Fix C++ thunk triggering for functions with default args which return a simple type #6152
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…etScopeIdOffset()` After this change, we correctly increment the offset by the next switch case type. Before this change, we accidentally incremented the offset by `functions()` size instead of `cpp_overload_sets()` size and vice versa. Also sorted the switch cases according to the order of the enum, for consistency which might help prevent a future similar incident. This fix prevents crashing in the newly introduced test `multiple_too_few_args_calls`. This also has the side effect of showing `null name` for `cpp_overload_set_type` and `cpp_overload_set_value`, instead of having an arbitrary name. Examples that deomnstrate the old name is arbitrary can easily be seen in tests like `cpp_namespace.carbon` and `decayed_param.carbon`, but careful review would show that all old names are arbitrary, though often luckily almost make sense.
… a simple type Before this change, we wrongly ignore the decision to generate a thunk for a function with default args by overriding this decision with the fact the return type by itself doesn't require a thunk. This causes not generating a thunk which leads to crashing in lowering. Add tests that show that now thunk is generated in `check` and it no longer crashes in `lower. Based on carbon-language#6151. Follow up of carbon-language#6108.
dwblaikie
approved these changes
Oct 1, 2025
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Before this change, we wrongly ignore the decision to generate a thunk for a function with default args by overriding this decision with the fact the return type by itself doesn't require a thunk.
This causes not generating a thunk which leads to crashing in lowering.
Add tests that show that now thunk is generated in
checkand it no longer crashes inlower.Follow up of #6108.