${DEBFULLNAME-${user}} falls back to ${user} when DEBFULLNAME is unset.
It is more reasonable to do so when DEBFULLNAME is unset or null.

Otherwise, the command:

  $ DEBFULLNAME= make deb-pkg

will leave the name field blank.

The same applies to KBUILD_BUILD_USER and KBUILD_BUILD_HOST.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Set -e to make these scripts fail on the first error.

Set -u because these scripts are invoked by Makefile, and do not work
properly without necessary variables defined.

I tweaked mkdebian to cope with optional environment variables.

Remove the explicit "test -n ..." from install-extmod-build.

Both options are described in POSIX. [1]

[1]: https://pubs.opengroup.org/onlinepubs/009604499/utilities/set.html

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Commit d5940c60e057 ("kbuild: deb-pkg improve maintainer address
generation") supported the "name <email>" form for DEBEMAIL, with
behavior slightly different from devscripts.

In Kbuild, if DEBEMAIL is given in the form "name <email>", it is used
as-is, and DEBFULLNAME is ignored.

In contrast, debchange takes the name from DEBFULLNAME (or NAME) if set,
as described in 'man debchange':

  If this variable has the form "name <email>", then the maintainer name
  will also be taken from here if neither DEBFULLNAME nor NAME is set.

This commit removes support for the "name <email> form for DEBEMAIL,
as the current behavior is already different from debchange, and the
Debian manual suggests setting the email address and name separately in
DEBEMAIL and DEBFULLNAME. [1]

If there are any complaints about this removal, we can re-add it,
with better alignment with the debchange implementation. [2]

[1]: https://www.debian.org/doc/manuals/debmake-doc/ch03.en.html#email-setup
[2]: https://salsa.debian.org/debian/devscripts/-/blob/v2.23.7/scripts/debchange.pl#L802

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Commit edec611db047 ("kbuild, deb-pkg: improve maintainer
identification") added the EMAIL and NAME environment variables.

Commit d5940c60e057 ("kbuild: deb-pkg improve maintainer address
generation") removed support for NAME, but kept support for EMAIL.

The EMAIL and NAME environment variables are supported by some tools
(see 'man debchange'), but not by all.

We should support both of them, or neither of them. We should not stop
halfway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

At first, I thought this script would be needed only in init/Makefile.

However, commit 5db8face97f8 ("kbuild: Restore .version auto-increment
behaviour for Debian packages") and commit 1789fc912541 ("kbuild:
rpm-pkg: invoke the kernel build from rpmbuild for binrpm-pkg")
revealed that it was actually needed for scripts/package/mk* as well.

After all, scripts/ is a better place for it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Commit 36862e14e316 ("kbuild: deb-pkg: use dh_listpackages to know
enabled packages") started to require the debhelper tool suite.

Use more dh_* commands in create_package():

 - dh_installdocs to install copyright
 - dh_installchangelogs to install changelog
 - dh_compress to compress changelog
 - dh_fixperms to replace the raw chmod command
 - dh_gencontrol to replace the raw dpkg-gencontrol command
 - dh_md5sums to record the md5sum of included files
 - dh_builddeb to replace the raw dpkg-deb command

Set DEB_RULES_REQUIRES_ROOT to 'no' in case debian/rules is executed
directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

The condition to require libelf-dev:native is stale because objtool is
now enabled by CONFIG_OBJTOOL instead of CONFIG_UNWINDER_ORC. Not only
objtool but also resolve_btfids requires libelf-dev:native; therefore,
CONFIG_DEBUG_INFO_BTF should be checked as well.

Similarly, CONFIG_SYSTEM_TRUSTED_KEYRING is not the only case that
requires libssl-dev:native.

Perhaps, the following code would provide better coverage, but it is
hard to maintain (and may still be imperfect).

  if is_enabled CONFIG_OBJTOOL ||
     is_enabled CONFIG_DEBUG_INFO_BTF; then
          build_depends="${build_depends}, libelf-dev:native"
  fi

  if is_enabled CONFIG_SYSTEM_TRUSTED_KEYRING ||
     is_enabled CONFIG_SYSTEM_REVOCATION_LIST ||
     is_enabled CONFIG_MODULE_SIG_FORMAT; then
          build_depends="${build_depends}, libssl-dev:native"
  fi

Let's hard-code the build dependency.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

Copy debian/copyright instead of generating it by the 'cat' command.

I also updated '2018' to '2023' while I was here.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

A little more janitorial work after commit cf8e8658100d ("arch: Remove
Itanium (IA-64) architecture").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

debian/rules is generated by shell, but the escape sequence (\$) is
unreadable.

debian/rules embeds only two variables (ARCH and KERNELRELEASE).

Split them out to debian/rules.vars, and check-in the rest of Makefile
code to scripts/package/debian/rules.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>