--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/update-rules.sh	Tue Jun 02 19:30:34 2026 +0200
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+# the directory where the executed Makefile is
+dir="$1"
+
+# extra flags to add to the compile recipe (if you want to use extra
+# flags for the dependency resolution, set CFLAGS environment variable)
+extra_flags="$2"
+
+# additional source prefix in case the recipes are for a included Makefile
+src_prefix="$3"
+
+# the target directory for the object files (default: ../build/$dir/)
+target="$4"
+
+# the object file extension to use (default: $(OBJ_EXT) from the config.mk)
+obj_ext="$5"
+
+
+if [ -z "$dir" ]; then
+  echo "Usage: $0 <src_dir>"
+  exit 1
+fi
+
+if [ -z "$target" ]; then
+  target="../build/$dir/"
+fi
+
+if [ -z "$obj_ext" ]; then
+  obj_ext='$(OBJ_EXT)'
+fi
+
+if [ -d "$dir" ]; then
+  :
+else
+  echo "'$dir' is not a directory"
+  exit 1
+fi
+
+if [ -z "$CC" ]; then
+  for cc in gcc clang ; do
+    if command -v "$cc" > /dev/null ; then
+      CC="$cc"
+      break
+    fi
+  done
+fi
+
+if [ -z "$CC" ]; then
+  echo "No suitable compiler found to generate make rules"
+  exit 1
+fi
+
+if command -v sed > /dev/null ; then
+  :
+else
+  echo "You need the 'sed' program for this script to work."
+  exit 1
+fi
+
+# cleanup include paths to only depend on non-system headers
+cflags=`echo $CFLAGS | sed 's/-I\//-isystem \//g'`
+
+# switch into the directory of the executed Makefile and generate the recipes
+cd "$dir"
+
+mv ${src_prefix}Makefile ${src_prefix}Makefile.old
+sed '/FORCE:/q' ${src_prefix}Makefile.old > ${src_prefix}Makefile
+echo >> ${src_prefix}Makefile
+for file in `ls ${src_prefix}*.c` ; do
+  "$CC" -MT "$target$(basename $file .c)$obj_ext" -MM $cflags "$file"
+  printf '\t$(CC) -o $@ $(CFLAGS) %s -c $<\n\n' "$extra_flags"
+done  >> ${src_prefix}Makefile
+rm ${src_prefix}Makefile.old