On Fri, Jun 9, 2023 at 5:46 PM Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote:
>
> From: Johannes Berg <johannes.berg@xxxxxxxxx>
>
> The kernel-doc script currently reports a number of issues
> only in "verbose" mode, but that's initialized from V=1
> (via KBUILD_VERBOSE), so if you use KDOC_WERROR=1 then
> adding V=1 might actually break the build. This is rather
> unexpected.
>
> Change kernel-doc to not change its behaviour wrt. errors
> (or warnings) when verbose mode is enabled, but rather add
> separate warning flags (and -Wall) for it. Allow enabling
> those flags via environment/make variables in the kernel's
> build system for easier user use, but to not have to parse
> them in the script itself.
>
> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Applied to linux-kbuild with Jon's Ack.
Thanks.
> ---
> v2: - parse environment variables in build system rather than
> the script itself, as suggested by Masahiro Yamada
> - fix indentation
> v3: - use a single KDOCFLAGS variable
> ---
> Documentation/kbuild/kbuild.rst | 6 ++++++
> scripts/Makefile.build | 2 +-
> scripts/kernel-doc | 28 +++++++++++++++++++++++-----
> 3 files changed, 30 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> index 2a22ddb1b848..bd906407e307 100644
> --- a/Documentation/kbuild/kbuild.rst
> +++ b/Documentation/kbuild/kbuild.rst
> @@ -150,6 +150,12 @@ the UTS_MACHINE variable, and on some architectures also the kernel config.
> The value of KBUILD_DEBARCH is assumed (not checked) to be a valid Debian
> architecture.
>
> +KDOCFLAGS
> +---------
> +Specify extra (warning/error) flags for kernel-doc checks during the build,
> +see scripts/kernel-doc for which flags are supported. Note that this doesn't
> +(currently) apply to documentation builds.
> +
> ARCH
> ----
> Set ARCH to the architecture to be built.
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 9f94fc83f086..a0b4fb58201c 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -101,7 +101,7 @@ else ifeq ($(KBUILD_CHECKSRC),2)
> endif
>
> ifneq ($(KBUILD_EXTRA_WARN),)
> - cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
> + cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) $<
> endif
>
> # Compile C sources (.c)
> diff --git a/scripts/kernel-doc b/scripts/kernel-doc
> index 2486689ffc7b..8f8440870a0f 100755
> --- a/scripts/kernel-doc
> +++ b/scripts/kernel-doc
> @@ -23,7 +23,7 @@ kernel-doc - Print formatted kernel documentation to stdout
>
> =head1 SYNOPSIS
>
> - kernel-doc [-h] [-v] [-Werror]
> + kernel-doc [-h] [-v] [-Werror] [-Wall] [-Wreturn] [-Wshort-description] [-Wcontents-before-sections]
> [ -man |
> -rst [-sphinx-version VERSION] [-enable-lineno] |
> -none
> @@ -133,6 +133,9 @@ my $dohighlight = "";
>
> my $verbose = 0;
> my $Werror = 0;
> +my $Wreturn = 0;
> +my $Wshort_desc = 0;
> +my $Wcontents_before_sections = 0;
> my $output_mode = "rst";
> my $output_preformatted = 0;
> my $no_doc_sections = 0;
> @@ -187,9 +190,14 @@ if (defined($ENV{'KCFLAGS'})) {
> }
> }
>
> +# reading this variable is for backwards compat just in case
> +# someone was calling it with the variable from outside the
> +# kernel's build system
> if (defined($ENV{'KDOC_WERROR'})) {
> $Werror = "$ENV{'KDOC_WERROR'}";
> }
> +# other environment variables are converted to command-line
> +# arguments in cmd_checkdoc in the build system
>
> # Generated docbook code is inserted in a template at a point where
> # docbook v3.1 requires a non-zero sequence of RefEntry's; see:
> @@ -318,6 +326,16 @@ while ($ARGV[0] =~ m/^--?(.*)/) {
> $verbose = 1;
> } elsif ($cmd eq "Werror") {
> $Werror = 1;
> + } elsif ($cmd eq "Wreturn") {
> + $Wreturn = 1;
> + } elsif ($cmd eq "Wshort-desc") {
> + $Wshort_desc = 1;
> + } elsif ($cmd eq "Wcontents-before-sections") {
> + $Wcontents_before_sections = 1;
> + } elsif ($cmd eq "Wall") {
> + $Wreturn = 1;
> + $Wshort_desc = 1;
> + $Wcontents_before_sections = 1;
> } elsif (($cmd eq "h") || ($cmd eq "help")) {
> pod2usage(-exitval => 0, -verbose => 2);
> } elsif ($cmd eq 'no-doc-sections') {
> @@ -1748,9 +1766,9 @@ sub dump_function($$) {
> # This check emits a lot of warnings at the moment, because many
> # functions don't have a 'Return' doc section. So until the number
> # of warnings goes sufficiently down, the check is only performed in
> - # verbose mode.
> + # -Wreturn mode.
> # TODO: always perform the check.
> - if ($verbose && !$noret) {
> + if ($Wreturn && !$noret) {
> check_return_section($file, $declaration_name, $return_type);
> }
>
> @@ -2054,7 +2072,7 @@ sub process_name($$) {
> $state = STATE_NORMAL;
> }
>
> - if (($declaration_purpose eq "") && $verbose) {
> + if (($declaration_purpose eq "") && $Wshort_desc) {
> emit_warning("${file}:$.", "missing initial short description on line:\n$_");
> }
>
> @@ -2103,7 +2121,7 @@ sub process_body($$) {
> }
>
> if (($contents ne "") && ($contents ne "\n")) {
> - if (!$in_doc_sect && $verbose) {
> + if (!$in_doc_sect && $Wcontents_before_sections) {
> emit_warning("${file}:$.", "contents before sections\n");
> }
> dump_section($file, $section, $contents);
> --
> 2.40.1
>
--
Best Regards
Masahiro Yamada
