Accept empty 'case' or 'default' labels (#564)

Author: ignatirabo

pycparser/c_parser.py

@@ -1584,6 +1584,14 @@ def p_labeled_statement_4(self, p):
         """ labeled_statement : ID COLON """
         p[0] = c_ast.Label(p[1], c_ast.EmptyStatement(self._token_coord(p, 1)), self._token_coord(p, 1))
 
+    def p_labeled_statement_5(self, p):
+        """ labeled_statement : CASE constant_expression COLON """
+        p[0] = c_ast.Case(p[2], [c_ast.EmptyStatement(self._token_coord(p, 2))], self._token_coord(p, 1))
+
+    def p_labeled_statement_6(self, p):
+        """ labeled_statement : DEFAULT COLON """
+        p[0] = c_ast.Default([c_ast.EmptyStatement(self._token_coord(p, 1))], self._token_coord(p, 1))
+
     def p_selection_statement_1(self, p):
         """ selection_statement : IF LPAREN expression RPAREN pragmacomp_or_statement """
         p[0] = c_ast.If(p[3], p[5], None, self._token_coord(p, 1))

tests/test_c_parser.py

@@ -2504,6 +2504,40 @@ def test_label_empty_statement(self):
         self.assertIsInstance(s1_ast.ext[0].body.block_items[2], Label)
         self.assertIsInstance(s1_ast.ext[0].body.block_items[2].stmt, EmptyStatement)
 
+    def test_case_empty_statement(self):
+        # Labels with empty statements and no semicolon should be parsed correctly
+        s1 = r'''
+            int main() {
+                int i = 0;
+                switch (i) {
+                    case 0:
+                        i = 1;
+                    case 1:
+                }
+                return i;
+            }
+            '''
+        s2 = r'''
+            int main() {
+                int i = 0;
+                switch (i) {
+                    case 0:
+                        i = 1;
+                    default:
+                }
+                return i;
+            }
+            '''
+        s1_ast : FileAST = self.parse(s1)
+        s2_ast : FileAST = self.parse(s2)
+        self.assertIsInstance(s1_ast.ext[0].body.block_items[1], Switch)
+        self.assertIsInstance(s1_ast.ext[0].body.block_items[1].stmt, Compound)
+        self.assertIsInstance(s1_ast.ext[0].body.block_items[1].stmt.block_items[0], Case)
+        self.assertIsInstance(s1_ast.ext[0].body.block_items[1].stmt.block_items[0].stmts[0], Assignment)
+        self.assertIsInstance(s1_ast.ext[0].body.block_items[1].stmt.block_items[1], Case)
+        self.assertIsInstance(s1_ast.ext[0].body.block_items[1].stmt.block_items[1].stmts[0], EmptyStatement)
+        self.assertIsInstance(s2_ast.ext[0].body.block_items[1].stmt.block_items[1].stmts[0], EmptyStatement)
+
 if __name__ == '__main__':
     #~ suite = unittest.TestLoader().loadTestsFromNames(
         #~ ['test_c_parser.TestCParser_fundamentals.test_typedef'])