From 285f88d4a3b99dcfef3d5c00eb0db50127ac27e3 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze@braunis.de>
Date: Mon, 24 Apr 2017 18:41:00 +0000
Subject: [PATCH] Pragma: Fix DebugOverflowStack() resulting in endless loop.

Drive-by fix (noticed while working on https://reviews.llvm.org/D32205):
DebugOverflowStack() is supposed to provoke a stack overflow, however
LLVM was smart enough to use the red-zone and fold the load into a tail
jump on x86_64 optimizing this to an endless loop instead of a stack
overflow.

llvm-svn: 301218
---
 clang/lib/Lex/Pragma.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
index f81eaa31e9e9..87e105d1d03d 100644
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -989,9 +989,9 @@ struct PragmaDebugHandler : public PragmaHandler {
 #ifdef _MSC_VER
     #pragma warning(disable : 4717)
 #endif
-  static void DebugOverflowStack() {
-    void (*volatile Self)() = DebugOverflowStack;
-    Self();
+  static void DebugOverflowStack(void (*P)() = nullptr) {
+    void (*volatile Self)(void(*P)()) = DebugOverflowStack;
+    Self(reinterpret_cast<void(*)()>(Self));
   }
 #ifdef _MSC_VER
     #pragma warning(default : 4717)