archive mirror
 help / color / mirror / Atom feed
From: Nick Desaulniers <>
To: Masahiro Yamada <>
Cc: Miguel Ojeda <>,
	Fangrui Song <>,
	Michal Marek <>,
	Arnd Bergmann <>,,,,
	Geert Uytterhoeven <>,
	Christoph Hellwig <>,
	Linus Torvalds <>,
	Nick Desaulniers <>
Subject: [PATCH v3 0/2] infer CROSS_COMPILE from SRCARCH for CC=clang LLVM_IAS=1
Date: Thu, 29 Jul 2021 09:50:37 -0700	[thread overview]
Message-ID: <> (raw)

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 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)

  $ 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
* 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 (2):
  Makefile: move initial clang flag handling into scripts/Makefile.clang
  Makefile: infer CROSS_COMPILE from SRCARCH for CC=clang LLVM_IAS=1

 Documentation/kbuild/llvm.rst |  6 +++++
 MAINTAINERS                   |  1 +
 Makefile                      | 15 +------------
 scripts/Makefile.clang        | 42 +++++++++++++++++++++++++++++++++++
 4 files changed, 50 insertions(+), 14 deletions(-)
 create mode 100644 scripts/Makefile.clang

base-commit: 27932b6a2088eac7a5afa5471963b926cfbb4de7

             reply	other threads:[~2021-07-29 16:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-29 16:50 Nick Desaulniers [this message]
2021-07-29 16:50 ` [PATCH v3 1/2] Makefile: move initial clang flag handling into scripts/Makefile.clang Nick Desaulniers
2021-07-29 16:50 ` [PATCH v3 2/2] Makefile: infer CROSS_COMPILE from SRCARCH for CC=clang LLVM_IAS=1 Nick Desaulniers
2021-07-29 19:40   ` Arnd Bergmann
2021-07-29 21:00   ` Nathan Chancellor
2021-07-30  0:19     ` Nick Desaulniers
2021-07-30  6:50       ` Miguel Ojeda
2021-07-30 15:15       ` Masahiro Yamada
2021-07-30 15:10     ` Masahiro Yamada

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).