2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-25 05:34:00 +08:00
linux-next/tools/objtool
Masahiro Yamada a0d1c951ef kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
As Documentation/kbuild/llvm.rst implies, building the kernel with a
full set of LLVM tools gets very verbose and unwieldy.

Provide a single switch LLVM=1 to use Clang and LLVM tools instead
of GCC and Binutils. You can pass it from the command line or as an
environment variable.

Please note LLVM=1 does not turn on the integrated assembler. You need
to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the
integrated assembler, I think we can make it default.

We discussed what we need, and we agreed to go with a simple boolean
flag that switches both target and host tools:

  https://lkml.org/lkml/2020/3/28/494
  https://lkml.org/lkml/2020/4/3/43

Some items discussed, but not adopted:

- LLVM_DIR

  When multiple versions of LLVM are installed, I just thought supporting
  LLVM_DIR=/path/to/my/llvm/bin/ might be useful.

  CC      = $(LLVM_DIR)clang
  LD      = $(LLVM_DIR)ld.lld
    ...

  However, we can handle this by modifying PATH. So, we decided to not do
  this.

- LLVM_SUFFIX

  Some distributions (e.g. Debian) package specific versions of LLVM with
  naming conventions that use the version as a suffix.

  CC      = clang$(LLVM_SUFFIX)
  LD      = ld.lld(LLVM_SUFFIX)
    ...

  will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc.,
  but the suffixed versions in /usr/bin/ are symlinks to binaries in
  /usr/lib/llvm-#/bin/, so this can also be handled by PATH.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-09 03:18:21 +09:00
..
arch/x86 objtool: Move x86 insn decoder to a common location 2019-08-31 22:27:52 -03:00
Documentation docs: fix broken documentation links 2019-06-08 13:42:13 -06:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
arch.h objtool: Support conditional retpolines 2019-07-18 21:01:10 +02:00
Build objtool: Optimize find_symbol_*() and read_symbols() 2020-03-25 18:28:29 +01:00
builtin-check.c objtool: Add a statistics mode 2020-03-25 18:28:28 +01:00
builtin-orc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
builtin.h objtool: Add a statistics mode 2020-03-25 18:28:28 +01:00
cfi.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
check.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-30 16:17:15 -07:00
check.h objtool: Resize insn_hash 2020-03-25 18:28:30 +01:00
elf.c objtool: Optimize find_rela_by_dest_range() 2020-03-25 18:28:31 +01:00
elf.h objtool: Optimize find_rela_by_dest_range() 2020-03-25 18:28:31 +01:00
Makefile kbuild: support LLVM=1 to switch the default tools to Clang/LLVM 2020-04-09 03:18:21 +09:00
objtool.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
orc_dump.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
orc_gen.c objtool: Optimize read_sections() 2020-03-25 18:28:30 +01:00
orc.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
special.c objtool: Optimize read_sections() 2020-03-25 18:28:30 +01:00
special.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
sync-check.sh objtool: Silence build output 2020-01-22 07:54:34 +01:00
warn.h objtool: Rename find_containing_func() 2020-03-25 18:28:29 +01:00