[clang] Fix __try/__finally blocks in C++ constructors.

We were crashing trying to convert a GlobalDecl from a
CXXConstructorDecl.  Instead of trying to do that conversion, just pass
down the original GlobalDecl.

I think we could actually compute the correct constructor/destructor
kind from the context, given the way Microsoft mangling works, but it's
simpler to just pass through the correct constructor/destructor kind.

Differential Revision: https://reviews.llvm.org/D136776

clang/include/clang/AST/Mangle.h

@@ -166,10 +166,10 @@ public:
   virtual void mangleDynamicAtExitDestructor(const VarDecl *D,
                                              raw_ostream &) = 0;
 
-  virtual void mangleSEHFilterExpression(const NamedDecl *EnclosingDecl,
+  virtual void mangleSEHFilterExpression(GlobalDecl EnclosingDecl,
                                          raw_ostream &Out) = 0;
 
-  virtual void mangleSEHFinallyBlock(const NamedDecl *EnclosingDecl,
+  virtual void mangleSEHFinallyBlock(GlobalDecl EnclosingDecl,
                                      raw_ostream &Out) = 0;
 
   /// Generates a unique string for an externally visible type for use with TBAA

clang/lib/AST/ItaniumMangle.cpp

@@ -118,9 +118,9 @@ public:
   void mangleDynamicAtExitDestructor(const VarDecl *D,
                                      raw_ostream &Out) override;
   void mangleDynamicStermFinalizer(const VarDecl *D, raw_ostream &Out) override;
-  void mangleSEHFilterExpression(const NamedDecl *EnclosingDecl,
+  void mangleSEHFilterExpression(GlobalDecl EnclosingDecl,
                                  raw_ostream &Out) override;
-  void mangleSEHFinallyBlock(const NamedDecl *EnclosingDecl,
+  void mangleSEHFinallyBlock(GlobalDecl EnclosingDecl,
                              raw_ostream &Out) override;
   void mangleItaniumThreadLocalInit(const VarDecl *D, raw_ostream &) override;
   void mangleItaniumThreadLocalWrapper(const VarDecl *D,
@@ -6430,23 +6430,25 @@ void ItaniumMangleContextImpl::mangleDynamicStermFinalizer(const VarDecl *D,
 }
 
 void ItaniumMangleContextImpl::mangleSEHFilterExpression(
-    const NamedDecl *EnclosingDecl, raw_ostream &Out) {
+    GlobalDecl EnclosingDecl, raw_ostream &Out) {
   CXXNameMangler Mangler(*this, Out);
   Mangler.getStream() << "__filt_";
-  if (shouldMangleDeclName(EnclosingDecl))
+  auto *EnclosingFD = cast<FunctionDecl>(EnclosingDecl.getDecl());
+  if (shouldMangleDeclName(EnclosingFD))
     Mangler.mangle(EnclosingDecl);
   else
-    Mangler.getStream() << EnclosingDecl->getName();
+    Mangler.getStream() << EnclosingFD->getName();
 }
 
 void ItaniumMangleContextImpl::mangleSEHFinallyBlock(
-    const NamedDecl *EnclosingDecl, raw_ostream &Out) {
+    GlobalDecl EnclosingDecl, raw_ostream &Out) {
   CXXNameMangler Mangler(*this, Out);
   Mangler.getStream() << "__fin_";
-  if (shouldMangleDeclName(EnclosingDecl))
+  auto *EnclosingFD = cast<FunctionDecl>(EnclosingDecl.getDecl());
+  if (shouldMangleDeclName(EnclosingFD))
     Mangler.mangle(EnclosingDecl);
   else
-    Mangler.getStream() << EnclosingDecl->getName();
+    Mangler.getStream() << EnclosingFD->getName();
 }
 
 void ItaniumMangleContextImpl::mangleItaniumThreadLocalInit(const VarDecl *D,

clang/lib/AST/MicrosoftMangle.cpp

@@ -142,8 +142,8 @@ class MicrosoftMangleContextImpl : public MicrosoftMangleContext {
   llvm::DenseMap<DiscriminatorKeyTy, unsigned> Discriminator;
   llvm::DenseMap<const NamedDecl *, unsigned> Uniquifier;
   llvm::DenseMap<const CXXRecordDecl *, unsigned> LambdaIds;
-  llvm::DenseMap<const NamedDecl *, unsigned> SEHFilterIds;
-  llvm::DenseMap<const NamedDecl *, unsigned> SEHFinallyIds;
+  llvm::DenseMap<GlobalDecl, unsigned> SEHFilterIds;
+  llvm::DenseMap<GlobalDecl, unsigned> SEHFinallyIds;
   SmallString<16> AnonymousNamespaceHash;
 
 public:
@@ -201,9 +201,9 @@ public:
   void mangleDynamicInitializer(const VarDecl *D, raw_ostream &Out) override;
   void mangleDynamicAtExitDestructor(const VarDecl *D,
                                      raw_ostream &Out) override;
-  void mangleSEHFilterExpression(const NamedDecl *EnclosingDecl,
+  void mangleSEHFilterExpression(GlobalDecl EnclosingDecl,
                                  raw_ostream &Out) override;
-  void mangleSEHFinallyBlock(const NamedDecl *EnclosingDecl,
+  void mangleSEHFinallyBlock(GlobalDecl EnclosingDecl,
                              raw_ostream &Out) override;
   void mangleStringLiteral(const StringLiteral *SL, raw_ostream &Out) override;
   bool getNextDiscriminator(const NamedDecl *ND, unsigned &disc) {
@@ -3730,7 +3730,7 @@ void MicrosoftMangleContextImpl::mangleCXXRTTICompleteObjectLocator(
 }
 
 void MicrosoftMangleContextImpl::mangleSEHFilterExpression(
-    const NamedDecl *EnclosingDecl, raw_ostream &Out) {
+    GlobalDecl EnclosingDecl, raw_ostream &Out) {
   msvc_hashing_ostream MHO(Out);
   MicrosoftCXXNameMangler Mangler(*this, MHO);
   // The function body is in the same comdat as the function with the handler,
@@ -3742,7 +3742,7 @@ void MicrosoftMangleContextImpl::mangleSEHFilterExpression(
 }
 
 void MicrosoftMangleContextImpl::mangleSEHFinallyBlock(
-    const NamedDecl *EnclosingDecl, raw_ostream &Out) {
+    GlobalDecl EnclosingDecl, raw_ostream &Out) {
   msvc_hashing_ostream MHO(Out);
   MicrosoftCXXNameMangler Mangler(*this, MHO);
   // The function body is in the same comdat as the function with the handler,

clang/lib/CodeGen/CGException.cpp

@@ -249,7 +249,7 @@ const EHPersonality &EHPersonality::get(CodeGenFunction &CGF) {
   // For outlined finallys and filters, use the SEH personality in case they
   // contain more SEH. This mostly only affects finallys. Filters could
   // hypothetically use gnu statement expressions to sneak in nested SEH.
-  FD = FD ? FD : CGF.CurSEHParent;
+  FD = FD ? FD : CGF.CurSEHParent.getDecl();
   return get(CGF.CGM, dyn_cast_or_null<FunctionDecl>(FD));
 }
 
@@ -2005,7 +2005,7 @@ void CodeGenFunction::startOutlinedSEHHelper(CodeGenFunction &ParentCGF,
   SmallString<128> Name;
   {
     llvm::raw_svector_ostream OS(Name);
-    const NamedDecl *ParentSEHFn = ParentCGF.CurSEHParent;
+    GlobalDecl ParentSEHFn = ParentCGF.CurSEHParent;
     assert(ParentSEHFn && "No CurSEHParent!");
     MangleContext &Mangler = CGM.getCXXABI().getMangleContext();
     if (IsFilter)

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -701,7 +701,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
   CurCodeDecl = D;
   const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D);
   if (FD && FD->usesSEHTry())
-    CurSEHParent = FD;
+    CurSEHParent = GD;
   CurFuncDecl = (D ? D->getNonClosureContext() : nullptr);
   FnRetTy = RetTy;
   CurFn = Fn;

clang/lib/CodeGen/CodeGenFunction.h

@@ -539,7 +539,7 @@ public:
   /// potentially set the return value.
   bool SawAsmBlock = false;
 
-  const NamedDecl *CurSEHParent = nullptr;
+  GlobalDecl CurSEHParent;
 
   /// True if the current function is an outlined SEH helper. This can be a
   /// finally block or filter expression.
@@ -2021,7 +2021,7 @@ public:
     return getInvokeDestImpl();
   }
 
-  bool currentFunctionUsesSEHTry() const { return CurSEHParent != nullptr; }
+  bool currentFunctionUsesSEHTry() const { return !!CurSEHParent; }
 
   const TargetInfo &getTarget() const { return Target; }
   llvm::LLVMContext &getLLVMContext() { return CGM.getLLVMContext(); }

clang/test/CodeGenCXX/exceptions-seh.cpp

@@ -121,6 +121,15 @@ void use_seh_in_lambda() {
 // CHECK: invoke void @might_throw() #[[NOINLINE]]
 // CHECK: catchpad
 
+class use_seh_in_constructor { use_seh_in_constructor(); };
+use_seh_in_constructor::use_seh_in_constructor(){
+  __try {
+  } __finally {
+  }
+}
+
+// CHECK: define internal void @"?fin$0@0@?0use_seh_in_constructor@@"
+
 static int my_unique_global;
 
 extern "C" inline void use_seh_in_inline_func() {