Fix error transforming an empty switch (#346)
* Fix error transforming an empty switch
The parser would crash on that line for `switch(1) {}`
because NoneType is not iterable.
Fixes #345
* Add a test of empty switch statements
* Address review comments
diff --git a/pycparser/ast_transforms.py b/pycparser/ast_transforms.py
index ba50966..0aeb88f 100644
--- a/pycparser/ast_transforms.py
+++ b/pycparser/ast_transforms.py
@@ -74,7 +74,8 @@
# Goes over the children of the Compound below the Switch, adding them
# either directly below new_compound or below the last Case as appropriate
- for child in switch_node.stmt.block_items:
+ # (for `switch(cond) {}`, block_items would have been None)
+ for child in (switch_node.stmt.block_items or []):
if isinstance(child, (c_ast.Case, c_ast.Default)):
# If it's a Case/Default:
# 1. Add it to the Compound and mark as "last case"
diff --git a/tests/test_c_parser.py b/tests/test_c_parser.py
index ad9a218..49cada3 100755
--- a/tests/test_c_parser.py
+++ b/tests/test_c_parser.py
@@ -1792,6 +1792,7 @@
switch = ps1.ext[0].body.block_items[0]
block = switch.stmt.block_items
+ self.assertEqual(len(block), 4)
assert_case_node(block[0], '10')
self.assertEqual(len(block[0].stmts), 3)
assert_case_node(block[1], '20')
@@ -1819,6 +1820,7 @@
switch = ps2.ext[0].body.block_items[0]
block = switch.stmt.block_items
+ self.assertEqual(len(block), 5)
assert_default_node(block[0])
self.assertEqual(len(block[0].stmts), 2)
assert_case_node(block[1], '10')
@@ -1830,6 +1832,18 @@
assert_case_node(block[4], '40')
self.assertEqual(len(block[4].stmts), 1)
+ s3 = r'''
+ int foo(void) {
+ switch (myvar) {
+ }
+ return 0;
+ }
+ '''
+ ps3 = self.parse(s3)
+ switch = ps3.ext[0].body.block_items[0]
+
+ self.assertEqual(switch.stmt.block_items, [])
+
def test_for_statement(self):
s2 = r'''
void x(void)
