init.sh now regenerated build/etc/generated.make with perfect precision

init.sh

@@ -32,13 +32,15 @@ else
   if [[ "$1" == "-h" ]] || [[ "$1" == "-help" ]] || [[ "$1" == "--help" ]]; then
     echo "usage: $0 [options]" >&2
     echo "options:" >&2
-    echo "  -clean  Start from scratch" >&2
+    echo "  -clean     Start from scratch" >&2
+    echo "  -h, -help  Show help and exit" >&2
     exit 1
   fi
 
   clean=false
   if [[ "$1" == "-clean" ]]; then
     clean=true
+    shift
   fi
 
   platform=osx
@@ -362,59 +364,75 @@ else
 
   # ————————————————————————————————————————————————————————————————————————————————————————————————
   # $BUILD_DIR/etc/generated.make
-  master_styles=( \
-    Thin \
-    ThinItalic \
-    Regular \
-    Italic \
-    Black \
-    BlackItalic \
-  )
-  derived_styles=( \
-    "Light            : Thin Regular" \
-    "LightItalic      : ThinItalic Italic" \
-    "ExtraLight       : Thin Regular" \
-    "ExtraLightItalic : ThinItalic Italic" \
-    "Medium           : Regular Black" \
-    "MediumItalic     : Italic BlackItalic" \
-    "SemiBold         : Regular Black" \
-    "SemiBoldItalic   : Italic BlackItalic" \
-    "Bold             : Regular Black" \
-    "BoldItalic       : Italic BlackItalic" \
-    "ExtraBold        : Regular Black" \
-    "ExtraBoldItalic  : Italic BlackItalic" \
-  )
-  web_formats=( woff woff2 )  # Disabled/unused: eot
 
-  mkdir -p "$BUILD_DIR/etc"
   GEN_MAKE_FILE=$BUILD_DIR/etc/generated.make
-
-  # Warning about UFOs moving from src to build/ufo
-  for f in src/Inter-*.ufo; do
-    if [ -f "$f" ]; then
-      echo "" >&2
-      echo "--------------------------- WARNING ----------------------------" >&2
-      echo "" >&2
-      echo "     UFO files have moved from ./src to ./build/ufo" >&2
-      echo "" >&2
-      echo "If you are working with a UFO workflow, please manually move" >&2
-      echo "your UFO source files from ./src to ./build/ufo." >&2
-      echo "" >&2
-      echo "If you are working in a Glyphps workflow, then simply remove" >&2
-      echo "the UFO files in ./src to silence this warning." >&2
-      echo "" >&2
-      echo "----------------------------------------------------------------" >&2
-      echo "" >&2
+  INIT_FILE_HASH= ; if [ -d .git ]; then INIT_FILE_HASH=$(git hash-object -w init.sh); fi
+  GENERATE_MAKE_FILE=false
+  if $clean || [[ ! -f "$GEN_MAKE_FILE" ]]; then
+    GENERATE_MAKE_FILE=true
+  else
+    # check to see if stored hash of init.sh is the same as the current init.sh
+    GEN_MAKE_FILE_LINE1=$(head -n 1 "$GEN_MAKE_FILE")
+    if [[ "$GEN_MAKE_FILE_LINE1" != "#$INIT_FILE_HASH" ]]; then
+      # the makefile was generated by a different version of init.sh
+      GENERATE_MAKE_FILE=true
     fi
-    break
-  done
+  fi
 
   # Generate BUILD_DIR/etc/generated.make
-  if $clean || [[ ! -f "$GEN_MAKE_FILE" ]] || [[ "$0" -nt "$GEN_MAKE_FILE" ]]; then
+  if $GENERATE_MAKE_FILE; then
+
+    # Warning about UFOs moving from src to build/ufo
+    for f in src/Inter-*.ufo; do
+      if [ -f "$f" ]; then
+        echo "" >&2
+        echo "--------------------------- WARNING ----------------------------" >&2
+        echo "" >&2
+        echo "     UFO files have moved from ./src to ./build/ufo" >&2
+        echo "" >&2
+        echo "If you are working with a UFO workflow, please manually move" >&2
+        echo "your UFO source files from ./src to ./build/ufo." >&2
+        echo "" >&2
+        echo "If you are working in a Glyphps workflow, then simply remove" >&2
+        echo "the UFO files in ./src to silence this warning." >&2
+        echo "" >&2
+        echo "----------------------------------------------------------------" >&2
+        echo "" >&2
+      fi
+      break
+    done
+
     echo "Generating '$GEN_MAKE_FILE'"
-    echo "# Generated by init.sh -- do not modify manually" > "$GEN_MAKE_FILE"
+    echo "#$INIT_FILE_HASH" > "$GEN_MAKE_FILE"
+    echo "# Generated by init.sh -- do not modify manually" >> "$GEN_MAKE_FILE"
     echo "" >> "$GEN_MAKE_FILE"
 
+    master_styles=( \
+      Thin \
+      ThinItalic \
+      Regular \
+      Italic \
+      Black \
+      BlackItalic \
+    )
+    derived_styles=( \
+      "Light            : Thin Regular" \
+      "LightItalic      : ThinItalic Italic" \
+      "ExtraLight       : Thin Regular" \
+      "ExtraLightItalic : ThinItalic Italic" \
+      "Medium           : Regular Black" \
+      "MediumItalic     : Italic BlackItalic" \
+      "SemiBold         : Regular Black" \
+      "SemiBoldItalic   : Italic BlackItalic" \
+      "Bold             : Regular Black" \
+      "BoldItalic       : Italic BlackItalic" \
+      "ExtraBold        : Regular Black" \
+      "ExtraBoldItalic  : Italic BlackItalic" \
+    )
+    web_formats=( woff woff2 )
+
+    mkdir -p "$BUILD_DIR/etc"
+
     all_styles=()
     instance_styles=()