On Fri, Jul 30, 2021 at 1:17 PM 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 it from SRCARCH, and move some flag handling into a > new file included from the top level Makefile. > > 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. > > *** BLURB HERE *** Err, sorry, it looks like I did: $ git format-patch HEAD~2 ... when I meant to do HEAD~3 ..., will resend. > > Nick Desaulniers (2): > Makefile: infer --target from ARCH for CC=clang > Documentation/llvm: update CROSS_COMPILE inferencing > > Documentation/kbuild/llvm.rst | 17 +++++++++++++++++ > scripts/Makefile.clang | 30 ++++++++++++++++++++++++++++-- > 2 files changed, 45 insertions(+), 2 deletions(-) > > > base-commit: 27932b6a2088eac7a5afa5471963b926cfbb4de7 > prerequisite-patch-id: 0d3072ecb5fd06ff6fd6ea81fe601f6c54c23910 > -- > 2.32.0.554.ge1b32706d8-goog > -- Thanks, ~Nick Desaulniers
