Re: [PATCH 5.4 2/6] kbuild: Update assembler calls to use proper flags and language target

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
ℹ️ This is part 2/6 of a series
⚠️ Found follow-up fixes in mainline

The upstream commit SHA1 provided is correct: d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0

WARNING: Author mismatch between patch and upstream commit:
Backport author: Nathan Chancellor <nathan@kernel.org>
Commit author: Nick Desaulniers <ndesaulniers@google.com>

Status in newer kernel trees:
6.15.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Present (exact SHA1)
6.1.y | Present (different SHA1: a76d4933c38e)
5.15.y | Present (different SHA1: cefb372db498)
5.10.y | Present (different SHA1: 7fa1764188bf)

Found fixes commits:
87c4e1459e80 ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS

Note: The patch differs from the upstream commit:
---
1:  d5c8d6e0fa61 ! 1:  e516ff739515 kbuild: Update assembler calls to use proper flags and language target
    @@ Metadata
      ## Commit message ##
         kbuild: Update assembler calls to use proper flags and language target
     
    +    commit d5c8d6e0fa61401a729e9eb6a9c7077b2d3aebb0 upstream.
    +
         as-instr uses KBUILD_AFLAGS, but as-option uses KBUILD_CFLAGS. This can
         cause as-option to fail unexpectedly when CONFIG_WERROR is set, because
         clang will emit -Werror,-Wunused-command-line-argument for various -m
    @@ Commit message
         Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
         Tested-by: Anders Roxell <anders.roxell@linaro.org>
         Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
    +    Signed-off-by: Nathan Chancellor <nathan@kernel.org>
     
    - ## scripts/Kconfig.include ##
    -@@ scripts/Kconfig.include: ld-option = $(success,$(LD) -v $(1))
    - 
    - # $(as-instr,<instr>)
    - # Return y if the assembler supports <instr>, n otherwise
    --as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler -o /dev/null -)
    -+as-instr = $(success,printf "%b\n" "$(1)" | $(CC) $(CLANG_FLAGS) -c -x assembler-with-cpp -o /dev/null -)
    - 
    - # check if $(CC) and $(LD) exist
    - $(error-if,$(failure,command -v $(CC)),C compiler '$(CC)' not found)
    -
    - ## scripts/Makefile.compiler ##
    -@@ scripts/Makefile.compiler: try-run = $(shell set -e;		\
    + ## scripts/Kbuild.include ##
    +@@ scripts/Kbuild.include: try-run = $(shell set -e;		\
      	fi)
      
      # as-option
    @@ scripts/Makefile.compiler: try-run = $(shell set -e;		\
      
      # __cc-option
      # Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586)
    -
    - ## scripts/as-version.sh ##
    -@@ scripts/as-version.sh: orig_args="$@"
    - # Get the first line of the --version output.
    - IFS='
    - '
    --set -- $(LC_ALL=C "$@" -Wa,--version -c -x assembler /dev/null -o /dev/null 2>/dev/null)
    -+set -- $(LC_ALL=C "$@" -Wa,--version -c -x assembler-with-cpp /dev/null -o /dev/null 2>/dev/null)
    - 
    - # Split the line on spaces.
    - IFS=' '

---

NOTE: These results are for this patch alone. Full series testing will be
performed when all parts are received.

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| 5.4                       | Success     | Success    |