From b8e386a6bce7abc00c392934ce610cfc18e202f7 Mon Sep 17 00:00:00 2001
From: Gleb Chesnokov <gleb.chesnokov@scst.dev>
Date: Mon, 24 Aug 2026 21:05:55 +0300
Subject: [PATCH] build: Add warnings-as-errors mode

Add a WERROR=y|n build setting that keeps the local default unchanged
and exports -Werror for user-space and kernel compilation. Honor the same
setting in direct regression kernel builds.
---
 Makefile                     | 29 +++++++++++++++++++++++++++--
 debian/rules                 | 11 +++++++++++
 scripts/run-regression-tests | 21 +++++++++++++++++++++
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 08bcfc688..d81740cbd 100644
--- a/Makefile
+++ b/Makefile
@@ -42,6 +42,26 @@ endif
 
 PKG_BUILD_MODE ?= 2release
 
+WERROR ?= n
+ifneq ($(words $(strip $(WERROR))),1)
+$(error WERROR must be one of: y n (got '$(WERROR)'))
+endif
+ifneq ($(filter y n,$(strip $(WERROR))),$(strip $(WERROR)))
+$(error WERROR must be one of: y n (got '$(WERROR)'))
+endif
+override WERROR := $(strip $(WERROR))
+export WERROR
+
+ifeq ($(WERROR),y)
+ifeq ($(filter -Werror,$(CFLAGS)),)
+override CFLAGS += -Werror
+endif
+ifeq ($(filter -Werror,$(KCFLAGS)),)
+override KCFLAGS += -Werror
+endif
+export CFLAGS KCFLAGS
+endif
+
 OLD_QLA_INI_DIR = qla2x00t
 OLD_QLA_DIR = $(OLD_QLA_INI_DIR)/qla2x00-target
 
@@ -117,6 +137,9 @@ SCST_SOURCE_FILES = $(shell if [ -e scripts/list-source-files ]; then	\
 			fi)
 
 help:
+	@echo "Build variables:"
+	@echo "		WERROR=y|n            : treat warnings as errors (default: n)"
+	@echo ""
 	@echo "		tags                  : make tags"
 	@echo "		cov-build             : make coverity build"
 	@echo "		shellcheck            : check Bash scripts"
@@ -478,6 +501,7 @@ docker-rpm: docker-rpm-image
 	$(DOCKER) run --rm \
 		--user "$$(id -u):$$(id -g)" \
 		--env HOME=/tmp \
+		--env WERROR="$(WERROR)" \
 		--mount "type=bind,source=$(CURDIR),target=/source,readonly" \
 		--mount "type=bind,source=$${git_common_dir},target=$${git_common_dir},readonly" \
 		--mount "type=bind,source=$(DOCKER_RPM_OUTPUT),target=/output" \
@@ -536,8 +560,9 @@ dpkg: ../scst_$(VERSION).orig.tar.gz
 	else								\
 	  buildopts+=(-j4);						\
 	fi &&								\
-	DEB_CC_SET="$(CC)" DEB_KVER_SET=$(KVER) DEB_KDIR_SET=$(KDIR) DEB_QLA_DIR_SET=$(QLA_DIR) \
-	   DEB_QLA_INI_DIR_SET=$(QLA_INI_DIR) DEB_PKG_BUILD_MODE=$(PKG_BUILD_MODE) \
+	DEB_CC_SET="$(CC)" DEB_KVER_SET=$(KVER) DEB_KDIR_SET=$(KDIR) \
+	   DEB_QLA_DIR_SET=$(QLA_DIR) DEB_QLA_INI_DIR_SET=$(QLA_INI_DIR) \
+	   DEB_PKG_BUILD_MODE=$(PKG_BUILD_MODE) DEB_WERROR_SET="$(WERROR)" \
 	   debuild "$${buildopts[@]}" --lintian-opts --profile debian && \
 	mkdir -p dpkg &&						\
 	for f in "$${output_files[@]}" ../scst_$(VERSION).orig.tar.[gx]z; do\
diff --git a/debian/rules b/debian/rules
index 79ab0bdff..41ec4f33e 100755
--- a/debian/rules
+++ b/debian/rules
@@ -21,6 +21,17 @@ export CC=$(DEB_CC_SET)
 export QLA_DIR=$(DEB_QLA_DIR_SET)
 export QLA_INI_DIR=$(DEB_QLA_INI_DIR_SET)
 export PKG_BUILD_MODE=$(DEB_PKG_BUILD_MODE)
+DEB_WERROR_SET?=n
+export WERROR=$(DEB_WERROR_SET)
+ifeq ($(WERROR),y)
+ifeq ($(filter -Werror,$(CFLAGS)),)
+override CFLAGS += -Werror
+endif
+ifeq ($(filter -Werror,$(KCFLAGS)),)
+override KCFLAGS += -Werror
+endif
+export CFLAGS KCFLAGS
+endif
 
 # Default to building optional modules (override by changing specific ?=m to =n)
 CONFIG_SCST_LOCAL?=m
diff --git a/scripts/run-regression-tests b/scripts/run-regression-tests
index 8600cf2a2..e99c6b12f 100755
--- a/scripts/run-regression-tests
+++ b/scripts/run-regression-tests
@@ -57,6 +57,26 @@
 # shellcheck source=./kernel-functions
 source "$(dirname "$0")/kernel-functions"
 
+readonly WERROR="${WERROR-n}"
+case "${WERROR}" in
+  y|n) ;;
+  *)
+    echo "Error: WERROR must be one of: y n (got '${WERROR}')." >&2
+    exit 2
+    ;;
+esac
+if [ "${WERROR}" = y ]; then
+  case " ${CFLAGS:-} " in
+    *" -Werror "*) ;;
+    *) CFLAGS="${CFLAGS:+${CFLAGS} }-Werror" ;;
+  esac
+  case " ${KCFLAGS:-} " in
+    *" -Werror "*) ;;
+    *) KCFLAGS="${KCFLAGS:+${KCFLAGS} }-Werror" ;;
+  esac
+  export CFLAGS KCFLAGS
+fi
+
 function usage {
   echo "Usage: $0 [-c <dir>] [-d <dir>] [-h] [-j <jobs>] [-k] [-l]" \
        "[-p] [-q] <kver1> <kver2> ..."
@@ -321,6 +341,7 @@ CONFIG_TRACER_MAX_TRACE				\
 CONFIG_TRACE_BRANCH_PROFILING			\
 CONFIG_TRACING					\
 CONFIG_UNWINDER_ORC				\
+CONFIG_WERROR					\
 CONFIG_X86_32					\
 CONFIG_X86_X32					\
 CONFIG_X86_KERNEL_IBT				\