Adding support for offsetof()

4 files changed, 28 insertions, 1 deletions

diff --git a/pycparser/c_lexer.py b/pycparser/c_lexer.py
index e8d2af0..ce53af0 100644
--- a/pycparser/c_lexer.py
+++ b/pycparser/c_lexer.py
@@ -102,7 +102,8 @@ class CLexer(object):
     keywords = (
         '_BOOL', '_COMPLEX', 'AUTO', 'BREAK', 'CASE', 'CHAR', 'CONST',
         'CONTINUE', 'DEFAULT', 'DO', 'DOUBLE', 'ELSE', 'ENUM', 'EXTERN',
-        'FLOAT', 'FOR', 'GOTO', 'IF', 'INLINE', 'INT', 'LONG', 'REGISTER',
+        'FLOAT', 'FOR', 'GOTO', 'IF', 'INLINE', 'INT', 'LONG', 
+        'REGISTER', 'OFFSETOF',
         'RESTRICT', 'RETURN', 'SHORT', 'SIGNED', 'SIZEOF', 'STATIC', 'STRUCT',
         'SWITCH', 'TYPEDEF', 'UNION', 'UNSIGNED', 'VOID',
         'VOLATILE', 'WHILE',
diff --git a/pycparser/c_parser.py b/pycparser/c_parser.py
index 2041d4f..e4fa503 100644
--- a/pycparser/c_parser.py
+++ b/pycparser/c_parser.py
@@ -1572,6 +1572,14 @@ class CParser(PLYParser):
         """ primary_expression  : LPAREN expression RPAREN """
         p[0] = p[2]
 
+    def p_primary_expression_5(self, p):
+        """ primary_expression  : OFFSETOF LPAREN type_name COMMA identifier RPAREN
+        """
+        coord = self._coord(p.lineno(1))
+        p[0] = c_ast.FuncCall(c_ast.ID(p[1], coord),
+                              c_ast.ExprList([p[3], p[5]], coord),
+                              coord)
+
     def p_argument_expression_list(self, p):
         """ argument_expression_list    : assignment_expression
                                         | argument_expression_list COMMA assignment_expression
diff --git a/tests/test_c_lexer.py b/tests/test_c_lexer.py
index 6d0b52d..033963e 100644
--- a/tests/test_c_lexer.py
+++ b/tests/test_c_lexer.py
@@ -84,6 +84,9 @@ class TestCLexerNoErrors(unittest.TestCase):
         # - is MINUS, the rest a constnant
         self.assertTokensTypes('-1', ['MINUS', 'INT_CONST_DEC'])
 
+    def test_special_names(self):
+        self.assertTokensTypes('sizeof offsetof', ['SIZEOF', 'OFFSETOF'])
+
     def test_floating_constants(self):
         self.assertTokensTypes('1.5f', ['FLOAT_CONST'])
         self.assertTokensTypes('01.5', ['FLOAT_CONST'])
diff --git a/tests/test_c_parser.py b/tests/test_c_parser.py
index 035182d..556748c 100755
--- a/tests/test_c_parser.py
+++ b/tests/test_c_parser.py
@@ -475,6 +475,21 @@ class TestCParser_fundamentals(TestCParser_base):
                         ['TypeDecl',
                             ['IdentifierType', ['int']]]]]])
 
+    def test_offsetof(self):
+        e = """
+            void foo() {
+                int a = offsetof(struct S, p);
+                a.b = offsetof(struct sockaddr, sp) + strlen(bar);
+            }
+            """
+        compound = self.parse(e).ext[0].body
+        s1 = compound.block_items[0].init
+        self.assertIsInstance(s1, FuncCall)
+        self.assertIsInstance(s1.name, ID)
+        self.assertEqual(s1.name.name, 'offsetof')
+        self.assertIsInstance(s1.args.exprs[0], Typename)
+        self.assertIsInstance(s1.args.exprs[1], ID)
+
     # The C99 compound literal feature
     #
     def test_compound_literals(self):