tree 0f20e41c114a288fa558627e7780f6558268b37c
parent 87cca254c9c392c67ad39e6a8fd01cb0394a3f7b
author Nick Desaulniers <ndesaulniers@google.com> 1597961395 -0700
committer Nick Desaulniers <ndesaulniers@google.com> 1600466251 -0700

FROMLIST: Makefile: add -fuse-ld=lld to KBUILD_HOSTLDFLAGS when LLVM=1

While moving Android kernels over to use LLVM=1, we observe the failure
when building in a hermetic docker image:
  HOSTCC  scripts/basic/fixdep
clang: error: unable to execute command: Executable "ld" doesn't exist!

The is because the build of the host utility fixdep builds the fixdep
executable in one step by invoking the compiler as the driver, rather
than individual compile then link steps.

Clang when configured from source defaults to use the system's linker,
and not LLVM's own LLD, unless the CMake config
-DCLANG_DEFAULT_LINKER='lld' is set when configuring a build of clang
itself.

Don't rely on the compiler's implicit default linker; be explicit.

Fixes: commit a0d1c951ef08 ("kbuild: support LLVM=1 to switch the default tools to Clang/LLVM")
Reported-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: stable@vger.kernel.org

Bug: 116869922
Bug: 141693040
Link: https://lore.kernel.org/lkml/20200820220955.3325555-1-ndesaulniers@google.com/T/#u
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: I54b79beceb669ec06a017d3f5c3627ccf3655986