prevents the TLC variable GenerateSampleERTMain from being set to TLC_TRUE.

See the rtwgensettings Structure section for information on creating a SelectCallback function.

The following code illustrates how to deselect and disable the Generate an example main program option in the context of a SelectCallback function.

slConfigUISetVal(hDlg, hSrc, 'GenerateSampleERTMain', 'off');
slConfigUISetEnabled(hDlg, hSrc, 'GenerateSampleERTMain',0);
hSrc.refreshDialog;