linux-yocto/scripts/misc-check

#!/bin/sh

SPDX-License-Identifier: GPL-2.0-only

set -e

Detect files that are tracked but ignored by git.

check_tracked_ignored_files () { git -C "${srctree:-.}" ls-files -i -c --exclude-per-directory=.gitignore 2>/dev/null | sed 's/$/: warning: ignored by one of the .gitignore files/' >&2 }

Check for missing #include <linux/export.h>

The rule for including <linux/export.h> is very simple:

Include <linux/export.h> only when you use EXPORT_SYMBOL(). That's it.

However, some headers include <linux/export.h> even though they are completely

unrelated to EXPORT_SYMBOL().

One example is include/linux/module.h. Please note <linux/module.h> and

<linux/export.h> are orthogonal. <linux/module.h> should be included by files

that can be compiled as modules. In other words, <linux/module.h> should be

included by EXPORT_SYMBOL consumers. In contrast, <linux/export.h> should be

included from EXPORT_SYMBOL providers, which may or may not be modular.

Hence, include/linux/module.h should not include <linux/export.h>.

Another example is include/linux/linkage.h, which is completely unrelated to

EXPORT_SYMBOL(). Worse, it is included by most C files, which means, most C

files end up including <linux/export.h>, even though only some of them

actually export symbols. Hence, include/linux/linkage.h should not include

<linux/export.h>.

Before fixing such headers, we must ensure that C files using EXPORT_SYMBOL()

include <linux/export.h> directly, since many C files currently rely on

<linux/export.h> being included indirectly (likely, via <linux/linkage> etc.).

Therefore, this check.

The problem is simple - the warned files use EXPORT_SYMBOL(), but do not

include <linux/export.h>. Please add #include <linux/export.h> to them.

If the included headers are sorted alphabetically, please insert

<linux/export.h> in the appropriate position to maintain the sort order.

For this reason, this script only checks missing <linux/export.h>, but

does not automatically fix it.

check_missing_include_linux_export_h () {

git -C "${srctree:-.}" grep --files-with-matches -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_GPL_FOR_MODULES)\(.*\)' \
    -- '*.[ch]' :^tools/ :^include/linux/export.h |
xargs -r git -C "${srctree:-.}" grep --files-without-match '#include[[:space:]]*<linux/export\.h>' |
xargs -r printf "%s: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing\n" >&2

}

If you do not use EXPORT_SYMBOL(), please do not include <linux/export.h>.

Currently, this is checked for *.c files, but not for *.h files, because some

*.c files rely on <linux/export.h> being included indirectly.

check_unnecessary_include_linux_export_h () {

git -C "${srctree:-.}" grep --files-with-matches '#include[[:space:]]*<linux/export\.h>' \
    -- '*.[c]' :^tools/ |
xargs -r git -C "${srctree:-.}" grep --files-without-match -E 'EXPORT_SYMBOL((_NS)?(_GPL)?|_GPL_FOR_MODULES)\(.*\)' |
xargs -r printf "%s: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present\n" >&2

}

case "${KBUILD_EXTRA_WARN}" in 1) check_tracked_ignored_files ;; esac

case "${KBUILD_EXTRA_WARN}" in 2) check_missing_include_linux_export_h check_unnecessary_include_linux_export_h ;; esac