Re: feedback on 2.69b

[Peter Eisentraut]

On 2020-07-24 16:31, Zack Weinberg wrote:
> > checking for g++ option to enable C++11 features... none needed
> >
> > takes on the order of 10 seconds for some developers.  And that is for
> > one loop, since "none needed"; good luck if you need more than none.
>
> I suspect that this is because the test program for C++11 includes a
> bunch of large and complicated C++ standard library headers.   To
> confirm that possibility, could you please ask someone who sees
> "checking for g++ option to enable C++11 features ... none needed"
> take 10 seconds to compile the appended test program with  `g++ -O2 -g
> -c` and report how long it takes.  (It takes ~3s on my computer, which
> is already too long IMHO, but if it doesn't take any longer than that
> for them, something else must be wrong as well.)

Yeah, this takes about 6-7 seconds.  Tried different versions of g++ (7, 
8, 9, 10) without much difference.

Btw., clang issues a warning for that test program:

test.cc:113:25: warning: empty parentheses interpreted as a function 
declaration [-Wvexing-parse]
  cxx11test::delegate d2();
                        ^~
test.cc:113:25: note: remove parentheses to declare a variable
  cxx11test::delegate d2();
                        ^~
1 warning generated.

I don't know whether that's something that should be cleaned up, or 
whether it's part of what's being tested.