Abstract-syntax tree for subset of C

For teaching purpose we are building a javascript step by step interpreter for (a subset of) C code.

Basically we have : int,float..., arrays, functions, for, while... no pointers. The javascript interpreter is done and allow us to explain how a boolean expression is evaluated, will show the variables stack...

For now, we are manually converting our C examples to some javascript that will run and build a stack of actions (affectation, function call...) that can later on be used to do the step by step stuff. Since we are limiting ourselves to a subset of C it's quite easy to do.开发者_运维问答

Now we would like to compile the C code to our javascript representation. All we need is a Abstract-syntax tree of the C code and the javascript generation is straightforward.

Do you know a good C-parser that could generate a such tree ? No need to be in javascript (but that would be perfect), any language is alright as this can be done offline.

I've looked at Emscripten ( https://github.com/kripken/emscripten ) but it's more a C=>javascript compiler and that's not what we want.

I've recently used Eli Bendersky's pycparser to mess with ASTs of C code. I think it'd work well for your purposes.

I think that ANTLR has a full C parser.

To do your translation task, I suspect you will need full symbol table support; you have to know what the symbols mean. Here most "parsers" will fail you; they don't build a full symbol table. I think ANTLR does not, but I could be wrong.

Our DMS Software Reengineering Toolkit with its C Front End provides a full C arser, and builds complete symbol tables. (You may not need it for your application, but it includes a full C preprocessor, too). It also provide control flow, data flow, points-to-analysis and call graph construction, all of which can be useful in translating C to whatever your target virtual machine is.