[WinEH] Pass the catch adjectives to catchpad directly

This avoids building a fake LLVM IR global variable just to ferry an i32
down into LLVM codegen. It also puts a nail in the coffin of using MS
ABI C++ EH with landingpads, since now we'll assert in the lpad code
when flags are present.

llvm-svn: 247843

8 files changed, 60 insertions, 58 deletions

diff --git a/clang/lib/CodeGen/CGCXXABI.cpp b/clang/lib/CodeGen/CGCXXABI.cpp
index 1f0c3c0e1b4..51f1b0730b3 100644
--- a/clang/lib/CodeGen/CGCXXABI.cpp
+++ b/clang/lib/CodeGen/CGCXXABI.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "CGCXXABI.h"
+#include "CGCleanup.h"
 
 using namespace clang;
 using namespace CodeGen;
@@ -321,3 +322,7 @@ CGCXXABI::emitTerminateForUnexpectedException(CodeGenFunction &CGF,
   // Just call std::terminate and ignore the violating exception.
   return CGF.EmitNounwindRuntimeCall(CGF.CGM.getTerminateFn());
 }
+
+CatchTypeInfo CGCXXABI::getCatchAllTypeInfo() {
+  return CatchTypeInfo{nullptr, 0};
+}
diff --git a/clang/lib/CodeGen/CGCXXABI.h b/clang/lib/CodeGen/CGCXXABI.h
index 6461a478b16..dc4d6d38275 100644
--- a/clang/lib/CodeGen/CGCXXABI.h
+++ b/clang/lib/CodeGen/CGCXXABI.h
@@ -37,6 +37,7 @@ class MangleContext;
 namespace CodeGen {
 class CodeGenFunction;
 class CodeGenModule;
+struct CatchTypeInfo;
 
 /// \brief Implements C++ ABI-specific code generation functions.
 class CGCXXABI {
@@ -236,8 +237,9 @@ public:
                                       llvm::Value *Exn);
 
   virtual llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) = 0;
-  virtual llvm::Constant *
+  virtual CatchTypeInfo
   getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) = 0;
+  virtual CatchTypeInfo getCatchAllTypeInfo();
 
   virtual bool shouldTypeidBeNullChecked(bool IsDeref,
                                          QualType SrcRecordTy) = 0;
diff --git a/clang/lib/CodeGen/CGCleanup.h b/clang/lib/CodeGen/CGCleanup.h
index 5782343013c..51b33f43e90 100644
--- a/clang/lib/CodeGen/CGCleanup.h
+++ b/clang/lib/CodeGen/CGCleanup.h
@@ -33,6 +33,13 @@ namespace CodeGen {
 class CodeGenModule;
 class CodeGenFunction;
 
+/// The MS C++ ABI needs a pointer to RTTI data plus some flags to describe the
+/// type of a catch handler, so we use this wrapper.
+struct CatchTypeInfo {
+  llvm::Constant *RTTI;
+  unsigned Flags;
+};
+
 /// A protected scope for zero-cost EH handling.
 class EHScope {
   llvm::BasicBlock *CachedLandingPad;
@@ -153,12 +160,12 @@ public:
   struct Handler {
     /// A type info value, or null (C++ null, not an LLVM null pointer)
     /// for a catch-all.
-    llvm::Constant *Type;
+    CatchTypeInfo Type;
 
     /// The catch handler for this type.
     llvm::BasicBlock *Block;
 
-    bool isCatchAll() const { return Type == nullptr; }
+    bool isCatchAll() const { return Type.RTTI == nullptr; }
   };
 
 private:
@@ -188,11 +195,17 @@ public:
   }
 
   void setCatchAllHandler(unsigned I, llvm::BasicBlock *Block) {
-    setHandler(I, /*catchall*/ nullptr, Block);
+    setHandler(I, CatchTypeInfo{nullptr, 0}, Block);
   }
 
   void setHandler(unsigned I, llvm::Constant *Type, llvm::BasicBlock *Block) {
     assert(I < getNumHandlers());
+    getHandlers()[I].Type = CatchTypeInfo{Type, 0};
+    getHandlers()[I].Block = Block;
+  }
+
+  void setHandler(unsigned I, CatchTypeInfo Type, llvm::BasicBlock *Block) {
+    assert(I < getNumHandlers());
     getHandlers()[I].Type = Type;
     getHandlers()[I].Block = Block;
   }
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 858b83da36e..6c4a3670e5f 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -554,16 +554,16 @@ void CodeGenFunction::EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock) {
       QualType CaughtType = CGM.getContext().getUnqualifiedArrayType(
           C->getCaughtType().getNonReferenceType(), CaughtTypeQuals);
 
-      llvm::Constant *TypeInfo = nullptr;
+      CatchTypeInfo TypeInfo{nullptr, 0};
       if (CaughtType->isObjCObjectPointerType())
-        TypeInfo = CGM.getObjCRuntime().GetEHType(CaughtType);
+        TypeInfo.RTTI = CGM.getObjCRuntime().GetEHType(CaughtType);
       else
-        TypeInfo =
-            CGM.getAddrOfCXXCatchHandlerType(CaughtType, C->getCaughtType());
+        TypeInfo = CGM.getCXXABI().getAddrOfCXXCatchHandlerType(
+            CaughtType, C->getCaughtType());
       CatchScope->setHandler(I, TypeInfo, Handler);
     } else {
       // No exception decl indicates '...', a catch-all.
-      CatchScope->setCatchAllHandler(I, Handler);
+      CatchScope->setHandler(I, CGM.getCXXABI().getCatchAllTypeInfo(), Handler);
     }
   }
 }
@@ -807,18 +807,20 @@ llvm::BasicBlock *CodeGenFunction::EmitLandingPad() {
     EHCatchScope &catchScope = cast<EHCatchScope>(*I);
     for (unsigned hi = 0, he = catchScope.getNumHandlers(); hi != he; ++hi) {
       EHCatchScope::Handler handler = catchScope.getHandler(hi);
+      assert(handler.Type.Flags == 0 &&
+             "landingpads do not support catch handler flags");
 
       // If this is a catch-all, register that and abort.
-      if (!handler.Type) {
+      if (!handler.Type.RTTI) {
         assert(!hasCatchAll);
         hasCatchAll = true;
         goto done;
       }
 
       // Check whether we already have a handler for this type.
-      if (catchTypes.insert(handler.Type).second)
+      if (catchTypes.insert(handler.Type.RTTI).second)
         // If not, add it directly to the landingpad.
-        LPadInst->addClause(handler.Type);
+        LPadInst->addClause(handler.Type.RTTI);
     }
   }
 
@@ -881,10 +883,9 @@ static llvm::BasicBlock *emitMSVCCatchDispatchBlock(CodeGenFunction &CGF,
   for (unsigned I = 0, E = CatchScope.getNumHandlers(); I < E; ++I) {
     const EHCatchScope::Handler &Handler = CatchScope.getHandler(I);
 
-    llvm::Value *TypeValue = Handler.Type;
-    assert(TypeValue != nullptr || Handler.isCatchAll());
-    if (!TypeValue)
-      TypeValue = llvm::Constant::getNullValue(CGF.VoidPtrTy);
+    CatchTypeInfo TypeInfo = Handler.Type;
+    if (!TypeInfo.RTTI)
+      TypeInfo.RTTI = llvm::Constant::getNullValue(CGF.VoidPtrTy);
 
     // If this is the last handler, we're at the end, and the next
     // block is the block for the enclosing EH scope.
@@ -897,11 +898,12 @@ static llvm::BasicBlock *emitMSVCCatchDispatchBlock(CodeGenFunction &CGF,
     }
 
     if (EHPersonality::get(CGF).isMSVCXXPersonality()) {
-      CGF.Builder.CreateCatchPad(
-          Handler.Block, NextBlock,
-          {TypeValue, llvm::Constant::getNullValue(CGF.VoidPtrTy)});
+      CGF.Builder.CreateCatchPad(Handler.Block, NextBlock,
+                                 {TypeInfo.RTTI,
+                                  CGF.Builder.getInt32(TypeInfo.Flags),
+                                  llvm::Constant::getNullValue(CGF.VoidPtrTy)});
     } else {
-      CGF.Builder.CreateCatchPad(Handler.Block, NextBlock, {TypeValue});
+      CGF.Builder.CreateCatchPad(Handler.Block, NextBlock, {TypeInfo.RTTI});
     }
 
     // Otherwise we need to emit and continue at that block.
@@ -948,7 +950,9 @@ static llvm::BasicBlock *emitCatchDispatchBlock(CodeGenFunction &CGF,
     assert(i < e && "ran off end of handlers!");
     const EHCatchScope::Handler &handler = catchScope.getHandler(i);
 
-    llvm::Value *typeValue = handler.Type;
+    llvm::Value *typeValue = handler.Type.RTTI;
+    assert(handler.Type.Flags == 0 &&
+           "landingpads do not support catch handler flags");
     assert(typeValue && "fell into catch-all case!");
     typeValue = CGF.Builder.CreateBitCast(typeValue, CGF.Int8PtrTy);
 
@@ -1841,7 +1845,8 @@ void CodeGenFunction::EnterSEHTryStmt(const SEHTryStmt &S) {
       HelperCGF.GenerateSEHFilterFunction(*this, *Except);
   llvm::Constant *OpaqueFunc =
       llvm::ConstantExpr::getBitCast(FilterFunc, Int8PtrTy);
-  CatchScope->setHandler(0, OpaqueFunc, createBasicBlock("__except.ret"));
+  CatchScope->setHandler(0, CatchTypeInfo{OpaqueFunc},
+                         createBasicBlock("__except.ret"));
 }
 
 void CodeGenFunction::ExitSEHTryStmt(const SEHTryStmt &S) {
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index bb3bbf28183..34eb06d7207 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -3808,12 +3808,6 @@ llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
   return llvm::ConstantStruct::getAnon(Fields);
 }
 
-llvm::Constant *
-CodeGenModule::getAddrOfCXXCatchHandlerType(QualType Ty,
-                                            QualType CatchHandlerType) {
-  return getCXXABI().getAddrOfCXXCatchHandlerType(Ty, CatchHandlerType);
-}
-
 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
                                                        bool ForEH) {
   // Return a bogus pointer if RTTI is disabled, unless it's for EH.
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index e7ae20fce03..5f40d41261c 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -723,9 +723,6 @@ public:
   /// Get the address of the RTTI descriptor for the given type.
   llvm::Constant *GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH = false);
 
-  llvm::Constant *getAddrOfCXXCatchHandlerType(QualType Ty,
-                                               QualType CatchHandlerType);
-
   /// Get the address of a uuid descriptor .
   ConstantAddress GetAddrOfUuidDescriptor(const CXXUuidofExpr* E);
 
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index da67b16c24d..8392f6a7ba2 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -179,10 +179,10 @@ public:
   void EmitFundamentalRTTIDescriptor(QualType Type);
   void EmitFundamentalRTTIDescriptors();
   llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
-  llvm::Constant *
+  CatchTypeInfo
   getAddrOfCXXCatchHandlerType(QualType Ty,
                                QualType CatchHandlerType) override {
-    return getAddrOfRTTIDescriptor(Ty);
+    return CatchTypeInfo{getAddrOfRTTIDescriptor(Ty), 0};
   }
 
   bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index a2f7165a380..504dc3fa09b 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "CGCXXABI.h"
+#include "CGCleanup.h"
 #include "CGVTables.h"
 #include "CodeGenModule.h"
 #include "CodeGenTypes.h"
@@ -105,9 +106,14 @@ public:
                                                    const VPtrInfo *Info);
 
   llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
-  llvm::Constant *
+  CatchTypeInfo
   getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
 
+  /// MSVC needs an extra flag to indicate a catchall.
+  CatchTypeInfo getCatchAllTypeInfo() override {
+    return CatchTypeInfo{nullptr, 0x40};
+  }
+
   bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
   void EmitBadTypeidCall(CodeGenFunction &CGF) override;
   llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
@@ -926,7 +932,7 @@ void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
     llvm::Value *Args[2] = {Exn, ParamAddr.getPointer()};
     CGF.EmitNounwindRuntimeCall(BeginCatch, Args);
   } else {
-    CPI->setArgOperand(1, var.getObjectAddress(CGF).getPointer());
+    CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
   }
   CGF.EHStack.pushCleanup<CallEndCatchMSVC>(NormalCleanup, CPI);
   CGF.EmitAutoVarCleanups(var);
@@ -3687,7 +3693,7 @@ static QualType decomposeTypeForEH(ASTContext &Context, QualType T,
   return T;
 }
 
-llvm::Constant *
+CatchTypeInfo
 MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
                                               QualType CatchHandlerType) {
   // TypeDescriptors for exceptions never have qualified pointer types,
@@ -3706,28 +3712,8 @@ MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
   if (IsReference)
     Flags |= 8;
 
-  SmallString<256> MangledName;
-  {
-    llvm::raw_svector_ostream Out(MangledName);
-    getMangleContext().mangleCXXCatchHandlerType(Type, Flags, Out);
-  }
-
-  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
-    return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
-
-  llvm::Constant *Fields[] = {
-      llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
-      getAddrOfRTTIDescriptor(Type),            // TypeDescriptor
-  };
-  llvm::StructType *CatchHandlerTypeType = getCatchHandlerTypeType();
-  auto *Var = new llvm::GlobalVariable(
-      CGM.getModule(), CatchHandlerTypeType, /*Constant=*/true,
-      llvm::GlobalValue::PrivateLinkage,
-      llvm::ConstantStruct::get(CatchHandlerTypeType, Fields),
-      StringRef(MangledName));
-  Var->setUnnamedAddr(true);
-  Var->setSection("llvm.metadata");
-  return Var;
+  return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
+                       Flags};
 }
 
 /// \brief Gets a TypeDescriptor.  Returns a llvm::Constant * rather than a