 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Java Forum / General / January 2008C++ to Java Conversion Utility
I'm looking for a utility program that will convert C++ to Java. I have already searched this group on the topic, but most of the posts are quite old. I'm wondering if there is more up-to-date info. I saw one previous post suggesting C2J. I'm going to give that a try, but based on that thread it looks like the results from C2J may not be all that useful. Also, I did read all the advice explaining that a C++ to Java utility is a bad idea. I am in agreement. But here is my situation: I work on a tool, written in java, that monitors and displays messages exchanged between two C++ programs. The number of messages is growing quite fast, and even the definition for existing messages changes quite often. Currently I am converting these message definitions by hand from the original C++ source to java, but I am rapidly becoming unable to keep up with the changes. Also, the only things I really need to convert automatically are header files, and those header files have either: - a struct that defines the fields in a message - a enum that specifies the possible values for a field in a message So I am not trying to convert whole programs...just some fairly simple type definitions. Automation would help alot. I'll write my own tool if I need to, but why re-invent the wheel if I don't need to? Any advice is appreciated. > Also, the only things I really need to convert automatically are > header files, and those header files have either: [quoted text clipped - 6 lines] > Automation would help alot. I'll write my own tool if I need to, but > why re-invent the wheel if I don't need to? If it's just typedefs and header files, might it be possible to establish a fixed set of conversion rules (but still flexible enough to add new ones or tweak old ones) and write a Perl or Ruby script to do this? That's probably the road I'd take. > > Also, the only things I really need to convert automatically are > > header files, and those header files have either: [quoted text clipped - 11 lines] > to add new ones or tweak old ones) and write a Perl or Ruby script to > do this? That's probably the road I'd take. I agree. And I should probably just bite the bullet and do it. I just wanted to check if anything was already available before doing that work. Also, I confess I've never written anything in Perl or Ruby. In your opinion, do you think it would be more efficient for me to learn one of those and use it for the converter. Would either of those be significantly better than just writing the converter in java? > I agree. And I should probably just bite the bullet and do it. I > just wanted to check if anything was already available before doing [quoted text clipped - 4 lines] > of those and use it for the converter. Would either of those be > significantly better than just writing the converter in java? If you're not familiar with Perl or Ruby, then it might be best to write the converter in Java, seeing as you know it and are familiar with it. It would probably be fastest to get the job done in Java. But if time is not an issue and you want to learn something new, then go for Perl or Ruby. Personally, I would go with Perl because I know it much better than I know Ruby, but I've been picking up some Ruby and am liking it a lot. You could also try Python, which I understand could be used just as easily as Ruby or Perl for this sort of task. > I'm looking for a utility program that will convert C++ to Java. > [quoted text clipped - 27 lines] > > Any advice is appreciated. I tried C2J, but I'm pretty sure it is not the tool for this job. It would seem that you need an entire, compilable C project; there is no single file conversion. And it also seems like you need to add files to a C2J workspace one at a time (the project I'm trying to convert has hundreds of files). And it crashes alot. And it won't take .cpp files...only .c files. Maybe someone out there has looked deeper than I have, and has discovered other ways to get C2J to convert files. I'd be interested in knowing if I misunderstood something about how C2J works. ... > Also, the only things I really need to convert automatically are > header files, and those header files have either: [quoted text clipped - 3 lines] > So I am not trying to convert whole programs...just some fairly simple > type definitions. ... Do you have influence over the C++ part of the project? If so, I suggest the following: 1. Define a language for the logical structure of the messages files, and maintain the files in that language. 2. Write a program that converts from the logical messages language to C++ header file. 3. Write a program that converts from the logical messages language to Java, or write Java code to read and interpret the logical messages language. This avoids a major risk of your current plan. Suppose you find or create something that converts from some subset of C++ to Java. Some time in the future, a C++ developer might use, in the header file, some valid C++ structure that is not supported by your conversion utility. If you are lucky, the incompatibility will be detected during the build. If not, you may have a tough debug job on your hands. Patricia > ...> Also, the only things I really need to convert automatically are > > header files, and those header files have either: [quoted text clipped - 27 lines] > > Patricia Agreed, that would be better for the work I am doing. Unfortunately I don't have any influence over the C++ part. > 1. Define a language for the logical structure of the messages files, > and maintain the files in that language. And maybe call it IDL ... Like when used by CORBA, COM and UNO. :-) Arne >Currently I am converting these message definitions by >hand from the original C++ source to java, but I am rapidly becoming >unable to keep up with the changes. I would write a generator to generate both the C++ and the Java source code (only the message definitions). Better, but possibly more effort: Both programs read the message definitions at run-time,, so it will not be necessary anymore to change the source code, when a message definition has to be changed. > >Currently I am converting these message definitions by > >hand from the original C++ source to java, but I am rapidly becoming [quoted text clipped - 8 lines] > so it will not be necessary anymore to change the source > code, when a message definition has to be changed. That is a good idea, but not possible in my situation. I have no influence over the C++ development. Also, they are writing DSP code that has no filesystem access. So the language independent definitions would need to get pulled into their build product at compile time. I think it is more work than I can take on to make that happen. It might not even be possible, given their development environment. Even if I could, I think I would have trouble getting the C++ project managers to accept that change anyway. Something I didn't mention before: the C++ code is generated by a 3rd party design tool. Thus the source I'm trying to translate has very standard formatting and syntax. It should be acceptably future-proof for me to treat this as my "logical language" for message definitions. Also, I just want the conversion grunt-work to be automated, but not the whole process. I will monitor churn to existing message defintions, so I should be able to catch any changes that cause the automated conversion to produce undesirable results. > Something I didn't mention before: the C++ code is generated by a 3rd > party design tool. Thus the source I'm trying to translate has very > standard formatting and syntax. It should be acceptably future-proof > for me to treat this as my "logical language" for message definitions. I also like the idea of using a language-neutral data definition and using it to generate C++ and Java, but I see your problem. A couple of thoughts: If the design tool has the ability to export and/or import message definitions in a language neutral format, it would open up two possibilities: - maintain a separate, definitive set of language definitions that is imported into the design tool to generate C++ and processed by your tool to generate Java source. The master definitions could be either written in the design tool's import format or be generated from your own format, database or whatever. - treat the design tool's repository as definitive. Export the definitions from it and use them to feet your Java generator. I know this sounds very similar to translating the C++ source but it may be easier to integrate with the project work flows. This might be better than translating generated C++, especially if the import/export format is documented, stable and is more easily parsed than C++ source. > Also, I just want the conversion grunt-work to be automated, but not > the whole process. I will monitor churn to existing message > defintions, so I should be able to catch any changes that cause the > automated conversion to produce undesirable results. As you're evidently in a separate project team from the C++ gang, it stands to reason that manual change monitoring would be necessary. Have you considered using a parser generator, such as Coco/R to write your translation tool? I've used it to generate Java code to parse C preprocessor directives and that was pretty straight forward. Even with the learning curve (it was the first time I'd used it) I was able to create a parser faster than I could have written it by hand.  Signaturemartin@ | Martin Gregorie gregorie. | Essex, UK org | >As you're evidently in a separate project team from the C++ gang, it >stands to reason that manual change monitoring would be necessary. Ron can explain to his supervisor that the current procedure requires continuous human effort and suggest changes. Even if a C++-to-Java translator would translate the structural definitions, usually a program still needs to be adjusted manually to a change in the interface structure. If Ron still is required to follow whatever the C++ section delievers, then this is not so much his problem if he is paid by the hour. The supervisor can understand that the additional effort is not Rons fault; and Ron gets paid for his effort. > Even if a C++-to-Java translator would translate the > structural definitions, usually a program still needs to > be adjusted manually to a change in the interface structure. Quite, and the only real solution to that is, as Patricia said, to store the definitions in some form of database and load it at run time, but this would require a fairly major rewrite on both the C++ and Java programs. If the design is good and the designer has paid attention to run-time efficiency the performance can be surprisingly good once the data definitions have been loaded. IME this is a place where the designers can't delegate run-time efficiency to the programmers. > If Ron still is required to follow whatever the C++ section > delievers, then this is not so much his problem if he is paid > by the hour. The supervisor can understand that the additional > effort is not Rons fault; and Ron gets paid for his effort. ...but the more straight forward change implementation is once the project managers have got their heads together, the less likelihood there is of mistakes and recriminations. Signaturemartin@ | Martin Gregorie gregorie. | Essex, UK org | ... > Something I didn't mention before: the C++ code is generated by a 3rd > party design tool. Thus the source I'm trying to translate has very > standard formatting and syntax. It should be acceptably future-proof > for me to treat this as my "logical language" for message definitions. ... That makes a big difference. It is both an opportunity, because the code is less likely to incorporate arbitrary idiosyncrasies than direct human-written code, and a limitation, because it would be practically impossible for you to change what the design tool generates. At the best, the design tool has a document describing the output file rules. That would make it easier to find out not just what it generates for current cases, but what it might generate for future inputs. Patricia > I would write a generator to generate both the C++ and the > Java source code (only the message definitions). like CORBA? see http://mindprod.com/jgloss/corba.html SignatureRoedy Green, Canadian Mind Products The Java Glossary, http://mindprod.com >I'm looking for a utility program that will convert C++ to Java. Consider using a Funduc Search/Replace script. You can use from-to pairs and from-to regex pairs. see http://mindprod.com/jgloss/funduc.html SignatureRoedy Green, Canadian Mind Products The Java Glossary, http://mindprod.com > I work on a tool, written in java, that monitors and displays messages > exchanged between two C++ programs. The number of messages is growing [quoted text clipped - 7 lines] > - a struct that defines the fields in a message > - a enum that specifies the possible values for a field in a message This is better done by definining your messages with YAML or JSON, then using the corresponding language bindings for marshalling and unmarshalling the messages. > Automation would help alot. I'll write my own tool if I need to, but > why re-invent the wheel if I don't need to? Indeed. /gordon -- >> I work on a tool, written in java, that monitors and displays messages >> exchanged between two C++ programs. The number of messages is growing [quoted text clipped - 11 lines] > then using the corresponding language bindings for marshalling and > unmarshalling the messages. That would either only be transport not API or not be very type safe. Arne Ron schreef: > I'm looking for a utility program that will convert C++ to Java. > [quoted text clipped - 27 lines] > > Any advice is appreciated. I recently was pointed to SWIG. It does a great job creating Java wrappers to existing C/C++ classes and functions, using JNI. It might do what you want. I had quite a hard time setting up Eclipse to handle the SWIG project, (or JNI, for that matter) so if you want to do that, you can ask again. HTH, H. SignatureHendrik Maryns http://tcl.sfs.uni-tuebingen.de/~hendrik/ ================== http://aouw.org Ask smart questions, get good answers: http://www.catb.org/~esr/faqs/smart-questions.html Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.