From: Matthias Braun <matze@braunis.de>
Date: Mon, 24 Apr 2017 18:41:00 +0000 (+0000)
Subject: Pragma: Fix DebugOverflowStack() resulting in endless loop.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2987ebbf305f2209d4a40e3f0b2c9fe2e014df3a;p=clang

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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@301218 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Lex/Pragma.cpp b/lib/Lex/Pragma.cpp
index f81eaa31e9..87e105d1d0 100644
--- a/lib/Lex/Pragma.cpp
+++ b/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)