[WebAssembly] Rename methods in WasmEHFuncInfo (NFC)

[aheejin]

Summary

This renames variable and method names in WasmEHFuncInfo class to be
simpler and clearer. For example, unwind destinations are EH pads by
definition so it doesn't necessarily need to be included in every method
name. Also I am planning to add the reverse mapping in a later CL,
something like UnwindDestToSrc, so this renaming will make meanings
clearer.

llvm/include/llvm/CodeGen/WasmEHFuncInfo.h

 enum EventTag { CPP_EXCEPTION = 0, C_LONGJMP = 1 };
 }
 
 using BBOrMBB = PointerUnion<const BasicBlock *, MachineBasicBlock *>;
 
 struct WasmEHFuncInfo {
   // When there is an entry <A, B>, if an exception is not caught by A, it
   // should next unwind to the EH pad B.
-  DenseMap<BBOrMBB, BBOrMBB> EHPadUnwindMap;
+  DenseMap<BBOrMBB, BBOrMBB> SrcToUnwindDest;
 
   // Helper functions
-  const BasicBlock *getEHPadUnwindDest(const BasicBlock *BB) const {
-    return EHPadUnwindMap.lookup(BB).get<const BasicBlock *>();
+  const BasicBlock *getUnwindDest(const BasicBlock *BB) const {
+    return SrcToUnwindDest.lookup(BB).get<const BasicBlock *>();
   }
-  void setEHPadUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
-    EHPadUnwindMap[BB] = Dest;
+  void setUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
+    SrcToUnwindDest[BB] = Dest;
   }
-  bool hasEHPadUnwindDest(const BasicBlock *BB) const {
-    return EHPadUnwindMap.count(BB);
+  bool hasUnwindDest(const BasicBlock *BB) const {
+    return SrcToUnwindDest.count(BB);
   }
 
-  MachineBasicBlock *getEHPadUnwindDest(MachineBasicBlock *MBB) const {
-    return EHPadUnwindMap.lookup(MBB).get<MachineBasicBlock *>();
+  MachineBasicBlock *getUnwindDest(MachineBasicBlock *MBB) const {
+    return SrcToUnwindDest.lookup(MBB).get<MachineBasicBlock *>();
   }
-  void setEHPadUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
-    EHPadUnwindMap[MBB] = Dest;
+  void setUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
+    SrcToUnwindDest[MBB] = Dest;
   }
-  bool hasEHPadUnwindDest(MachineBasicBlock *MBB) const {
-    return EHPadUnwindMap.count(MBB);
+  bool hasUnwindDest(MachineBasicBlock *MBB) const {
+    return SrcToUnwindDest.count(MBB);
   }
 };
 
 // Analyze the IR in the given function to build WasmEHFuncInfo.
 void calculateWasmEHInfo(const Function *F, WasmEHFuncInfo &EHInfo);
 
 } // namespace llvm
 
 #endif // LLVM_CODEGEN_WASMEHFUNCINFO_H

llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp

for (ClrEHUnwindMapEntry &CME : EHInfo.ClrEHUnwindMap) {
       CME.Handler = MBBMap[BB];
     }
   }
 
   else if (Personality == EHPersonality::Wasm_CXX) {
     WasmEHFuncInfo &EHInfo = *MF->getWasmEHFuncInfo();
     // Map all BB references in the WinEH data to MBBs.
     DenseMap<BBOrMBB, BBOrMBB> NewMap;
-    for (auto &KV : EHInfo.EHPadUnwindMap) {
+    for (auto &KV : EHInfo.SrcToUnwindDest) {
       const auto *Src = KV.first.get<const BasicBlock *>();
       const auto *Dst = KV.second.get<const BasicBlock *>();
       NewMap[MBBMap[Src]] = MBBMap[Dst];
     }
-    EHInfo.EHPadUnwindMap = std::move(NewMap);
+    EHInfo.SrcToUnwindDest = std::move(NewMap);
   }
 }
 
 /// clear - Clear out all the function-specific state. This returns this
 /// FunctionLoweringInfo to an empty state, ready to be used for a
 /// different function.
 void FunctionLoweringInfo::clear() {
   MBBMap.clear();

llvm/lib/CodeGen/WasmEHPrepare.cpp

for (const auto &BB : *F) {
 
     if (const auto *CatchPad = dyn_cast<CatchPadInst>(Pad)) {
       const auto *UnwindBB = CatchPad->getCatchSwitch()->getUnwindDest();
       if (!UnwindBB)
         continue;
       const Instruction *UnwindPad = UnwindBB->getFirstNonPHI();
       if (const auto *CatchSwitch = dyn_cast<CatchSwitchInst>(UnwindPad))
         // Currently there should be only one handler per a catchswitch.
-        EHInfo.setEHPadUnwindDest(&BB, *CatchSwitch->handlers().begin());
+        EHInfo.setUnwindDest(&BB, *CatchSwitch->handlers().begin());
       else // cleanuppad
-        EHInfo.setEHPadUnwindDest(&BB, UnwindBB);
+        EHInfo.setUnwindDest(&BB, UnwindBB);
     }
   }
 }

llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp

for (auto &MI : reverse(MBB)) {
 
         // catch_all always catches an exception, so we don't need to do
         // anything
         if (MI.getOpcode() == WebAssembly::CATCH_ALL) {
         }
 
         // This can happen when the unwind dest was removed during the
         // optimization, e.g. because it was unreachable.
-        else if (EHPadStack.empty() && EHInfo->hasEHPadUnwindDest(EHPad)) {
+        else if (EHPadStack.empty() && EHInfo->hasUnwindDest(EHPad)) {
           LLVM_DEBUG(dbgs() << "EHPad (" << EHPad->getName()
                             << "'s unwind destination does not exist anymore"
                             << "\n\n");
         }
 
         // The EHPad's next unwind destination is the caller, but we incorrectly
         // unwind to another EH pad.
-        else if (!EHPadStack.empty() && !EHInfo->hasEHPadUnwindDest(EHPad)) {
+        else if (!EHPadStack.empty() && !EHInfo->hasUnwindDest(EHPad)) {
           EHPadToUnwindDest[EHPad] = getFakeCallerBlock(MF);
           LLVM_DEBUG(dbgs()
                      << "- Catch unwind mismatch:\nEHPad = " << EHPad->getName()
                      << "  Original dest = caller  Current dest = "
                      << EHPadStack.back()->getName() << "\n\n");
         }
 
         // The EHPad's next unwind destination is an EH pad, whereas we
         // incorrectly unwind to another EH pad.
-        else if (!EHPadStack.empty() && EHInfo->hasEHPadUnwindDest(EHPad)) {
-          auto *UnwindDest = EHInfo->getEHPadUnwindDest(EHPad);
+        else if (!EHPadStack.empty() && EHInfo->hasUnwindDest(EHPad)) {
+          auto *UnwindDest = EHInfo->getUnwindDest(EHPad);
           if (EHPadStack.back() != UnwindDest) {
             EHPadToUnwindDest[EHPad] = UnwindDest;
             LLVM_DEBUG(dbgs() << "- Catch unwind mismatch:\nEHPad = "
                               << EHPad->getName() << "  Original dest = "
                               << UnwindDest->getName() << "  Current dest = "
                               << EHPadStack.back()->getName() << "\n\n");
           }
         }