docs: Fix bitfield handling in kernel-doc

kernel-doc doesn't handle bitfields that are specified with symbolic
name, e.g. u32 cs_index_mask : SPI_CS_CNT_MAX

This results in the following warnings when running `make htmldocs`:

include/linux/spi/spi.h:246: warning: Function parameter or struct member 'cs_index_mask:SPI_CS_CNT_MAX' not described in 'spi_device'
include/linux/spi/spi.h:246: warning: Excess struct member 'cs_index_mask' description in 'spi_device'

Update the regexp for bitfields to accept all word chars, not just
digits.

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240326173825.99190-1-donald.hunter@gmail.com

kernel-doc: Add unary operator * to $type_param_ref

In kernel-doc comments, unary operator * collides with Sphinx/
docutil's markdown for emphasizing.

This resulted in additional warnings from "make htmldocs":

WARNING: Inline emphasis start-string without end-string.

, as reported recently [1].

Those have been worked around either by escaping * (like \*param) or by
using inline-literal form of ``*param``, both of which are specific
to Sphinx/docutils.

Such workarounds are against the kenrel-doc's ideal and should better
be avoided.

Instead, add "*" to the list of unary operators kernel-doc recognizes
and make the form of *@param available in kernel-doc comments.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: [1] https://lore.kernel.org/r/20240223153636.41358be5@canb.auug.org.au/
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

kernel-doc: handle #if in enums as well

In addition to #ifdef, #define and #endif, also handle
any #if since we may be using e.g. #if IS_ENABLED(...).

I didn't find any instances of this in the kernel now,
there are enums with such ifs inside, but I didn't find
any with kernel-doc as well. However, it came up as we
were adding such a construct in our driver and warnings
from kernel-doc were the result.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240214142937.80ee86a3beae.Ibcc5bd97a20cd10a792663e4b254cd46c7e8b520@changeid

scripts/kernel-doc: simplify signature printing

Untangle some of the $is_macro logic and the nested conditionals.

This makes it easier to see where and how the signature is actually
printed.

No functional change.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240215134828.1277109-5-vegard.nossum@oracle.com

scripts/kernel-doc: separate out function signature

Format the entire function signature and place it in a separate variable;
this both makes it easier to understand what these lines of code are doing
and will allow us to simplify the code further in the following patch.

No functional change.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240215134828.1277109-4-vegard.nossum@oracle.com

scripts/kernel-doc: simplify function printing

Get rid of the $start variable, since it's really not necessary.

No functional change.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240215134828.1277109-3-vegard.nossum@oracle.com

scripts/kernel-doc: add modeline for vim users

Set 'softtabstop' to 4 spaces, which will hopefully help keep the
indentation in this file consistent going forwards.

This mirrors the modeline in scripts such as recordmcount.pl, ktest.pl,
and others.

Emacs seems to use 4 spaces to indent by default, so it doesn't require
anything special here.

No functional change.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240215134828.1277109-2-vegard.nossum@oracle.com

scripts/kernel-doc: reindent

This file is using an ungodly mixture of 4 spaces, 2-wide tabs, 4-wide
tabs, _and_ 8-wide tabs, making it really hard to find good editor
settings for working with this file.

Bite the bullet and reindent it by hand. I tried using both perltidy
and vim, but neither of them were up to the task without changing too
much or getting confused about what they were supposed to be doing.

I did change a few instances of

}
else

into

} else

(and same for elsif); the file is again written using both styles, and
I left functions which already seemed self-consistent alone.

You can verify that this commit only changes whitespace using e.g.:

git diff --ignore-all-space --word-diff

or to see (only) the instances where newlines were added/removed:

git diff --ignore-all-space

You can also see the delta from what perltidy would have wanted to
do to this file (when asked to only indent it), which isn't that much
in the end:

perltidy -io -fnl scripts/kernel-doc
git diff --no-index scripts/kernel-doc{,.tdy}

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240208161705.888385-1-vegard.nossum@oracle.com

kernel-doc: Support arrays of pointers struct fields

In a rather unusual arrangement in include/media/v4l2-vp9.h struct
v4l2_vp9_frame_symbol_counts has fields that are arrays of pointers, not a
pointer to an array, which is what's usually done.

Add support for such arrays of pointers to kernel-doc.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240131084934.191226-1-sakari.ailus@linux.intel.com

kernel-doc: drop looking for "MACDOC"

Linux kernel does not use "MACDOC" in any documenation or any
source files, so stop searching for it.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240108003700.13418-1-rdunlap@infradead.org

scripts/kernel-doc: Do not process backslash lines in comments

To prevent this, do the pre-processing only for lines which are no
comments, e.g. do not start with ' *'.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240122093152.22536-3-anna-maria@linutronix.de

kernel-doc: handle a void function without producing a warning

Currently a void function can produce a warning:
main.c:469: warning: contents before sections

This one is from arch/x86/kernel/cpu/sgx/main.c (which is not included
in any produced kernel documentation output).

Handle this by setting $in_doc_sect to 1 whenever any recognized
document section name is processed.

Fixes: f624adef3d0b ("kernel-doc: limit the "section header:" detection to a select few")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231226065219.319-1-rdunlap@infradead.org

kernel-doc: Align quick help and the code

The update to the quick help mentions -Wshort-description, but
code never supported for that. Align that with the code by allowing
both: -Wshort-description and -Wshort-desc.

Fixes: 56b0f453db74 ("kernel-doc: don't let V=1 change outcome")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231215150341.1996720-1-andriy.shevchenko@linux.intel.com

docs: ignore __counted_by attribute in structure definitions

kernel-doc appeared to ignore __counted_by, but appearances can be
deceiving; it caused member names to not be recognized, which manifested as
a number of spurious "Excess struct member" warnings. Filter that
attribute out and reduce the warning onslaught slightly.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Clarify missing struct member description

The output "or member" should be more specific, instead saying "struct
member".

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231215001513.work.563-kees@kernel.org

scripts/kernel-doc: restore warning for Excess struct/union

The warning for Excess struct or union member description was
removed when the $nested parameter of check_sections() was removed.
This causes some kernel-doc notation warnings to be missed.

Recently the kernel test robot somehow reported an Excess member. The
code in kernel-doc has not issued that warning since kernel v4.16, so I
don't know how the robot did it. (See the Link for the report.)

drivers/net/wireless/intel/iwlwifi/fw/dbg.c:86: warning: Excess struct/union/enum/typedef member 'trans_len' description in 'iwl_fw_dump_ptrs'

I patched that warning away even though I could not reproduce the
warning from kernel-doc. The warning should be issued for extraneous
struct member or union member description, so restore it.

Fixes: 1081de2d2f91 ("scripts: kernel-doc: get rid of $nested parameter")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/all/202312060810.QT9zourt-lkp@intel.com/
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231214070200.24405-1-rdunlap@infradead.org

cache: enforce cache groups

Set up build time warnings to safeguard against future header changes of
organized structs.

Warning includes:

1) whether all variables are still in the same cache group
2) whether all the cache groups have the sum of the members size (in the
maximum condition, including all members defined in configs)

The __cache_group* variables are ignored in kernel-doc check in the
various header files they appear in to enforce the cache groups.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

scripts/kernel-doc: Fix the regex for matching -Werror flag

Swarup reported a "make htmldocs" warning:

Variable length lookbehind is experimental in regex;
marked by <-- HERE in m/(?<=^|\s)-Werror(?=$|\s)
<-- HERE / at ./scripts/kernel-doc line 188.

Akira managed to reproduce it by perl v5.34.0.

On second thought, it is not necessary to have the complicated
"lookahead and lookbehind" things, and the regex can be simplified.

Generally, the kernel-doc warnings should be considered as errors only
when "-Werror" flag is set in KCFLAGS, but not when
"-Werror=<diagnostic-type>" is set, which means there needs to be a
space or start of string before "-Werror", and a space or end of string
after "-Werror".

The following cases have been tested to work as expected:

* kernel-doc warnings are considered as errors:

$ KCFLAGS="-Werror" make W=1
$ KCFLAGS="-Wcomment -Werror" make W=1
$ KCFLAGS="-Werror -Wundef" make W=1
$ KCFLAGS="-Wcomment -Werror -Wundef" make W=1

* kernel-doc warnings remain as warnings:

$ KCFLAGS="-Werror=return-type" make W=1
$ KCFLAGS="-Wcomment -Werror=return-type" make W=1
$ KCFLAGS="-Werror=return-type -Wundef" make W=1
$ KCFLAGS="-Wcomment -Werror=return-type -Wundef" make W=1

The "Variable length lookbehind is experimental in regex" warning is
also resolved by this patch.

Fixes: 91f950e8b9d8 ("scripts/kernel-doc: match -Werror flag strictly")
Reported-by: Swarup Laxman Kotiaklapudi <swarupkotikalapudi@gmail.com>
Signed-off-by: Yujie Liu <yujie.liu@intel.com>
Closes: https://lore.kernel.org/r/20231028182231.123996-1-swarupkotikalapudi@gmail.com/
Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231030085404.3343403-1-yujie.liu@intel.com

scripts/kernel-doc: match -Werror flag strictly

In our CI testing, we use some commands as below to only turn a specific
type of warnings into errors, but we notice that kernel-doc warnings
are also turned into errors unexpectedly.

$ make KCFLAGS="-Werror=return-type" W=1 kernel/fork.o

kernel/fork.c:1406: warning: Function parameter or member 'mm' not described in 'set_mm_exe_file'
kernel/fork.c:1406: warning: Function parameter or member 'new_exe_file' not described in 'set_mm_exe_file'
kernel/fork.c:1441: warning: Function parameter or member 'mm' not described in 'replace_mm_exe_file'
kernel/fork.c:1441: warning: Function parameter or member 'new_exe_file' not described in 'replace_mm_exe_file'
kernel/fork.c:1491: warning: Function parameter or member 'mm' not described in 'get_mm_exe_file'
kernel/fork.c:1510: warning: Function parameter or member 'task' not described in 'get_task_exe_file'
kernel/fork.c:1534: warning: Function parameter or member 'task' not described in 'get_task_mm'
kernel/fork.c:2109: warning: bad line:
kernel/fork.c:2130: warning: Function parameter or member 'ret' not described in '__pidfd_prepare'
kernel/fork.c:2130: warning: Excess function parameter 'pidfd' description in '__pidfd_prepare'
kernel/fork.c:2179: warning: Function parameter or member 'ret' not described in 'pidfd_prepare'
kernel/fork.c:2179: warning: Excess function parameter 'pidfd' description in 'pidfd_prepare'
kernel/fork.c:3195: warning: expecting prototype for clone3(). Prototype was for sys_clone3() instead
13 warnings as Errors
make[3]: *** [scripts/Makefile.build:243: kernel/fork.o] Error 13
make[3]: *** Deleting file 'kernel/fork.o'
make[2]: *** [scripts/Makefile.build:480: kernel] Error 2
make[1]: *** [/root/linux/Makefile:1913: .] Error 2
make: *** [Makefile:234: __sub-make] Error 2

>From the git history, commit 2c12c8103d8f ("scripts/kernel-doc:
optionally treat warnings as errors") introduces a new command-line
option to make kernel-doc warnings into errors. It can also read the
KCFLAGS environment variable to decide whether to turn this option on,
but the regex used for matching may not be accurate enough. It can match
both "-Werror" and "-Werror=<diagnostic-type>", so the option is turned
on by mistake in the latter case.

Fix this by strictly matching the flag "-Werror": there must be a space
or start of string in the front, and a space or end of string at the
end. This can handle all the following cases correctly:

KCFLAGS="-Werror" make W=1 [MATCH]
KCFLAGS="-Werror=return-type" make W=1 [NO MATCH]
KCFLAGS="-Wcomment -Werror -Wundef" make W=1 [MATCH]
KCFLAGS="-Wcomment -Werror=return-type -Wundef" make W=1 [NO MATCH]

Fixes: 2c12c8103d8f ("scripts/kernel-doc: optionally treat warnings as errors")
Signed-off-by: Yujie Liu <yujie.liu@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20231019095637.2471840-1-yujie.liu@intel.com>

scripts: kernel-doc: fix macro handling in enums

drivers/net/ethernet/intel/idpf/idpf.h uses offsetof to
initialize the enum enumerators:

enum idpf_cap_field {
IDPF_BASE_CAPS = -1,
IDPF_CSUM_CAPS = offsetof(struct virtchnl2_get_capabilities,
csum_caps),
IDPF_SEG_CAPS = offsetof(struct virtchnl2_get_capabilities,
seg_caps),
IDPF_RSS_CAPS = offsetof(struct virtchnl2_get_capabilities,
rss_caps),
IDPF_HSPLIT_CAPS = offsetof(struct virtchnl2_get_capabilities,
hsplit_caps),
IDPF_RSC_CAPS = offsetof(struct virtchnl2_get_capabilities,
rsc_caps),
IDPF_OTHER_CAPS = offsetof(struct virtchnl2_get_capabilities,
other_caps),
};

kernel-doc parses the above enumerator with a ',' inside the
macro and treats 'csum_caps', 'seg_caps' etc. also as enumerators
resulting in the warnings:

drivers/net/ethernet/intel/idpf/idpf.h:130: warning: Enum value
'csum_caps' not described in enum 'idpf_cap_field'
drivers/net/ethernet/intel/idpf/idpf.h:130: warning: Enum value
'seg_caps' not described in enum 'idpf_cap_field'
drivers/net/ethernet/intel/idpf/idpf.h:130: warning: Enum value
'rss_caps' not described in enum 'idpf_cap_field'
drivers/net/ethernet/intel/idpf/idpf.h:130: warning: Enum value
'hsplit_caps' not described in enum 'idpf_cap_field'
drivers/net/ethernet/intel/idpf/idpf.h:130: warning: Enum value
'rsc_caps' not described in enum 'idpf_cap_field'
drivers/net/ethernet/intel/idpf/idpf.h:130: warning: Enum value
'other_caps' not described in enum 'idpf_cap_field'

Fix it by removing the macro arguments within the parentheses.

Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230815210417.98749-3-pavan.kumar.linga@intel.com

scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN]

At present, if the macros DEFINE_DMA_UNMAP_ADDR() and
DEFINE_DMA_UNMAP_LEN() are used in the structures as shown
below, instead of parsing the parameter in the parentheses,
kernel-doc parses 'DEFINE_DMA_UNMAP_ADDR(' and
'DEFINE_DMA_UNMAP_LEN(' which results in the following
warnings:

drivers/net/ethernet/intel/idpf/idpf_txrx.h:201: warning: Function
parameter or member 'DEFINE_DMA_UNMAP_ADDR(dma' not described in
'idpf_tx_buf'
drivers/net/ethernet/intel/idpf/idpf_txrx.h:201: warning: Function
parameter or member 'DEFINE_DMA_UNMAP_LEN(len' not described in
'idpf_tx_buf'

struct idpf_tx_buf {
DEFINE_DMA_UNMAP_ADDR(dma);
DEFINE_DMA_UNMAP_LEN(len);
};

Fix the warnings by parsing DEFINE_DMA_UNMAP_ADDR() and
DEFINE_DMA_UNMAP_LEN().

Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230815210417.98749-2-pavan.kumar.linga@intel.com

scripts: kernel-doc: support private / public marking for enums

Enums benefit from private markings, too. For netlink attribute
name enums always end with a pair of __$n_MAX and $n_MAX members.
Documenting them feels a bit tedious.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20230621223525.2722703-1-kuba@kernel.org>

kernel-doc: don't let V=1 change outcome

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@intel.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

docs: scripts: kernel-doc: accept bitwise negation like ~@var

In some cases we'd like to indicate the bitwise negation of a parameter,
e.g.

~@var

This will be helpful for describing the atomic andnot operations, where
we'd like to write comments of the form:

Atomically updates @v to (@v & ~@i)

Which kernel-doc currently transforms to:

Atomically updates **v** to (**v** & ~**i**)

Rather than the preferable form:

Atomically updates **v** to (**v** & **~i**)

This is similar to what we did for '!@var' in commit:

ee2aa7590398 ("scripts: kernel-doc: accept negation like !@var")

This patch follows the same pattern that commit used to permit a '!'
prefix on a param ref, allowing a '~' prefix on a param ref, cuasing
kernel-doc to generate the preferred form above.

Suggested-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230605070124.3741859-25-mark.rutland@arm.com

kbuild: do not print extra logs for V=2

Some scripts increase the verbose level when V=1, but others when
not V=0.

I think the former is correct because V=2 is not a log level but
a switch to print the reason for rebuilding.

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

scripts: kernel-doc: Remove workaround for @param... syntax

Commit 43756e347f21 ("scripts/kernel-doc: Add support for named variable
macro arguments") improved how named variable macro arguments are
handled, and changed how they are documented in kerneldoc comments
from "@param...", to "@param", deprecating the old syntax.

All users of the old syntax have since been converted, so this commit
finally removes support for it.

The output of "make htmldocs" is the same with and without this commit.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20230129150435.1510400-1-j.neuschaefer@gmx.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: support EXPORT_SYMBOL_NS_GPL() with -export

Parse EXPORT_SYMBOL_NS_GPL() in addition to EXPORT_SYMBOL_GPL() for use
with the -export flag.

Link: https://lore.kernel.org/r/4-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

string: Rewrite and add more kern-doc for the str*() functions

While there were varying degrees of kern-doc for various str*()-family
functions, many needed updating and clarification, or to just be
entirely written. Update (and relocate) existing kern-doc and add missing
functions, sadly shaking my head at how many times I have written "Do
not use this function". Include the results in the core kernel API doc.

Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-hardening@vger.kernel.org
Tested-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/lkml/9b0cf584-01b3-3013-b800-1ef59fe82476@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>

docs: improve the HTML formatting of kerneldoc comments

Make a few changes to cause functions documented by kerneldoc to stand out
better in the rendered documentation. Specifically, change kernel-doc to
put the description section into a ".. container::" section, then add a bit
of CSS to indent that section relative to the function prototype (or struct
or enum definition). Tweak a few other CSS parameters while in the
neighborhood to improve the formatting.

Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Always increment warnings counter

Some warnings do not increment the warnings counter making the behavior
of running kernel-doc with -Werror unlogical as some warnings will be
generated but not treated as errors.

Fix this by creating a helper function that always incrementing the
warnings counter every time a warning is emitted. There is one location
in get_sphinx_version() where a warning is not touched as it concerns
the execution environment of the kernel-doc and not the documentation
being processed.

Incrementing the counter only have effect when running kernel-doc in
either verbose mode (-v or environment variable KBUILD_VERBOSE) or when
treating warnings as errors (-Werror or environment variable
KDOC_WERROR). In both cases the number of warnings printed is printed to
stderr and for the later the exit code of kernel-doc is non-zero if
warnings where encountered.

Simple test case to demo one of the warnings,

$ cat test.c
/**
* foo() - Description
*/
int bar();

# Without this change
$ ./scripts/kernel-doc -Werror -none test.c
test.c:4: warning: expecting prototype for foo(). Prototype was for
bar() instead

# With this change
$ ./scripts/kernel-doc -Werror -none test.c
test.c:4: warning: expecting prototype for foo(). Prototype was for
bar() instead
1 warnings as Errors

Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Link: https://lore.kernel.org/r/20220613090510.3088294-1-niklas.soderlund@corigine.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: change the line number meta info

In order to make it more standard and ReST compatible,
change the meta-tag used with --enable-lineno from:

#define LINENO

to
.. LINENO

In practice, no functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/40725032b5a4a33db740bf1de397523af958ff8a.1648290305.git.mchehab@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: scripts/kernel-doc: Detect absence of FILE arg

Currently, when there is no FILE argument following a switch such
as -man, -rst, or -none, kernel-doc exits with a warning from perl
(long msg folded):

Use of uninitialized value $ARGV[0] in pattern match (m//)
at ./scripts/kernel-doc line 438.

, which is unhelpful.

Improve the behavior by adding a check at the bottom of parsing
loop.
If the argument is absent, display help text and exit with
the code of 1 (via usage()).

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/7b136049-a3ba-0eb5-8717-364d773ff914@gmail.com
[jc: reworked to fix conflict with pod patches]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Refresh the copyright lines

I wanted to clean up these lines, but in the end decided not to touch
the old ones and just add my own about POD. I'll leave the cleanup
for lawyers.

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-12-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Drop obsolete comments

What for? To improve the script maintainability.

1. License

As stated by Jonathan Corbet in the reply to my version 1, the SPDX line
is enough.

2. The to-do list comment

As suggested by Jonathan Corbet in reply to my version 3, this section
doesn't need to be transitioned. And so it is removed for clarity.

3. The historical changelog comments

As suggested by Jonathan Corbet in a reply to v3, this section can go.
I wanted to keep it, but since it doesn't contain copyright notices,
let's just have it clean and simple.

4. The "format of comments" comment block

As suggested by Jani Nikula in a reply to my first version of this
transformation, Documentation/doc-guide/kernel-doc.rst can serve as the
information hub for comment formatting. The section DESCRIPTION already
points there, so the original comment block can just be removed.

Suggested-by: Jonathan Corbet <corbet@lwn.net>
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-11-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Replace the usage function

Aim: unified POD, user more satisfied, script better structured

You can see the results with:

$ scripts/kernel-doc -help

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-10-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Translate the "Other parameters" subsection of OPTIONS

Aim: unified POD, user more satisfied, script better structured

Notes:
- The -help token is added.
- The entries are sorted alphbetically.

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-9-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Translate the "Output selection modifiers" subsection of OPTIONS

Aim: unified POD, user more satisfied, script better structured

A subsection "reStructuredText only" is added for -enable-lineno.

Other notes:
- paragraphing correction

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-8-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Translate the "Output selection" subsection of OPTIONS

Aim: unified POD, user more satisfied, script better structured

The plurals in -function and -nosymbol are corrected to singulars.
That's how the script works now. I think this describes the syntax better.
The plurar suggests multiple FILE arguments might be possible. So this
seems more coherent.

Other notes:
- paragraphing correction
- article correction

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-7-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Translate the "Output format selection modifier" subsection of OPTIONS

Aim: unified POD, user more happy

This section is renamed to "Output format modifiers" to make it simple.

To make it even more simple, a subsection is added:
"reStructuredText only".

Other notes:
- paragraphing correction
- article correction

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-6-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Translate the "Output format selection" subsection of OPTIONS

Another step in the direction of a uniform POD documentation, which will
make users happier.

Options land at the end of the script, not to clutter the file top.

The default output format is corrected to rst. That's what it is now.

A POD delimiting comment is added to the script head, which improves
the script logical structure.

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-5-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Translate the DESCRIPTION section

Transition the description section into POD. This is one of the standard
documentation sections. This adjustment makes the section available for
POD and makes it look better.

Notes:
- an article addition
- paragraphing correction

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-4-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Relink argument parsing error handling to pod2usage

The former usage function is substituted, although not as the -h and -help
parameter handler yet.

Purpose: Use Pod::Usage to handle documentation printing in an integrated
way.

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-3-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Add the basic POD sections

The NAME section provides the doc title, while SYNOPSIS contains
the basic syntax and usage description, which will be printed
in the help document and in the error output produced on wrong script
usage.

The rationale is to give users simple and succinct enlightment,
at the same time structuring the script internally for the maintainers.

In the synopsis, Rst-only options are grouped around rst, and the rest is
arranged as in the OPTIONS subsections (yet to be translated into POD,
check at the end of the series).

The third of the basic sections, DESCRIPTION, is added separately.

Signed-off-by: Tomasz Warniełło <tomasz.warniello@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Disliked-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/20220218181628.1411551-2-tomasz.warniello@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: support DECLARE_PHY_INTERFACE_MASK()

Support the DECLARE_PHY_INTERFACE_MASK() macro that is used to declare
a bitmap by converting the macro to DECLARE_BITMAP(), as has been done
for the __ETHTOOL_DECLARE_LINK_MODE_MASK() macro.

This fixes a 'make htmldocs' warning:

include/linux/phylink.h:82: warning: Function parameter or member 'DECLARE_PHY_INTERFACE_MASK(supported_interfaces' not described in 'phylink_config'

that was introduced by commit
38c310eb46f5 ("net: phylink: add MAC phy_interface_t bitmap")

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/45934225-7942-4326-f883-a15378939db9@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Ignore __alloc_size() attribute

Fixes "Compiler Attributes: add __alloc_size() for better bounds checking"
so that the __alloc_size() macro is ignored for function prototypes when
generating kerndoc. Avoids warnings like:

./include/linux/slab.h:662: warning: Function parameter or member '1' not described in '__alloc_size'
./include/linux/slab.h:662: warning: Function parameter or member '2' not described in '__alloc_size'
./include/linux/slab.h:662: warning: expecting prototype for kcalloc(). Prototype was for __alloc_size() instead

Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211011180650.3603988-1-keescook@chromium.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

stddef: Introduce DECLARE_FLEX_ARRAY() helper

There are many places where kernel code wants to have several different
typed trailing flexible arrays. This would normally be done with multiple
flexible arrays in a union, but since GCC and Clang don't (on the surface)
allow this, there have been many open-coded workarounds, usually involving
neighboring 0-element arrays at the end of a structure. For example,
instead of something like this:

struct thing {
...
union {
struct type1 foo[];
struct type2 bar[];
};
};

code works around the compiler with:

struct thing {
...
struct type1 foo[0];
struct type2 bar[];
};

Another case is when a flexible array is wanted as the single member
within a struct (which itself is usually in a union). For example, this
would be worked around as:

union many {
...
struct {
struct type3 baz[0];
};
};

These kinds of work-arounds cause problems with size checks against such
zero-element arrays (for example when building with -Warray-bounds and
-Wzero-length-bounds, and with the coming FORTIFY_SOURCE improvements),
so they must all be converted to "real" flexible arrays, avoiding warnings
like this:

fs/hpfs/anode.c: In function 'hpfs_add_sector_to_btree':
fs/hpfs/anode.c:209:27: warning: array subscript 0 is outside the bounds of an interior zero-length array 'struct bplus_internal_node[0]' [-Wzero-length-bounds]
209 | anode->btree.u.internal[0].down = cpu_to_le32(a);
| ~~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from fs/hpfs/hpfs_fn.h:26,
from fs/hpfs/anode.c:10:
fs/hpfs/hpfs.h:412:32: note: while referencing 'internal'
412 | struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
| ^~~~~~~~

drivers/net/can/usb/etas_es58x/es58x_fd.c: In function 'es58x_fd_tx_can_msg':
drivers/net/can/usb/etas_es58x/es58x_fd.c:360:35: warning: array subscript 65535 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[]'} [-Wzero-length-bounds]
360 | tx_can_msg = (typeof(tx_can_msg))&es58x_fd_urb_cmd->raw_msg[msg_len];
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/net/can/usb/etas_es58x/es58x_core.h:22,
from drivers/net/can/usb/etas_es58x/es58x_fd.c:17:
drivers/net/can/usb/etas_es58x/es58x_fd.h:231:6: note: while referencing 'raw_msg'
231 | u8 raw_msg[0];
| ^~~~~~~

However, it _is_ entirely possible to have one or more flexible arrays
in a struct or union: it just has to be in another struct. And since it
cannot be alone in a struct, such a struct must have at least 1 other
named member -- but that member can be zero sized. Wrap all this nonsense
into the new DECLARE_FLEX_ARRAY() in support of having flexible arrays
in unions (or alone in a struct).

As with struct_group(), since this is needed in UAPI headers as well,
implement the core there, with a non-UAPI wrapper.

Additionally update kernel-doc to understand its existence.

https://github.com/KSPP/linux/issues/137

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

stddef: Introduce struct_group() helper macro

Kernel code has a regular need to describe groups of members within a
structure usually when they need to be copied or initialized separately
from the rest of the surrounding structure. The generally accepted design
pattern in C is to use a named sub-struct:

struct foo {
int one;
struct {
int two;
int three, four;
} thing;
int five;
};

This would allow for traditional references and sizing:

memcpy(&dst.thing, &src.thing, sizeof(dst.thing));

However, doing this would mean that referencing struct members enclosed
by such named structs would always require including the sub-struct name
in identifiers:

do_something(dst.thing.three);

This has tended to be quite inflexible, especially when such groupings
need to be added to established code which causes huge naming churn.
Three workarounds exist in the kernel for this problem, and each have
other negative properties.

To avoid the naming churn, there is a design pattern of adding macro
aliases for the named struct:

#define f_three thing.three

This ends up polluting the global namespace, and makes it difficult to
search for identifiers.

Another common work-around in kernel code avoids the pollution by avoiding
the named struct entirely, instead identifying the group's boundaries using
either a pair of empty anonymous structs of a pair of zero-element arrays:

struct foo {
int one;
struct { } start;
int two;
int three, four;
struct { } finish;
int five;
};

struct foo {
int one;
int start[0];
int two;
int three, four;
int finish[0];
int five;
};

This allows code to avoid needing to use a sub-struct named for member
references within the surrounding structure, but loses the benefits of
being able to actually use such a struct, making it rather fragile. Using
these requires open-coded calculation of sizes and offsets. The efforts
made to avoid common mistakes include lots of comments, or adding various
BUILD_BUG_ON()s. Such code is left with no way for the compiler to reason
about the boundaries (e.g. the "start" object looks like it's 0 bytes
in length), making bounds checking depend on open-coded calculations:

if (length > offsetof(struct foo, finish) -
offsetof(struct foo, start))
return -EINVAL;
memcpy(&dst.start, &src.start, offsetof(struct foo, finish) -
offsetof(struct foo, start));

However, the vast majority of places in the kernel that operate on
groups of members do so without any identification of the grouping,
relying either on comments or implicit knowledge of the struct contents,
which is even harder for the compiler to reason about, and results in
even more fragile manual sizing, usually depending on member locations
outside of the region (e.g. to copy "two" and "three", use the start of
"four" to find the size):

BUILD_BUG_ON((offsetof(struct foo, four) <
offsetof(struct foo, two)) ||
(offsetof(struct foo, four) <
offsetof(struct foo, three));
if (length > offsetof(struct foo, four) -
offsetof(struct foo, two))
return -EINVAL;
memcpy(&dst.two, &src.two, length);

In order to have a regular programmatic way to describe a struct
region that can be used for references and sizing, can be examined for
bounds checking, avoids forcing the use of intermediate identifiers,
and avoids polluting the global namespace, introduce the struct_group()
macro. This macro wraps the member declarations to create an anonymous
union of an anonymous struct (no intermediate name) and a named struct
(for references and sizing):

struct foo {
int one;
struct_group(thing,
int two;
int three, four;
);
int five;
};

if (length > sizeof(src.thing))
return -EINVAL;
memcpy(&dst.thing, &src.thing, length);
do_something(dst.three);

There are some rare cases where the resulting struct_group() needs
attributes added, so struct_group_attr() is also introduced to allow
for specifying struct attributes (e.g. __align(x) or __packed).
Additionally, there are places where such declarations would like to
have the struct be tagged, so struct_group_tagged() is added.

Given there is a need for a handful of UAPI uses too, the underlying
__struct_group() macro has been defined in UAPI so it can be used there
too.

To avoid confusing scripts/kernel-doc, hide the macro from its struct
parsing.

Co-developed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728023217.GC35706@embeddedor
Enhanced-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/lkml/41183a98-bdb9-4ad6-7eab-5a7292a6df84@rasmusvillemoes.dk
Enhanced-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/lkml/1d9a2e6df2a9a35b2cdd50a9a68cac5991e7e5f0.camel@intel.com
Enhanced-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/lkml/YQKa76A6XuFqgM03@phenom.ffwll.local
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

scripts/kernel-doc: Override -Werror from KCFLAGS with KDOC_WERROR

Since commit 2c12c8103d8f ("scripts/kernel-doc: optionally treat
warnings as errors"), the kernel-doc script will treat warnings as
errors when one of the following conditions is true:

- The KDOC_WERROR environment variable is non-zero
- The KCFLAGS environment variable contains -Werror
- The -Werror parameter is passed to kernel-doc

Checking KCFLAGS for -Werror allows piggy-backing on the C compiler
error handling. However, unlike the C compiler, kernel-doc has no
provision for -Wno-error. This makes compiling the kernel with -Werror
(to catch regressions) and W=1 (to enable more checks) always fail,
without the same possibility as offered by the C compiler to treating
some selected warnings as warnings despite the global -Werror setting.

To fix this, evaluate KDOC_WERROR after KCFLAGS, which allows disabling
the warnings-as-errors behaviour of kernel-doc selectively by setting
KDOC_WERROR=0.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20210730225401.4401-1-laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: reduce repeated regex expressions into variables

There are some regex expressions in the kernel-doc script, which are used
repeatedly in the script.

Reduce such expressions into variables, which can be used everywhere.

A quick manual check found that no errors and warnings were added/removed
in this process.

Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210514144244.25341-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Add support for __deprecated

The current linux-next tree has a new error:

./Documentation/gpu/drm-mm:445: ./drivers/gpu/drm/drm_prime.c:994: WARNING: Error in declarator or parameters
Invalid C declaration: Expecting "(" in parameters. [error at 17]
int __deprecated drm_prime_sg_to_page_array (struct sg_table *sgt, struct page **pages, int max_entries)
-----------------^

While we might consider that documenting a deprecated interface is not
necessarily best practice, removing the error is easy.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Link: https://lore.kernel.org/r/20210427114828.GY235567@casper.infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: improve parsing for kernel-doc comments syntax

Currently kernel-doc does not identify some cases of probable kernel
doc comments, for e.g. pointer used as declaration type for identifier,
space separated identifier, etc.

Some example of these cases in files can be:
i)" * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure"
in fs/jbd2/journal.c

ii) "* dget, dget_dlock - get a reference to a dentry" in
include/linux/dcache.h

iii) " * DEFINE_SEQLOCK(sl) - Define a statically allocated seqlock_t"
in include/linux/seqlock.h

Also improve identification for non-kerneldoc comments. For e.g.,

i) " * The following functions allow us to read data using a swap map"
in kernel/power/swap.c does follow the kernel-doc like syntax, but the
content inside does not adheres to the expected format.

Improve parsing by adding support for these probable attempts to write
kernel-doc comment.

Suggested-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/lkml/87mtujktl2.fsf@meer.lwn.net
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210414192529.9080-1-yashsri421@gmail.com
[ jc: fixed some line-length issues ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: add warning for comment not following kernel-doc syntax

Currently, kernel-doc start parsing the comment as a kernel-doc comment if
it starts with '/**', but does not take into account if the content inside
the comment too, adheres with the expected format.
This results in unexpected and unclear warnings for the user.

E.g., running scripts/kernel-doc -none mm/memcontrol.c emits:
"mm/memcontrol.c:961: warning: expecting prototype for do not fallback to current(). Prototype was for get_mem_cgroup_from_current() instead"

Here kernel-doc parses the corresponding comment as a kernel-doc comment
and expects prototype for it in the next lines, and as a result causing
this warning.

Provide a clearer warning message to the users regarding the same, if the
content inside the comment does not follow the kernel-doc expected format.

Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210329092945.13152-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: properly recognize parameter lines with colons

The previous attempt to properly handle literal blocks broke parsing of
parameter lines containing colons; fix it by tweaking the regex to
specifically exclude the "::" pattern while accepting lines containing
colons in general. Add a little documentation to the regex while in the
neighborhood.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 8d295fbad687 ("kernel-doc: better handle '::' sequences")
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: better handle '::' sequences

Right now, if one of the following headers end with a '::', the
kernel-doc script will do the wrong thing:

description|context|returns?|notes?|examples?

The real issue is with examples, as people could try to write
something like:

example::

/* Some C code */

and this won't be properly evaluated. So, improve the regex
to not catch '\w+::' regex for the above identifiers.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/2cf44cf1fa42588632735d4fbc8e84304bdc235f.1616696051.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: ignore identifier on anonymous enums

When anonymous enums are used, the identifier is empty.

While, IMO, it should be avoided the usage of such enums,
adding support for it is not hard.

So, postpone the check for empty identifiers to happen
only at the dump phase.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/055ad57879f1b9381b90879e00f72fde1c3a5647.1614760910.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: fix attribute capture in function parsing

Currently, kernel-doc warns for function prototype parsing on the
presence of attributes "__attribute_const__" and "__flatten" in the
definition.

There are 166 occurrences in ~70 files in the kernel tree for
"__attribute_const__" and 5 occurrences in 4 files for "__flatten".

Out of 166, there are 3 occurrences in three different files with
"__attribute_const__" and a preceding kernel-doc; and, 1 occurrence in
./mm/percpu.c for "__flatten" with a preceding kernel-doc. All other
occurrences have no preceding kernel-doc.

Add support for "__attribute_const__" and "__flatten" attributes.

A quick evaluation by running 'kernel-doc -none' on kernel-tree reveals
that no additional warning or error has been added or removed by the fix.

Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210306113510.31023-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: fix typedef support for struct/union parsing

Currently, there are ~1290 occurrences in 447 files in the kernel tree
'typedef struct/union' syntax for defining some struct/union. However,
kernel-doc currently does not support that syntax. Of the ~1290
occurrences, there are four occurrences in ./include/linux/zstd.h with
typedef struct/union syntax and a preceding kernel-doc; all other
occurrences have no preceding kernel-doc.

Add support for parsing struct/union following this syntax.

Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Link: https://lore.kernel.org/r/20210225145033.11431-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: fix array element capture in pointer-to-func parsing

Currently, kernel-doc causes an unexpected error when array element (i.e.,
"type (*foo[bar])(args)") is present as pointer parameter in
pointer-to-function parsing.

For e.g., running kernel-doc -none on kernel/gcov/gcc_4_7.c causes this
error:
"Use of uninitialized value $param in regexp compilation at ...", in
combination with:
"warning: Function parameter or member '' not described in 'gcov_info'"

Here, the parameter parsing does not take into account the presence of
array element (i.e. square brackets) in $param.

Provide a simple fix by adding square brackets in the regex, responsible
for capturing $param.

A quick evaluation, by running 'kernel-doc -none' on entire kernel-tree,
reveals that no additional warning or error has been added or removed by
the fix.

Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20210217145625.14006-1-yashsri421@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: add internal hyperlink to DOC: sections

While DOC: section titles are not converted into RST headings
sections and are only decorated with strong emphasis markup,
nothing stops us from generating internal hyperlinks for them,
to mimic implicit hyperlinks to RST headings.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://lore.kernel.org/r/20210118110813.1490-1-michal.wajdeczko@intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: validate kernel-doc markup with the actual names

Kernel-doc currently expects that the kernel-doc markup to come
just before the function/enum/struct/union/typedef prototype.

Yet, if it find things like:

/**
* refcount_add - add a value to a refcount
* @i: the value to add to the refcount
* @r: the refcount
*/
static inline void __refcount_add(int i, refcount_t *r, int *oldp);
static inline void refcount_add(int i, refcount_t *r);

Kernel-doc will do the wrong thing:

foobar.h:6: warning: Function parameter or member 'oldp' not described in '__refcount_add'
.. c:function:: void __refcount_add (int i, refcount_t *r, int *oldp)

add a value to a refcount

**Parameters**

``int i``
the value to add to the refcount

``refcount_t *r``
the refcount

``int *oldp``
*undescribed*

Basically, it will document "__refcount_add" with the kernel-doc
markup for refcount_add.

If both functions have the same arguments, this won't even
produce any warning!

Add a logic to check if the kernel-doc identifier matches the actual
name of the C function or data structure that will be documented.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/081546f141a496d6cabb99a4adc140444c705e93.1610610937.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: fix parsing function-like typedefs

Changeset 6b80975c6308 ("scripts: kernel-doc: fix typedef parsing")
added support for things like:

typedef unsigned long foo();

However, it caused a regression on this prototype:

typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);

This is only noticed after adding a patch that checks if the
kernel-doc identifier matches the typedef:

./scripts/kernel-doc -none $(git grep '^.. kernel-doc::' Documentation/ |cut -d ' ' -f 3|sort|uniq) 2>&1|grep expecting
include/media/v4l2-dv-timings.h:38: warning: expecting prototype for typedef v4l2_check_dv_timings_fnc. Prototype was for typedef nc instead

The problem is that, with the new parsing logic, it is not
checking for complete words at the type part.

Fix it by adding a \b at the end of each type word at the
regex.

fixes: 6b80975c6308 ("scripts: kernel-doc: fix typedef parsing")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/218ff56dcb8e73755005d3fb64586eb1841a276b.1606896997.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: Restore anonymous enum parsing

The commit d38c8cfb0571 ("scripts: kernel-doc: add support for typedef enum")
broke anonymous enum parsing. Restore it by relying on members rather than
its name.

Fixes: d38c8cfb0571 ("scripts: kernel-doc: add support for typedef enum")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20201102170637.36138-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: use :c:union when needed

Sphinx C domain code after 3.2.1 will start complaning if :c:struct
would be used for an union type:

.../Documentation/gpu/drm-kms-helpers:352: ../drivers/video/hdmi.c:851: WARNING: C 'identifier' cross-reference uses wrong tag: reference name is 'union hdmi_infoframe' but found name is 'struct hdmi_infoframe'. Full reference name is 'union hdmi_infoframe'. Full found name is 'struct hdmi_infoframe'.

So, let's address this issue too in advance, in order to
avoid future issues.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6e4ec3eec914df62389a299797a3880ae4490f35.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: split typedef complex regex

The typedef regex for function prototypes are very complex.
Split them into 3 separate regex and then join them using
qr.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/3a4af999a0d62d4ab9dfae1cdefdfcad93383356.1603792384.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: fix typedef parsing

The include/linux/genalloc.h file defined this typedef:

typedef unsigned long (*genpool_algo_t)(unsigned long *map,unsigned long size,unsigned long start,unsigned int nr,void *data, struct gen_pool *pool, unsigned long start_addr);

Because it has a type composite of two words (unsigned long),
the parser gets the typedef name wrong:

.. c:macro:: long

**Typedef**: Allocation callback function type definition

Fix the regex in order to accept composite types when
defining a typedef for a function pointer.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/328e8018041cc44f7a1684e57f8d111230761c4f.1603792384.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: try to use c:function if possible

There are a few namespace clashes by using c:macro everywhere:

basically, when using it, we can't have something like:

.. c:struct:: pwm_capture

.. c:macro:: pwm_capture

So, we need to use, instead:

.. c:function:: int pwm_capture (struct pwm_device * pwm, struct pwm_capture * result, unsigned long timeout)

for the function declaration.

The kernel-doc change was proposed by Jakob Lykke Andersen here:

https://github.com/jakobandersen/linux_docs/commit/6fd2076ec001cca7466857493cd678df4dfe4a65

Although I did a different implementation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: fix line number handling

Address several issues related to pointing to the wrong line
number:

1) ensure that line numbers will always be initialized

When section is the default (Description), the line number
is not initializing, producing this:

$ ./scripts/kernel-doc --enable-lineno ./drivers/media/v4l2-core/v4l2-mem2mem.c|less

**Description**

#define LINENO 0
In case of streamoff or release called on any context,
1] If the context is currently running, then abort job will be called
2] If the context is queued, then the context will be removed from
the job_queue

Which is not right. Ensure that the line number will always
be there. After applied, the result now points to the right location:

**Description**

#define LINENO 410
In case of streamoff or release called on any context,
1] If the context is currently running, then abort job will be called
2] If the context is queued, then the context will be removed from
the job_queue

2) The line numbers for function prototypes are always + 1,
because it is taken at the line after handling the prototype.
Change the logic to point to the next line after the /** */
block;

3) The "DOC:" line number should point to the same line as this
markup is found, and not to the next one.

Probably part of the issues were due to a but that was causing
the line number offset to be incremented by one, if --export
were used.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: allow passing desired Sphinx C domain dialect

When kernel-doc is called via kerneldoc.py, there's no need to
auto-detect the Sphinx version, as the Sphinx module already
knows it. So, add an optional parameter to allow changing the
Sphinx dialect.

As kernel-doc can also be manually called, keep the auto-detection
logic if the parameter was not specified. On such case, emit
a warning if sphinx-build can't be found at PATH.

I ended using a suggestion from Joe for using a more readable
regex, instead of using a complex one with a hidden group like:

m/^(\d+)\.(\d+)(?:\.?(\d+)?)/

in order to get the optional <patch> argument.

Thanks-to: Joe Perches <joe@perches.com>
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: don't mangle with parameter list

While kernel-doc needs to parse parameters in order to
identify its name, it shouldn't be touching the type,
as parsing it is very difficult, and errors happen.

One current error is when parsing this parameter:

const u32 (*tab)[256]

Found at ./lib/crc32.c, on this function:

u32 __pure crc32_be_generic (u32 crc, unsigned char const *p, size_t len, const u32 (*tab)[256], u32 polynomial);

The current logic mangles it, producing this output:

const u32 ( *tab

That's something that it is not recognizeable.

So, instead, let's push the argument as-is, and use it
when printing the function prototype and when describing
each argument.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: fix typedef identification

Some typedef expressions are output as normal functions.

As we need to be clearer about the type with Sphinx 3.x,
detect such cases.

While here, fix a wrongly-indented block.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: reimplement -nofunction argument

Right now, the build system doesn't use -nofunction, as
it is pretty much useless, because it doesn't consider
the other output modes (extern, internal), working only
with all.

Also, it is limited to exclude functions.

Re-implement it in order to allow excluding any symbols from
the document output, no matter what mode is used.

The parameter was also renamed to "-nosymbol", as it express
better its meaning.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: fix troubles with line counts

There's currently a bug with the way kernel-doc script
counts line numbers that can be seen with:

$ ./scripts/kernel-doc -rst -enable-lineno include/linux/math64.h >all && ./scripts/kernel-doc -rst -internal -enable-lineno include/linux/math64.h >int && diff -U0 int all

--- int 2020-09-28 12:58:08.927486808 +0200
+++ all 2020-09-28 12:58:08.905486845 +0200
@@ -1 +1 @@
-#define LINENO 27
+#define LINENO 26
@@ -3 +3 @@
-#define LINENO 16
+#define LINENO 15
@@ -9 +9 @@
-#define LINENO 17
+#define LINENO 16
...

This is happening with perl version 5.30.3, but I'm not
so sure if this is a perl bug, or if this is due to something
else.

In any case, fixing it is easy. Basically, when "-internal"
parameter is used, the process_export_file() function opens the
handle "IN". This makes the line number to be incremented, as the
handler for the main open is also "IN".

Fix the problem by using a different handler for the
main open().

While here, add a missing close for it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: use a less pedantic markup for funcs on Sphinx 3.x

Unfortunately, Sphinx 3.x parser for c functions is too pedantic:

https://github.com/sphinx-doc/sphinx/issues/8241

While it could be relaxed with some configurations, there are
several corner cases that it would make it hard to maintain,
and will require teaching conf.py about several macros.

So, let's instead use the :c:macro notation. This will
produce an output that it is not as nice as currently, but it
should still be acceptable, and will provide cross-references,
removing thousands of warnings when building with newer
versions of Sphinx.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: make it more compatible with Sphinx 3.x

With Sphinx 3.x, the ".. c:type:" tag was changed to accept either:

.. c:type:: typedef-like declaration
.. c:type:: name

Using it for other types (including functions) don't work anymore.

So, there are newer tags for macro, enum, struct, union, and others,
which doesn't exist on older versions.

Add a check for the Sphinx version and change the produced tags
accordingly.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

scripts: kernel-doc: add support for typedef enum

The PHY kernel-doc markup has gained support for documenting
a typedef enum.

However, right now the parser was not prepared for it.

So, add support for parsing it.

Fixes: 4069a572d423 ("net: phy: Document core PHY structures")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

kernel-doc: add support for ____cacheline_aligned attribute

Subroutine dump_struct uses type attributes to check if the struct
syntax is valid. Then, it removes all attributes before using it for
output. `____cacheline_aligned` is an attribute that is
not included in both steps. Add it, since it is used by kernel structs.

Based on previous patch to add ____cacheline_aligned_in_smp.
Motivated by patches to reorder this attribute to before the
variable name. Whilst we could do that in all cases, that would
be a massive change and it is more common in the kernel to place
this particular attribute after the variable name. A quick grep
suggests approximately 400 instances of which 341 have this
attribute just before a semicolon and hence after the variable name.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200910185415.653139-1-jic23@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: include line numbers for function prototypes

This should solve bad error reports like this one:

./include/linux/iio/iio.h:0: WARNING: Unknown target name: "devm".

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/56eed0ba50cd726236acd12b11b55ce54854c5ea.1599660067.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: optionally treat warnings as errors

The kbuild bot recently added the W=1 option, which triggered
documentation cleanups to squelch hundreds of kernel-doc warnings.

To make sure new kernel contributions don't add regressions to
kernel-doc descriptors, this patch suggests an option to treat
warnings as errors in CI/automated tests.

A -Werror command-line option is added to the kernel-doc script. When
this option is set, the script will return the number of warnings
found. The caller can then treat this positive return value as an
error and stop the build.

Using this command line option is however not straightforward when the
kernel-doc script is called from other scripts. To align with typical
kernel compilation or documentation generation, the Werror option is
also set by checking the KCFLAGS environment variable, or if
KDOC_WERROR is defined, as in the following examples:

KCFLAGS="-Wall -Werror" make W=1 sound/
KCFLAGS="-Wall -Werror" make W=1 drivers/soundwire/
KDOC_WERROR=1 make htmldocs

Note that in the last example the documentation build does not stop,
only an additional log is provided.

Credits to Randy Dunlap for suggesting the use of environment variables.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200728162040.92467-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: handle function pointer prototypes

There are some function pointer prototypes inside the net
includes, like this one:

int (*pcs_config)(struct phylink_config *config, unsigned int mode,
phy_interface_t interface, const unsigned long *advertising);

There's nothing wrong using it with kernel-doc, but we need to
add a rule for it to parse such kind of prototype.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/fec520dd731a273013ae06b7653a19c7d15b9562.1592895969.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: parse __ETHTOOL_DECLARE_LINK_MODE_MASK

The __ETHTOOL_DECLARE_LINK_MODE_MASK macro is a variant of
DECLARE_BITMAP(), used by phylink.h. As we have already a
parser for DECLARE_BITMAP(), let's add one for this macro,
in order to avoid such warnings:

./include/linux/phylink.h:54: warning: Function parameter or member '__ETHTOOL_DECLARE_LINK_MODE_MASK(advertising' not described in 'phylink_link_state'
./include/linux/phylink.h:54: warning: Function parameter or member '__ETHTOOL_DECLARE_LINK_MODE_MASK(lp_advertising' not described in 'phylink_link_state'

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/d1d1dea67a28117c0b0c33271b139c4455fef287.1592895969.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Replace HTTP links with HTTPS ones: documentation

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200526060544.25127-1-grandmaster@al2klimov.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: accept blank lines on parameter description

Sphinx is very pedantic with respect to blank lines. Sometimes,
in order to make it to properly handle something, we need to
add a blank line. However, currently, any blank line inside a
kernel-doc comment like:

/*
* @foo: bar
*
* foobar
*
* some description

will be considered as if "foobar" was part of the description.

This patch changes kernel-doc behavior. After it, foobar will
be considered as part of the parameter text. The description
will only be considered as such if it starts with:

zero spaces after asterisk:

*foo

one space after asterisk:
* foo

or have a explicit Description section:

* Description:

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c07d2862792d75a2691d69c9eceb7b89a0164cc0.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: accept negation like !@var

On a few places, it sometimes need to indicate a negation of a
parameter, like:

!@fshared

This pattern happens, for example, at:

kernel/futex.c

and it is perfectly valid. However, kernel-doc currently
transforms it into:

!**fshared**

This won't do what it would be expected.

Fortunately, fixing the script is a simple matter of storing
the "!" before "@" and adding it after the bold markup, like:

**!fshared**

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/0314b47f8c3e1f9db00d5375a73dc3cddd8a21f2.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: proper handle @foo->bar()

The pattern @foo->bar() is valid, as it can be used by a
function pointer inside a struct passed as a parameter.

Right now, it causes a warning:

./drivers/firewire/core-transaction.c:606: WARNING: Inline strong start-string without end-string.

In this specific case, the kernel-doc markup is:

/**
* fw_core_remove_address_handler() - unregister an address handler
* @handler: callback
*
* To be called in process context.
*
* When fw_core_remove_address_handler() returns, @handler->callback() is
* guaranteed to not run on any CPU anymore.
*/

With seems valid on my eyes. So, instead of trying to hack
the kernel-doc markup, let's teach it about how to handle
such things. This should likely remove lots of other similar
warnings as well.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/48b46426d7bf6ff7529f20e5718fbf4e9758e62c.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Add missing close-paren in c:function directives

When kernel-doc generates a 'c:function' directive for a function
one of whose arguments is a function pointer, it fails to print
the close-paren after the argument list of the function pointer
argument. For instance:

long work_on_cpu(int cpu, long (*fn) (void *, void * arg)

in driver-api/basics.html is missing a ')' separating the
"void *" of the 'fn' arguments from the ", void * arg" which
is an argument to work_on_cpu().

Add the missing close-paren, so that we render the prototype
correctly:

long work_on_cpu(int cpu, long (*fn)(void *), void * arg)

(Note that Sphinx stops rendering a space between the '(fn*)' and the
'(void *)' once it gets something that's syntactically valid.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Link: https://lore.kernel.org/r/20200414143743.32677-1-peter.maydell@linaro.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Add support for named variable macro arguments

Currently, when kernel-doc encounters a macro with a named variable
argument[1], such as this:

#define hlist_for_each_entry_rcu(pos, head, member, cond...)

... it expects the variable argument to be documented as `cond...`,
rather than `cond`. This is semantically wrong, because the name (as
used in the macro body) is actually `cond`.

With this patch, kernel-doc will accept the name without dots (`cond`
in the example above) in doc comments, and warn if the name with dots
(`cond...`) is used and verbose mode[2] is enabled.

The support for the `cond...` syntax can be removed later, when the
documentation of all such macros has been switched to the new syntax.

Testing this patch on top of v5.4-rc6, `make htmldocs` shows a few
changes in log output and HTML output:

1) The following warnings[3] are eliminated:

./include/linux/rculist.h:374: warning:
Excess function parameter 'cond' description in 'list_for_each_entry_rcu'
./include/linux/rculist.h:651: warning:
Excess function parameter 'cond' description in 'hlist_for_each_entry_rcu'

2) For list_for_each_entry_rcu and hlist_for_each_entry_rcu, the
correct description is shown

3) Named variable arguments are shown without dots

[1]: https://gcc.gnu.org/onlinedocs/cpp/Variadic-Macros.html
[2]: scripts/kernel-doc -v
[3]: See also https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?h=dev&id=5bc4bc0d6153617eabde275285b7b5a8137fdf3c

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: add support for ____cacheline_aligned_in_smp attribute

Subroutine dump_struct uses type attributes to check if the struct
syntax is valid. Then, it removes all attributes before using it for
output. `____cacheline_aligned_in_smp` is an attribute that is
not included in both steps. Add it, since it is used by kernel structs.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: fix processing nested structs with attributes

The current regular expression for strip attributes of structs (and
for nested ones as well) also removes all whitespaces that may
surround the attribute. After that, the code will split structs and
iterate for each symbol separated by comma at the end of struct
definition (e.g. "} alias1, alias2;"). However, if the nested struct
does not have any alias and has an attribute, it will result in a
empty string at the closing bracket (e.g "};"). This will make the
split return nothing and $newmember will keep uninitialized. Fix
that, by ensuring that the attribute substitution will leave at least
one whitespace.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Allow anonymous enum

In C is a valid construction to have an anonymous enumerator.

Though we have now:

drivers/pinctrl/intel/pinctrl-intel.c:240: error: Cannot parse enum!

Support it in the kernel-doc script.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: ignore __printf attribute

Ignore __printf() function attributes just as other __attribute__
strings are ignored.

Fixes this kernel-doc warning message:
include/kunit/kunit-stream.h:58: warning: Function parameter or member '2' not described in '__printf'

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Don't try to mark up function names

We now have better automarkup in sphinx itself and, besides, this markup
was incorrect and left :c:func: gunk in the processed docs. Sort of
discouraging that nobody ever noticed...:)

As a first step toward the removal of impenetrable regex magic from
kernel-doc it's a tiny one, but you have to start somewhere.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: always name missing kerneldoc sections

The "no structured comments found" warning is not particularly useful if
there are several invocations, one of which is looking for something
wrong. So if something specific has been requested, make it clear that
it's the one we weren't able to find.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: suppress 'not described' warnings for embedded struct fields

The ability to add kerneldoc comments for fields in embedded structures is
useful, but it brought along a whole bunch of warnings for fields that
could not be described before. In many cases, there's little value in
adding docs for these nested fields, and in cases like:

struct a {
struct b {
int c;
} d, e;
};

"c" would have to be described twice (as d.c and e.c) to make the warnings
go away.

We can no doubt do something smarter, but simply suppressing the warnings
for this case removes about 70 warnings from the docs build, freeing us to
focus on the ones that matter more. So make kerneldoc be silent about
missing descriptions for any field containing a ".".

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Fix struct and struct field attribute processing

The kernel-doc attempts to clear the struct and struct member attributes
from the API documentation it produces. It falls short of the job in the
following respects:

- extra whitespaces are left where __attribute__((...)) was removed,

- only a single attribute is removed per struct,

- attributes (such as aligned) containing numbers were not removed,

- attributes are only cleared from struct fields, not structs themselves.

This patch addresses these issues by removing the attributes.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: extend $type_param to match members referenced by pointer

Currently, function parameter description can match '@type.member'
expressions but fails to match '@type->member'.
Extend the $type_param regex to allow matching both

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: kill trailing whitespace

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: fix declaration type determination

Make declaration type determination more robust.

When scripts/kernel-doc is deciding if some kernel-doc notation
contains an enum, a struct, a union, a typedef, or a function,
it does a pattern match on the beginning of the string, looking
for a match with one of "struct", "union", "enum", or "typedef",
and otherwise defaults to a function declaration type.
However, if a function or a function-like macro has a name that
begins with "struct" (e.g., struct_size()), then kernel-doc
incorrectly decides that this is a struct declaration.

Fix this by looking for the declaration type keywords having an
ending word boundary (\b), so that "struct_size" will not match
a struct declaration.

I compared lots of html before/after output from core-api, driver-api,
and networking. There were no differences in any of the files that
I checked.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Escape all literal braces in regexes

Commit 701b3a3c0ac4 ("PATCH scripts/kernel-doc") fixed the two
instances of literal braces that Perl 5.28 warns about, but there are
still more than it doesn't warn about.

Escape all left braces that are treated as literal characters. Also
escape literal right braces, for consistency and to avoid confusing
bracket-matching in text editors.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

PATCH scripts/kernel-doc

Fix a warning whinge from Perl introduced by "scripts: kernel-doc: parse next structs/unions"

Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.32), passed through in regex; marked by <-- HERE in m/({ <-- HERE [^\{\}]*})/ at ./scripts/kernel-doc line 1155.
Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.32), passed through in regex; marked by <-- HERE in m/({ <-- HERE )/ at ./scripts/kernel-doc line 1179.

Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: fix parsing of arrays

The logic with parses array has a bug that prevents it to
parse arrays like:
struct {
...
struct {
u64 msdu[IEEE80211_NUM_TIDS + 1];
...
...

Fix the parser to accept it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Remove __sched markings

I find the __sched annotations unaesthetic in the kernel-doc. Remove
them like we remove __inline, __weak, __init and so on.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: Add an SPDX header to kernel-doc

Add the SPDX header while I'm in the neighborhood. The source itself just
says "GNU General Public License", but it also refers people to the COPYING
file for further information. Since COPYING says 2.0-only, that is what I
have put into the header.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: support in-line comments on nested structs/unions

The parser at kernel-doc rejects names with dots in the middle.
Fix it, in order to support nested structs/unions.

Tested-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel_doc: fixup reporting of function identifiers

When function description includes brackets after the function name as
suggested by Documentation/doc-guide/kernel-doc, the kernel-doc script
omits the function name from "Scanning doc for" report.
Extending match for identifier name with optional brackets fixes this
issue.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Don't mangle literal code blocks in comments

It can be useful to put code snippets into kerneldoc comments; that can be
done with the "::" operator at the end of a line like this::

if (desperate)
run_in_circles();

The ".. code-block::" directive can also be used to this end. kernel-doc
currently fails to understand these literal blocks and applies its normal
markup to them, which is then treated as literal by sphinx. The result is
unsightly markup instead of a useful code snippet.

Apply a hack to the output code to recognize literal blocks and avoid
performing any special markup on them. It's ugly, but that means it fits
in well with the rest of the script.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Finish moving STATE_* code out of process_file()

Move STATE_INLINE and STATE_DOCBLOCK code out of process_file(), which now
actually fits on a single screen. Delete an unused variable and add a
couple of comments while I'm at it.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Move STATE_PROTO processing into its own function

Move the top-level prototype-processing code out of process_file().

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Move STATE_BODY processing to a separate function

Also group the pseudo-global $leading_space variable with its peers.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Move STATE_NAME processing into its own function

Move this code out of process_file() in the name of readability and
maintainability.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Move STATE_NORMAL processing into its own function

Begin the process of splitting up the nearly 500-line process_file()
function by moving STATE_NORMAL processing to a separate function.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Rename and split STATE_FIELD

STATE_FIELD describes a parser state that can handle any part of a
kerneldoc comment body; rename it to STATE_BODY to reflect that.

The $in_purpose variable was a hidden substate of STATE_FIELD; get rid of
it and make a proper state (STATE_BODY_MAYBE) instead. This will make the
subsequent process_file() splitup easier.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: kernel-doc: Get rid of xml_escape() and friends

XML escaping is a worry that came with DocBook, which we no longer have any
dealings with. So get rid of the useless xml_escape()/xml_unescape()
functions. No change to the generated output.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel_doc: better handle show warnings logic

The logic with inhibits warnings for definitions that is not
output is incomplete: it doesn't cover the cases where
OUTPUT_INTERNAL and OUTPUT_EXPORTED are used.

As the most common case is OUTPUT_ALL, place it first,
in order to optimize a litte bit the check logic.

Fixes: 2defb2729217 ("scripts: kernel-doc: apply filtering rules to warnings")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-and-Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: apply filtering rules to warnings

When kernel-doc is called with output selection filters,
it will be called lots of time for a single file. If
there is a warning present there, it means that it may
print hundreds of identical warnings.

Worse than that, the -function NAME actually filters only
functions. So, it makes no sense at all to print warnings
for structs or enums.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: improve nested logic to handle multiple identifiers

It is possible to use nested structs like:

struct {
struct {
void *arg1;
} st1, st2, *st3, st4;
};

Handling it requires to split each parameter. Change the logic
to allow such definitions.

In order to test the new nested logic, the following file
was used to test

<code>
struct foo { int a; }; /* Just to avoid errors if compiled */

/**
* struct my_struct - a struct with nested unions and structs
* @arg1: first argument of anonymous union/anonymous struct
* @arg2: second argument of anonymous union/anonymous struct
* @arg1b: first argument of anonymous union/anonymous struct
* @arg2b: second argument of anonymous union/anonymous struct
* @arg3: third argument of anonymous union/anonymous struct
* @arg4: fourth argument of anonymous union/anonymous struct
* @bar.st1.arg1: first argument of struct st1 on union bar
* @bar.st1.arg2: second argument of struct st1 on union bar
* @bar.st1.bar1: bar1 at st1
* @bar.st1.bar2: bar2 at st1
* @bar.st2.arg1: first argument of struct st2 on union bar
* @bar.st2.arg2: second argument of struct st2 on union bar
* @bar.st3.arg2: second argument of struct st3 on union bar
* @f1: nested function on anonimous union/struct
* @bar.st2.f2: nested function on named union/struct
*/
struct my_struct {
/* Anonymous union/struct*/
union {
struct {
char arg1 : 1;
char arg2 : 3;
};
struct {
int arg1b;
int arg2b;
};
struct {
void *arg3;
int arg4;
int (*f1)(char foo, int bar);
};
};
union {
struct {
int arg1;
int arg2;
struct foo bar1, *bar2;
} st1; /* bar.st1 is undocumented, cause a warning */
struct {
void *arg1; /* bar.st3.arg1 is undocumented, cause a warning */
int arg2;
int (*f2)(char foo, int bar); /* bar.st3.fn2 is undocumented, cause a warning */
} st2, st3, *st4;
int (*f3)(char foo, int bar); /* f3 is undocumented, cause a warning */
} bar; /* bar is undocumented, cause a warning */

/* private: */
int undoc_privat; /* is undocumented but private, no warning */

/* public: */
int undoc_public; /* is undocumented, cause a warning */
};
</code>

It produces the following warnings, as expected:

test2.h:57: warning: Function parameter or member 'bar' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st1' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st2' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st3' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st3.arg1' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st3.f2' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st4' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st4.arg1' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st4.arg2' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.st4.f2' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'bar.f3' not described in 'my_struct'
test2.h:57: warning: Function parameter or member 'undoc_public' not described in 'my_struct'

Suggested-by: Markus Heiser <markus.heiser@darmarit.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: handle nested struct function arguments

Function arguments are different than usual ones. So, an
special logic is needed in order to handle such arguments
on nested structs.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: print the declaration name on warnings

The logic at create_parameterlist()'s ancillary push_parameter()
function has already a way to output the declaration name, with
would help to discover what declaration is missing.

However, currently, the logic is utterly broken, as it uses
the var $type with a wrong meaning. With the current code,
it will never print anything. I suspect that originally
it was using the second argument of output_declaration().

I opted to not rely on a globally defined $declaration_name,
but, instead, to pass it explicitly as a parameter.

While here, I removed a unaligned check for !$anon_struct_union.
This is not needed, as, if $anon_struct_union is not zero,
$parameterdescs{$param} will be defined.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: get rid of $nested parameter

The check_sections() function has a $nested parameter, meant
to identify when a nested struct is present. As we now have
a logic that handles it, get rid of such parameter.

Suggested-by: Markus Heiser <markus.heiser@darmarit.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: parse next structs/unions

There are several places within the Kernel tree with nested
structs/unions, like this one:

struct ingenic_cgu_clk_info {
const char *name;
enum {
CGU_CLK_NONE = 0,
CGU_CLK_EXT = BIT(0),
CGU_CLK_PLL = BIT(1),
CGU_CLK_GATE = BIT(2),
CGU_CLK_MUX = BIT(3),
CGU_CLK_MUX_GLITCHFREE = BIT(4),
CGU_CLK_DIV = BIT(5),
CGU_CLK_FIXDIV = BIT(6),
CGU_CLK_CUSTOM = BIT(7),
} type;
int parents[4];
union {
struct ingenic_cgu_pll_info pll;
struct {
struct ingenic_cgu_gate_info gate;
struct ingenic_cgu_mux_info mux;
struct ingenic_cgu_div_info div;
struct ingenic_cgu_fixdiv_info fixdiv;
};
struct ingenic_cgu_custom_info custom;
};
};

Currently, such struct is documented as:

**Definition**

::
struct ingenic_cgu_clk_info {
const char * name;
};

**Members**

``name``
name of the clock

With is obvioulsy wrong. It also generates an error:
drivers/clk/ingenic/cgu.h:169: warning: No description found for parameter 'enum'

However, there's nothing wrong with this kernel-doc markup: everything
is documented there.

It makes sense to document all fields there. So, add a
way for the core to parse those structs.

With this patch, all documented fields will properly generate
documentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: replace tabs by spaces

Sphinx has a hard time dealing with tabs, causing it to
misinterpret paragraph continuation.

As we're now mainly focused on supporting ReST output,
replace tabs by spaces, in order to avoid troubles when
the output is parsed by Sphinx.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: change default to ReST format

Right now, if kernel-doc is called without arguments, it
defaults to man pages. IMO, it makes more sense to
default to ReST, as this is the output that it is most
used nowadays, and it easier to check if everything got
parsed fine on an enriched text mode format.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: improve argument handling

Right now, if one uses "--rst" instead of "-rst", it just
ignore the argument and produces a man page. Change the
logic to accept both "-cmd" and "--cmd". Also, if
"cmd" doesn't exist, print the usage information and exit.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: get rid of unused output formats

Since there isn't any docbook code anymore upstream,
we can get rid of several output formats:

- docbook/xml, html, html5 and list formats were used by
the old build system;
- As ReST is text, there's not much sense on outputting
on a different text format.

After this patch, only man and rst output formats are
supported.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: get rid of kernel-doc-nano-HOWTO.txt

Everything there is already described at
Documentation/doc-guide/kernel-doc.rst. So, there's no reason why
to keep it anymore.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: parse DECLARE_KFIFO and DECLARE_KFIFO_PTR()

On media, we now have an struct declared with:

struct lirc_fh {
struct list_head list;
struct rc_dev *rc;
int carrier_low;
bool send_timeout_reports;
DECLARE_KFIFO_PTR(rawir, unsigned int);
DECLARE_KFIFO_PTR(scancodes, struct lirc_scancode);
wait_queue_head_t wait_poll;
u8 send_mode;
u8 rec_mode;
};

gpiolib.c has a similar declaration with DECLARE_KFIFO().

Currently, those produce the following error:

./include/media/rc-core.h:96: warning: No description found for parameter 'int'
./include/media/rc-core.h:96: warning: No description found for parameter 'lirc_scancode'
./include/media/rc-core.h:96: warning: Excess struct member 'rawir' description in 'lirc_fh'
./include/media/rc-core.h:96: warning: Excess struct member 'scancodes' description in 'lirc_fh'
../drivers/gpio/gpiolib.c:601: warning: No description found for parameter '16'
../drivers/gpio/gpiolib.c:601: warning: Excess struct member 'events' description in 'lineevent_state'

So, teach kernel-doc how to parse DECLARE_KFIFO() and DECLARE_KFIFO_PTR().

While here, relax at the past DECLARE_foo() macros, accepting a random
number of spaces after comma.

The addition of DECLARE_KFIFO() was
Suggested-by: Randy Dunlap <rdunlap@infradead.org>

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Don't fail with status != 0 if error encountered with -none

My bisect scripts starting running into build failures when trying to
compile 4.15-rc1 with the builds failing with things like:

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c:2078: error: Cannot parse struct or union!

The line in question is actually just a #define, but after some digging
it turns out that my scripts pass W=1 and since commit 3a025e1d1c2ea
("Add optional check for bad kernel-doc comments") that results in
kernel-doc running on each source file. The file in question has a
badly formatted comment immediately before the #define:

/**
* struct brcmf_skbuff_cb reserves first two bytes in sk_buff::cb for
* bus layer usage.
*/

which causes the regex in dump_struct to fail (lack of braces following
struct declaration) and kernel-doc returns 1, which causes the build
to fail.

Fix the issue by always returning 0 from kernel-doc when invoked with
-none. It successfully generates no documentation, and prints out any
issues.

Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add optional check for bad kernel-doc comments

Implement a '-none' output mode for kernel-doc which will only output
warning messages, and suppresses the warning message about there being
no kernel-doc in the file.

If the build has requested additional warnings, automatically check all
.c files. This patch does not check .h files. Enabling the warning
by default would add about 1300 warnings, so it's default off for now.
People who care can use this to check they didn't break the docs and
maybe we'll get all the warnings fixed and be able to enable this check
by default in the future.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kmemcheck: rip it out

Fix up makefiles, remove references, and git rm kmemcheck.

Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: warn on excess enum value descriptions

The existing message
"Excess struct/union/enum/typedef member [...]"
made it sound like this would already be done, but the
code is never invoked for enums or typedefs (and really
can't be).

Add some code to the enum dumper to handle this there
instead.

While at it, also make the above message more accurate
by simply dumping the type that was passed in, and pass
the struct/union differentiation in.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc parser mishandles declarations split into lines

Reported by Johannes Berg [1]. Problem here: function
process_proto_type() concatenates the striped lines of declaration
without any whitespace. A one-liner of::

struct something {
struct foo
bar;
};

has to be::

struct something {struct foo bar;};

Without the patching process_proto_type(), the result missed the space
between 'foo' and 'bar'::

struct something {struct foobar;};

Bugfix of process_proto_type() brings next error when blank lines
between enum declaration::

warning: Enum value ' ' not described in enum 'foo'

Problem here: dump_enum() does not strip leading whitespaces from
the concatenated string (with the new additional space from
process_proto_type).

[1] https://www.mail-archive.com/linux-doc@vger.kernel.org/msg12410.html

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: handle DECLARE_HASHTABLE

DECLARE_HASHTABLE needs similar handling to DECLARE_BITMAP
because otherwise kernel-doc assumes the member name is the
second, not first macro parameter.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: Switch to more portable Perl shebang

The default NetBSD package manager is pkgsrc and it installs Perl
along other third party programs under custom and configurable prefix.
The default prefix for binary prebuilt packages is /usr/pkg, and the
Perl executable lands in /usr/pkg/bin/perl.

This change switches "/usr/bin/perl" to "/usr/bin/env perl" as it's
the most portable solution that should work for almost everybody.
Perl's executable is detected automatically.

This change switches -w option passed to the executable with more
modern "use warnings;" approach. There is no functional change to the
default behavior.

While there, drop "require 5" from scripts/namespace.pl (Perl from 1994?).

Signed-off-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/kernel-doc: fix handling of parameters with parenthesis

lib/crc32c defines one parameter as:
const u32 (*tab)[256]

Better handle parenthesis, to avoid those warnings:

./lib/crc32.c:149: warning: No description found for parameter 'tab)[256]'
./lib/crc32.c:149: warning: Excess function parameter 'tab' description in 'crc32_le_generic'
./lib/crc32.c:294: warning: No description found for parameter 'tab)[256]'
./lib/crc32.c:294: warning: Excess function parameter 'tab' description in 'crc32_be_generic'

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: fix parser for apostrophes

On ReST, adding a text like ``literal`` is valid. However,
the kernel-doc script won't handle it fine.

We really need this feature, in order to escape things like
%ph, with is found on some C files.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Handle returning pointers to pointers

Clearly nobody ever tried to build the documentation for the radix tree
before:

include/linux/radix-tree.h:400: warning: cannot understand function
prototype: 'void ** radix_tree_iter_init(struct radix_tree_iter *iter,
unsigned long start) '

Indeed, the regexes only handled a single '*', not one-or-more. I have
tried to fix that, but now I have perl regexes all over my hands, and
I fear I shall never be clean again.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: properly document array arguments of function

Documentation for array parameters passed in a function, like the first
argument in the function below, weren't getting exported in the rst
format, although they work fine for html and pdf formats:

void drm_clflush_pages(struct page * pages[], unsigned long num_pages)

That's because the string key to store the description in the
parameterdescs dictionary doesn't have the [] suffix. This cleans up
the suffix from the key before accessing the dictionary.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Fixes: c0d1b6ee780a ("kernel-doc: produce RestructuredText output")
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: make highlights more homogenous for the various backends

$type_struct_full and friends are only used by the restructuredText
backend, because it needs to separate enum/struct/typedef/union from
the name of the type. However, $type_struct is *also* used by the rST
backend. This is confusing.

This patch replaces $type_struct's use in the rST backend with a new
$type_fallback; it modifies $type_struct so that it can be used in the
rST backend; and creates regular expressions like $type_struct
for enum/typedef/union, for use in all backends.

Note that, compared to $type_*_full, in the new regexes $1 includes both
the "kind" and the name (before, $1 was pretty much a constant).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: make member highlighting available in all backends

Note that, in order to produce the correct Docbook markup, the "." or "->"
must be separated from the member name in the regex's captured fields. For
consistency, this change is applied to $type_member and $type_member_func
too, not just to $type_member_xml.

List mode only prints the struct name, to avoid any undesired change in
the operation of docproc.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: include parameter type in docbook output

The restructuredText output includes both the parameter type and
the name for functions and function-typed members. Do the same
for docbook.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: strip attributes even if they have an argument

An inline function can have an attribute, as in include/linux/log2.h,
and kernel-doc handles this already for simple cases. However,
some attributes have arguments (e.g. the "target" attribute).
Handle those too.

Furthermore, attributes could be at the beginning of a function
declaration, before the return type. To correctly handle this case,
you need to strip spaces after the attributes; otherwise, dump_function
is left confused.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: cleanup parameter type in function-typed arguments

A prototype like

/**
* foo - sample definition
* @bar: a parameter
*/
int foo(int (*bar)(int x,
int y));

is currently producing

.. c:function:: int foo (int (*bar) (int x, int y)

sample definition

**Parameters**

``int (*)(int x, int y) bar``
a parameter

Collapse the spaces so that the output is nicer.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: add support for one line inline struct member doc comments

kernel-doc supports documenting struct members "inline" since
a4c6ebede2f9 ("scripts/kernel-doc Allow struct arguments documentation
in struct body"). This requires the inline kernel-doc comments to have
the opening and closing comment markers (/** and */ respectively) on
lines of their own, even for short comments. For example:

/**
* struct foo - struct documentation
*/
struct foo {
/**
* @bar: member documentation
*/
int bar;
};

Add support for one line inline comments:

/**
* struct foo - struct documentation
*/
struct foo {
/** @bar: member documentation */
int bar;
};

Note that mixing of the two in one doc comment is not allowed; either
both comment markers must be on lines of their own, or both must be on
the one line. This limitation keeps both the comments more uniform, and
kernel-doc less complicated.

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: better parsing of named variable arguments

Without this patch we get warnings for named variable arguments.

warning: No description found for parameter '...'
warning: Excess function parameter 'args' description in 'alloc_ordered_workqueue'

Signed-off-by: Silvio Fricke <silvio.fricke@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: Special-case function-pointer parameters in kernel-doc

Add yet another regex to kernel-doc to trap @param() references separately
and not produce corrupt RST markup.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: make kernel-doc handle varargs properly

As far as I can tell, the handling of "..." arguments has never worked
right, so any documentation provided was ignored in favor of "variable
arguments." This makes kernel-doc handle "@...:" as documented. It does
*not* fix spots in kerneldoc comments that don't follow that convention,
but they are no more broken than before.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs-rst: kernel-doc: fix typedef output in RST format

When using a typedef function like this one:
typedef bool v4l2_check_dv_timings_fnc (const struct v4l2_dv_timings * t, void * handle);

The Sphinx C domain expects it to create a c:type: reference,
as that's the way it creates the type references when parsing
a c:function:: declaration.

So, a declaration like:

.. c:function:: bool v4l2_valid_dv_timings (const struct v4l2_dv_timings * t, const struct v4l2_dv_timings_cap * cap, v4l2_check_dv_timings_fnc fnc, void * fnc_handle)

Will create a cross reference for :c:type:`v4l2_check_dv_timings_fnc`.

So, when outputting such typedefs in RST format, we need to handle
this special case, as otherwise it will produce those warnings:

./include/media/v4l2-dv-timings.h:43: WARNING: c:type reference target not found: v4l2_check_dv_timings_fnc
./include/media/v4l2-dv-timings.h:60: WARNING: c:type reference target not found: v4l2_check_dv_timings_fnc
./include/media/v4l2-dv-timings.h:81: WARNING: c:type reference target not found: v4l2_check_dv_timings_fnc

So, change the kernel-doc script to produce a RST output for the
above typedef as:
.. c:type:: v4l2_check_dv_timings_fnc

**Typedef**: timings check callback

**Syntax**

``bool v4l2_check_dv_timings_fnc (const struct v4l2_dv_timings * t, void * handle);``

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs-rst: improve typedef parser

Improve the parser to handle typedefs like:

typedef bool v4l2_check_dv_timings_fnc(const struct v4l2_dv_timings *t, void *handle);

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs-rst: kernel-doc: better output struct members

Right now, for a struct, kernel-doc produces the following output:

.. c:type:: struct v4l2_prio_state

stores the priority states

**Definition**

::

struct v4l2_prio_state {
atomic_t prios[4];
};

**Members**

``atomic_t prios[4]``
array with elements to store the array priorities

Putting a member name in verbatim and adding a continuation line
causes the LaTeX output to generate something like:
item[atomic_t prios\[4\]] array with elements to store the array priorities

Everything inside "item" is non-breakable, with may produce
lines bigger than the column width.

Also, for function members, like:

int (* rx_read) (struct v4l2_subdev *sd, u8 *buf, size_t count,ssize_t *num);

It puts the name of the member at the end, like:

int (*) (struct v4l2_subdev *sd, u8 *buf, size_t count,ssize_t *num) read

With is very confusing.

The best is to highlight what really matters: the member name.
is a secondary information.

So, change kernel-doc, for it to produce the output on a different way:

**Members**

``prios[4]``

array with elements to store the array priorities

Also, as the type is not part of LaTeX "item[]", LaTeX will split it into
multiple lines, if needed.

So, both LaTeX/PDF and HTML outputs will look good.

It should be noticed, however, that the way Sphinx LaTeX output handles
things like:

Foo
bar

is different than the HTML output. On HTML, it will produce something
like:

**Foo**
bar

While, on LaTeX, it puts both foo and bar at the same line, like:

**Foo** bar

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

doc-rst: Revert "kernel-doc: fix handling of address_space tags"

This reverts commit a88b1672d4ddf9895eb53e6980926d5e960dea8e.

From the origin comit log::

The RST cpp:function handler is very pedantic: it doesn't allow any
macros like __user on it

Since the kernel-doc parser does NOT make use of the cpp:domain, there
is no need to change the kernel-doc parser eleminating the address_space
tags.

Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

doc-rst: kernel-doc: fix a change introduced by mistake

changeset b7e67f6c1bf7 ("doc-rst: linux_tv: supress lots of warnings")
were meant to touch only on media files, but it also touched
at this script by mistake. Revert such change.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

doc-rst: kernel-doc: fix handling of address_space tags

The RST cpp:function handler is very pedantic: it doesn't allow any
macros like __user on it:

Documentation/media/kapi/dtv-core.rst:28: WARNING: Error when parsing function declaration.
If the function has no return type:
Error in declarator or parameters and qualifiers
Invalid definition: Expecting "(" in parameters_and_qualifiers. [error at 8]
ssize_t dvb_ringbuffer_pkt_read_user (struct dvb_ringbuffer * rbuf, size_t idx, int offset, u8 __user * buf, size_t len)
--------^
If the function has a return type:
Error in declarator or parameters and qualifiers
If pointer to member declarator:
Invalid definition: Expected '::' in pointer to member (function). [error at 37]
ssize_t dvb_ringbuffer_pkt_read_user (struct dvb_ringbuffer * rbuf, size_t idx, int offset, u8 __user * buf, size_t len)
-------------------------------------^
If declarator-id:
Invalid definition: Expecting "," or ")" in parameters_and_qualifiers, got "*". [error at 102]
ssize_t dvb_ringbuffer_pkt_read_user (struct dvb_ringbuffer * rbuf, size_t idx, int offset, u8 __user * buf, size_t len)
------------------------------------------------------------------------------------------------------^

So, we have to remove it from the function prototype.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Fix up warning output

While trying to make gpu docs warning free I stumbled over one output
which wasn't following proper compiler error output standards. Fix it
up for more quickfix awesomeness.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

doc-rst: linux_tv: remove trailing comments

The conversion script added some comments at the end.
They point to the original DocBook files, with will be
removed after the manual fixes. So, they'll be pointing
to nowere. So, remove those comments.

They'll be forever stored at the Kernel tree. So, if
someone wants the references, it is just a matter of
looking at the backlog.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

doc-rst: linux_tv: supress lots of warnings

The c language parser checks if there are duplicated object
definitions. That causes lots of warnings like:
WARNING: duplicate C object description of ioctl

Let's remove those by telling Sphinx that the language for
those objects are c++. The look of the descriptions will
be close, and the warnings will be gone.

Please notice that we had to keep a few of them as C, as
the c++ parser seems to be broken when it finds an enum.

Yet, this reduced from 219 warnings to 143, with is
a good thing.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

kernel-doc: unify all EXPORT_SYMBOL scanning to one place

Scan all input files for EXPORT_SYMBOLs along with the explicitly
specified export files before actually parsing anything.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: add support for specifying extra files for EXPORT_SYMBOLs

If the kernel-doc comments for functions are not in the same file as the
EXPORT_SYMBOL statements, the -export and -internal output selections do
not work as expected. This is typically the case when the kernel-doc
comments are in header files next to the function declarations and the
EXPORT_SYMBOL statements are next to the function definitions in the
source files.

Let the user specify additional source files in which to look for the
EXPORT_SYMBOLs using the new -export-file FILE option, which may be
given multiple times.

The pathological example for this is include/net/mac80211.h, which has
all the kernel-doc documentation for the exported functions defined in a
plethora of source files net/mac80211/*.c.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: abstract filename mapping

Reduce duplication in follow-up work. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: add missing semi-colons in option parsing

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: do not warn about duplicate default section names

Since

commit 32217761ee9db0215350dfe1ca4e66f312fb8c54
Author: Jani Nikula <jani.nikula@intel.com>
Date: Sun May 29 09:40:44 2016 +0300

kernel-doc: concatenate contents of colliding sections

we started getting (more) errors on duplicate section names, especially
on the default section name "Description":

include/net/mac80211.h:3174: warning: duplicate section name 'Description'

This is usually caused by a slightly unorthodox placement of parameter
descriptions, like in the above case, and kernel-doc resetting back to
the default section more than once within a kernel-doc comment.

Ignore warnings on the duplicate section name automatically assigned by
kernel-doc, and only consider explicitly user assigned duplicate section
names an issue.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: remove old debug cruft from dump_section()

No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

docs: kernel-doc: Add "example" and "note" to the magic section types

Lots of kerneldoc entries use "example:" or "note:" as section headers.
Until such a time as we can make them use proper markup, make them work as
intended.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Add option to inject line numbers

Opt-in since this wreaks the rst output and must be removed
by consumers again. This is useful to adjust the linenumbers
for included kernel-doc snippets in shinx. With that sphinx
error message will be accurate when there's issues with the
rst-ness of the kernel-doc comments.

Especially when transitioning a new docbook .tmpl to .rst this
is extremely useful, since you can just use your editors compilation
quickfix list to accurately jump from error to error.

v2:
- Also make sure that we filter the LINENO for purpose/at declaration
start so it only shows for selected blocks, not all of them (Jani).
While at it make it a notch more accurate.
- Avoid undefined $lineno issues. I tried filtering these out at the
callsite, but Jani spotted more when linting the entire kernel.
Unamed unions and similar things aren't stored consistently and end
up with an undefined line number (but also no kernel-doc text, just
the parameter type). Simplify things and filter undefined line
numbers in print_lineno() to catch them all.

v3: Fix LINENO 0 issue for kernel-doc comments without @param: lines
or any other special sections that directly jump to the description
after the "name - purpose" line. Only really possible for functions
without parameters. Noticed by Jani.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

scripts/kernel-doc: Also give functions symbolic names

state3 = prototype parsing, so name them accordingly.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

scripts/kernel-doc: Remove duplicated DOC: start handling

Further up in the state machinery we switch from STATE_NAME to
STATE_DOCBLOCK when we match /$doc_block/. Which means this block of
code here is entirely unreachable, unless there are multiple DOC:
sections within a single kernel-doc comment.

Getting a list of all the files with more than one DOC: section using

$ git grep -c " * DOC:" | grep -v ":1$"

and then doing a full audit of them reveals there are no such comment
blocks in the kernel.

Supporting multiple DOC: sections in a single kernel-doc comment does
not seem like a recommended way of doing things anyway, so nuke the code
for simplicity.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[Jani: amended the commit message]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: reset contents and section harder

If the documentation comment does not have params or sections, the
section heading may leak from the previous documentation comment.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: concatenate contents of colliding sections

If there are multiple sections with the same section name, the current
implementation results in several sections by the same heading, with the
content duplicated from the last section to all. Even if there's the
error message, a more graceful approach is to combine all the
identically named sections into one, with concatenated contents.

With the supported sections already limited to select few, there are
massively fewer collisions than there used to be, but this is still
useful for e.g. when function parameters are documented in the middle of
a documentation comment, with description spread out above and
below. (This is not a recommended documentation style, but used in the
kernel nonetheless.)

We can now also demote the error to a warning.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: limit the "section header:" detection to a select few

kernel-doc currently identifies anything matching "section header:"
(specifically a string of word characters and spaces followed by a
colon) as a new section in the documentation comment, and renders the
section header accordingly.

Unfortunately, this turns all uses of colon into sections, mostly
unintentionally. Considering the output, erroneously creating sections
when not intended is always worse than erroneously not creating sections
when intended. For example, a line with "http://example.com" turns into
a "http" heading followed by "//example.com" in normal text style, which
is quite ugly. OTOH, "WARNING: Beware of the Leopard" is just fine even
if "WARNING" does not turn into a heading.

It is virtually impossible to change all the kernel-doc comments, either
way. The compromise is to pick the most commonly used and depended on
section headers (with variants) and accept them as section headers.

The accepted section headers are, case insensitive:

* description:
* context:
* return:
* returns:

Additionally, case sensitive:

* @return:

All of the above are commonly used in the kernel-doc comments, and will
result in worse output if not identified as section headers. Also,
kernel-doc already has some special handling for all of them, so there's
nothing particularly controversial in adding more special treatment for
them.

While at it, improve the whitespace handling surrounding section
names. Do not consider the whitespace as part of the name.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: remove fixme comment

Yes, for our purposes the type should contain typedef.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: use *undescribed* instead of _undescribed_

The latter isn't special to rst.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: strip leading whitespace from continued param descs

If a param description spans multiple lines, check any leading
whitespace in the first continuation line, and remove same amount of
whitespace from following lines.

This allows indentation in the multi-line parameter descriptions for
aesthetical reasons while not causing accidentally significant
indentation in the rst output.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: improve handling of whitespace on the first line param description

Handle whitespace on the first line of param text as if it was the empty
string. There is no need to add the newline in this case. This improves
the rst output in particular, where blank lines may be problematic in
parameter lists.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: change the output layout

Move away from field lists, and simply use **strong emphasis** for
section headings on lines of their own. Do not use rst section headings,
because their nesting depth depends on the surrounding context, which
kernel-doc has no knowledge of. Also, they do not need to end up in any
table of contexts or indexes.

There are two related immediate benefits. Field lists are typically
rendered in two columns, while the new style uses the horizontal width
better. With no extra indent on the left, there's no need to be as fussy
about it. Field lists are more susceptible to indentation problems than
the new style.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: strip leading blank lines from inline doc comments

The inline member markup allows whitespace lines before the actual
documentation starts. Strip the leading blank lines. This improves the
rst output.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: blank lines in output are not needed

Current approach leads to two blank lines, while one is enough.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: fix wrong code indentation

No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: do not regard $, %, or & prefixes as special in section names

The use of these is confusing in the script, and per this grep, they're
not used anywhere anyway:

$ git grep " \* [%$&][a-zA-Z0-9_]*:" -- *.[ch] | grep -v "\$\(Id\|Revision\|Date\)"

While at it, throw out the constants array, nothing is ever put there
again.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: highlight function/struct/enum purpose lines too

Let the user use @foo, &bar, %baz, etc. in the first kernel-doc purpose
line too.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: drop redundant unescape in highlighting

This bit is already done by xml_unescape() above.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: add support for struct/union/enum member references

Link "&foo->bar", "&foo->bar()", "&foo.bar", and "&foo.bar()" to the
struct/union/enum foo definition. The members themselves do not
currently have anchors to link to, but this is better than nothing, and
promotes a universal notation.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: add support for &union foo and &typedef foo references

Let the user use "&union foo" and "&typedef foo" to reference foo. The
difference to using "union &foo", "typedef &foo", or just "&foo" (which
are valid too) is that "union" and "typedef" become part of the link
text.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: &foo references are more universal than structs

It's possible to use &foo to reference structs, enums, typedefs, etc. in
the Sphinx C domain. Thus do not prefix the links with "struct".

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: reference functions according to C domain spec

The Sphinx C domain spec says function references should include the
parens ().

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: do not output DOC: section titles for requested ones

If the user requests a specific DOC: section by name, do not output its
section title. In these cases, the surrounding context already has a
heading, and the DOC: section title is only used as an identifier and a
heading for clarity in the source file.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: add names for output selection

Make the output selection a bit more readable by adding constants for
the various types of output selection. While at it, actually call the
variable for choosing what to output $output_selection.

No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: add names for states and substates

Make the state machine a bit more readable by adding constants for
parser states and inline member documentation parser substates. While at
it, rename the "split" documentation to "inline" documentation.

No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: support printing exported and non-exported symbols

Currently we use docproc to figure out which symbols are exported, and
then docproc calls kernel-doc on specific functions, to get
documentation on exported functions. According to git blame and docproc
comments, this is due to historical reasons, as functions and their
corresponding EXPORT_SYMBOL* may have been in different files. However
for more than ten years the recommendation in CodingStyle has been to
place the EXPORT_SYMBOL* immediately after the closing function brace
line.

Additionally, the kernel-doc comments for functions are generally placed
above the function definition in the .c files (i.e. where the
EXPORT_SYMBOL* is) rather than above the declaration in the .h
files. There are some exceptions to this, but AFAICT none of these are
included in DocBook documentation using the "!E" docproc directive.

Therefore, assuming the EXPORT_SYMBOL* and kernel-doc are with the
function definition, kernel-doc can extract the exported vs. not
information by making two passes on the input file. Add support for that
via the new -export and -internal parameters.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc/rst: fix use of uninitialized value

I'm not quite sure why the errors below are happening, but this fixes
them.

Use of uninitialized value in string ne at ./scripts/kernel-doc line 1819, <IN> line 6494.
Use of uninitialized value $_[0] in join or string at ./scripts/kernel-doc line 1759, <IN> line 6494.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

kernel-doc: use rst C domain directives and references for types

First, the headings for structs, enums and typedefs will be similar to
functions. Second, this provides a kind of namespace for cross
references. Third, and most importantly, the return and parameter types
from .. c:function:: definitions will automagically become cross
references to the documented types.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: produce RestructuredText output

If given the -rst flag, output will now be in RestructuredText. Various
glitches to be worked out yet.

In the end I decided not to use RST section headings within the kerneldoc
comments. gpu.tmpl already has headings five levels deep; adding more is
not going to bring clarity.

This is really just Jani Nikula's asciidoc change with the serial numbers
filed off. It's a hack job that doubtless needs a lot of cleaning up.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: rewrite usage description, remove duplicated comments

Instead of having the kernel-doc usage in both comments and in output to
the user, merge them all to one here document. While at it, imrove the
text and make it pretty. Give shoemaker's children some shoes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Fix parsing of DECLARE_BITMAP in struct

Some documented structures in the kernel use DECLARE_BITMAP to create
arrays of unsigned longs to store information using the bitmap functions.
These have to be replaced with a parsable version for kernel-doc.

For example a simple input like

/**
* struct something - some test
* @members: active members
*/
struct something {
DECLARE_BITMAP(members, MAX_MEMBERS);
};

resulted in parsing warnings like

warning: No description found for parameter 'MAX_MEMBERS)'
warning: Excess struct/union/enum/typedef member 'members' description in 'something'

Signed-off-by: Conchúr Navid <conchur@web.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Strip #ifdef/#endif in enums

Some enumerations in the kernel headers use #ifdef to reduce their size
based on the the configuration. These lines have to be stripped to avoid
parsing problems.

For example a simple input like

/**
* enum flags - test flags
* @flag1: first flag
* @flag2: second flag
*/
enum flags {
flag1 = BIT(0),
#ifdef SECOND_FLAG
flag2 = BIT(1),
#endif
};

resulted in parsing warnings like

warning: Enum value '#ifdef SECOND_FLAG;flag2 = BIT(1)' not described in enum 'flags'
warning: Enum value '#endif;' not described in enum 'flags'

Signed-off-by: Conchúr Navid <conchur@web.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Fix stripping of #define in enums

The regex to strip single line #define's in enumerations depends on the
fact that the defines are still stored on separate lines. But the
surrounding code already removed newlines and replaced them with
semicolons.

For example a simple input like

/**
* enum flags - test flags
* @flag1: first flag
* @flag2: second flag
* @flag3: third flag
* @flag4: fourth flag
*/
enum flags {
flag1 = BIT(0),
flag2 = BIT(1),
#define flags_small (flag1 | flag2)
flag3 = BIT(2),
flag4 = BIT(3),
#define flags_big (flag2 | flag3)
};

resulted in parsing warnings like

warning: Enum value '#define flags_small (flag1 | flag2);flag3 = BIT(2)' not described in enum 'flags'
warning: Enum value '#define flags_big (flag2 | flag3);' not described in enum 'flags'

Signed-off-by: Conchúr Navid <conchur@web.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: Make it compatible with Perl versions below 5.12 again

Changeset 4d73270192ec('scripts/kernel-doc: Replacing highlights
hash by an array') broke compatibility of the kernel-doc script with
older versions of perl by using "keys ARRAY" syntax with is available
only on Perl 5.12 or newer, according with:
http://perldoc.perl.org/functions/keys.html

Restore backward compatibility by replacing "foreach my $k (keys ARRAY)"
by a C-like variant: "for (my $k = 0; $k < !ARRAY; $k++)"

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

DocBook: Fix kernel-doc to be case-insensitive for private:

On some places, people could use Private: to tag the private fields
of an struct. So, be case-insensitive when parsing "private:"
meta-tag.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kernel-doc: better format typedef function output

A typedef function looks more likely a function and not a
normal typedef. Change the code to use the output_function_*,
in order to properly parse the function prototype parameters.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

kernel-doc: Add a parser for function typedefs

The current typedef parser only works for non-function typedefs.

As we need to also document some function typedefs, add a
parser for it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

scripts/kernel-doc: Replacing highlights hash by an array

The "highlight" code is very sensible to the order of the hash keys,
but the order of the keys cannot be predicted. It generates
faulty DocBook entries like:
- @<function>device_for_each_child</function>

Sorting the result is not enough some times (as it's deterministic but
we can't control it).
We should use an array for that job, so we can guarantee that the order
of the regex execution on dohighlight is correct.

[jc: I think this is kind of papering around the real problem, that people
are saying @function() when "function" is not a parameter. But this makes
things better than they were before, so...]

Signed-off-by: Danilo Cesar Lemes de Paula <danilo.cesar@collabora.co.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation: Avoid creating man pages in source tree

Currently kernel-doc generates a dummy DocBook file when asked to
convert a C source file with no structured comments. For an
out-of-tree build (objtree != srctree), the title of the output file
is the absolute path name of the C source file, which later results
in a manual page being created alongside the C source file.

Change the title to be a relative path.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Processing -nofunc for functions only

Docproc processes the EXPORT_SYMBOL(f1) macro and uses -nofunc f1 to
avoid duplicated documentation in the next call.
It works for most of the cases, but there are some specific situations
where a struct has the same name of an already-exported function.

Current kernel-doc behavior ignores those structs and does not add them
to the final documentation. This patch fixes it.

This is unusual, the only case I've found is the drm_modeset_lock
(function and struct) defined in drm_modeset_lock.h and
drm_modeset_lock.c. Considering this, it should only affect the DRM
documentation by including struct drm_modeset_lock to the final Docbook.

Signed-off-by: Danilo Cesar Lemes de Paula <danilo.cesar@collabora.co.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

kerneldoc: Convert error messages to GNU error message format

Editors like emacs and vi recognize a number of error message formats.
The format used by the kerneldoc tool is not recognized by emacs.

Change the kerneldoc error message format to the GNU style such that the
emacs prev-error and next-error commands can be used to navigate through
kerneldoc error messages. For more information about the GNU error
message format, see also
https://www.gnu.org/prep/standards/html_node/Errors.html.

This patch has been generated via the following sed command:

sed -i.orig 's/Error(\${file}:\$.):/\${file}:\$.: error:/g;s/Warning(\${file}:\$.):/\${file}:\$.: warning:/g;s/Warning(\${file}):/\${file}:1: warning:/g;s/Info(\${file}:\$.):/\${file}:\$.: info:/g' scripts/kernel-doc

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: ignore unneeded attribute information

The kernel-doc script gets confused by __attribute__(()) strings in
structures, so just clean the out. Also ignore the CRYPTO_MINALIGN_ATTR
macro used in the crypto subsystem.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc Allow struct arguments documentation in struct body

Describing arguments at top of a struct definition works fine
for small/medium size structs, but it definitely doesn't work well
for struct with a huge list of elements.

Keeping the arguments list inside the struct body makes it easier
to maintain the documentation.
ie:
/**
* struct my_struct - short description
* @a: first member
* @b: second member
*
* Longer description
*/
struct my_struct {
int a;
int b;
/**
* @c: This is longer description of C
*
* You can use paragraphs to describe arguments
* using this method.
*/
int c;
};

This patch allows the use of this kind of syntax. Only one argument
per comment and user can use how many paragraphs he needs. It should
start with /**, which is already being used by kernel-doc. If those
comment doesn't follow those rules, it will be ignored.

Signed-off-by: Danilo Cesar Lemes de Paula <danilo.cesar@collabora.co.uk>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kernel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Use $KBUILD_BUILD_TIMESTAMP as man page date

Together with the preceding changes, this allows man pages to be built
reproducibly.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: parse kernel-doc deterministically

Regular expressions for highlights in kernel-doc are stored in a Perl
hash. These hashes are ordered differently for each Perl run. This will
prevent kernel-doc to behave deterministically when parsing “@foo()” as
in some runs it will be interpreted as a parameter and in the others it
will be interpreted as a function.

We now sort the %highlights hash to get the same behavior on every run.

Signed-off-by: Jérémy Bobbio <lunar@debian.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: don't eat struct members with __aligned

The change from \d+ to .+ inside __aligned() means that the following
structure:

struct test {
u8 a __aligned(2);
u8 b __aligned(2);
};

essentially gets modified to

struct test {
u8 a;
};

for purposes of kernel-doc, thus dropping a struct member, which in
turns causes warnings and invalid kernel-doc generation.

Fix this by replacing the catch-all (".") with anything that's not a
semicolon ("[^;]").

Fixes: 9dc30918b23f ("scripts/kernel-doc: handle struct member __aligned without numbers")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: recognize __meminit

Fix scripts/kernel-doc to recognize __meminit in a function prototype
and to strip it, as done with many other attributes.

Fixes this warning:

Warning(..//mm/page_alloc.c:2973): cannot understand function prototype: 'void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) '

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: handle object-like macros

Object-like macros are different than function-like macros:
https://gcc.gnu.org/onlinedocs/cpp/Object-like-Macros.html
https://gcc.gnu.org/onlinedocs/cpp/Function-like-Macros.html

They are not parsed correctly, generating invalid intermediate
files (xmls) for cases like:
#define BIT_MASK (0xFF << BIT_SHIFT)
where "OxFF <<" is considered to be parameter type.

When parsing, we can differentiate beween these two types of macros by
checking whether there is at least one whitespace b/w "#define" and
first opening parenthesis.

Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: make unknown function prototype a Warning instead of an Error

When scripts/kernel-doc cannot understand a function prototype,
it had been generating a fatal error and stopping immediately.
Make this a Warning instead of an Error and keep going.

Note that this can happen if the kernel-doc notation that is being
parsed is not actually a function prototype; maybe it's a struct or
something else, so I added "function" to the warning message to try
to make it clearer that scripts/kernel-doc is looking for a function
prototype here.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kernel-doc: improve "no structured comments found" error

When using '!Ffile function' in a docbook template, and the function no
longer exists, you get a "no structured comments found" error from the
kernel-doc processing script. It's useful to know which functions it was
looking for, so print them out in this case. Also do the same for '!Pfile
doc-section'

The same error also happens when using '!Efile' when some exported
functions aren't documented (in the same file.) There's a very large
number of such functions though, so don't print the message in this case
-- right now it would give ~850 messages.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Rob Landley <rob@landley.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: make unknown function prototype a Warning instead of an Error

When scripts/kernel-doc cannot understand a function prototype,
it had been generating a fatal error and stopping immediately.
Make this a Warning instead of an Error and keep going.

Note that this can happen if the kernel-doc notation that is being
parsed is not actually a function prototype; maybe it's a struct or
something else, so I added "function" to the warning message to try
to make it clearer that scripts/kernel-doc is looking for a function
prototype here.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/kernel-doc: handle struct member __aligned without numbers

Commit ef5da59f1260 ("scripts/kernel-doc: handle struct member
__aligned") permits "char something [123] __aligned(8);".

However, by using \d we constraint ourselves with integers. This is not
always the case. In fact, it might be better to do char something[123]
__aligned(sizeof(u16));

For example, With wireless_dev defining:

u8 address[ETH_ALEN] __aligned(sizeof(u16));

With \d, scripts/kernel-doc erroneously says:

Warning(include/net/cfg80211.h:2618): Excess struct/union/enum/typedef member 'address' description in 'wireless_dev'

This is because the regex __aligned\s*\(\d+\) fails match at \d as
sizeof is used.

So replace \d with . to indicate "something" in kernel-doc to ignore
__aligned(SOMETHING) in structs. With this change, we can use integers
OR sizeof() or macros as we please.

Signed-off-by: Nishanth Menon <nm@ti.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

misc: remove __dev* attributes.

CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.

This change removes the last of the __dev* markings from the kernel from
a variety of different, tiny, places.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/kernel-doc: check that non-void fcts describe their return value

If a function has a return value, but its kernel-doc comment doesn't contain a
"Return" section, then emit the following warning:

Warning(file.h:129): No description found for return value of 'fct'

Note: 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.

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/kernel-doc: check that non-void fcts describe their return value

If a function has a return value, but its kernel-doc comment doesn't contain a
"Return" section, then emit the following warning:

Warning(file.h:129): No description found for return value of 'fct'

Note: 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.

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kernel-doc: don't mangle whitespace in Example section

A section with the name "Example" (case-insensitive) has a special meaning
to kernel-doc. These sections are output using mono-type fonts. However,
leading whitespace is stripped, thus robbing a lot of meaning from this,
as indented code examples will be mangled.

This patch preserves the leading whitespace for "Example" sections. More
accurately, it preserves it for all sections, but removes it later if the
section isn't an "Example" section.

Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: bugfix - empty line in Example section

If you have a section named "Example" that contains an empty line,
attempting to generate htmldocs give you the error:

/path/Documentation/DocBook/kernel-api.xml:3455: parser error : Opening and ending tag mismatch: programlisting line 3449 and para
</para><para>
^
/path/Documentation/DocBook/kernel-api.xml:3473: parser error : Opening and ending tag mismatch: para line 3467 and programlisting
</programlisting></informalexample>
^
/path/Documentation/DocBook/kernel-api.xml:3678: parser error : Opening and ending tag mismatch: programlisting line 3672 and para
</para><para>
^
/path/Documentation/DocBook/kernel-api.xml:3701: parser error : Opening and ending tag mismatch: para line 3690 and programlisting
</programlisting></informalexample>
^
unable to parse
/path/Documentation/DocBook/kernel-api.xml

Essentially, the script attempts to close a <programlisting> with a
closing tag for a <para> block. This patch corrects the problem by
simply not outputting anything extra when we're dumping pre-formatted
text, since the empty line will be rendered correctly anyway.

Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: bugfix - multi-line macros

Prior to this patch the following code breaks:

/**
* multiline_example - this breaks kernel-doc
*/
#define multiline_example( \
myparam)

Producing this error:

Error(somefile.h:983): cannot understand prototype: 'multiline_example( \ '

This patch fixes the issue by appending all lines ending in a blackslash
(optionally followed by whitespace), removing the backslash and any
whitespace after it prior to appending (just like the C pre-processor
would).

This fixes a break in kerel-doc introduced by the additions to rbtree.h.

Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: added support for html5

New output option html5 writes validating HTML5 and adds
CSS classes ready to be selected by third-party stylesheets.
HTML ids have been added to block-level elements "article" for
direct reference of particular objects via URL.

Signed-off-by: Dan Luedtke <mail@danrl.de>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/kernel-doc: fix fatal script error

Fix fatal error in scripts/kernel-doc by ignoring the "__weak" attribute:

Error(drivers/pci/pci.c:2820): cannot understand prototype: 'char * __weak pcibios_setup(char *str) '

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: fix fatal error caused by cfg80211.h

include/net/cfg80211.h uses __must_check in functions that
have kernel-doc notation. This was confusing scripts/kernel-doc,
so have scripts/kernel-doc ignore "__must_check".

Error(include/net/cfg80211.h:2702): cannot understand prototype: 'struct cfg80211_bss * __must_check cfg80211_inform_bss(...)

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

kernel-doc: code reorganization

Move 'main' code vs. subroutines around so that they are not so
intermixed, for better readability/understanding (relative to Perl).
It was messy to follow the primary flow of code execution with the
code being mixed. Now the code begins with data initialization,
followed by all subroutines, then ends with the main code execution.

This is almost totally source code movement, with a few changes as
needed for forward declarations.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: escape xml for structs

scripts/kernel-doc was leaving unescaped '<', '>', and '&' in
generated xml output for structs. This causes xml parser errors.
Convert these characters to "&lt;", "&gt;", and "&amp;" as needed
to prevent errors.

Most of the conversion was already done; complete it just before
output.

Documentation/DocBook/device-drivers.xml:41883: parser error : StartTag: invalid element name
#define INPUT_KEYMAP_BY_INDEX (1 << 0)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

docbook: warn on unused doc entries

When you don't use !E or !I but only !F, then it's very easy to miss
including some functions, structs etc. in documentation. To help
finding which ones were missed, allow printing out the unused ones as
warnings.

For example, using this on mac80211 yields a lot of warnings like this:

Warning: didn't use docs for DOC: mac80211 workqueue
Warning: didn't use docs for ieee80211_max_queues
Warning: didn't use docs for ieee80211_bss_change
Warning: didn't use docs for ieee80211_bss_conf

when generating the documentation for it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: ignore case when stripping attributes

There are valid attributes that could have upper case letters, but we
still want to remove, like for example
__attribute__((aligned(NETDEV_ALIGN)))
as encountered in the wireless code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd/nand_base: fix kernel-doc warnings & typos

Fix mtd/nand_base.c kernel-doc warnings and typos.

Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mtd/nand_base: fix kernel-doc warnings & typos

Fix mtd/nand_base.c kernel-doc warnings and typos.

Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs'
Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len'
Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

scripts/kernel-doc: fix fatal error on function prototype

Fix a fatal error in scripts/kernel-doc when a function signature uses
__init_or_module (just ignore that string):

Error(drivers/base/platform.c:568): cannot understand prototype: 'struct platform_device * __init_or_module platform_create_bundle(struct platform_driver *driver, int (*probe)(struct platform_device *), struct resource *res, unsigned int n_res, const void *data, size_t size) '

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: handle struct member __aligned

scripts/kernel-doc erroneously says:

Warning(include/linux/skbuff.h:410): Excess struct/union/enum/typedef member 'cb' description in 'sk_buff'

on this line in struct sk_buff:
char cb[48] __aligned(8);

due to treating the last field as the struct member name, so teach
kernel-doc to ignore __aligned(x) in structs.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc: fix empty function description section

scripts/kernel-doc mishandles a function that has a multi-line function
short description and no function parameters. The observed problem was
from drivers/scsi/scsi_netlink.c:

/**
* scsi_netlink_init - Called by SCSI subsystem to intialize
* the SCSI transport netlink interface
*
**/

kernel-doc treated the " * " line as a Description: section with only a
newline character in the Description contents. This caused
output_highlight() to complain: "output_highlight got called with no
args?", plus produce a perl call stack backtrace.

The fix is just to ignore Description sections if they only contain "\n".

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: drop the -filelist option, it doesn't work

I also found the -filelist option, but apparently the implementation
is broken, and it was broken from the very first git commit.
For the -filelist option I suggest the removal (I wasn't able to find
any users of it, moreover it's not even listed in the
usage() output, so presumably nobody knows about it).

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: track line numbers for each file separately

The problem is that $. keeps track of the current record number (which
is line number by default). But if you pass it multiple files, it does
not wrap at the end of file, and therefore contains the *total* number
of processed lines.
I suppose we can fix line numbering by introducing a simple assignment
$. = 1
before processing every new file.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tracing: Add DEFINE_EVENT(), DEFINE_SINGLE_EVENT() support to docbook

The introduction of the new 'DECLARE_EVENT_CLASS()' obviates the
need for the 'TRACE_EVENT()' macro in some cases. Thus, docbook
style comments that used to live with 'TRACE_EVENT()' are now
moved to 'DEFINE_EVENT()'. Thus, we need to make the docbook
system understand the new 'DEFINE_EVENT()' macro. In addition
I've tried to futureproof the patch, by also adding support for
'DEFINE_SINGLE_EVENT()', since there has been discussion about
renaming: TRACE_EVENT() -> DEFINE_SINGLE_EVENT().

Without this patch the tracepoint docbook fails to build.

I've verified that this patch correctly builds the tracepoint
docbook which currently covers signals, and irqs.

Changes in v2:
- properly indent perl 'if' statements

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: William Cohen <wcohen@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <200912011718.nB1HIn7t011371@int-mx04.intmail.prod.int.phx2.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel-doc: allow multi-line declaration purpose descriptions

Allow the short description after symbol name and dash in a kernel-doc
comment to span multiple lines, e.g. like this:

/**
* unmap_mapping_range - unmap the portion of all mmaps in the
* specified address_space corresponding to the specified
* page range in the underlying file.
* @mapping: the address space containing mmaps to be unmapped.
* ...
*/

The short description ends with a parameter description, an empty line
or the end of the comment block.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: move ignoring kmemcheck

Somehow I managed to generate a diff that put these 2 lines
into the wrong function: should have been in dump_struct()
instead of in dump_enum().

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: fix param matching for array params

Fix function actual parameter vs. kernel-doc description matching
so that a warning is not printed when it should not be:

Warning(include/linux/etherdevice.h:199): Excess function parameter 'addr' description in 'is_etherdev_addr'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel-doc: ignore kmemcheck_bitfield_begin/end

Teach kernel-doc to ignore kmemcheck_bitfield_{begin,end} sugar
so that it won't generate warnings like this:

Warning(include/net/sock.h:297): No description found for parameter 'kmemcheck_bitfield_begin(flags)'
Warning(include/net/sock.h:297): No description found for parameter 'kmemcheck_bitfield_end(flags)'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel-doc: cleanup perl script

Various cleanups of scripts/kernel-doc:
- don't use **/ as an ending kernel-doc block since it's not preferred;
- typos/spellos
- add whitespace around ==, after comma, & around . operator;

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel-doc: restrict syntax for private: and public:

scripts/kernel-doc can (incorrectly) delete struct members that are
surrounded by /* ... */ <struct members> /* ... */ if there is a /*
private: */ comment in there somewhere also.

Fix that by making the "/* private:" only allow whitespace between /* and
"private:", not anything/everything in the world.

This fixes some erroneous kernel-doc warnings that popped up while
processing include/linux/usb/composite.h.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kerneldoc, tracing: make kernel-doc understand TRACE_EVENT() macro (take #2)

Add support to kernel-doc for tracepoint comments above TRACE_EVENT()
macro definitions. Paves the way for tracepoint docbook.

[ Impact: extend DocBook infrastructure ]

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: akpm@linux-foundation.org
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: wcohen@redhat.com
LKML-Reference: <d80706b6797e277924d2f3ec9af176c6b2951f88.1241107197.git.jbaron@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel-doc: fix syscall wrapper processing

Fix kernel-doc processing of SYSCALL wrappers.

The SYSCALL wrapper patches played havoc with kernel-doc for
syscalls. Syscalls that were scanned for DocBook processing
reported warnings like this one, for sys_tgkill:

Warning(kernel/signal.c:2285): No description found for parameter 'tgkill'
Warning(kernel/signal.c:2285): No description found for parameter 'pid_t'
Warning(kernel/signal.c:2285): No description found for parameter 'int'

because the macro parameters all "look like" function parameters,
although they are not:

/**
* sys_tgkill - send signal to one specific thread
* @tgid: the thread group ID of the thread
* @pid: the PID of the thread
* @sig: signal to be sent
*
* This syscall also checks the @tgid and returns -ESRCH even if the PID
* exists but it's not belonging to the target process anymore. This
* method solves the problem of threads exiting and PIDs getting reused.
*/
SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig)
{
...

This patch special-cases the handling SYSCALL_DEFINE* function
prototypes by expanding them to
long sys_foobar(type1 arg1, type1 arg2, ...)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: check for extra kernel-doc notations

Add functionality to check for function parameters or structure (or
union/typedef/enum) field members that are described in kernel-doc but
are not part of the expected (declared) parameters or structure.
These generate warnings that are called "Excess" descriptions.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel-doc: handle varargs cleanly

The method for listing varargs in kernel-doc notation is:
* @...: these arguments are printed by the @fmt argument

but scripts/kernel-doc is confused: it always lists varargs as:
... variable arguments
and ignores the @...: line's description, but then prints that
line after the list of function parameters as though it's
not part of the function parameters.

This patch makes kernel-doc print the supplied @... description if it is
present; otherwise a boilerplate "variable arguments" is printed.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: allow more whitespace in macros

Allow macros that are annotated with kernel-doc to contain whitespace
between the '#' and "define". It's valid and being used, so allow it.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: allow structs whose members are all private

Struct members may be marked as private by using
/* private: */
before them, as noted in Documentation/kernel-doc-nano-HOWTO.txt

Fix kernel-doc to handle structs whose members are all private;
otherwise invalid XML is generated:

xmlto: input does not validate (status 3)
linux-2.6.27-rc6-git4/Documentation/DocBook/debugobjects.xml:146: element variablelist: validity error : Element variablelist content does not follow the DTD, expecting ((title , titleabbrev?)? , varlistentry+), got ()
Document linux-2.6.27-rc6-git4/Documentation/DocBook/debugobjects.xml does not validate
make[1]: *** [Documentation/DocBook/debugobjects.html] Error 3

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reported-by: Roland McGrath <roland@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: skip nested struct/union cleanly

Fix handling of nested structs or unions. The regex to strip (eliminate)
nested structs or unions was limited to only 0 or 1 matches. This can
cause an uneven number of left/right braces to be stripped, which causes
this:

Warning(linux-2.6.27-rc1-git2//include/net/mac80211.h:336): No description found for parameter '}'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: handle/strip __init

Handle __init in functions with kernel-doc notation by stripping the
__init away from the output doc. This is already being done for
"__devinit". This patch fixes these kernel-doc error/aborts:

Error(linux-next-20080619//drivers/usb/gadget/config.c:132): cannot understand prototype: 'struct usb_descriptor_header **__init usb_copy_descriptors(struct usb_descriptor_header **src) '
Error(linux-next-20080619//drivers/usb/gadget/config.c:182): cannot understand prototype: 'struct usb_endpoint_descriptor *__init usb_find_endpoint( struct usb_descriptor_header **src, struct usb_descriptor_header **copy, struct usb_endpoint_descriptor *match ) '

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel-doc: allow unnamed bit-fields

Allow for unnamed bit-fields and skip them instead of printing an
erroneous warning message for them, such as:

Warning(include/asm-s390/cio.h:103): No description found for parameter 'u32'

which contains:

struct tm_scsw {
u32 :1;

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kernel-doc: detect trailing kernel-doc line trash

Print a warning when a kernel-doc comment block ends with text on the same
line as the ending comment characters, e.g.:

* this text is lost. */

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel-doc: detect/prevent duplicate doc section names

I saw this problem recently. With this kernel-doc:

* Note: some important info
*
* Note: other important info

kernel-doc uses the "section name" (preceding the ':', like "Note") as a hash
key for storing the descriptive text ("blah important info"). It is (was)
possible to have duplicate (colliding) section names, without any kind of
warning or error.

kernel-doc happily used the latter descriptive text for all instances of
printing the <section-name> descriptive text and the former important info
was lost.

One way to "fix" this is to modify the kernel-doc comments, e.g.:

* Note1: foo bar
*
* Note.2: blah zay

For now, kernel-doc will signal an error when it sees colliding section names
like this.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>