From 0829a511f03d75121f2a8aa557fc0b45f5f2069c Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Wed, 7 Feb 2024 18:09:36 -0600
Subject: [PATCH] =?UTF-8?q?=F0=9F=A7=91=E2=80=8D=F0=9F=92=BB=20"static=5Fw?=
 =?UTF-8?q?arning"?=
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---
 Marlin/src/inc/Warnings.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Marlin/src/inc/Warnings.cpp b/Marlin/src/inc/Warnings.cpp
index c2c0e63a5240..f889ce38e05c 100644
--- a/Marlin/src/inc/Warnings.cpp
+++ b/Marlin/src/inc/Warnings.cpp
@@ -31,6 +31,24 @@
 // Warnings! Located here so they will appear just once in the build output.
 //
 
+// static_warning works like a static_assert but only emits a (messy) warning.
+#ifdef __GNUC__
+  namespace mfwarn {
+    struct true_type {};
+    struct false_type {};
+    template <int test> struct converter : public true_type {};
+    template <> struct converter<0> : public false_type {};
+  }
+  #define static_warning(cond, msg) \
+    struct CAT(static_warning, __LINE__) { \
+      void _(::mfwarn::false_type const&) __attribute__((deprecated(msg))) {}; \
+      void _(::mfwarn::true_type const&) {}; \
+      CAT(static_warning, __LINE__)() {_(::mfwarn::converter<(cond)>());} \
+    }
+#else
+  #define static_warning(...)
+#endif
+
 #if ENABLED(MARLIN_DEV_MODE)
   #warning "WARNING! Disable MARLIN_DEV_MODE for the final build!"
   #ifdef __LONG_MAX__