[PATCH 00/15] kbuild: refactor headers_install and support compile-test of UAPI headers

[Masahiro Yamada]

Multiple people have suggested to compile-test UAPI headers.

Currently, Kbuild provides simple sanity checks by headers_check
but they are not enough to catch bugs.

The most recent patch I know is David Howells' work:
https://patchwork.kernel.org/patch/10590203/

I agree that we need better tests for UAPI headers,
but I want to integrate it in a clean way.

The idea that has been in my mind is to compile each header
to make sure the selfcontainedness.

Recently, Jani Nikula proposed a new syntax 'header-test-y'.
https://patchwork.kernel.org/patch/10947005/

So, I implemented UAPI compile-testing on top of that.

When adding a new feature, cleaning the code first is a
good practice.

[1] Remove headers_install_all

This target installs UAPI headers of all architectures
in a single tree.
It does not make sense to compile test of headers from
multiple arches at the same time. Hence, removed.

[2] Split header installation into 'make headers' and 'make headers_install'

To compile-test UAPI headers, we need a work-directory somewhere
to save objects and .*.cmd files.

usr/include/ will be the work-directory.

Since we cannot pollute the final destination of headers_install,

I split the header installation into two stages.

'make headers' will build up
the ready-to-install headers in usr/include,
which will be also used as a work-directory for the compile-test.

'make headers_install' will copy headers
from usr/include to $(INSTALL_HDR_PATH)/include.

[3] Support compile-test of UAPI headers

This is implemented in usr/include/Makefile


Jani Nikula (1):
  kbuild: add support for ensuring headers are self-contained

Masahiro Yamada (14):
  kbuild: remove headers_{install,check}_all
  kbuild: remove stale dependency between Documentation/ and
    headers_install
  kbuild: make gdb_script depend on prepare0 instead of prepare
  kbuild: fix Kconfig prompt of CONFIG_HEADERS_CHECK
  kbuild: add CONFIG_HEADERS_INSTALL and loosen the dependency of
    samples
  kbuild: remove build_unifdef target in scripts/Makefile
  kbuild: build all prerequisite of headers_install simultaneously
  kbuild: add 'headers' target to build up ready-to-install uapi headers
  kbuild: re-implement Makefile.headersinst without directory descending
  kbuild: move hdr-inst shorthand to top Makefile
  kbuild: simplify scripts/headers_install.sh
  kbuild: deb-pkg: do not run headers_check
  fixup: kbuild: add support for ensuring headers are self-contained
  kbuild: compile test UAPI headers to ensure they are self-contained

 Documentation/kbuild/headers_install.txt |   7 --
 Documentation/kbuild/makefiles.txt       |  13 ++-
 Makefile                                 |  56 +++++-----
 arch/arc/configs/tb10x_defconfig         |   1 +
 arch/nds32/configs/defconfig             |   1 +
 arch/parisc/configs/a500_defconfig       |   1 +
 arch/parisc/configs/b180_defconfig       |   1 +
 arch/parisc/configs/c3000_defconfig      |   1 +
 arch/parisc/configs/default_defconfig    |   1 +
 arch/powerpc/configs/ppc6xx_defconfig    |   1 +
 arch/s390/configs/debug_defconfig        |   1 +
 include/uapi/{linux => }/Kbuild          |   6 +-
 init/Kconfig                             |  20 ++++
 lib/Kconfig.debug                        |  25 +++--
 samples/Kconfig                          |  14 ++-
 samples/Makefile                         |   4 +-
 scripts/Kbuild.include                   |   6 --
 scripts/Makefile                         |   5 -
 scripts/Makefile.build                   |   9 ++
 scripts/Makefile.headersinst             | 132 ++++++++++-------------
 scripts/Makefile.lib                     |   3 +
 scripts/cc-system-headers.sh             |   8 ++
 scripts/headers.sh                       |  29 -----
 scripts/headers_install.sh               |  48 ++++-----
 scripts/package/builddeb                 |   2 +-
 usr/.gitignore                           |   1 -
 usr/Makefile                             |   2 +
 usr/include/.gitignore                   |   3 +
 usr/include/Makefile                     | 132 +++++++++++++++++++++++
 29 files changed, 329 insertions(+), 204 deletions(-)
 rename include/uapi/{linux => }/Kbuild (77%)
 create mode 100755 scripts/cc-system-headers.sh
 delete mode 100755 scripts/headers.sh
 create mode 100644 usr/include/.gitignore
 create mode 100644 usr/include/Makefile

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2.17.1