>From 0e70974912f6b2cd95a18192418a438f9c57f690 Mon Sep 17 00:00:00 2001
In-Reply-To: <CAK7LNAR+Lp2g1kzGNALoge7_51_PKcOd37ebZTV=X-QJEwCn5w@xxxxxxxxxxxxxx>
References: <CAK7LNAR+Lp2g1kzGNALoge7_51_PKcOd37ebZTV=X-QJEwCn5w@xxxxxxxxxxxxxx>
From: Owen Rafferty <owen@xxxxxxxxxxxxxxxx>
Date: Sat, 27 Aug 2022 11:52:18 -0500
Subject: [PATCH v3] kbuild: rewrite check-local-export in sh/awk
To: masahiroy@xxxxxxxxxx
Cc: linux-kbuild@xxxxxxxxxxxxxxx
---
scripts/check-local-export | 96 +++++++++++++++++++-------------------
1 file changed, 47 insertions(+), 49 deletions(-)
diff --git a/scripts/check-local-export b/scripts/check-local-export
index 6ccc2f467416..0c049ff44aca 100755
--- a/scripts/check-local-export
+++ b/scripts/check-local-export
@@ -1,26 +1,14 @@
-#!/usr/bin/env bash
+#!/bin/sh
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2022 Masahiro Yamada <masahiroy@xxxxxxxxxx>
+# Copyright (C) 2022 Owen Rafferty <owen@xxxxxxxxxxxxxxxx>
#
# Exit with error if a local exported symbol is found.
# EXPORT_SYMBOL should be used for global symbols.
set -e
-# catch errors from ${NM}
-set -o pipefail
-
-# Run the last element of a pipeline in the current shell.
-# Without this, the while-loop would be executed in a subshell, and
-# the changes made to 'symbol_types' and 'export_symbols' would be lost.
-shopt -s lastpipe
-
-declare -A symbol_types
-declare -a export_symbols
-
-exit_code=0
-
# 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
@@ -29,43 +17,53 @@ exit_code=0
# TODO:
# 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:
-# ${NM} --quiet ${1} |
+# Then, the following line will be simpler:
+# { ${NM} --quiet ${1} || kill 0; } |
+
+{ ${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; kill 0; } } |
+${AWK} -v "file=${1}" '
+BEGIN {
+ i = 0
+}
+
+# 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"
+!length($3) {
+ next
+}
-{ ${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; false; } } |
-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[$3]=$2 }
- # save (name, type) in the associative array
- symbol_types[${name}]=${type}
+# append the exported symbol to the array
+($3 ~ /^__ksymtab_/) {
+ export_symbols[i] = $3
+ sub(/^__ksymtab_/, "", export_symbols[i])
+ i++
+}
- # append the exported symbol to the array
- if [[ ${name} == __ksymtab_* ]]; then
- export_symbols+=(${name#__ksymtab_})
- fi
-done
+END {
+ exit_code = 0
+ for (j = 0; j < i; ++j) {
+ name = export_symbols[j]
+ # nm(3) says "If lowercase, the symbol is usually local"
+ if (symbol_types[name] ~ /[a-z]/) {
+ printf "%s: error: local symbol %s was exported\n",
+ file, name | "cat 1>&2"
+ exit_code = 1
+ }
+ }
-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
+}'
-exit ${exit_code}
+exit $?
--
2.37.2
