Hi, On 2021-11-18 11:56:59 -0500, Tom Lane wrote: > I noticed that, a week after Michael pushed 9ff47ea41 to silence > -Wcompound-token-split-by-macro warnings, buildfarm member sidewinder > is still spewing them. Investigation shows that it's building with > > configure: using compiler=cc (nb4 20200810) 7.5.0 > configure: using CLANG=ccache clang > > and the system cc doesn't know -Wcompound-token-split-by-macro, > so we don't use it, but the modules that are built into bytecode > still produce the warnings because they're built with clang.
> I think this idea of using clang with switches selected for some other > compiler is completely horrid, and needs to be nuked from orbit before > it causes problems worse than mere warnings. We can test separately for flags, see BITCODE_CFLAGS/BITCODE_CXXFLAGS. > Why did we not simply insist that if you want to use --with-llvm, the > selected compiler must be clang? I cannot see any benefit of mix-and-match > here. It seemed like a problematic restriction at the time. And still does to me. For one, gcc does generate somewhat better code. For another, extensions could still compile with a different compiler, and generate bitcode with another compiler, so it's good to have that easily testable. It also just seems architecturally wrong: People pressed for making the choice of JIT runtime replaceable, and it now is, at some pain. And forcing the main compiler seems problematic from that angle. With the meson port jit compilation actually kinda works on windows - but it seems we shouldn't force people to not use visual studio there, just for that? I think the issue is more with trying to be miserly in the choice of compiler flag tests to duplicate and how many places to change to choose the right flag variable. It's taken a while for this to become a real issue, so it perhaps was the right choice at the time. Greetings, Andres Freund
