[ObjC] Allow declaring __weak pointer fields in C structs in ARC.
This patch uses the infrastructure added in r326307 for enabling
non-trivial fields to be declared in C structs to allow __weak fields in
C structs in ARC.
This recommits r327206, which was reverted because it caused
module-enabled builders to fail. I discovered that the
CXXRecordDecl::CanPassInRegisters flag wasn't being set correctly in
some cases after I moved it to RecordDecl.
Thanks to Eric Liu for helping me investigate the bug.
rdar://problem/33599681
https://reviews.llvm.org/D44095
llvm-svn: 327870
diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp
index 663f1d0..1a69049 100644
--- a/clang/lib/CodeGen/CGBlocks.cpp
+++ b/clang/lib/CodeGen/CGBlocks.cpp
@@ -1525,6 +1525,9 @@
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
@@ -1542,10 +1545,6 @@
// 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 3b0b173..731938a 100644
--- a/clang/lib/CodeGen/CGNonTrivialStruct.cpp
+++ b/clang/lib/CodeGen/CGNonTrivialStruct.cpp
@@ -77,6 +77,8 @@
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:
@@ -108,6 +110,8 @@
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:
@@ -141,11 +145,6 @@
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");
}
@@ -245,6 +244,13 @@
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);
@@ -615,6 +621,12 @@
*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(
@@ -636,6 +648,12 @@
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) {
@@ -678,6 +696,14 @@
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),
@@ -700,6 +726,14 @@
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),
@@ -720,6 +754,14 @@
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(
@@ -747,6 +789,13 @@
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 e812ef3..6ece1d3 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -2307,6 +2307,21 @@
"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 fa65b1d..5852788 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -3551,6 +3551,8 @@
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 aadbd30..939679e 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -140,8 +140,11 @@
static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT,
CGCXXABI &CXXABI) {
const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
- if (!RD)
+ if (!RD) {
+ if (!RT->getDecl()->canPassInRegisters())
+ return CGCXXABI::RAA_Indirect;
return CGCXXABI::RAA_Default;
+ }
return CXXABI.getRecordArgABI(RD);
}
@@ -153,6 +156,20 @@
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) {
@@ -1749,7 +1766,7 @@
} else
State.FreeRegs = DefaultNumRegisterParameters;
- if (!getCXXABI().classifyReturnType(FI)) {
+ if (!::classifyReturnType(getCXXABI(), FI, *this)) {
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
@@ -3545,7 +3562,7 @@
unsigned FreeSSERegs = IsRegCall ? 16 : 8;
unsigned NeededInt, NeededSSE;
- if (!getCXXABI().classifyReturnType(FI)) {
+ if (!::classifyReturnType(getCXXABI(), FI, *this)) {
if (IsRegCall && FI.getReturnType()->getTypePtr()->isRecordType() &&
!FI.getReturnType()->getTypePtr()->isUnionType()) {
FI.getReturnInfo() =
@@ -4895,7 +4912,7 @@
bool isIllegalVectorType(QualType Ty) const;
void computeInfo(CGFunctionInfo &FI) const override {
- if (!getCXXABI().classifyReturnType(FI))
+ if (!::classifyReturnType(getCXXABI(), FI, *this))
FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
for (auto &it : FI.arguments())
@@ -5626,7 +5643,7 @@
}
void ARMABIInfo::computeInfo(CGFunctionInfo &FI) const {
- if (!getCXXABI().classifyReturnType(FI))
+ if (!::classifyReturnType(getCXXABI(), FI, *this))
FI.getReturnInfo() =
classifyReturnType(FI.getReturnType(), FI.isVariadic());