Add Windows support for the GNUstep Objective-C ABI V2.

Summary:
Introduces funclet-based unwinding for Objective-C and fixes an issue
where global blocks can't have their isa pointers initialised on
Windows.

After discussion with Dustin, this changes the name mangling of
Objective-C types to prevent a C++ catch statement of type struct X*
from catching an Objective-C object of type X*.

Reviewers: rjmccall, DHowett-MSFT

Reviewed By: rjmccall, DHowett-MSFT

Subscribers: mgrang, mstorsjo, smeenai, cfe-commits

Differential Revision: https://reviews.llvm.org/D50144

llvm-svn: 339428

clang/include/clang/Driver/Options.td

@@ -1488,7 +1488,7 @@ def fobjc_weak : Flag<["-"], "fobjc-weak">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Enable ARC-style weak references in Objective-C">;
 
 // Objective-C ABI options.
-def fobjc_runtime_EQ : Joined<["-"], "fobjc-runtime=">, Group<f_Group>, Flags<[CC1Option]>,
+def fobjc_runtime_EQ : Joined<["-"], "fobjc-runtime=">, Group<f_Group>, Flags<[CC1Option, CoreOption]>,
   HelpText<"Specify the target Objective-C runtime kind and version">;
 def fobjc_abi_version_EQ : Joined<["-"], "fobjc-abi-version=">, Group<f_Group>;
 def fobjc_nonfragile_abi_version_EQ : Joined<["-"], "fobjc-nonfragile-abi-version=">, Group<f_Group>;

clang/lib/AST/MicrosoftMangle.cpp

@@ -445,7 +445,7 @@ void MicrosoftCXXNameMangler::mangle(const NamedDecl *D, StringRef Prefix) {
     mangleFunctionEncoding(FD, Context.shouldMangleDeclName(FD));
   else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
     mangleVariableEncoding(VD);
-  else
+  else if (!isa<ObjCInterfaceDecl>(D))
     llvm_unreachable("Tried to mangle unexpected NamedDecl!");
 }
 
@@ -1884,13 +1884,13 @@ void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T, Qualifiers,
     llvm_unreachable("placeholder types shouldn't get to name mangling");
 
   case BuiltinType::ObjCId:
-    mangleArtificalTagType(TTK_Struct, "objc_object");
+    mangleArtificalTagType(TTK_Struct, ".objc_object");
     break;
   case BuiltinType::ObjCClass:
-    mangleArtificalTagType(TTK_Struct, "objc_class");
+    mangleArtificalTagType(TTK_Struct, ".objc_class");
     break;
   case BuiltinType::ObjCSel:
-    mangleArtificalTagType(TTK_Struct, "objc_selector");
+    mangleArtificalTagType(TTK_Struct, ".objc_selector");
     break;
 
 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
@@ -2570,9 +2570,10 @@ void MicrosoftCXXNameMangler::mangleType(const DependentAddressSpaceType *T,
 
 void MicrosoftCXXNameMangler::mangleType(const ObjCInterfaceType *T, Qualifiers,
                                          SourceRange) {
-  // ObjC interfaces have structs underlying them.
+  // ObjC interfaces are mangled as if they were structs with a name that is
+  // not a valid C/C++ identifier
   mangleTagTypeKind(TTK_Struct);
-  mangleName(T->getDecl());
+  mangle(T->getDecl(), ".objc_cls_");
 }
 
 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectType *T, Qualifiers,
@@ -2590,11 +2591,11 @@ void MicrosoftCXXNameMangler::mangleType(const ObjCObjectType *T, Qualifiers,
 
   Out << "?$";
   if (T->isObjCId())
-    mangleSourceName("objc_object");
+    mangleSourceName(".objc_object");
   else if (T->isObjCClass())
-    mangleSourceName("objc_class");
+    mangleSourceName(".objc_class");
   else
-    mangleSourceName(T->getInterface()->getName());
+    mangleSourceName((".objc_cls_" + T->getInterface()->getName()).str());
 
   for (const auto &Q : T->quals())
     mangleObjCProtocol(Q);

clang/lib/CodeGen/CGException.cpp

@@ -1829,7 +1829,7 @@ void CodeGenFunction::startOutlinedSEHHelper(CodeGenFunction &ParentCGF,
   SmallString<128> Name;
   {
     llvm::raw_svector_ostream OS(Name);
-    const FunctionDecl *ParentSEHFn = ParentCGF.CurSEHParent;
+    const NamedDecl *ParentSEHFn = ParentCGF.CurSEHParent;
     assert(ParentSEHFn && "No CurSEHParent!");
     MangleContext &Mangler = CGM.getCXXABI().getMangleContext();
     if (IsFilter)
@@ -1972,6 +1972,11 @@ llvm::Value *CodeGenFunction::EmitSEHAbnormalTermination() {
   return Builder.CreateZExt(&*AI, Int32Ty);
 }
 
+void CodeGenFunction::pushSEHCleanup(CleanupKind Kind,
+                                     llvm::Function *FinallyFunc) {
+  EHStack.pushCleanup<PerformSEHFinally>(Kind, FinallyFunc);
+}
+
 void CodeGenFunction::EnterSEHTryStmt(const SEHTryStmt &S) {
   CodeGenFunction HelperCGF(CGM, /*suppressNewContext=*/true);
   if (const SEHFinallyStmt *Finally = S.getFinallyHandler()) {