From 262be577418917aa0b9688d938cf1c5145e3cb25 Mon Sep 17 00:00:00 2001
From: Jan Lindemann <jan@janware.com>
Date: Tue, 5 May 2026 16:54:18 +0200
Subject: [PATCH] cache.mk: Don't overwrite defined variables

Check with ifndef if a variable is defined before hard defining it in
cache.mk. This gives more flexibility when overriding variables with
local.mk.

Signed-off-by: Jan Lindemann <jan@janware.com>
---
 make/cache.mk | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/make/cache.mk b/make/cache.mk
index 8ea15f55..0c049057 100644
--- a/make/cache.mk
+++ b/make/cache.mk
@@ -20,8 +20,9 @@ clean-cache:
 
 cache: $(CACHE_PROJECT_MK)
 $(CACHE_PROJECT_MK): $(CACHED_FILES) $(JWBDIR)/make/cache.mk
-	@echo $(foreach v,$(CACHED_VARS),$v = $(value $(v))EOL) | \
-		$(SED) 's/EOL */\n/g;' | \
+	@echo $(foreach v,$(CACHED_VARS),$v = $(value $(v)) EOL) | \
+		$(SED) 's/\s\+EOL/\n/g;' | \
+		$(SED) 's/\s*\(\S\+\)\s*=\s*\(.*\)\s*/ifndef \1\n  \1 = \2\nendif\n/g;' | \
 		$(SED) 's|$(realpath $(TOPDIR))|$$(TOPDIR)|g' | \
 		$(SED) 's|$(realpath $(PROJECTS_DIR))|$$(PROJECTS_DIR)|g' | \
 		$(GREP) . | \