From 6f96c4bc96be60e494d22c58df2f16f6f5890732 Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Mon, 5 Dec 2022 14:13:51 +0800
Subject: [PATCH] ref #20846; give a deprecation message for overriding `=`
 hook (#21020)

give a deprecation message for overriding `=` hook
---
 compiler/semstmts.nim           |  2 ++
 tests/deprecated/tequalhook.nim | 11 +++++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 tests/deprecated/tequalhook.nim

diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index cbc633383..f1875a3d8 100644
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -1881,6 +1881,8 @@ proc semOverride(c: PContext, s: PSym, n: PNode) =
     if s.magic == mAsgn: return
     incl(s.flags, sfUsed)
     incl(s.flags, sfOverriden)
+    if name == "=":
+      message(c.config, n.info, warnDeprecated, "Overriding `=` hook is deprecated; Override `=copy` hook instead")
     let t = s.typ
     if t.len == 3 and t[0] == nil and t[1].kind == tyVar:
       var obj = t[1][0]
diff --git a/tests/deprecated/tequalhook.nim b/tests/deprecated/tequalhook.nim
new file mode 100644
index 000000000..79ee835f8
--- /dev/null
+++ b/tests/deprecated/tequalhook.nim
@@ -0,0 +1,11 @@
+discard """
+  errormsg: "Overriding `=` hook is deprecated; Override `=copy` hook instead"
+  matrix: "--warningAsError[Deprecated]:on"
+"""
+
+type
+  SharedString = object
+    data: string
+
+proc `=`(x: var SharedString, y: SharedString) =
+  discard
\ No newline at end of file