From 086fec23ec438976a69e7232816e9c9d59d5d41c Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Fri, 8 Jan 2016 08:03:55 +0000
Subject: [WinEH] Update WinEHFuncInfo if StackColoring merges allocas

Windows EH keeping track of which frame index corresponds to a catchpad
in order to inform the runtime where the catch parameter should be
initialized.  LLVM's optimizations are able to prove that the memory
used by the catch parameter can be reused with another memory
optimization, changing it's frame index.

We need to keep WinEHFuncInfo up to date with respect to this or we will
miscompile/assert.

This fixes PR26069.

llvm-svn: 257158
---
 llvm/lib/CodeGen/StackColoring.cpp | 7 +++++++
 llvm/lib/CodeGen/WinEHPrepare.cpp  | 7 ++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

(limited to 'llvm/lib')

diff --git a/llvm/lib/CodeGen/StackColoring.cpp b/llvm/lib/CodeGen/StackColoring.cpp
index 3541b33a844..d0c0cf77702 100644
--- a/llvm/lib/CodeGen/StackColoring.cpp
+++ b/llvm/lib/CodeGen/StackColoring.cpp
@@ -43,6 +43,7 @@
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/CodeGen/StackProtector.h"
+#include "llvm/CodeGen/WinEHFuncInfo.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
@@ -570,6 +571,12 @@ void StackColoring::remapInstructions(DenseMap<int, int> &SlotRemap) {
       }
     }
 
+  if (WinEHFuncInfo *EHInfo = MF->getWinEHFuncInfo())
+    for (WinEHTryBlockMapEntry &TBME : EHInfo->TryBlockMap)
+      for (WinEHHandlerType &H : TBME.HandlerArray)
+        if (SlotRemap.count(H.CatchObj.FrameIndex))
+          H.CatchObj.FrameIndex = SlotRemap[H.CatchObj.FrameIndex];
+
   DEBUG(dbgs()<<"Fixed "<<FixedMemOp<<" machine memory operands.\n");
   DEBUG(dbgs()<<"Fixed "<<FixedDbg<<" debug locations.\n");
   DEBUG(dbgs()<<"Fixed "<<FixedInstr<<" machine instructions.\n");
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index f112b1bb3b9..886c5f6070c 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -144,10 +144,11 @@ static void addTryBlockMapEntry(WinEHFuncInfo &FuncInfo, int TryLow,
       HT.TypeDescriptor = cast<GlobalVariable>(TypeInfo->stripPointerCasts());
     HT.Adjectives = cast<ConstantInt>(CPI->getArgOperand(1))->getZExtValue();
     HT.Handler = CPI->getParent();
-    if (isa<ConstantPointerNull>(CPI->getArgOperand(2)))
-      HT.CatchObj.Alloca = nullptr;
+    if (auto *AI =
+            dyn_cast<AllocaInst>(CPI->getArgOperand(2)->stripPointerCasts()))
+      HT.CatchObj.Alloca = AI;
     else
-      HT.CatchObj.Alloca = cast<AllocaInst>(CPI->getArgOperand(2));
+      HT.CatchObj.Alloca = nullptr;
     TBME.HandlerArray.push_back(HT);
   }
   FuncInfo.TryBlockMap.push_back(TBME);
-- 
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