From 1d72037dd39e3e53172d7605f22851b75f4e1a1b Mon Sep 17 00:00:00 2001
From: Dan Robertson <dan@dlrobertson.com>
Date: Thu, 7 Mar 2019 03:50:50 +0000
Subject: Fix segfaults in release build C-variadic fns

`va_start` and `va_end` must be called to initialize/cleanup the
"spoofed" `VaList` in a Rust defined C-variadic function even if
the `VaList` is not used.
---
 src/test/codegen/c-variadic-opt.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 src/test/codegen/c-variadic-opt.rs

(limited to 'src/test/codegen')

diff --git a/src/test/codegen/c-variadic-opt.rs b/src/test/codegen/c-variadic-opt.rs
new file mode 100644
index 00000000000..8594d309b0a
--- /dev/null
+++ b/src/test/codegen/c-variadic-opt.rs
@@ -0,0 +1,19 @@
+// compile-flags: -C opt-level=3
+
+#![crate_type = "lib"]
+#![feature(c_variadic)]
+#![no_std]
+use core::ffi::VaList;
+
+extern "C" {
+    fn vprintf(fmt: *const i8, ap: VaList) -> i32;
+}
+
+// Ensure that `va_start` and `va_end` are properly injected even
+// when the "spoofed" `VaList` is not used.
+#[no_mangle]
+pub unsafe extern "C" fn c_variadic_no_use(fmt: *const i8, mut ap: ...) -> i32 {
+    // CHECK: call void @llvm.va_start
+    vprintf(fmt, ap)
+    // CHECK: call void @llvm.va_end
+}
-- 
cgit 1.4.1-3-g733a5