On Mon, May 28, 2018 at 02:53:47AM -0400, Gavin Hu wrote: > The "-Wimplicit-fallthrough=2" option was introduced into gcc 7.0, it was > enabled when the cross compiler gcc is greater than 7.0, but for the host > side buildtools/pmdinfogen, if the native is older than 7.0, it should not > be enabled. > > The fix is to differentiate the host gcc Werror options from the cross gcc. > > gcc -Wp,-MD,./.pmdinfogen.o.d.tmp -W -Wall -Wstrict-prototypes > -Wmissing-prototypes -Wmissing-declarations -Wold-style-definition > -Wpointer-arith -Wcast-align -Wnested-externs -Wcast-qual > -Wformat-nonliteral -Wformat-security -Wundef -Wwrite-strings -Wdeprecated > -Werror -Wimplicit-fallthrough=2 -Dbbb -Wno-format-truncation -g > -I/home/gavin/arm_repo/dpdk/build/include -o pmdinfogen.o -c > ~/dpdk/buildtools/pmdinfogen/pmdinfogen.c gcc: error: > unrecognized command line option ‘-Wimplicit-fallthrough=2’ > ~/dpdk/mk/internal/rte.compile-pre.mk:114: recipe for target 'pmdinfogen.o' > failed make[3]: *** [pmdinfogen.o] Error 1 > > Fixes: ced3e6f8 ("mk: adjust gcc flags for new gcc 7 warnings") > Cc: sta...@dpdk.org > > Signed-off-by: Gavin Hu <gavin...@arm.com> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com> > Reviewed-by: Steve Capper <steve.cap...@arm.com> > Reviewed-by: Thomas Monjalon <tho...@monjalon.net> > ---
Would a simpler solution for this not be to put "-Wno-implicit-fallthrough" for pmdinfogen? GCC will not give a warning for an unrecognised "-Wno" flag when compiling, unless there are other errors. This means we can just use the flag without bothering with version checks. /Bruce