liwc is a tool suite which includes programs for converting C++ comments to C comments, removing C comments, printing string literals, and converting characters to trigraphs and trigraphs to characters.
pyC11 is a grammar to parse programs in the C programming language following ISO/IEC 9899:2011. It is written using pyPEG, a parsing framework for Python. The grammar supports Python 2.7 and 3.x. The test bench requires py.test.