scripts: kconfig: merge_config.sh: use awk in checks too

Converting from shell/sed/grep loop to awk improves runtime
checks of Yocto genericarm64 kernel config from 20 seconds
to under 1 second. The checks catch this kind of issues:

WARNING: CONFIG_BLK_DEV_DM differs:
Requested value: CONFIG_BLK_DEV_DM=y
Actual value:    CONFIG_BLK_DEV_DM=m
WARNING: CONFIG_SECURITY_NETWORK differs:
Requested value: CONFIG_SECURITY_NETWORK=n
Actual value:    CONFIG_SECURITY_NETWORK=y
WARNING: Value requested for CONFIG_ARM64_BTI_KERNEL not in final .config
Requested value: CONFIG_ARM64_BTI_KERNEL=y
Actual value:

Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>
Link: https://patch.msgid.link/20260122105751.2186609-2-mikko.rapeli@linaro.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh
index de217771b78ce201084fd5e03e4d89e6efe3ef9d..9eda9dbd4542d6efd44f255c085297d7f47c4215 100755 (executable)
--- a/scripts/kconfig/merge_config.sh
+++ b/scripts/kconfig/merge_config.sh
@@ -286,16 +286,91 @@ fi
 # allnoconfig: Fills in any missing symbols with # CONFIG_* is not set
 make KCONFIG_ALLCONFIG=$TMP_FILE $OUTPUT_ARG $ALLTARGET
 
+# Check all specified config values took effect (might have missed-dependency issues)
+if ! "$AWK" -v prefix="$CONFIG_PREFIX" \
+       -v warnoverride="$WARNOVERRIDE" \
+       -v strict="$STRICT" \
+       -v warnredun="$WARNREDUN" '
+BEGIN {
+       strict_violated = 0
+       cfg_regex = "^" prefix "[a-zA-Z0-9_]+"
+       notset_regex = "^# " prefix "[a-zA-Z0-9_]+ is not set$"
+}
 
-# Check all specified config values took (might have missed-dependency issues)
-for CFG in $(sed -n -e "$SED_CONFIG_EXP1" -e "$SED_CONFIG_EXP2" $TMP_FILE); do
+# Extract config name from a line, returns "" if not a config line
+function get_cfg(line) {
+       if (match(line, cfg_regex)) {
+               return substr(line, RSTART, RLENGTH)
+       } else if (match(line, notset_regex)) {
+               # Extract CONFIG_FOO from "# CONFIG_FOO is not set"
+               sub(/^# /, "", line)
+               sub(/ is not set$/, "", line)
+               return line
+       }
+       return ""
+}
 
-       REQUESTED_VAL=$(grep -w -e "$CFG" $TMP_FILE)
-       ACTUAL_VAL=$(grep -w -e "$CFG" "$KCONFIG_CONFIG" || true)
-       if [ "x$REQUESTED_VAL" != "x$ACTUAL_VAL" ] ; then
-               echo "Value requested for $CFG not in final .config"
-               echo "Requested value:  $REQUESTED_VAL"
-               echo "Actual value:     $ACTUAL_VAL"
-               echo ""
-       fi
-done
+function warn_mismatch(cfg, merged, final) {
+       if (warnredun == "true") return
+       if (final == "" && !(merged ~ / is not set$/ || merged ~ /=n$/)) {
+               print "WARNING: Value requested for " cfg " not in final .config"
+               print "Requested value: " merged
+               print "Actual value:    " final
+       } else if (final == "" && merged ~ / is not set$/) {
+               # not set, pass
+       } else if (merged == "" && final != "") {
+               print "WARNING: " cfg " not in merged config but added in final .config:"
+               print "Requested value: " merged
+               print "Actual value:    " final
+       } else {
+               print "WARNING: " cfg " differs:"
+               print "Requested value: " merged
+               print "Actual value:    " final
+       }
+}
+
+# First pass: read effective config file, store all lines
+FILENAME == ARGV[1] {
+       cfg = get_cfg($0)
+       if (cfg != "") {
+               config_cfg[cfg] = $0
+       }
+       next
+}
+
+# Second pass: process merged config and compare against effective config
+{
+       cfg = get_cfg($0)
+       if (cfg == "") next
+
+       # strip trailing comment
+       sub(/[[:space:]]+#.*/, "", $0)
+       merged_val = $0
+       final_val = config_cfg[cfg]
+
+       if (merged_val == final_val) next
+
+       if (merged_val ~ /=n$/ && final_val ~ / is not set$/) next
+       if (merged_val ~ /=n$/ && final_val == "") next
+
+       warn_mismatch(cfg, merged_val, final_val)
+
+       if (strict == "true") {
+               strict_violated = 1
+       }
+}
+
+END {
+       if (strict_violated) {
+               exit 1
+       }
+}' \
+"$KCONFIG_CONFIG" "$TMP_FILE"; then
+       # awk exited non-zero, strict mode was violated
+       STRICT_MODE_VIOLATED=true
+fi
+
+if [ "$STRICT" == "true" ] && [ "$STRICT_MODE_VIOLATED" == "true" ]; then
+       echo "Requested and effective config differ"
+       exit 1
+fi