WebAssembly: Remove MachineFunction reference from MFI

The MachineFunctionInfo here is a bit awkward because
WasmEHInfo is in the MachineFunction but handled from
the target code. Either everything should move into WebAssembly
or into the MachineFunction for MIR serialization.

llvm/include/llvm/CodeGen/MachineFunction.h

@@ -280,6 +280,7 @@ class LLVM_EXTERNAL_VISIBILITY MachineFunction {
   // Keep track of the function section.
   MCSection *Section = nullptr;
 
+  // Catchpad unwind destination info for wasm EH.
   // Keeps track of Wasm exception handling related data. This will be null for
   // functions that aren't using a wasm EH personality.
   WasmEHFuncInfo *WasmEHInfo = nullptr;

llvm/lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.cpp

@@ -28,10 +28,9 @@ MachineFunctionInfo *WebAssemblyFunctionInfo::clone(
     BumpPtrAllocator &Allocator, MachineFunction &DestMF,
     const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB)
     const {
-  WebAssemblyFunctionInfo *Clone =
-      DestMF.cloneInfo<WebAssemblyFunctionInfo>(*this);
-  Clone->MF = &DestMF;
-  return Clone;
+  // TODO: Implement cloning for WasmEHFuncInfo. This will have invalid block
+  // references.
+  return DestMF.cloneInfo<WebAssemblyFunctionInfo>(*this);
 }
 
 void WebAssemblyFunctionInfo::initWARegs(MachineRegisterInfo &MRI) {
@@ -122,11 +121,8 @@ llvm::signatureFromMVTs(const SmallVectorImpl<MVT> &Results,
 }
 
 yaml::WebAssemblyFunctionInfo::WebAssemblyFunctionInfo(
-    const llvm::WebAssemblyFunctionInfo &MFI)
+    const llvm::MachineFunction &MF, const llvm::WebAssemblyFunctionInfo &MFI)
     : CFGStackified(MFI.isCFGStackified()) {
-  auto *EHInfo = MFI.getWasmEHFuncInfo();
-  const llvm::MachineFunction &MF = MFI.getMachineFunction();
-
   for (auto VT : MFI.getParams())
     Params.push_back(EVT(VT).getEVTString());
   for (auto VT : MFI.getResults())
@@ -134,7 +130,8 @@ yaml::WebAssemblyFunctionInfo::WebAssemblyFunctionInfo(
 
   //  MFI.getWasmEHFuncInfo() is non-null only for functions with the
   //  personality function.
-  if (EHInfo) {
+
+  if (auto *EHInfo = MF.getWasmEHFuncInfo()) {
     // SrcToUnwindDest can contain stale mappings in case BBs are removed in
     // optimizations, in case, for example, they are unreachable. We should not
     // include their info.
@@ -155,15 +152,19 @@ void yaml::WebAssemblyFunctionInfo::mappingImpl(yaml::IO &YamlIO) {
 }
 
 void WebAssemblyFunctionInfo::initializeBaseYamlFields(
-    const yaml::WebAssemblyFunctionInfo &YamlMFI) {
+    MachineFunction &MF, const yaml::WebAssemblyFunctionInfo &YamlMFI) {
   CFGStackified = YamlMFI.CFGStackified;
   for (auto VT : YamlMFI.Params)
     addParam(WebAssembly::parseMVT(VT.Value));
   for (auto VT : YamlMFI.Results)
     addResult(WebAssembly::parseMVT(VT.Value));
-  if (WasmEHInfo) {
+
+  // FIXME: WasmEHInfo is defined in the MachineFunction, but serialized
+  // here. Either WasmEHInfo should be moved out of MachineFunction, or the
+  // serialization handling should be moved to MachineFunction.
+  if (WasmEHFuncInfo *WasmEHInfo = MF.getWasmEHFuncInfo()) {
     for (auto KV : YamlMFI.SrcToUnwindDest)
-      WasmEHInfo->setUnwindDest(MF->getBlockNumbered(KV.first),
-                                MF->getBlockNumbered(KV.second));
+      WasmEHInfo->setUnwindDest(MF.getBlockNumbered(KV.first),
+                                MF.getBlockNumbered(KV.second));
   }
 }

llvm/lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.h

@@ -31,8 +31,6 @@ struct WebAssemblyFunctionInfo;
 /// This class is derived from MachineFunctionInfo and contains private
 /// WebAssembly-specific information for each MachineFunction.
 class WebAssemblyFunctionInfo final : public MachineFunctionInfo {
-  const MachineFunction *MF;
-
   std::vector<MVT> Params;
   std::vector<MVT> Results;
   std::vector<MVT> Locals;
@@ -66,12 +64,8 @@ class WebAssemblyFunctionInfo final : public MachineFunctionInfo {
   // Function properties.
   bool CFGStackified = false;
 
-  // Catchpad unwind destination info for wasm EH.
-  WasmEHFuncInfo *WasmEHInfo = nullptr;
-
 public:
-  explicit WebAssemblyFunctionInfo(MachineFunction &MF_)
-      : MF(&MF_), WasmEHInfo(MF_.getWasmEHFuncInfo()) {}
+  explicit WebAssemblyFunctionInfo(MachineFunction &) {}
   ~WebAssemblyFunctionInfo() override;
 
   MachineFunctionInfo *
@@ -79,9 +73,8 @@ public:
         const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB)
       const override;
 
-  const MachineFunction &getMachineFunction() const { return *MF; }
-
-  void initializeBaseYamlFields(const yaml::WebAssemblyFunctionInfo &YamlMFI);
+  void initializeBaseYamlFields(MachineFunction &MF,
+                                const yaml::WebAssemblyFunctionInfo &YamlMFI);
 
   void addParam(MVT VT) { Params.push_back(VT); }
   const std::vector<MVT> &getParams() const { return Params; }
@@ -166,9 +159,6 @@ public:
 
   bool isCFGStackified() const { return CFGStackified; }
   void setCFGStackified(bool Value = true) { CFGStackified = Value; }
-
-  WasmEHFuncInfo *getWasmEHFuncInfo() const { return WasmEHInfo; }
-  void setWasmEHFuncInfo(WasmEHFuncInfo *Info) { WasmEHInfo = Info; }
 };
 
 void computeLegalValueVTs(const WebAssemblyTargetLowering &TLI,
@@ -205,7 +195,8 @@ struct WebAssemblyFunctionInfo final : public yaml::MachineFunctionInfo {
   BBNumberMap SrcToUnwindDest;
 
   WebAssemblyFunctionInfo() = default;
-  WebAssemblyFunctionInfo(const llvm::WebAssemblyFunctionInfo &MFI);
+  WebAssemblyFunctionInfo(const llvm::MachineFunction &MF,
+                          const llvm::WebAssemblyFunctionInfo &MFI);
 
   void mappingImpl(yaml::IO &YamlIO) override;
   ~WebAssemblyFunctionInfo() = default;

llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp

@@ -585,7 +585,7 @@ WebAssemblyTargetMachine::createDefaultFuncInfoYAML() const {
 yaml::MachineFunctionInfo *WebAssemblyTargetMachine::convertFuncInfoToYAML(
     const MachineFunction &MF) const {
   const auto *MFI = MF.getInfo<WebAssemblyFunctionInfo>();
-  return new yaml::WebAssemblyFunctionInfo(*MFI);
+  return new yaml::WebAssemblyFunctionInfo(MF, *MFI);
 }
 
 bool WebAssemblyTargetMachine::parseMachineFunctionInfo(
@@ -593,6 +593,6 @@ bool WebAssemblyTargetMachine::parseMachineFunctionInfo(
     SMDiagnostic &Error, SMRange &SourceRange) const {
   const auto &YamlMFI = static_cast<const yaml::WebAssemblyFunctionInfo &>(MFI);
   MachineFunction &MF = PFS.MF;
-  MF.getInfo<WebAssemblyFunctionInfo>()->initializeBaseYamlFields(YamlMFI);
+  MF.getInfo<WebAssemblyFunctionInfo>()->initializeBaseYamlFields(MF, YamlMFI);
   return false;
 }