CODEWITHSUNDEEP
pythonc++libclang
DarkMorford
DarkMorford

Reputation: 525

How can I retrieve fully-qualified function names with libclang?

I need to parse a C++ code file and find all the function calls in it with fully-qualified names. I'm using libclang's Python bindings because it seems easier than writing my own C++ parser, even if the documentation is sparse.

Example C++ code:

namespace a {
  namespace b {
    class Thing {
    public:
      Thing();
      void DoSomething();
      int DoAnotherThing();
    private:
      int thisThing;
    };
  }
}

int main()
{
  a::b::Thing *thing = new a::b::Thing();
  thing->DoSomething();
  return 0;
}

Python script:

import clang.cindex
import sys

def find_function_calls(node):
  if node.kind == clang.cindex.CursorKind.CALL_EXPR:
    # What do I do here?
    pass
  for child in node.get_children():
    find_function_calls(child)

index = clang.cindex.Index.create()
tu = index.parse(sys.argv[1])
find_function_calls(tu.cursor)

The output I'm looking for is a list of fully-qualified names of functions that were called:

a::b::Thing::Thing
a::b::Thing::DoSomething

I can get the function's "short" name by using node.spelling, but I don't know how to find the class/namespace that it belongs to.

Upvotes: 4

Views: 4477

Answers (1)

Andrew Walker
Andrew Walker

Reputation: 42490

You can use the cursor referenced property to get a handle to the definition, and then you can recurse up the AST via the semantic_parent property (stopping at the root or when the cursor kind is translation unit) to build the fully qualified name. 

import clang.cindex
from clang.cindex import CursorKind

def fully_qualified(c):
    if c is None:
        return ''
    elif c.kind == CursorKind.TRANSLATION_UNIT:
        return ''
    else:
        res = fully_qualified(c.semantic_parent)
        if res != '':
            return res + '::' + c.spelling
    return c.spelling

idx = clang.cindex.Index.create()
tu = idx.parse('tmp.cpp', args='-xc++ --std=c++11'.split())
for c in tu.cursor.walk_preorder():
    if c.kind == CursorKind.CALL_EXPR:
        print fully_qualified(c.referenced)

Which produces:

a::b::Thing::Thing
a::b::Thing::DoSomething

Upvotes: 6

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