[WinEH] Move WinEHFuncInfo from MachineModuleInfo to MachineFunction

Summary:
Now that there is a one-to-one mapping from MachineFunction to
WinEHFuncInfo, we don't need to use a DenseMap to select the right
WinEHFuncInfo for the current funclet.

The main challenge here is that X86WinEHStatePass is an IR pass that
doesn't have access to the MachineFunction. I gave it its own
WinEHFuncInfo object that it uses to calculate state numbers, which it
then throws away. As long as nobody creates or removes EH pads between
this pass and SDAG construction, we will get the same state numbers.

The other thing X86WinEHStatePass does is to mark the EH registration
node. Instead of communicating which alloca was the registration through
WinEHFuncInfo, I added the llvm.x86.seh.ehregnode intrinsic.  This
intrinsic generates no code and simply marks the alloca in use.

Reviewers: JCTremoulet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14668

llvm-svn: 253378

1 files changed, 27 insertions, 27 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
index 33eb3906fce..cd1f3f51bc4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/WinException.cpp
@@ -299,7 +299,8 @@ const MCExpr *WinException::getOffsetPlusOne(const MCSymbol *OffsetOf,
                                  Asm->OutContext);
 }
 
-int WinException::getFrameIndexOffset(int FrameIndex, WinEHFuncInfo &FuncInfo) {
+int WinException::getFrameIndexOffset(int FrameIndex,
+                                      const WinEHFuncInfo &FuncInfo) {
   const TargetFrameLowering &TFI = *Asm->MF->getSubtarget().getFrameLowering();
   unsigned UnusedReg;
   if (Asm->MAI->usesWindowsCFI())
@@ -340,7 +341,7 @@ struct InvokeStateChange {
 /// reported is the first change to something other than NullState, and a
 /// change back to NullState is always reported at the end of iteration).
 class InvokeStateChangeIterator {
-  InvokeStateChangeIterator(WinEHFuncInfo &EHInfo,
+  InvokeStateChangeIterator(const WinEHFuncInfo &EHInfo,
                             MachineFunction::const_iterator MFI,
                             MachineFunction::const_iterator MFE,
                             MachineBasicBlock::const_iterator MBBI)
@@ -353,7 +354,7 @@ class InvokeStateChangeIterator {
 
 public:
   static iterator_range<InvokeStateChangeIterator>
-  range(WinEHFuncInfo &EHInfo, const MachineFunction &MF) {
+  range(const WinEHFuncInfo &EHInfo, const MachineFunction &MF) {
     // Reject empty MFs to simplify bookkeeping by ensuring that we can get the
     // end of the last block.
     assert(!MF.empty());
@@ -366,7 +367,7 @@ public:
         InvokeStateChangeIterator(EHInfo, FuncEnd, FuncEnd, BlockEnd));
   }
   static iterator_range<InvokeStateChangeIterator>
-  range(WinEHFuncInfo &EHInfo, MachineFunction::const_iterator Begin,
+  range(const WinEHFuncInfo &EHInfo, MachineFunction::const_iterator Begin,
         MachineFunction::const_iterator End) {
     // Reject empty ranges to simplify bookkeeping by ensuring that we can get
     // the end of the last block.
@@ -402,7 +403,7 @@ public:
 private:
   InvokeStateChangeIterator &scan();
 
-  WinEHFuncInfo &EHInfo;
+  const WinEHFuncInfo &EHInfo;
   const MCSymbol *CurrentEndLabel = nullptr;
   MachineFunction::const_iterator MFI;
   MachineFunction::const_iterator MFE;
@@ -521,7 +522,7 @@ void WinException::emitCSpecificHandlerTable(const MachineFunction *MF) {
   auto &OS = *Asm->OutStreamer;
   MCContext &Ctx = Asm->OutContext;
 
-  WinEHFuncInfo &FuncInfo = MMI->getWinEHFuncInfo(MF->getFunction());
+  const WinEHFuncInfo &FuncInfo = *MF->getWinEHFuncInfo();
   // Use the assembler to compute the number of table entries through label
   // difference and division.
   MCSymbol *TableBegin =
@@ -564,7 +565,7 @@ void WinException::emitCSpecificHandlerTable(const MachineFunction *MF) {
   OS.EmitLabel(TableEnd);
 }
 
-void WinException::emitSEHActionsForRange(WinEHFuncInfo &FuncInfo,
+void WinException::emitSEHActionsForRange(const WinEHFuncInfo &FuncInfo,
                                           const MCSymbol *BeginLabel,
                                           const MCSymbol *EndLabel, int State) {
   auto &OS = *Asm->OutStreamer;
@@ -572,7 +573,7 @@ void WinException::emitSEHActionsForRange(WinEHFuncInfo &FuncInfo,
 
   assert(BeginLabel && EndLabel);
   while (State != -1) {
-    SEHUnwindMapEntry &UME = FuncInfo.SEHUnwindMap[State];
+    const SEHUnwindMapEntry &UME = FuncInfo.SEHUnwindMap[State];
     const MCExpr *FilterOrFinally;
     const MCExpr *ExceptOrNull;
     auto *Handler = UME.Handler.get<MachineBasicBlock *>();
@@ -600,7 +601,7 @@ void WinException::emitSEHActionsForRange(WinEHFuncInfo &FuncInfo,
 void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
   const Function *F = MF->getFunction();
   auto &OS = *Asm->OutStreamer;
-  WinEHFuncInfo &FuncInfo = MMI->getWinEHFuncInfo(F);
+  const WinEHFuncInfo &FuncInfo = *MF->getWinEHFuncInfo();
 
   StringRef FuncLinkageName = GlobalValue::getRealLinkageName(F->getName());
 
@@ -688,7 +689,7 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
     OS.EmitLabel(TryBlockMapXData);
     SmallVector<MCSymbol *, 1> HandlerMaps;
     for (size_t I = 0, E = FuncInfo.TryBlockMap.size(); I != E; ++I) {
-      WinEHTryBlockMapEntry &TBME = FuncInfo.TryBlockMap[I];
+      const WinEHTryBlockMapEntry &TBME = FuncInfo.TryBlockMap[I];
 
       MCSymbol *HandlerMapXData = nullptr;
       if (!TBME.HandlerArray.empty())
@@ -721,7 +722,7 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
     }
 
     for (size_t I = 0, E = FuncInfo.TryBlockMap.size(); I != E; ++I) {
-      WinEHTryBlockMapEntry &TBME = FuncInfo.TryBlockMap[I];
+      const WinEHTryBlockMapEntry &TBME = FuncInfo.TryBlockMap[I];
       MCSymbol *HandlerMapXData = HandlerMaps[I];
       if (!HandlerMapXData)
         continue;
@@ -772,7 +773,7 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
 }
 
 void WinException::computeIP2StateTable(
-    const MachineFunction *MF, WinEHFuncInfo &FuncInfo,
+    const MachineFunction *MF, const WinEHFuncInfo &FuncInfo,
     SmallVectorImpl<std::pair<const MCExpr *, int>> &IPToStateTable) {
   // Indicate that all calls from the prologue to the first invoke unwind to
   // caller. We handle this as a special case since other ranges starting at end
@@ -803,15 +804,15 @@ void WinException::emitEHRegistrationOffsetLabel(const WinEHFuncInfo &FuncInfo,
   // registration in order to recover the parent frame pointer. Now that we know
   // we've code generated the parent, we can emit the label assignment that
   // those helpers use to get the offset of the registration node.
-  assert(FuncInfo.EHRegNodeEscapeIndex != INT_MAX &&
-         "no EH reg node localescape index");
+  MCContext &Ctx = Asm->OutContext;
   MCSymbol *ParentFrameOffset =
-      Asm->OutContext.getOrCreateParentFrameOffsetSymbol(FLinkageName);
-  MCSymbol *RegistrationOffsetSym = Asm->OutContext.getOrCreateFrameAllocSymbol(
-      FLinkageName, FuncInfo.EHRegNodeEscapeIndex);
-  const MCExpr *RegistrationOffsetSymRef =
-      MCSymbolRefExpr::create(RegistrationOffsetSym, Asm->OutContext);
-  Asm->OutStreamer->EmitAssignment(ParentFrameOffset, RegistrationOffsetSymRef);
+      Ctx.getOrCreateParentFrameOffsetSymbol(FLinkageName);
+  unsigned UnusedReg;
+  const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
+  int64_t Offset = TFI->getFrameIndexReference(
+      *Asm->MF, FuncInfo.EHRegNodeFrameIndex, UnusedReg);
+  const MCExpr *MCOffset = MCConstantExpr::create(Offset, Ctx);
+  Asm->OutStreamer->EmitAssignment(ParentFrameOffset, MCOffset);
 }
 
 /// Emit the language-specific data that _except_handler3 and 4 expect. This is
@@ -822,7 +823,7 @@ void WinException::emitExceptHandlerTable(const MachineFunction *MF) {
   const Function *F = MF->getFunction();
   StringRef FLinkageName = GlobalValue::getRealLinkageName(F->getName());
 
-  WinEHFuncInfo &FuncInfo = MMI->getWinEHFuncInfo(F);
+  const WinEHFuncInfo &FuncInfo = *MF->getWinEHFuncInfo();
   emitEHRegistrationOffsetLabel(FuncInfo, FLinkageName);
 
   // Emit the __ehtable label that we use for llvm.x86.seh.lsda.
@@ -857,7 +858,7 @@ void WinException::emitExceptHandlerTable(const MachineFunction *MF) {
   }
 
   assert(!FuncInfo.SEHUnwindMap.empty());
-  for (SEHUnwindMapEntry &UME : FuncInfo.SEHUnwindMap) {
+  for (const SEHUnwindMapEntry &UME : FuncInfo.SEHUnwindMap) {
     MCSymbol *ExceptOrFinally =
         UME.Handler.get<MachineBasicBlock *>()->getSymbol();
     // -1 is usually the base state for "unwind to caller", but for
@@ -869,7 +870,7 @@ void WinException::emitExceptHandlerTable(const MachineFunction *MF) {
   }
 }
 
-static int getRank(WinEHFuncInfo &FuncInfo, int State) {
+static int getRank(const WinEHFuncInfo &FuncInfo, int State) {
   int Rank = 0;
   while (State != -1) {
     ++Rank;
@@ -878,7 +879,7 @@ static int getRank(WinEHFuncInfo &FuncInfo, int State) {
   return Rank;
 }
 
-static int getAncestor(WinEHFuncInfo &FuncInfo, int Left, int Right) {
+static int getAncestor(const WinEHFuncInfo &FuncInfo, int Left, int Right) {
   int LeftRank = getRank(FuncInfo, Left);
   int RightRank = getRank(FuncInfo, Right);
 
@@ -905,8 +906,7 @@ void WinException::emitCLRExceptionTable(const MachineFunction *MF) {
   // states, handlers, and funclets all have 1:1 mappings between them, and a
   // handler/funclet's "state" is its index in the ClrEHUnwindMap.
   MCStreamer &OS = *Asm->OutStreamer;
-  const Function *F = MF->getFunction();
-  WinEHFuncInfo &FuncInfo = MMI->getWinEHFuncInfo(F);
+  const WinEHFuncInfo &FuncInfo = *MF->getWinEHFuncInfo();
   MCSymbol *FuncBeginSym = Asm->getFunctionBegin();
   MCSymbol *FuncEndSym = Asm->getFunctionEnd();
 
@@ -1085,7 +1085,7 @@ void WinException::emitCLRExceptionTable(const MachineFunction *MF) {
         getOffsetPlusOne(Clause.StartLabel, FuncBeginSym);
     const MCExpr *ClauseEnd = getOffsetPlusOne(Clause.EndLabel, FuncBeginSym);
 
-    ClrEHUnwindMapEntry &Entry = FuncInfo.ClrEHUnwindMap[Clause.State];
+    const ClrEHUnwindMapEntry &Entry = FuncInfo.ClrEHUnwindMap[Clause.State];
     MachineBasicBlock *HandlerBlock = Entry.Handler.get<MachineBasicBlock *>();
     MCSymbol *BeginSym = getMCSymbolForMBB(Asm, HandlerBlock);
     const MCExpr *HandlerBegin = getOffset(BeginSym, FuncBeginSym);