How to use pycparser - 10 common examples

# Good luck!

from pycparser import CParser
from pycparser.c_ast import NodeVisitor, Constant
import re
import sys

DIRECTIVE_RE = re.compile("^#(.+)$", re.MULTILINE)

class DictWrapper(object):
	def __init__(self, dict):
		self.dict = dict
	def __getattr__(self, key):
		return self.dict[key]

class OptionParser(NodeVisitor):
	def __init__(self):
		self.commands = []

	def visit_ExprList(self, node):
		bits = [n[1] for n in node.children()]
		if isinstance(bits[0], Constant) and bits[0].type == "string":
			self.add_option(node, bits)
		
		self.generic_visit(node)

	def parse_file(self, filename):
		parser = CParser()
		buf = file(filename).read()
		buf = DIRECTIVE_RE.sub("", buf)#r"/* directive \1 elided */", buf)
		t = parser.parse(buf, filename)
		self.visit(t)

'int64': 'int64_t',
                }
                print(f'typedef {ctype_names[info["getCType"]]} {mangle_name(name)};')
            elif name == 'Builtin.NativeObject':
                print(f'typedef void *{mangle_name(name)};')
            else:
                print(f'typedef char {mangle_name(name)}[{info["size"]}];')
        elif info['kind'] == 'Function':
            print(f"typedef void *func_{str(hash(name))[1:]};")  # TODO: proper names
        else:
            print(f'typedef char {mangle_name(name)}[{info["size"]}];')

        if ctype:
            type_decl = TypeDecl(mangle_name(name), None, ctype)
            ctypes[name] = type_decl
            type_decl_forward = Struct(mangle_name(name) + "_s", [])
            if isinstance(type_decl, PtrDecl):
                ptr_types.add(name)
                type_decl_forward = PtrDecl(None, type_decl_forward)
                print(generator.visit(Typedef(mangle_name(name), None, ['typedef'], type_decl_forward)) + ";")

    for name in ptr_types:
        req_graph.pop(name, None)

    for name in top_sort(req_graph):
        if name in ctypes:
            print(f"\n// {name}")
            print(generator.visit(Typedef(mangle_name(name), None, ['typedef'], ctypes[name])) + ";")

def test_scalar_children(self):
        b1 = c_ast.BinaryOp(
            op='+',
            left=c_ast.Constant(type='int', value='6'),
            right=c_ast.ID(name='joe'))

        cv = self.ConstantVisitor()
        cv.visit(b1)

        self.assertEqual(cv.values, ['6'])

        b2 = c_ast.BinaryOp(
            op='*',
            left=c_ast.Constant(type='int', value='111'),
            right=b1)

        b3 = c_ast.BinaryOp(
            op='^',
            left=b2,
            right=b1)

def _run_c_to_c(self, src):
        ast = parse_to_ast(src)
        generator = c_generator.CGenerator()
        return generator.visit(ast)

def fnames_found():
    return [
        fname for fname in fnames_to_track
        if os.path.isfile(fname)
    ]


if __name__ == '__main__':

    # Confirm no files exist before we start.
    if fnames_found():
        raise SystemExit('FAIL: Files present before test.')

    # Minimal invocation that generates the files.
    from pycparser import c_parser
    parser = c_parser.CParser()

    # Were the files generated?
    fnames_generated = fnames_found()

    # Try to remove them, if so.
    for fname in fnames_generated:
        try:
            os.unlink(fname)
        except OSError:
            pass

    # Did we fail at deleting any file?
    fnames_left = fnames_found()

    # Fail if any file was generated.
    if fnames_generated:

def test_scalar_children(self):
        b1 = c_ast.BinaryOp(
            op='+',
            left=c_ast.Constant(type='int', value='6'),
            right=c_ast.ID(name='joe'))

        cv = self.ConstantVisitor()
        cv.visit(b1)

        self.assertEqual(cv.values, ['6'])

        b2 = c_ast.BinaryOp(
            op='*',
            left=c_ast.Constant(type='int', value='111'),
            right=b1)

        b3 = c_ast.BinaryOp(
            op='^',
            left=b2,
            right=b1)

        cv = self.ConstantVisitor()
        cv.visit(b3)

        self.assertEqual(cv.values, ['111', '6', '6'])

b1 = c_ast.BinaryOp(
            op='+',
            left=c_ast.Constant(type='int', value='6'),
            right=c_ast.ID(name='joe'))

        cv = self.ConstantVisitor()
        cv.visit(b1)

        self.assertEqual(cv.values, ['6'])

        b2 = c_ast.BinaryOp(
            op='*',
            left=c_ast.Constant(type='int', value='111'),
            right=b1)

        b3 = c_ast.BinaryOp(
            op='^',
            left=b2,
            right=b1)

        cv = self.ConstantVisitor()
        cv.visit(b3)

        self.assertEqual(cv.values, ['111', '6', '6'])

import os
import platform
import sys
import unittest

# Run from the root dir
sys.path.insert(0, '.')

from pycparser import c_parser, c_generator, c_ast, parse_file

_c_parser = c_parser.CParser(
                lex_optimize=False,
                yacc_debug=True,
                yacc_optimize=False,
                yacctab='yacctab')


def compare_asts(ast1, ast2):
    if type(ast1) != type(ast2):
        return False
    if isinstance(ast1, tuple) and isinstance(ast2, tuple):
        if ast1[0] != ast2[0]:
            return False
        ast1 = ast1[1]
        ast2 = ast2[1]
        return compare_asts(ast1, ast2)
    for attr in ast1.attr_names: