From 5fa9b82cbcfc524a2dad581ac2af136536d4e8e5 Mon Sep 17 00:00:00 2001 From: Anders Roxell Date: Thu, 22 Jan 2026 12:57:49 +0200 Subject: [PATCH] scripts: kconfig: merge_config.sh: refactor from shell/sed/grep to awk merge_config.sh shell/sed/grep loop scales poorly and is slow. With Yocto genericarm64 kernel and around 190 config fragments the script takes more than 20 minutes to run on a fast build machine. Re-implementation with awk does the same job in 10 seconds. Using awk since it is likely available in the build environments and using perl, python etc would introduce more complex runtime dependencies. awk is good enough and lot better than shell/sed/grep. Output stays the same but changed execution time means that parallel job output may be ordered differently. Signed-off-by: Anders Roxell Signed-off-by: Mikko Rapeli Link: https://patch.msgid.link/20260122105751.2186609-1-mikko.rapeli@linaro.org Signed-off-by: Nathan Chancellor --- scripts/kconfig/merge_config.sh | 168 ++++++++++++++++++++++++-------- 1 file changed, 128 insertions(+), 40 deletions(-) diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh index 79c09b378be81..de217771b78ce 100755 --- a/scripts/kconfig/merge_config.sh +++ b/scripts/kconfig/merge_config.sh @@ -16,8 +16,8 @@ set -e clean_up() { - rm -f $TMP_FILE - rm -f $MERGE_FILE + rm -f "$TMP_FILE" + rm -f "$TMP_FILE.new" } usage() { @@ -43,6 +43,10 @@ STRICT=false CONFIG_PREFIX=${CONFIG_-CONFIG_} WARNOVERRIDE=echo +if [ -z "$AWK" ]; then + AWK=awk +fi + while true; do case $1 in "-n") @@ -117,11 +121,8 @@ if [ ! -r "$INITFILE" ]; then fi MERGE_LIST=$* -SED_CONFIG_EXP1="s/^\(${CONFIG_PREFIX}[a-zA-Z0-9_]*\)=.*/\1/p" -SED_CONFIG_EXP2="s/^# \(${CONFIG_PREFIX}[a-zA-Z0-9_]*\) is not set$/\1/p" TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX) -MERGE_FILE=$(mktemp ./.merge_tmp.config.XXXXXXXXXX) echo "Using $INITFILE as base" @@ -136,42 +137,129 @@ for ORIG_MERGE_FILE in $MERGE_LIST ; do echo "The merge file '$ORIG_MERGE_FILE' does not exist. Exit." >&2 exit 1 fi - cat $ORIG_MERGE_FILE > $MERGE_FILE - CFG_LIST=$(sed -n -e "$SED_CONFIG_EXP1" -e "$SED_CONFIG_EXP2" $MERGE_FILE) - - for CFG in $CFG_LIST ; do - grep -q -w $CFG $TMP_FILE || continue - PREV_VAL=$(grep -w $CFG $TMP_FILE) - NEW_VAL=$(grep -w $CFG $MERGE_FILE) - BUILTIN_FLAG=false - if [ "$BUILTIN" = "true" ] && [ "${NEW_VAL#CONFIG_*=}" = "m" ] && [ "${PREV_VAL#CONFIG_*=}" = "y" ]; then - ${WARNOVERRIDE} Previous value: $PREV_VAL - ${WARNOVERRIDE} New value: $NEW_VAL - ${WARNOVERRIDE} -y passed, will not demote y to m - ${WARNOVERRIDE} - BUILTIN_FLAG=true - elif [ "x$PREV_VAL" != "x$NEW_VAL" ] ; then - ${WARNOVERRIDE} Value of $CFG is redefined by fragment $ORIG_MERGE_FILE: - ${WARNOVERRIDE} Previous value: $PREV_VAL - ${WARNOVERRIDE} New value: $NEW_VAL - ${WARNOVERRIDE} - if [ "$STRICT" = "true" ]; then - STRICT_MODE_VIOLATED=true - fi - elif [ "$WARNREDUN" = "true" ]; then - ${WARNOVERRIDE} Value of $CFG is redundant by fragment $ORIG_MERGE_FILE: - fi - if [ "$BUILTIN_FLAG" = "false" ]; then - sed -i "/$CFG[ =]/d" $TMP_FILE - else - sed -i "/$CFG[ =]/d" $MERGE_FILE - fi - done - # In case the previous file lacks a new line at the end - echo >> $TMP_FILE - cat $MERGE_FILE >> $TMP_FILE -done + # Use awk for single-pass processing instead of per-symbol grep/sed + if ! "$AWK" -v prefix="$CONFIG_PREFIX" \ + -v warnoverride="$WARNOVERRIDE" \ + -v strict="$STRICT" \ + -v builtin="$BUILTIN" \ + -v warnredun="$WARNREDUN" ' + BEGIN { + strict_violated = 0 + cfg_regex = "^" prefix "[a-zA-Z0-9_]+" + notset_regex = "^# " prefix "[a-zA-Z0-9_]+ is not set$" + } + + # Extract config name from a line, returns "" if not a config line + function get_cfg(line) { + if (match(line, cfg_regex)) { + return substr(line, RSTART, RLENGTH) + } else if (match(line, notset_regex)) { + # Extract CONFIG_FOO from "# CONFIG_FOO is not set" + sub(/^# /, "", line) + sub(/ is not set$/, "", line) + return line + } + return "" + } + + function warn_builtin(cfg, prev, new) { + if (warnoverride == "true") return + print cfg ": -y passed, will not demote y to m" + print "Previous value: " prev + print "New value: " new + print "" + } + + function warn_redefined(cfg, prev, new) { + if (warnoverride == "true") return + print "Value of " cfg " is redefined by fragment " mergefile ":" + print "Previous value: " prev + print "New value: " new + print "" + } + + function warn_redundant(cfg) { + if (warnredun != "true" || warnoverride == "true") return + print "Value of " cfg " is redundant by fragment " mergefile ":" + } + + # First pass: read merge file, store all lines and index + FILENAME == ARGV[1] { + mergefile = FILENAME + merge_lines[FNR] = $0 + merge_total = FNR + cfg = get_cfg($0) + if (cfg != "") { + merge_cfg[cfg] = $0 + merge_cfg_line[cfg] = FNR + } + next + } + # Second pass: process base file (TMP_FILE) + FILENAME == ARGV[2] { + cfg = get_cfg($0) + + # Not a config or not in merge file - keep it + if (cfg == "" || !(cfg in merge_cfg)) { + print $0 >> ARGV[3] + next + } + + prev_val = $0 + new_val = merge_cfg[cfg] + + # BUILTIN: do not demote y to m + if (builtin == "true" && new_val ~ /=m$/ && prev_val ~ /=y$/) { + warn_builtin(cfg, prev_val, new_val) + print $0 >> ARGV[3] + skip_merge[merge_cfg_line[cfg]] = 1 + next + } + + # Values equal - redundant + if (prev_val == new_val) { + warn_redundant(cfg) + next + } + + # "=n" is the same as "is not set" + if (prev_val ~ /=n$/ && new_val ~ / is not set$/) { + print $0 >> ARGV[3] + next + } + + # Values differ - redefined + warn_redefined(cfg, prev_val, new_val) + if (strict == "true") { + strict_violated = 1 + } + } + + # output file, skip all lines + FILENAME == ARGV[3] { + nextfile + } + + END { + # Newline in case base file lacks trailing newline + print "" >> ARGV[3] + # Append merge file, skipping lines marked for builtin preservation + for (i = 1; i <= merge_total; i++) { + if (!(i in skip_merge)) { + print merge_lines[i] >> ARGV[3] + } + } + if (strict_violated) { + exit 1 + } + }' \ + "$ORIG_MERGE_FILE" "$TMP_FILE" "$TMP_FILE.new"; then + # awk exited non-zero, strict mode was violated + STRICT_MODE_VIOLATED=true + fi + mv "$TMP_FILE.new" "$TMP_FILE" +done if [ "$STRICT_MODE_VIOLATED" = "true" ]; then echo "The fragment redefined a value and strict mode had been passed." exit 1 -- 2.47.3