Thread

Re: Confused static assertion implementation

Peter Eisentraut <peter@eisentraut.org> — 2025-12-15T11:58:40Z

On 14.11.25 23:27, Thomas Munro wrote:
> On Fri, Nov 14, 2025 at 6:18 PM Chao Li <li.evan.chao@gmail.com> wrote:
>> As you added a semi-colon in the line, the one after the empty line can be deleted, though C allows empty statement, but unnecessary, and may lead to confusion for code readers.
> 
>> You missed to replace this pgac_cv__static_assert with the new name.
> 
> Ugh, yeah, the configure change was hopeless.  It looked like it
> worked in configure's stdout, which I mistook for success and posted
> too soon, sorry about that.  I have fixed those points and verified
> that pg_config.h actually has the expected value.

I have committed this, with some light editing of the comments.

We are now down to 4 from previously 12 static assertion implementation 
variants!

Note, however, that the now committed non-statement-expression fallback 
implementation of StaticAssertExpr() does not work under C++.  (The 
compiler complains about "types may not be defined in 'sizeof' 
expressions".)  This isn't a regression in the overall sense, since, as 
you had mentioned, previously all C++ variants required statement 
expressions.  So I think this can be added to the list of C++ 
portability issues that Jelte is currently working through.