CLANG_NO_IAS34 was introduced in r276696 to allow then-HEAD kernels to
be built with clang 3.4 in FreeBSD 10. As FreeBSD 11 and later includes
a version of Clang with a sufficiently capable integrated assembler we
do not need the workaround any longer.
Sponsored by: The FreeBSD Foundation
has support for the .codeXX directives). However, it is desirable, for
a time, to allow kernels to be built with clang 3.4. Historically, it
has been advantageous to allow stable X-1 to build kernels the old
way (so long as the impact of doing so is small), and this restores
that ability.
Also, centralize the addition of ${ASM_CFLAGS.${.IMPSRC}}, place it in
kern.mk rather than kern.pre.mk so that all modules can benefit, and
give the same treatment to CFLAGS in kern.mk as well.
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.
Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)
As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:
CC=clang
CXX=clang++
CPP=clang-cpp
MFC after: 2 weeks
