Re: warning: dereferencing type-punned pointer

On 24.07.24 16:05, Tom Lane wrote:
> I'm not very thrilled with these changes. It's not apparent why
> your compiler is warning about these usages of IsA and not any other
> ones,

I think one difference is that normally IsA is called on a Node * (since
you call IsA to decide what to cast it to), but in this case it's called
on a pointer that is already of type ErrorSaveContext *. You wouldn't
normally need to call IsA on that, but it comes with the
SOFT_ERROR_OCCURRED macro. Another difference is that most nodes are
dynamically allocated but in this case the ErrorSaveContext object (not
a pointer to it) is part of another struct, and so I think some
different aliasing rules might apply, but I'm not sure.

I think here you could just bypass the SOFT_ERROR_OCCURRED macro:

- if (SOFT_ERROR_OCCURRED(&jsestate->escontext))
+ if (jsestate->escontext.error_occurred)