From 582786b6cc903797626accfebe5f7bb84c2dfeb3 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <reid@kleckner.net>
Date: Thu, 30 Apr 2015 18:17:12 +0000
Subject: [PATCH] Add a note about permitting default member initializers

Use them in WinEHPrepare so that we can spot any toolchain bugs that
come up.

llvm-svn: 236244
---
 llvm/docs/CodingStandards.rst     | 8 +++++++-
 llvm/lib/CodeGen/WinEHPrepare.cpp | 8 ++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/llvm/docs/CodingStandards.rst b/llvm/docs/CodingStandards.rst
index 992939259ab9..8c8110d03321 100644
--- a/llvm/docs/CodingStandards.rst
+++ b/llvm/docs/CodingStandards.rst
@@ -131,6 +131,12 @@ unlikely to be supported by our host compilers.
     cannot synthesize them.
 * Initializer lists: N2627_
 * Delegating constructors: N1986_
+* Default member initializers (non-static data member initializers): N2756_
+
+  * Only use these for scalar members that would otherwise be left
+    uninitialized. Non-scalar members generally have appropriate default
+    constructors, and MSVC 2013 has problems when braced initializer lists are
+    involved.
 
 .. _N2118: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2118.html
 .. _N2439: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2439.htm
@@ -156,7 +162,7 @@ unlikely to be supported by our host compilers.
 .. _N2346: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2346.htm
 .. _N2627: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2672.htm
 .. _N1986: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1986.pdf
-.. _MSVC-compatible RTTI: http://llvm.org/PR18951
+.. _N2756: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2756.htm
 
 The supported features in the C++11 standard libraries are less well tracked,
 but also much greater. Most of the standard libraries implement most of C++11's
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 0461d71507b0..c1067c5d5600 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -72,7 +72,7 @@ class WinEHPrepare : public FunctionPass {
 public:
   static char ID; // Pass identification, replacement for typeid.
   WinEHPrepare(const TargetMachine *TM = nullptr)
-      : FunctionPass(ID), DT(nullptr), SEHExceptionCodeSlot(nullptr) {
+      : FunctionPass(ID) {
     if (TM)
       TheTriple = Triple(TM->getTargetTriple());
   }
@@ -119,8 +119,8 @@ private:
   Triple TheTriple;
 
   // All fields are reset by runOnFunction.
-  DominatorTree *DT;
-  EHPersonality Personality;
+  DominatorTree *DT = nullptr;
+  EHPersonality Personality = EHPersonality::Unknown;
   CatchHandlerMapTy CatchHandlerMap;
   CleanupHandlerMapTy CleanupHandlerMap;
   DenseMap<const LandingPadInst *, LandingPadMap> LPadMaps;
@@ -150,7 +150,7 @@ private:
   // 32-bit EH.
   DenseMap<Function *, Value *> HandlerToParentFP;
 
-  AllocaInst *SEHExceptionCodeSlot;
+  AllocaInst *SEHExceptionCodeSlot = nullptr;
 };
 
 class WinEHFrameVariableMaterializer : public ValueMaterializer {