Module Diagram for C

[hboehmer]

Hello Bruno,

I'm an engineer in the field of embedded systems. I think BOUML is great for support system development because of the ability to generate code direct from a class diagram. But it's necessary to have a compiler for C++. For a large amount of microcontroller families there are only C-Compilers avaliable.

When developing a small embedded system on step is to construct a module diagram. This is very similar to a class diagram. A module is like a class in common only with operations but without attributes. The code generated from a module should also be an implementation file and an declaration file (with the function prototypes).

The only association between modules is a directional dependency. When generating code this leads to an include statement in the implementation file of the module which depends on an other module.

Sometimes a module have also some attributes (global variables). They need to be defined in the implementation file when code generating. In the header file they needs a declaration with the keyword 'extern'.

I have tried to use the class diagram of BOUML to design a module diagram. I deleted the definition '${class}::' in the operation dialog for every operation on the tab 'C++'. Also I deleted some definitions in the class dialog (except '${members}'). So when generating code I get implementation files with only keywords my c-compiler understand. I have only to rename the files from *.cpp to *.c. But in the header file I can't suppress the keywords public, private, etc. For the global variables I also don't have a solution.

Can you imagine to support the language C with BOUML in the future?

Best regards,
Heiko Boehmer

[Bruno Pagès]

Hello,

To use a struct rather than a class allows to not generate public, but this solve only a part of the problem.

To support C means to have the code generator, reverse and roundtrip, but this have sense in UML only if the C code respect rules like your 'module', so is not 'standard' C. To have only a 'patched' version of the C++ code generator to be compatible with your request is not difficult to do but is only a partial answer.

[hboehmer]

Hello Bruno,

thanks for your answer. I understand that support for a new language is a very complex task. Especially for a language like C without direct support for object oriented concepts like classes.

The hint to stereotyp <<struct>> is a possible workaround. But it's for a C programmer a little bit confusing because in C this keyword don't allows to contain operations i.e. functions.

So I thought, perhaps there is a possibilty to add a new stereotyp <<module>> with the same functionality like <<struct>>.

In the generation settings of BOUML on the second tab 'Stereotype' there is a list with 'Classes stereotypes correspondence'. I added at the end of this list a new line with the keyword 'module' in the first column 'UML'. All other columns I set to 'struct'.

But if I choose the new stereotype <<module>> in the class dialog the generated source code will have again the keyword 'public'.

Is there an other way to add a new stereotype? Or is it not possible?

Best regards,
Heiko Boehmer

[Bruno Pagès]

But if I choose the new stereotype <<module>> in the class dialog the generated source code will have again the keyword 'public'.

At class level <<module>> is well managed as <<struct>>, but yes this is not the case at attribute/operation level, this is a bug, I will fix that.

Yes to fully add a new language is a huge work, I will not add C like that. Except for the generation settings the editions will use the C++ tab of the editors. The code generation will be done by a dedicated C generator, this is necessary because struct/union/enum must be managed but their use is not the same in C and C++, for instance if S is a struct the C++ form "S s" is invalid and must be "struct S s" in C. I don't plan to add C reverse nor roundtrip.

<<module>> is a new 'builtin' stereotype, applicable on classes, managed by the C generator. It is necessary to add this stereotype even there is a dedicated generator to get the right default definition and code generation preview during the editions.

a class stereotyped <<module>> generate nothing for itself, only its members are generated.
in a class stereotyped <<module>> a non static attribute or relation to an other class produces a global variable in the source file, and its declaration as extern in the header file.
in a class stereotyped <<module>> a static attribute or relation to an other class produces a static variable in the source file, nothing in header file
in a class stereotyped <<module>> a non static operation produces a C function in the source file, and its declaration as extern in the header file
in a class stereotyped <<module>> a static operation produces a static C function in the source file, nothing in header file

classes stereotyped struct/union/enum produce expected code in header files.

[hboehmer]

Hello Bruno,

thanks for your answer. This sounds all very good. I'm curious about the next Version of BOUML.

Best regards,
Heiko Boehmer

[Bruno Pagès]

At class level <<module>> is well managed as <<struct>>, but yes this is not the case at attribute/operation level, this is a bug, I will fix that.

I was wrong, there is no bug, the visibility is not generated when it is 'public'

[Bruno Pagès]

Hello Heiko,

First sorry for the very long delay between your request and its realization in Bouml.

Please, are you interested to test the new version of Bouml including the C generation before I deliver it officially ?

Best regards,
Bruno pagès

[Bruno Pagès]

Hello,

Feature available in Bouml 6.5, please refer to the documentation chapter C generator

Best regards,
Bruno Pagès

[hboehmer]

Hello Bruno,

thanks for the features concerning C. I have made some first successful tests.

A problem exist if someone forget to load the file C:\Program Files\Bouml\C\C.prj before creating a new project.
Consider the following situation:
Starting BOUML,
Project\New,
Languages\C managment and default...,
New class view,
New class, insert stereotype <<c_module>> in class dialog,
Add operation, then the Operation dialog hangs and can't be closed.

I think the problem is, when I choose the language C, the stereotype <<c_module>> is not in the Generation settings dialog.

Best regards,
Heiko Boehmer

[Bruno Pagès]

Hello,

I did your sequence and I am able to add operations without problems

you say "dialog hangs and can't be closed", do you mean bouml is dead/frozen ?

what it the name of the operation and which fields you set in the operation dialog ?