From ea3a4203fa06ba9d60e0796d66f35222bd08fcd7 Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Mon, 6 Jan 2025 01:10:36 +0800
Subject: [PATCH] fixes #24599; misleading error message with large array
 bounds (#24601)

fixes #24599

(cherry picked from commit aeeccee50a603c37c94ee3aa0c3d109654814654)
---
 compiler/semtypes.nim | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim
index 4855faf736..5f33df5c7d 100644
--- a/compiler/semtypes.nim
+++ b/compiler/semtypes.nim
@@ -409,8 +409,12 @@ proc semArrayIndex(c: PContext, n: PNode): PType =
       result = makeRangeWithStaticExpr(c, e.typ.n)
     elif e.kind in {nkIntLit..nkUInt64Lit}:
       if e.intVal < 0:
-        localError(c.config, n.info,
-          "Array length can't be negative, but was " & $e.intVal)
+        if e.kind in {nkIntLit..nkInt64Lit}:
+          localError(c.config, n.info,
+            "Array length can't be negative, but was " & $e.intVal)
+        else:
+          localError(c.config, n.info,
+            "Array length can't exceed its maximum value (9223372036854775807), but was " & $cast[BiggestUInt](e.intVal))
       result = makeRangeType(c, 0, e.intVal-1, n.info, e.typ)
     elif e.kind == nkSym and (e.typ.kind == tyStatic or e.typ.kind == tyTypeDesc):
       if e.typ.kind == tyStatic: