XOCFE is an concise, clearly, C compiler frontend, it is easy to understand and modify. XOCFE does not include preprocessor, so its input is pure C, output is an AST tree. XOCFE only support C99.
A concise and readable C++ Template Library is under 'src/com' directory. It can be used to build whole compiler, or anyother project.
BUILD: ./autogen.sh & ./configure & make
RUN: cd src & ./xocfe ../test/test_ansic.c -dump asttree.log
Enjoy the code.