I don't understand what this warning is about:

comparison of constant ‘0’ with boolean expression is always true [-Wbool-compare]

I don't understand what this warning is about:

comparison of constant ‘0’ with boolean expression is always true [-Wbool-compare]

I assume it's about this line (L1797):

STACK_GROW(((oparg & 1) != 0));

The compiler probably reasons that x >= 0 where x has type bool is always true and is trying to warn you that you've got a trivial condition (the expansion of STACK_GROW(n) uses assert(n >= 0) and presumably assert(x) expands to something like if (!x) ...).

That's silly since it doesn't warn us about the equally trivial 1 >= 0 that appears in the expansion of STACK_GROW(1) -- I'm guessing it's more likely to warn based on types rather than values.

I'm not sure what to do about it.

PS. I'm still looking into your suggestion to assign the condition to a flag variable, it's a bit messy.

Here's the new version. Let me know if you like it enough to go ahead -- if not, I can easily roll it back. Note that I also fixed a bunch of typing issues (which caught one genuine bug).

Here's the new version. Let me know if you like it enough to go ahead -- if not, I can easily roll it back. Note that I also fixed a bunch of typing issues (which caught one genuine bug).

I think this is easier to read. The warning about the bool comparison is gone too. There's just the one about res being potentially unassigned.

Finally this has no compiler warnings on GitHub. I prefer this version, the changes to generate_cases.py are simpler than the version with flags.