patch: fix NoneType error for 'visit_Case' function in c_generator.py…

[kmg3821]

… when a case is empty by adding none type checker

[eliben]

Thanks!

Would it be possible to add a test that triggers this? (fails before the PR, succeeds after)

[kmg3821]

Thanks!

Would it be possible to add a test that triggers this? (fails before the PR, succeeds after)

Scenario :
C code --> AST --> C code

Input C code :

void foo(int n) {
switch (n)
{
case 0:
case 1:
printf("Hello");
break;
case 2:
printf("World");
default:
break;
}
}

Error occurs when converting AST into C code :

This happens because of the "case 0" statement, which is empty :

After adding the None type checker :
The following C code is successfully generated.

[eliben]

Yes, I understand

My question is - can you add a test to https://github.com/eliben/pycparser/blob/main/tests/test_c_generator.py as part of your PR that triggers this behavior and verifies that the change fixes it

[kmg3821]

I'm sorry for the confusion, but the problem is not with the c_generator.py.

The issue lies with the "to_dict" function in c_json.py within the examples folder, which saves None instead of an empty list for the case node type.

It appears that tests are not performed for the examples, so I did not add the test you requested.

However, if needed, I can add it.

[eliben]

The PR name should be adjusted also to reflect what it's fixing

@mypalmike can you PTAL?

[eliben]

do an if...else here?