Revert "[ObjC] Allow declaring __weak pointer fields in C structs in

ARC."

This reverts commit r327206 as there were test failures caused by this
patch.

http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180312/221427.html

llvm-svn: 327294

5 files changed, 14 insertions, 96 deletions

diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp
index 2c34447ec7e..132314ad2dc 100644
--- a/clang/lib/CodeGen/CGBlocks.cpp
+++ b/clang/lib/CodeGen/CGBlocks.cpp
@@ -1525,9 +1525,6 @@ computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
   case QualType::PCK_Struct:
     return std::make_pair(BlockCaptureEntityKind::NonTrivialCStruct,
                           BlockFieldFlags());
-  case QualType::PCK_ARCWeak:
-    // We need to register __weak direct captures with the runtime.
-    return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
   case QualType::PCK_ARCStrong:
     // We need to retain the copied value for __strong direct captures.
     // If it's a block pointer, we have to copy the block and assign that to
@@ -1545,6 +1542,10 @@ computeCopyInfoForBlockCapture(const BlockDecl::Capture &CI, QualType T,
     // Special rules for ARC captures:
     Qualifiers QS = T.getQualifiers();
 
+    // We need to register __weak direct captures with the runtime.
+    if (QS.getObjCLifetime() == Qualifiers::OCL_Weak)
+      return std::make_pair(BlockCaptureEntityKind::ARCWeak, Flags);
+
     // Non-ARC captures of retainable pointers are strong and
     // therefore require a call to _Block_object_assign.
     if (!QS.getObjCLifetime() && !LangOpts.ObjCAutoRefCount)
diff --git a/clang/lib/CodeGen/CGNonTrivialStruct.cpp b/clang/lib/CodeGen/CGNonTrivialStruct.cpp
index 731938af867..3b0b1731987 100644
--- a/clang/lib/CodeGen/CGNonTrivialStruct.cpp
+++ b/clang/lib/CodeGen/CGNonTrivialStruct.cpp
@@ -77,8 +77,6 @@ struct DefaultInitializedTypeVisitor {
     switch (PDIK) {
     case QualType::PDIK_ARCStrong:
       return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
-    case QualType::PDIK_ARCWeak:
-      return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
     case QualType::PDIK_Struct:
       return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
     case QualType::PDIK_Trivial:
@@ -110,8 +108,6 @@ struct CopiedTypeVisitor {
     switch (PCK) {
     case QualType::PCK_ARCStrong:
       return asDerived().visitARCStrong(FT, std::forward<Ts>(Args)...);
-    case QualType::PCK_ARCWeak:
-      return asDerived().visitARCWeak(FT, std::forward<Ts>(Args)...);
     case QualType::PCK_Struct:
       return asDerived().visitStruct(FT, std::forward<Ts>(Args)...);
     case QualType::PCK_Trivial:
@@ -145,6 +141,11 @@ template <class Derived> struct StructVisitor {
 
   template <class... Ts> void visitTrivial(Ts... Args) {}
 
+  template <class... Ts> void visitARCWeak(Ts... Args) {
+    // FIXME: remove this when visitARCWeak is implemented in the subclasses.
+    llvm_unreachable("weak field is not expected");
+  }
+
   template <class... Ts> void visitCXXDestructor(Ts... Args) {
     llvm_unreachable("field of a C++ struct type is not expected");
   }
@@ -244,13 +245,6 @@ template <class Derived> struct GenFuncNameBase {
     appendStr(getVolatileOffsetStr(FT.isVolatileQualified(), FieldOffset));
   }
 
-  void visitARCWeak(QualType FT, const FieldDecl *FD,
-                    CharUnits CurStructOffset) {
-    appendStr("_w");
-    CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
-    appendStr(getVolatileOffsetStr(FT.isVolatileQualified(), FieldOffset));
-  }
-
   void visitStruct(QualType QT, const FieldDecl *FD,
                    CharUnits CurStructOffset) {
     CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
@@ -621,12 +615,6 @@ struct GenDestructor : StructVisitor<GenDestructor>,
         *CGF, getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD), QT);
   }
 
-  void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStackOffset,
-                    std::array<Address, 1> Addrs) {
-    CGF->destroyARCWeak(
-        *CGF, getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD), QT);
-  }
-
   void callSpecialFunction(QualType FT, CharUnits Offset,
                            std::array<Address, 1> Addrs) {
     CGF->callCStructDestructor(
@@ -648,12 +636,6 @@ struct GenDefaultInitialize
         getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD), QT);
   }
 
-  void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStackOffset,
-                    std::array<Address, 1> Addrs) {
-    CGF->EmitNullInitialization(
-        getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD), QT);
-  }
-
   template <class FieldKind, size_t... Is>
   void visitArray(FieldKind FK, QualType QT, const FieldDecl *FD,
                   CharUnits CurStackOffset, std::array<Address, 1> Addrs) {
@@ -696,14 +678,6 @@ struct GenCopyConstructor : GenBinaryFunc<GenCopyConstructor, false> {
     llvm::Value *Val = CGF->EmitARCRetain(QT, SrcVal);
     CGF->EmitStoreOfScalar(Val, CGF->MakeAddrLValue(Addrs[DstIdx], QT), true);
   }
-
-  void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStackOffset,
-                    std::array<Address, 2> Addrs) {
-    Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD);
-    Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStackOffset, FD);
-    CGF->EmitARCCopyWeak(Addrs[DstIdx], Addrs[SrcIdx]);
-  }
-
   void callSpecialFunction(QualType FT, CharUnits Offset,
                            std::array<Address, 2> Addrs) {
     CGF->callCStructCopyConstructor(CGF->MakeAddrLValue(Addrs[DstIdx], FT),
@@ -726,14 +700,6 @@ struct GenMoveConstructor : GenBinaryFunc<GenMoveConstructor, true> {
     CGF->EmitStoreOfScalar(SrcVal, CGF->MakeAddrLValue(Addrs[DstIdx], QT),
                            /* isInitialization */ true);
   }
-
-  void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStackOffset,
-                    std::array<Address, 2> Addrs) {
-    Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD);
-    Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStackOffset, FD);
-    CGF->EmitARCMoveWeak(Addrs[DstIdx], Addrs[SrcIdx]);
-  }
-
   void callSpecialFunction(QualType FT, CharUnits Offset,
                            std::array<Address, 2> Addrs) {
     CGF->callCStructMoveConstructor(CGF->MakeAddrLValue(Addrs[DstIdx], FT),
@@ -754,14 +720,6 @@ struct GenCopyAssignment : GenBinaryFunc<GenCopyAssignment, false> {
     CGF->EmitARCStoreStrong(CGF->MakeAddrLValue(Addrs[DstIdx], QT), SrcVal,
                             false);
   }
-
-  void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStackOffset,
-                    std::array<Address, 2> Addrs) {
-    Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD);
-    Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStackOffset, FD);
-    CGF->emitARCCopyAssignWeak(QT, Addrs[DstIdx], Addrs[SrcIdx]);
-  }
-
   void callSpecialFunction(QualType FT, CharUnits Offset,
                            std::array<Address, 2> Addrs) {
     CGF->callCStructCopyAssignmentOperator(
@@ -789,13 +747,6 @@ struct GenMoveAssignment : GenBinaryFunc<GenMoveAssignment, true> {
     CGF->EmitARCRelease(DstVal, ARCImpreciseLifetime);
   }
 
-  void visitARCWeak(QualType QT, const FieldDecl *FD, CharUnits CurStackOffset,
-                    std::array<Address, 2> Addrs) {
-    Addrs[DstIdx] = getAddrWithOffset(Addrs[DstIdx], CurStackOffset, FD);
-    Addrs[SrcIdx] = getAddrWithOffset(Addrs[SrcIdx], CurStackOffset, FD);
-    CGF->emitARCMoveAssignWeak(QT, Addrs[DstIdx], Addrs[SrcIdx]);
-  }
-
   void callSpecialFunction(QualType FT, CharUnits Offset,
                            std::array<Address, 2> Addrs) {
     CGF->callCStructMoveAssignmentOperator(
diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 6ece1d3bd7e..e812ef399e7 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -2307,21 +2307,6 @@ void CodeGenFunction::EmitARCCopyWeak(Address dst, Address src) {
                        "objc_copyWeak");
 }
 
-void CodeGenFunction::emitARCCopyAssignWeak(QualType Ty, Address DstAddr,
-                                            Address SrcAddr) {
-  llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
-  Object = EmitObjCConsumeObject(Ty, Object);
-  EmitARCStoreWeak(DstAddr, Object, false);
-}
-
-void CodeGenFunction::emitARCMoveAssignWeak(QualType Ty, Address DstAddr,
-                                            Address SrcAddr) {
-  llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
-  Object = EmitObjCConsumeObject(Ty, Object);
-  EmitARCStoreWeak(DstAddr, Object, false);
-  EmitARCDestroyWeak(SrcAddr);
-}
-
 /// Produce the code to do a objc_autoreleasepool_push.
 ///   call i8* \@objc_autoreleasePoolPush(void)
 llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 7bb9466ca2f..95d8229c7de 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -3548,8 +3548,6 @@ public:
   llvm::Value *EmitARCLoadWeak(Address addr);
   llvm::Value *EmitARCLoadWeakRetained(Address addr);
   llvm::Value *EmitARCStoreWeak(Address addr, llvm::Value *value, bool ignored);
-  void emitARCCopyAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
-  void emitARCMoveAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
   void EmitARCCopyWeak(Address dst, Address src);
   void EmitARCMoveWeak(Address dst, Address src);
   llvm::Value *EmitARCRetainAutorelease(QualType type, llvm::Value *value);
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 939679e7943..aadbd3016bf 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -140,11 +140,8 @@ bool SwiftABIInfo::isLegalVectorTypeForSwift(CharUnits vectorSize,
 static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT,
                                               CGCXXABI &CXXABI) {
   const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
-  if (!RD) {
-    if (!RT->getDecl()->canPassInRegisters())
-      return CGCXXABI::RAA_Indirect;
+  if (!RD)
     return CGCXXABI::RAA_Default;
-  }
   return CXXABI.getRecordArgABI(RD);
 }
 
@@ -156,20 +153,6 @@ static CGCXXABI::RecordArgABI getRecordArgABI(QualType T,
   return getRecordArgABI(RT, CXXABI);
 }
 
-static bool classifyReturnType(const CGCXXABI &CXXABI, CGFunctionInfo &FI,
-                               const ABIInfo &Info) {
-  QualType Ty = FI.getReturnType();
-
-  if (const auto *RT = Ty->getAs<RecordType>())
-    if (!isa<CXXRecordDecl>(RT->getDecl()) &&
-        !RT->getDecl()->canPassInRegisters()) {
-      FI.getReturnInfo() = Info.getNaturalAlignIndirect(Ty);
-      return true;
-    }
-
-  return CXXABI.classifyReturnType(FI);
-}
-
 /// Pass transparent unions as if they were the type of the first element. Sema
 /// should ensure that all elements of the union have the same "machine type".
 static QualType useFirstFieldIfTransparentUnion(QualType Ty) {
@@ -1766,7 +1749,7 @@ void X86_32ABIInfo::computeInfo(CGFunctionInfo &FI) const {
   } else
     State.FreeRegs = DefaultNumRegisterParameters;
 
-  if (!::classifyReturnType(getCXXABI(), FI, *this)) {
+  if (!getCXXABI().classifyReturnType(FI)) {
     FI.getReturnInfo() = classifyReturnType(FI.getReturnType(), State);
   } else if (FI.getReturnInfo().isIndirect()) {
     // The C++ ABI is not aware of register usage, so we have to check if the
@@ -3562,7 +3545,7 @@ void X86_64ABIInfo::computeInfo(CGFunctionInfo &FI) const {
   unsigned FreeSSERegs = IsRegCall ? 16 : 8;
   unsigned NeededInt, NeededSSE;
 
-  if (!::classifyReturnType(getCXXABI(), FI, *this)) {
+  if (!getCXXABI().classifyReturnType(FI)) {
     if (IsRegCall && FI.getReturnType()->getTypePtr()->isRecordType() &&
         !FI.getReturnType()->getTypePtr()->isUnionType()) {
       FI.getReturnInfo() =
@@ -4912,7 +4895,7 @@ private:
   bool isIllegalVectorType(QualType Ty) const;
 
   void computeInfo(CGFunctionInfo &FI) const override {
-    if (!::classifyReturnType(getCXXABI(), FI, *this))
+    if (!getCXXABI().classifyReturnType(FI))
       FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
 
     for (auto &it : FI.arguments())
@@ -5643,7 +5626,7 @@ void WindowsARMTargetCodeGenInfo::setTargetAttributes(
 }
 
 void ARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
-  if (!::classifyReturnType(getCXXABI(), FI, *this))
+  if (!getCXXABI().classifyReturnType(FI))
     FI.getReturnInfo() =
         classifyReturnType(FI.getReturnType(), FI.isVariadic());