使用pycparser在C结构中解析结构？

Question

I have this example c file I want to parse:

StrcutWithinStruct.c
// simple struct within a struct example

struct A {
 int a;
};

struct B {
 A a;
 int b;
};

I'm running pcyparser to parse it, with the following code

exploreStruct.py
#parse StructWithinStruct

from pycparser import parse_file
ast = parse_file(filename='..\StructWithinStruct.c')
ast.show()

As a result, I got the following:

Tracback (most recent call last):
  File "exploreStruct.py", line 3, in <module>
   ast = parse_file(filename='...\StructWithinStruct.c')
  File "D:\...\pycparser\__init__.py", line 93, in parse_file
   return parser.parse(text,filename)
  File "D:\...\pycparser\c_parser.py", line 146, in parse
   debug=debug_level)
  File "D:\...\pycparser\yacc.py", line 331, in parse
   return self.parseropt_notrack(input, lexer, debug, tracking, tokenfunc)
  File "D:\...\pycparser\yacc.py", line 1181, in parseropt_notrack
   tok=call_errorfunc(self.errorfunc, errtoken, self)
  File "D:\...\pycparser\yacc.py", line 193, in call_errorfunc
   r=errorfunc(token)
  File "D:\...\pycparser\c_parser.py", line 1699, in p_error
   column=self.clex.find_tok_column(p)))
  File "D:\...\pycparser\plyparser.py", line 55, in _parse_error
   raise ParseError("%s: %s % (coord, msg))
pycparser.plyparser.ParserError: D:...\StructWithinStruct.c:7:2: Before A

So, is pycparser can handle struct within struct, or not? I thought this is some basic requirement, so I'm pretty sure that the problem lying in my configuration somewhere...

One more thing: I know that pcypareser author, @ Eli Bendersky , says that one should use Clang to parse C++ , but I will like to know if there's another option nowadays to parse C++ (preferably over Python), and is user-friendly.

Thanks.

Answer 1

Your struct declarations are not closed with a semicolon:

Additionally A itself is not a type name in C. In C++ A alone would suffice, but in C you need to add the struct keyword.

struct A {
 int a;
};

struct B {
 struct A a;
 int b;
};

Or, you can declare a synonym with a typedef keyword:

struct A {
 int a;
};

typedef struct A A;

or, shorter:

typedef struct A {
 int a;
} A;

From that point the declaration

A a;

should compile properly.