[Changing subject since previous was erroneous] On 2011-06-28 23:10, Eric McCorkle wrote: > On 6/28/11 4:06 PM, Niclas Zeising wrote: >> On 2011-06-28 21:19, Pan Tsu wrote: >>> Niclas Zeising<zeis...@daemonic.se> writes: >>> >>>> Sorry for hijacking this thread, and cross posting. >>>> >>>> On 2011-06-26 03:07, Gabor PALI wrote: >>>>> >>>>> >>>>>> With Clang, an error occurs in one of the configure scripts, because >>>>>> Clang warns about unused command-line arguments, and the configure >>>>>> script assumes that to be a compiler error. You can deal with >>>>>> this by >>>>>> adding -Qunused-parameter to CFLAGS. >>>>> >>>>> Thanks for investigating this. >>>>> >>>> >>>> This should probably be made the default, at least for ports when clang >>>> is compiled, since the output generated when not using >>>> -Qunused-parameter confuses configure scripts, and stops at least >>>> FireFox 5 from compiling, that I know of. >>> >>> Do you use ccache? Try without. >>> >>> For example, the combo confuses libtool >>> >> >> It has nothing to do with cccache. The issue is that clang by default >> warns when passed flags (-std= -f -W etc.) that's not used during the >> compilation/linking. This can be silenced with -Qunused-arguments, and >> if not, it confuses configure scripts that believe this is an error in >> the code it uses to test for features. >> >> Regards! > > Example: In the GHC port, the configure script tries to figure out > whether the ISA supports PC-relative indexing. It does this by > generating a simple program, which contains some asm containing > PC-relative indexing, compiling it, and seeing if the compiler generates > a warning. If clang warns about unused arguments, then the configure > script assumes (falsely) that the ISA does not support PC-relative > indexing, and generates bad assembly code, which causes trouble downstream.
Firefox 5 does similar things, but it's looking for pc relative addressing instead, which is supported on my test system, although without -Qunused-arguments the configure script thinks otherwise, and generates bad asm. I think that option should be added by default, since this is a big difference from gcc, and bound to cause trouble in several places. Regards! -- Niclas _______________________________________________ freebsd-ports@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-ports To unsubscribe, send any mail to "freebsd-ports-unsubscr...@freebsd.org"
