CODEWITHSUNDEEP
c++regexfunctionvisual-studio-2012
Abdul Rehman Janjua
Abdul Rehman Janjua

Reputation: 1571

Regex for extracting functions from C++ code

I have sample C++ code (http://pastebin.com/6q7zs7tc) from which I have to extract functions names as well as the number of parameters that a function requires. So far I have written this regex, but it's not working perfectly for me.

(?![a-z])[^\:,>,\.]([a-z,A-Z]+[_]*[a-z,A-Z]*)+[(]

Upvotes: 2

Views: 5642

Answers (1)

Ira Baxter
Ira Baxter

Reputation: 95306

You can't parse C++ reliably with regex.

In fact, you can't parse it with weak parsing technology (See Why can't C++ be parsed with a LR(1) parser?). If you expect to get extract this information reliably from source files, you will need a time-tested C++ parser; see https://stackoverflow.com/a/28825789/120163

If you don't care that your extraction process is flaky, then you can use a regex and maybe some additional hackery. Your key problem for heuristic extraction is matching various kinds of brackets, e.g., [...], < ... > (which won't quite work for shift operators) and { ... }. Bracket matching requires you to keep a stack of seen brackets. And bracket matching may fail in the presence of macros and preprocessor conditionals.

Upvotes: 5

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