llvm-config-3.8.1 --cflags added -pedantic

When switching from LLVM-3.8 to LLVM-3.8.1 (I use the Ubuntu packages) I got a lot of warnings when compiling my code. It seems that that `llvm-config --cflags` added e.g. the -pedantic flag. The pedantic flag seems to remain in llvm-config-3.9. I wonder whether it is the business of llvm-config to choose my compiler warnings. Was this change intended and with what reasons?

Btw. the switch from llvm-3.8 to llvm-3.8.1 also removed include/llvm/Config/config.h without previous deprecation. I think it is a bad idea to do this in a bugfix release. I was always uncertain whether I should include config.h or llvm-config.h and it seems I chose the wrong one (namely config.h).

Henning Thielemann via llvm-dev <llvm-dev@lists.llvm.org> writes:

When switching from LLVM-3.8 to LLVM-3.8.1 (I use the Ubuntu packages)
I got a lot of warnings when compiling my code. It seems that that
`llvm-config --cflags` added e.g. the -pedantic flag. The pedantic
flag seems to remain in llvm-config-3.9. I wonder whether it is the
business of llvm-config to choose my compiler warnings. Was this
change intended and with what reasons?

This seems kind of bad, but I don't think it's a new problem. I'm pretty
sure llvm-config --cflags has always leaked the warning flags that llvm
happened to be built with. ISTR a discussion about changing this to a
more specific set of flags to pass through a while back, but I guess it
didn't result in anything.

Btw. the switch from llvm-3.8 to llvm-3.8.1 also removed
include/llvm/Config/config.h without previous deprecation. I think it
is a bad idea to do this in a bugfix release. I was always uncertain
whether I should include config.h or llvm-config.h and it seems I
chose the wrong one (namely config.h).

The change to stop installing the internal config.h header happened in
2014, in r210766, so I would have expected this to have been gone since
llvm 3.5 at the latest. Maybe the configure and cmake builds behaved
differently here, and the ubuntu packaging switched build systems?