On Wed, Mar 21, 2018 at 1:50 PM, Andres Freund <and...@anarazel.de> wrote: > On 2018-03-20 03:14:55 -0700, Andres Freund wrote: >> My current plan is to push the first few commits relatively soon, give >> the BF a few cycles to shake out. Set up a few BF animals with each >> supported LLVM version. Then continue mergin. > > I've done that. I'll set up a number of BF animals as soon as I've got > the buildfarm secrets for them.
Somehow your configure test correctly concludes that my $CC (clang 4.0) doesn't support -fexcess-precision=standard but that my $CXX (clang++ 4.0) does, despite producing a nearly identical warning: configure:5489: checking whether ccache cc supports -fexcess-precision=standard, for CFLAGS configure:5511: ccache cc -c -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard conftest.c >&5 cc: warning: optimization flag '-fexcess-precision=standard' is not supported [-Wignored-optimization-argument] configure:5511: $? = 0 configure: failed program was: ... configure:5521: result: no configure:5528: checking whether ccache c++ supports -fexcess-precision=standard, for CXXFLAGS configure:5556: ccache c++ -c -Wall -Wpointer-arith -fno-strict-aliasing -fwrapv -fexcess-precision=standard conftest.cpp >&5 c++: warning: optimization flag '-fexcess-precision=standard' is not supported [-Wignored-optimization-argument] configure:5556: $? = 0 configure:5572: result: yes So it goes into my $CXXFLAGS and then I get the same warning when compiling the three .cpp files in the tree. GCC also doesn't like that in C++ mode, but it seems to report an error (rather than a warning) so with g++ as your $CXX configure sees $? = 1 and draws the correct conclusion. $ gcc -fexcess-precision=standard -c test.c $ g++ -fexcess-precision=standard -c test.cpp cc1plus: sorry, unimplemented: -fexcess-precision=standard for C++ -- Thomas Munro http://www.enterprisedb.com
