| #!/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 [[ ${symbol_types[$name]} =~ [a-z] ]]; then |
| echo "$@: error: local symbol '${name}' was exported" >&2 |
| exit_code=1 |
| fi |
| done |
| |
| exit ${exit_code} |