On Tue, Aug 3, 2021 at 3:39 AM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > We get constant feedback that the command line invocation of make is too > long. CROSS_COMPILE is helpful when a toolchain has a prefix of the > target triple, or is an absolute path outside of $PATH, but it's mostly > redundant for a given ARCH. > > Instead, let's infer --target from SRCARCH, and move some flag handling into a > new file included from the top level Makefile. Series, applied to linux-kbuild. Thanks. > Changes v5 -> v6: > * Use indirection as per Linus. > * Change hexagon triple to use -musl rather than -gnu. glibc doesn't > have support for hexagon, and hexagon-linux-musl is the triple we use > in CI. > https://github.com/ClangBuiltLinux/continuous-integration2/blob/d659897d1700894d67feb64fe28e298da399a287/generator.yml#L53 > * Pick up Fangrui's RB. > * Reorder use of Env vars in documentation to use command line > parameters instead, for consistency. > > Changes v4 -> v5: > * Include previously missing first patch! > > Changes v3 -> v4: > * Remove the requirement that LLVM_IAS=1 be set, as per Masahiro. > * Remove the Documentation/ change from patch 2, as per Masahiro and > Nathan. > * Add Documentation/ change as patch 3, from Masahiro. > * Reword commit message of patch 2, as per Nathan. > * Change patch 2 oneline to refer to --target and CC=clang (not > CROSS_COMPILE). > * Carry Arnd's and Nathan's AB/RB/TB tags, confirmed ok on IRC+discord. > > Changes v2 -> v3: > * Remove requirement that LLVM=1 be set. Instead, if building with just > CC=clang LLVM_IAS=1 instead of LLVM=1 LLVM_IAS=1, you should use > LD=ld.lld explicitly, or LD=aarch64-linux-gnu-ld. (As per Masahiro) > Example: > > $ ARCH=arm64 make CC=clang LLVM_IAS=1 LD=ld.lld OBJCOPY=llvm-objcopy \ > STRIP=llvm-strip -j72 defconfig all > > (It's still preferable to use LLVM=1 IMO, but this is maximally > flexible.) > * Change oneliner from LLVM=1 to CC=clang. > * Update Docs slightly. > > Changes v1 -> v2: > * patch 1/2 untouched. > * Fix typos in commit message as per Geert and Masahiro. > * Use SRCARCH instead of ARCH, simplifying x86 handling, as per > Masahiro. Add his sugguested by tag. > * change commit oneline from 'drop' to 'infer.' > * Add detail about explicit host --target and relationship of ARCH to > SRCARCH, as per Masahiro. > > Nick Desaulniers (3): > Makefile: move initial clang flag handling into scripts/Makefile.clang > Makefile: infer --target from ARCH for CC=clang > Documentation/llvm: update CROSS_COMPILE inferencing > > Documentation/kbuild/llvm.rst | 19 ++++++++++++++++++- > MAINTAINERS | 1 + > Makefile | 15 +-------------- > scripts/Makefile.clang | 35 +++++++++++++++++++++++++++++++++++ > 4 files changed, 55 insertions(+), 15 deletions(-) > create mode 100644 scripts/Makefile.clang > > > base-commit: d7a86429dbc691bf540688fcc8542cc20246a85b > -- > 2.32.0.554.ge1b32706d8-goog > -- Best Regards Masahiro Yamada
