From dc022d53b99fae4d633144f87a344880e1ebb8fb Mon Sep 17 00:00:00 2001
From: Mihail Moskov <28909106+corleypc@users.noreply.github.com>
Date: Thu, 6 Aug 2026 17:42:13 +0300
Subject: [PATCH] fixes call site attribute->arg association when args are
 ignored

---
 src/llvm_backend_proc.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/llvm_backend_proc.cpp b/src/llvm_backend_proc.cpp
index b7d2d0bc7..b528980ec 100644
--- a/src/llvm_backend_proc.cpp
+++ b/src/llvm_backend_proc.cpp
@@ -1024,10 +1024,16 @@ gb_internal lbValue lb_emit_call_internal(lbProcedure *p, lbValue value, lbValue
 		}
 
 		for_array(i, ft->args) {
+			// lbArg_Ignore args are not present in the call arguments, so they must not
+			// advance param_offset (mirrors lb_add_function_type_attributes)
+			if (ft->args[i].kind == lbArg_Ignore) {
+				continue;
+			}
 			LLVMAttributeRef attribute = ft->args[i].attribute;
 			if (attribute != nullptr) {
-				LLVMAddCallSiteAttribute(ret, param_offset + cast(LLVMAttributeIndex)i, attribute);
+				LLVMAddCallSiteAttribute(ret, param_offset, attribute);
 			}
+			param_offset += 1;
 		}
 
 		switch (inlining) {