Using c++ to write c++

[Jordan C Atlas]

Hello, I'm interested in writing a program that reads an XML input file, and then based on the content of that file, writes another program which is then compiled. I imagine that I'd do this by defining an ofstream and literally writing the new prorgram line by line. The "preprocessing" program would look something like this: ofstream out("program.cpp"); out << "int main()" << endl; out << "{" << endl; out << "return 0;" << endl; out << "}" << endl; Where I'd have to write the relevant functions for my problem. I'd then run the proprocessing program and compile the "new" program using a batch file. My question is this: Is there a name for this type of programming? I'd like to read up about it in general before I dive in but the searches I have done haven't revealed much. Also, does MS VC++ provide any helpful methods for writing such programs? Thanks, --Jordan Atlas

[Lost User]

Its called code generation and its a pretty complex topic. Lots of high end programming tools do this. Rational Rose for example can generate code from UML models. You could look at using Lex. You could create an object model to represent the C++ entities (classes, function, variables etc etc). A program would be represented by a tree like structure of these objects. Each of these classes could construct itself from the xml and then write iteself to the stream. You could take it a step further and make this object model non language specific then apply formatting objects for the language you want (C++, c#, Java) this would mean however that your xml representation would be limited to features common to these languages.

[Bob Stanneveld]

Hello, Is the XML file a something you can change? I mean, if you can influence the data in the XML file, it may be better to stick to scripts. You'll avoid mass complexity of generating C++ code. Behind every great black man...             ... is the police. - Conspiracy brother Blog[^]

[Jordan C Atlas]

Hi, Thanks for the replies. The XML file is a representation of a model (variables and equations). The program that I'm trying to have it automatically write will solve the system of equations represented in the XML file. I'm trying to do this so that the (compiled) new simulation program will be faster than if I repeatedly sampled information in the XML file... --Jordan

[Bob Stanneveld]

So you are doing this for performance reasons. Than scripts are probably too slow for you too. Behind every great black man...             ... is the police. - Conspiracy brother Blog[^]