71 lines
1.7 KiB
Bash
Executable File
71 lines
1.7 KiB
Bash
Executable File
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0-only
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#
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# Copyright (C) 2022 Masahiro Yamada <masahiroy@kernel.org>
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# Copyright (C) 2022 Owen Rafferty <owen@owenrafferty.com>
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#
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# Exit with error if a local exported symbol is found.
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# EXPORT_SYMBOL should be used for global symbols.
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set -e
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pid=$$
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# If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm) shows
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# 'no symbols' diagnostic (but exits with 0). It is harmless and hidden by
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# '2>/dev/null'. However, it suppresses real error messages as well. Add a
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# hand-crafted error message here.
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#
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# TODO:
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# Use --quiet instead of 2>/dev/null when we upgrade the minimum version of
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# binutils to 2.37, llvm to 13.0.0.
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# Then, the following line will be simpler:
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# { ${NM} --quiet ${1} || kill 0; } |
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{ ${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; kill $pid; } } |
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${AWK} -v "file=${1}" '
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BEGIN {
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i = 0
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}
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# Skip the line if the number of fields is less than 3.
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#
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# case 1)
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# For undefined symbols, the first field (value) is empty.
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# The outout looks like this:
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# " U _printk"
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# It is unneeded to record undefined symbols.
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#
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# case 2)
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# For Clang LTO, llvm-nm outputs a line with type t but empty name:
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# "---------------- t"
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!length($3) {
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next
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}
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# save (name, type) in the associative array
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{ symbol_types[$3]=$2 }
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# append the exported symbol to the array
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($3 ~ /^__ksymtab_/) {
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export_symbols[i] = $3
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sub(/^__ksymtab_/, "", export_symbols[i])
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i++
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}
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END {
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exit_code = 0
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for (j = 0; j < i; ++j) {
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name = export_symbols[j]
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# nm(3) says "If lowercase, the symbol is usually local"
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if (symbol_types[name] ~ /[a-z]/) {
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printf "%s: error: local symbol %s was exported\n",
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file, name | "cat 1>&2"
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exit_code = 1
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}
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}
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exit exit_code
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}'
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exit $?
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