From 50ac31d0f560b5f65745598846e6afb8434a68c6 Mon Sep 17 00:00:00 2001
From: Michael Richters <gedankenexperimenter@gmail.com>
Date: Mon, 13 Nov 2017 15:02:58 -0600
Subject: [PATCH] Added a "sketch-trailer.h" header file

This file is meant to be included in sketch files in order to make
data available to Kaleidoscope functions. In particular, the size of
the keymaps[] array (i.e. the number of defined layers), which is
needed in order to prevent reading uninitialized memory past the end
of that array due to Key_KeymapNext_Momentary.
---
 examples/AppSwitcher/AppSwitcher.ino   | 8 +++-----
 examples/Kaleidoscope/Kaleidoscope.ino | 8 +++-----
 src/sketch-trailer.h                   | 6 ++++++
 3 files changed, 12 insertions(+), 10 deletions(-)
 create mode 100644 src/sketch-trailer.h

diff --git a/examples/AppSwitcher/AppSwitcher.ino b/examples/AppSwitcher/AppSwitcher.ino
index eb385cc4..6b561632 100644
--- a/examples/AppSwitcher/AppSwitcher.ino
+++ b/examples/AppSwitcher/AppSwitcher.ino
@@ -46,11 +46,6 @@ const Key keymaps[][ROWS][COLS] PROGMEM = {
 };
 /* *INDENT-ON* */
 
-// Calculate the number of layers defined in the "keymaps[]" array
-// above for use elsewhere in Kaleidoscope. Don't remove or modify
-// this line; it's used to prevent reading past the end of the array!
-const uint8_t LayerCount PROGMEM = sizeof(keymaps) / sizeof(*keymaps);
-
 
 const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState) {
   switch (macroIndex) {
@@ -71,3 +66,6 @@ void setup() {
 void loop() {
   Kaleidoscope.loop();
 }
+
+// This line should always be at the end of the sketch file
+#include <sketch-trailer.h>
diff --git a/examples/Kaleidoscope/Kaleidoscope.ino b/examples/Kaleidoscope/Kaleidoscope.ino
index b5f10424..eae88d7f 100644
--- a/examples/Kaleidoscope/Kaleidoscope.ino
+++ b/examples/Kaleidoscope/Kaleidoscope.ino
@@ -65,11 +65,6 @@ const Key keymaps[][ROWS][COLS] PROGMEM = {
 
 };
 
-// Calculate the number of layers defined in the "keymaps[]" array
-// above for use elsewhere in Kaleidoscope. Don't remove or modify
-// this line; it's used to prevent reading past the end of the array!
-const uint8_t LayerCount PROGMEM = sizeof(keymaps) / sizeof(*keymaps);
-
 static kaleidoscope::LEDSolidColor solidRed(60, 0, 0);
 static kaleidoscope::LEDSolidColor solidOrange(60, 20, 0);
 static kaleidoscope::LEDSolidColor solidYellow(40, 35, 0);
@@ -109,3 +104,6 @@ void setup() {
 void loop() {
   Kaleidoscope.loop();
 }
+
+// This line should always be at the end of the sketch file
+#include <sketch-trailer.h>
diff --git a/src/sketch-trailer.h b/src/sketch-trailer.h
new file mode 100644
index 00000000..9a928920
--- /dev/null
+++ b/src/sketch-trailer.h
@@ -0,0 +1,6 @@
+#pragma once
+
+// Calculate the number of layers defined in the "keymaps[]"
+// array. This needs to be included in the sketch after "keymaps" is
+// defined
+const uint8_t LayerCount PROGMEM = sizeof(keymaps) / sizeof(*keymaps);