This is a GLSL parser implemented with flex and bison. The grammar is based on the OpenGL 4.5 reference specs. The parser generates an AST represented in C data structures. The AST structure is documented in AstNodes.md.
The header file glsl_parser.h documents the interface to the parser and the header file glsl_ast.h defines some useful functions for working with the AST it generates.
The included Makefile builds a test program that reads a shader from a file or standard input and prints out a human readable version of the shader's AST and attempts to regenerate the input shader from the AST.