linux-yocto/scripts/check-local-export

#!/usr/bin/env bash

SPDX-License-Identifier: GPL-2.0-only

Copyright (C) 2022 Masahiro Yamada masahiroy@kernel.org

Exit with error if a local exported symbol is found.

EXPORT_SYMBOL should be used for global symbols.

set -e

declare -A symbol_types declare -a export_symbols

exit_code=0

while read value type name do # Skip the line if the number of fields is less than 3. # # case 1) # For undefined symbols, the first field (value) is empty. # The outout looks like this: # " U _printk" # It is unneeded to record undefined symbols. # # case 2) # For Clang LTO, llvm-nm outputs a line with type 't' but empty name: # "---------------- t" if -z ${name} ; then continue fi

# save (name, type) in the associative array
symbol_types[${name}]=${type}

# append the exported symbol to the array
if [[ ${name} == __ksymtab_* ]]; then
	export_symbols+=(${name#__ksymtab_})
fi

# If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm)
# shows 'no symbols' diagnostic (but exits with 0). It is harmless and
# hidden by '2>/dev/null'. However, it suppresses real error messages
# as well. Add a hand-crafted error message here.
#
# Use --quiet instead of 2>/dev/null when we upgrade the minimum version
# of binutils to 2.37, llvm to 13.0.0.
#
# Then, the following line will be really simple:
#   done < <(${NM} --quiet ${1})

done < <(${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; false; } )

Catch error in the process substitution

wait $!

for name in "${export_symbols[@]}" do # nm(3) says "If lowercase, the symbol is usually local" if ; then echo "$@: error: local symbol '${name}' was exported" >&2 exit_code=1 fi done

exit ${exit_code}