From 36d3b83e9c7bcb2a27902006d1409a3583fb0015 Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Wed, 15 Jul 2026 18:57:45 +0200
Subject: [PATCH] builder: add chkstk2.S to windows/386 builtins for __alloca
 symbol

Clang on i386 mingw emits calls to _alloca (decorated as __alloca)
for stack probing. This was provided by chkstk2.S, not chkstk.S
which only provides __chkstk_ms.

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 builder/builtins.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/builder/builtins.go b/builder/builtins.go
index 1feeb5d5a..60db1f28d 100644
--- a/builder/builtins.go
+++ b/builder/builtins.go
@@ -204,7 +204,8 @@ var avrBuiltins = []string{
 
 // Builtins needed specifically for windows/386.
 var windowsI386Builtins = []string{
-	"i386/chkstk.S", // also _alloca
+	"i386/chkstk.S",  // __chkstk_ms
+	"i386/chkstk2.S", // _alloca (__alloca)
 }
 
 // Builtins needed specifically for windows/amd64.