diff --git a/scripts/misc-check b/scripts/misc-check index 21551d721079..7cb61841a125 100755 --- a/scripts/misc-check +++ b/scripts/misc-check @@ -9,4 +9,47 @@ check_tracked_ignored_files () { sed 's/$/: warning: ignored by one of the .gitignore files/' >&2 } +# Check for missing #include +# +# The rule for including is very simple: +# Include only when you use EXPORT_SYMBOL(). That's it. +# +# However, some headers include even though they are completely +# unrelated to EXPORT_SYMBOL(). +# +# One example is include/linux/module.h. Please note and +# are orthogonal. should be included by files +# that can be compiled as modules. In other words, should be +# included by EXPORT_SYMBOL consumers. In contrast, should be +# included from EXPORT_SYMBOL providers, which may or may not be modular. +# Hence, include/linux/module.h should *not* include . +# +# Another example is include/linux/linkage.h, which is completely unrelated to +# EXPORT_SYMBOL(). Worse, it is included by most C files, which means, most C +# files end up including , even though only some of them +# actually export symbols. Hence, include/linux/linkage.h should *not* include +# . +# +# Before fixing such headers, we must ensure that C files using EXPORT_SYMBOL() +# include directly, since many C files currently rely on +# being included indirectly (likely, via etc.). +# +# Therefore, this check. +# +# The problem is simple - the warned files use EXPORT_SYMBOL(), but do not +# include . Please add #include to them. +# +# If the included headers are sorted alphabetically, please insert +# in the appropriate position to maintain the sort order. +# For this reason, this script only checks missing , but +# does not automatically fix it. +check_missing_include_linux_export_h () { + + git -C "${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:]]*' | + xargs -r printf "%s: warning: EXPORT_SYMBOL() is used, but #include is missing\n" >&2 +} + check_tracked_ignored_files +check_missing_include_linux_export_h