When we can't prove that the target of an aggregate copy is
a complete object, the memcpy needs to use the data size of
the structure instead of its sizeof() value. Fixes PR12204.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153613 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 9fe31cb..5e36d9e 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -734,7 +734,8 @@
AggValueSlot::forAddr(blockField, Align, Qualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject);
EmitAggExpr(copyExpr, Slot);
} else {
EmitSynthesizedCXXCopyCtor(blockField, src, copyExpr);
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 4455f1a..f5d7944 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -1875,7 +1875,8 @@
if (Align > AI->getAlignment())
AI->setAlignment(Align);
Args.push_back(AI);
- EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified());
+ EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified(),
+ /*destIsCompleteObject*/ true);
// Validate argument match.
checkArgMatches(AI, IRArgNo, IRFuncTy);
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index b452c1b..254ef80 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -401,7 +401,8 @@
AggValueSlot::forAddr(V, Alignment, Qualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsNotCompleteObject);
CGF.EmitAggExpr(BaseInit->getInit(), AggSlot);
@@ -449,7 +450,8 @@
AggValueSlot::forLValue(LV,
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject);
CGF.EmitAggExpr(Init, Slot);
}
@@ -589,7 +591,8 @@
// Copy the aggregate.
CGF.EmitAggregateCopy(LHS.getAddress(), Src.getAddress(), FieldType,
- LHS.isVolatileQualified());
+ LHS.isVolatileQualified(),
+ /*destIsCompleteObject*/ true);
return;
}
}
@@ -1371,7 +1374,10 @@
AggValueSlot::forAddr(ThisPtr, Alignment, Qualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ CurGD.getCtorType() == Ctor_Complete
+ ? AggValueSlot::IsCompleteObject
+ : AggValueSlot::IsNotCompleteObject);
EmitAggExpr(Ctor->init_begin()[0]->getInit(), AggSlot);
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 970f0b2..fa95377 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -1092,9 +1092,10 @@
} else {
// TODO: how can we delay here if D is captured by its initializer?
EmitAggExpr(init, AggValueSlot::forLValue(lvalue,
- AggValueSlot::IsDestructed,
+ AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
MaybeEmitStdInitializerListCleanup(lvalue.getAddress(), init);
}
}
diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index dc52b11..dfbd411 100644
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/lib/CodeGen/CGDeclCXX.cpp
@@ -46,9 +46,11 @@
} else if (type->isAnyComplexType()) {
CGF.EmitComplexExprIntoAddr(Init, DeclPtr, lv.isVolatile());
} else {
- CGF.EmitAggExpr(Init, AggValueSlot::forLValue(lv,AggValueSlot::IsDestructed,
- AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ CGF.EmitAggExpr(Init, AggValueSlot::forLValue(lv,
+ AggValueSlot::IsDestructed,
+ AggValueSlot::DoesNotNeedGCBarriers,
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
}
}
diff --git a/lib/CodeGen/CGException.cpp b/lib/CodeGen/CGException.cpp
index 95e0030..dcb9212 100644
--- a/lib/CodeGen/CGException.cpp
+++ b/lib/CodeGen/CGException.cpp
@@ -373,8 +373,7 @@
// evaluated but before the exception is caught. But the best way
// to handle that is to teach EmitAggExpr to do the final copy
// differently if it can't be elided.
- CGF.EmitAnyExprToMem(e, typedAddr, e->getType().getQualifiers(),
- /*IsInit*/ true);
+ CGF.EmitAnyExprToMem(e, typedAddr, e->getType().getQualifiers());
// Deactivate the cleanup block.
CGF.DeactivateCleanupBlock(cleanup, cast<llvm::Instruction>(typedAddr));
@@ -1048,7 +1047,8 @@
if (!copyExpr) {
llvm::Value *rawAdjustedExn = CallBeginCatch(CGF, Exn, true);
llvm::Value *adjustedExn = CGF.Builder.CreateBitCast(rawAdjustedExn, PtrTy);
- CGF.EmitAggregateCopy(ParamAddr, adjustedExn, CatchType);
+ CGF.EmitAggregateCopy(ParamAddr, adjustedExn, CatchType,
+ /*volatile*/ false, 0, /*destIsCompleteObject*/ true);
return;
}
@@ -1076,7 +1076,8 @@
AggValueSlot::forAddr(ParamAddr, Alignment, Qualifiers(),
AggValueSlot::IsNotDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
// Leave the terminate scope.
CGF.EHStack.popTerminate();
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 5119148..05348d1 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -133,17 +133,17 @@
/// location.
void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
llvm::Value *Location,
- Qualifiers Quals,
- bool IsInit) {
+ Qualifiers Quals) {
// FIXME: This function should take an LValue as an argument.
if (E->getType()->isAnyComplexType()) {
EmitComplexExprIntoAddr(E, Location, Quals.hasVolatile());
} else if (hasAggregateLLVMType(E->getType())) {
CharUnits Alignment = getContext().getTypeAlignInChars(E->getType());
EmitAggExpr(E, AggValueSlot::forAddr(Location, Alignment, Quals,
- AggValueSlot::IsDestructed_t(IsInit),
+ AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsAliased_t(!IsInit)));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
} else {
RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
LValue LV = MakeAddrLValue(Location, E->getType());
@@ -366,7 +366,8 @@
AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Alignment,
Qualifiers(), isDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject);
}
if (InitializedDecl) {
@@ -2151,8 +2152,7 @@
const Expr *InitExpr = E->getInitializer();
LValue Result = MakeAddrLValue(DeclPtr, E->getType());
- EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
- /*Init*/ true);
+ EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers());
return Result;
}
@@ -2283,7 +2283,7 @@
// as a value, copy it into a temporary, and return an lvalue referring to
// that temporary.
llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
- EmitAnyExprToMem(E, V, E->getType().getQualifiers(), false);
+ EmitAnyExprToMem(E, V, E->getType().getQualifiers());
return MakeAddrLValue(V, E->getType());
}
@@ -2754,8 +2754,7 @@
static llvm::Value *
EmitValToTemp(CodeGenFunction &CGF, Expr *E) {
llvm::Value *DeclPtr = CGF.CreateMemTemp(E->getType(), ".atomictmp");
- CGF.EmitAnyExprToMem(E, DeclPtr, E->getType().getQualifiers(),
- /*Init*/ true);
+ CGF.EmitAnyExprToMem(E, DeclPtr, E->getType().getQualifiers());
return DeclPtr;
}
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index b6efc1c..8f0d1db 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -179,7 +179,8 @@
void VisitVAArgExpr(VAArgExpr *E);
- void EmitInitializationToLValue(Expr *E, LValue Address);
+ void EmitInitializationToLValue(Expr *E, LValue Address,
+ AggValueSlot::IsCompleteObject_t isCompleteObject);
void EmitNullInitializationToLValue(LValue Address);
// case Expr::ChooseExprClass:
void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); }
@@ -279,7 +280,7 @@
// is volatile, unless copy has volatile for both source and destination..
CGF.EmitAggregateCopy(Dest.getAddr(), Src.getAggregateAddr(), E->getType(),
Dest.isVolatile()|Src.isVolatileQualified(),
- Alignment);
+ Alignment, Dest.isCompleteObject());
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
@@ -441,7 +442,8 @@
EmitStdInitializerList(element, initList);
} else {
LValue elementLV = CGF.MakeAddrLValue(element, elementType);
- EmitInitializationToLValue(E->getInit(i), elementLV);
+ EmitInitializationToLValue(E->getInit(i), elementLV,
+ AggValueSlot::IsCompleteObject);
}
}
@@ -488,7 +490,8 @@
// Emit the actual filler expression.
LValue elementLV = CGF.MakeAddrLValue(currentElement, elementType);
if (filler)
- EmitInitializationToLValue(filler, elementLV);
+ EmitInitializationToLValue(filler, elementLV,
+ AggValueSlot::IsCompleteObject);
else
EmitNullInitializationToLValue(elementLV);
@@ -567,7 +570,8 @@
llvm::Value *CastPtr = Builder.CreateBitCast(Dest.getAddr(),
CGF.ConvertType(PtrTy));
EmitInitializationToLValue(E->getSubExpr(),
- CGF.MakeAddrLValue(CastPtr, Ty));
+ CGF.MakeAddrLValue(CastPtr, Ty),
+ Dest.isCompleteObject());
break;
}
@@ -675,6 +679,29 @@
EmitFinalDestCopy(E, LV);
}
+/// Quickly check whether the object looks like it might be a complete
+/// object.
+static AggValueSlot::IsCompleteObject_t isCompleteObject(const Expr *E) {
+ E = E->IgnoreParens();
+
+ QualType objectType;
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
+ objectType = DRE->getDecl()->getType();
+ } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
+ objectType = ME->getMemberDecl()->getType();
+ } else {
+ // Be conservative.
+ return AggValueSlot::MayNotBeCompleteObject;
+ }
+
+ // The expression refers directly to some sort of object.
+ // If that object has reference type, be conservative.
+ if (objectType->isReferenceType())
+ return AggValueSlot::MayNotBeCompleteObject;
+
+ return AggValueSlot::IsCompleteObject;
+}
+
void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
// For an assignment to work, the value on the right has
// to be compatible with the value on the left.
@@ -682,7 +709,8 @@
E->getRHS()->getType())
&& "Invalid assignment");
- if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->getLHS()))
+ if (const DeclRefExpr *DRE
+ = dyn_cast<DeclRefExpr>(E->getLHS()->IgnoreParens()))
if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
if (VD->hasAttr<BlocksAttr>() &&
E->getRHS()->HasSideEffects(CGF.getContext())) {
@@ -692,18 +720,20 @@
LValue LHS = CGF.EmitLValue(E->getLHS());
Dest = AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed,
needsGC(E->getLHS()->getType()),
- AggValueSlot::IsAliased);
+ AggValueSlot::IsAliased,
+ AggValueSlot::IsCompleteObject);
EmitFinalDestCopy(E, RHS, true);
return;
}
-
+
LValue LHS = CGF.EmitLValue(E->getLHS());
// Codegen the RHS so that it stores directly into the LHS.
AggValueSlot LHSSlot =
AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed,
needsGC(E->getLHS()->getType()),
- AggValueSlot::IsAliased);
+ AggValueSlot::IsAliased,
+ isCompleteObject(E->getLHS()));
CGF.EmitAggExpr(E->getRHS(), LHSSlot, false);
EmitFinalDestCopy(E, LHS, true);
}
@@ -836,7 +866,8 @@
void
-AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV) {
+AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV,
+ AggValueSlot::IsCompleteObject_t isCompleteObject) {
QualType type = LV.getType();
// FIXME: Ignore result?
// FIXME: Are initializers affected by volatile?
@@ -854,6 +885,7 @@
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased,
+ isCompleteObject,
Dest.isZeroed()));
} else if (LV.isSimple()) {
CGF.EmitScalarInit(E, /*D=*/0, LV, /*Captured=*/false);
@@ -969,7 +1001,8 @@
LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestPtr, Field, 0);
if (NumInitElements) {
// Store the initializer into the field
- EmitInitializationToLValue(E->getInit(0), FieldLoc);
+ EmitInitializationToLValue(E->getInit(0), FieldLoc,
+ AggValueSlot::IsCompleteObject);
} else {
// Default-initialize to null.
EmitNullInitializationToLValue(FieldLoc);
@@ -1011,7 +1044,8 @@
if (curInitIndex < NumInitElements) {
// Store the initializer into the field.
- EmitInitializationToLValue(E->getInit(curInitIndex++), LV);
+ EmitInitializationToLValue(E->getInit(curInitIndex++), LV,
+ AggValueSlot::IsCompleteObject);
} else {
// We're out of initalizers; default-initialize to null
EmitNullInitializationToLValue(LV);
@@ -1186,30 +1220,94 @@
LValue LV = MakeAddrLValue(Temp, E->getType());
EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
return LV;
}
-void CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr,
- llvm::Value *SrcPtr, QualType Ty,
- bool isVolatile, unsigned Alignment) {
- assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex");
+void CodeGenFunction::EmitAggregateCopy(llvm::Value *dest, llvm::Value *src,
+ QualType type,
+ bool isVolatile, unsigned alignment,
+ bool destIsCompleteObject) {
+ assert(!type->isAnyComplexType() && "Shouldn't happen for complex");
+ // Get size and alignment info for this type. Note that the type
+ // might include an alignment attribute, so we can't just rely on
+ // the layout.
+ // FIXME: Do we need to handle VLAs here?
+ std::pair<CharUnits, CharUnits> typeInfo =
+ getContext().getTypeInfoInChars(type);
+
+ // If we weren't given an alignment, use the natural alignment.
+ if (!alignment) alignment = typeInfo.second.getQuantity();
+
+ CharUnits sizeToCopy = typeInfo.first;
+
+ // There's some special logic that applies to C++ classes:
if (getContext().getLangOpts().CPlusPlus) {
- if (const RecordType *RT = Ty->getAs<RecordType>()) {
- CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
- assert((Record->hasTrivialCopyConstructor() ||
- Record->hasTrivialCopyAssignment() ||
- Record->hasTrivialMoveConstructor() ||
- Record->hasTrivialMoveAssignment()) &&
+ if (const RecordType *RT = type->getAs<RecordType>()) {
+ // First, we want to assert that we're not doing this to
+ // something with a non-trivial operator/constructor.
+ CXXRecordDecl *record = cast<CXXRecordDecl>(RT->getDecl());
+ assert((record->hasTrivialCopyConstructor() ||
+ record->hasTrivialCopyAssignment() ||
+ record->hasTrivialMoveConstructor() ||
+ record->hasTrivialMoveAssignment()) &&
"Trying to aggregate-copy a type without a trivial copy "
"constructor or assignment operator");
- // Ignore empty classes in C++.
- if (Record->isEmpty())
+
+ // Second, we want to ignore empty classes.
+ if (record->isEmpty())
return;
+
+ // Third, if it's possible that the destination might not be a
+ // complete object, then we need to make sure we only copy the
+ // data size, not the full sizeof, so that we don't overwrite
+ // subclass fields in the tailing padding. It's generally going
+ // to be more efficient to copy the sizeof, since we can use
+ // larger stores.
+ //
+ // Unions and final classes can never be base classes.
+ if (!destIsCompleteObject && !record->isUnion() &&
+ !record->hasAttr<FinalAttr>()) {
+ const ASTRecordLayout &layout
+ = getContext().getASTRecordLayout(record);
+ sizeToCopy = layout.getDataSize();
+ }
}
}
+ llvm::PointerType *DPT = cast<llvm::PointerType>(dest->getType());
+ llvm::Type *DBP =
+ llvm::Type::getInt8PtrTy(getLLVMContext(), DPT->getAddressSpace());
+ dest = Builder.CreateBitCast(dest, DBP);
+
+ llvm::PointerType *SPT = cast<llvm::PointerType>(src->getType());
+ llvm::Type *SBP =
+ llvm::Type::getInt8PtrTy(getLLVMContext(), SPT->getAddressSpace());
+ src = Builder.CreateBitCast(src, SBP);
+
+ llvm::Value *sizeVal =
+ llvm::ConstantInt::get(CGM.SizeTy, sizeToCopy.getQuantity());
+
+ // Don't do any of the memmove_collectable tests if GC isn't set.
+ if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
+ // fall through
+ } else if (const RecordType *RT = type->getAs<RecordType>()) {
+ if (RT->getDecl()->hasObjectMember()) {
+ CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, dest, src, sizeVal);
+ return;
+ }
+ } else if (type->isArrayType()) {
+ QualType baseType = getContext().getBaseElementType(type);
+ if (const RecordType *RT = baseType->getAs<RecordType>()) {
+ if (RT->getDecl()->hasObjectMember()) {
+ CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, dest, src,sizeVal);
+ return;
+ }
+ }
+ }
+
// Aggregate assignment turns into llvm.memcpy. This is almost valid per
// C99 6.5.16.1p3, which states "If the value being stored in an object is
// read from another object that overlaps in anyway the storage of the first
@@ -1220,71 +1318,8 @@
// equal, but other compilers do this optimization, and almost every memcpy
// implementation handles this case safely. If there is a libc that does not
// safely handle this, we can add a target hook.
-
- // Get size and alignment info for this aggregate.
- std::pair<CharUnits, CharUnits> TypeInfo =
- getContext().getTypeInfoInChars(Ty);
-
- if (!Alignment)
- Alignment = TypeInfo.second.getQuantity();
-
- // FIXME: Handle variable sized types.
-
- // FIXME: If we have a volatile struct, the optimizer can remove what might
- // appear to be `extra' memory ops:
- //
- // volatile struct { int i; } a, b;
- //
- // int main() {
- // a = b;
- // a = b;
- // }
- //
- // we need to use a different call here. We use isVolatile to indicate when
- // either the source or the destination is volatile.
-
- llvm::PointerType *DPT = cast<llvm::PointerType>(DestPtr->getType());
- llvm::Type *DBP =
- llvm::Type::getInt8PtrTy(getLLVMContext(), DPT->getAddressSpace());
- DestPtr = Builder.CreateBitCast(DestPtr, DBP);
-
- llvm::PointerType *SPT = cast<llvm::PointerType>(SrcPtr->getType());
- llvm::Type *SBP =
- llvm::Type::getInt8PtrTy(getLLVMContext(), SPT->getAddressSpace());
- SrcPtr = Builder.CreateBitCast(SrcPtr, SBP);
-
- // Don't do any of the memmove_collectable tests if GC isn't set.
- if (CGM.getLangOpts().getGC() == LangOptions::NonGC) {
- // fall through
- } else if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
- RecordDecl *Record = RecordTy->getDecl();
- if (Record->hasObjectMember()) {
- CharUnits size = TypeInfo.first;
- llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
- llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity());
- CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
- SizeVal);
- return;
- }
- } else if (Ty->isArrayType()) {
- QualType BaseType = getContext().getBaseElementType(Ty);
- if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
- if (RecordTy->getDecl()->hasObjectMember()) {
- CharUnits size = TypeInfo.first;
- llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
- llvm::Value *SizeVal =
- llvm::ConstantInt::get(SizeTy, size.getQuantity());
- CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr,
- SizeVal);
- return;
- }
- }
- }
- Builder.CreateMemCpy(DestPtr, SrcPtr,
- llvm::ConstantInt::get(IntPtrTy,
- TypeInfo.first.getQuantity()),
- Alignment, isVolatile);
+ Builder.CreateMemCpy(dest, src, sizeVal, alignment, isVolatile);
}
void CodeGenFunction::MaybeEmitStdInitializerListCleanup(llvm::Value *loc,
diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index d3ba770..cefe7b6 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -781,7 +781,8 @@
= AggValueSlot::forAddr(NewPtr, Alignment, AllocType.getQualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject);
CGF.EmitAggExpr(Init, Slot);
CGF.MaybeEmitStdInitializerListCleanup(NewPtr, Init);
diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index b18060c..3f67562 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -885,7 +885,8 @@
// The return value slot is guaranteed to not be aliased, but
// that's not necessarily the same as "on the stack", so
// we still potentially need objc_memmove_collectable.
- EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType);
+ EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType,
+ /*volatile*/ false, 0, /*destIsCompleteObject*/ true);
} else {
llvm::Value *value;
if (propType->isReferenceType()) {
@@ -1309,7 +1310,8 @@
EmitAggExpr(IvarInit->getInit(),
AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
}
// constructor returns 'self'.
CodeGenTypes &Types = CGM.getTypes();
@@ -2931,7 +2933,8 @@
AggValueSlot::forAddr(DV.getScalarVal(), Alignment, Qualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
FinishFunction();
HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 670167b..489386d 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -722,7 +722,8 @@
if (RV.isScalar()) {
Builder.CreateStore(RV.getScalarVal(), ReturnValue);
} else if (RV.isAggregate()) {
- EmitAggregateCopy(ReturnValue, RV.getAggregateAddr(), Ty);
+ EmitAggregateCopy(ReturnValue, RV.getAggregateAddr(), Ty,
+ /*volatile*/ false, 0, /*destIsCompleteObject*/ true);
} else {
StoreComplexToAddr(RV.getComplexVal(), ReturnValue, false);
}
@@ -769,7 +770,8 @@
EmitAggExpr(RV, AggValueSlot::forAddr(ReturnValue, Alignment, Qualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased));
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject));
}
EmitBranchThroughCleanup(ReturnBlock);
diff --git a/lib/CodeGen/CGValue.h b/lib/CodeGen/CGValue.h
index ac704e7..731b6ab 100644
--- a/lib/CodeGen/CGValue.h
+++ b/lib/CodeGen/CGValue.h
@@ -318,22 +318,22 @@
// Qualifiers
Qualifiers Quals;
- unsigned short Alignment;
+ unsigned Alignment : 16;
/// DestructedFlag - This is set to true if some external code is
/// responsible for setting up a destructor for the slot. Otherwise
/// the code which constructs it should push the appropriate cleanup.
- bool DestructedFlag : 1;
+ unsigned DestructedFlag : 1;
/// ObjCGCFlag - This is set to true if writing to the memory in the
/// slot might require calling an appropriate Objective-C GC
/// barrier. The exact interaction here is unnecessarily mysterious.
- bool ObjCGCFlag : 1;
+ unsigned ObjCGCFlag : 1;
/// ZeroedFlag - This is set to true if the memory in the slot is
/// known to be zero before the assignment into it. This means that
/// zero fields don't need to be set.
- bool ZeroedFlag : 1;
+ unsigned ZeroedFlag : 1;
/// AliasedFlag - This is set to true if the slot might be aliased
/// and it's not undefined behavior to access it through such an
@@ -347,19 +347,32 @@
/// over. Since it's invalid in general to memcpy a non-POD C++
/// object, it's important that this flag never be set when
/// evaluating an expression which constructs such an object.
- bool AliasedFlag : 1;
+ unsigned AliasedFlag : 1;
+
+ /// CompleteObjectFlag - This is set to true if the slot is known to
+ /// be a complete object. When emitting an aggregate copy of a
+ /// non-POD C++ struct to a location which may not be a complete
+ /// object, only the data size of the type can be copied in order to
+ /// prevent unrelated fields from being overwritten.
+ unsigned CompleteObjectFlag : 1;
public:
enum IsAliased_t { IsNotAliased, IsAliased };
enum IsDestructed_t { IsNotDestructed, IsDestructed };
enum IsZeroed_t { IsNotZeroed, IsZeroed };
+ enum IsCompleteObject_t {
+ IsNotCompleteObject,
+ MayNotBeCompleteObject = IsNotCompleteObject,
+ IsCompleteObject
+ };
enum NeedsGCBarriers_t { DoesNotNeedGCBarriers, NeedsGCBarriers };
/// ignored - Returns an aggregate value slot indicating that the
/// aggregate value is being ignored.
static AggValueSlot ignored() {
return forAddr(0, CharUnits(), Qualifiers(), IsNotDestructed,
- DoesNotNeedGCBarriers, IsNotAliased);
+ DoesNotNeedGCBarriers, IsNotAliased,
+ IsCompleteObject);
}
/// forAddr - Make a slot for an aggregate value.
@@ -377,6 +390,7 @@
IsDestructed_t isDestructed,
NeedsGCBarriers_t needsGC,
IsAliased_t isAliased,
+ IsCompleteObject_t isCompleteObject,
IsZeroed_t isZeroed = IsNotZeroed) {
AggValueSlot AV;
AV.Addr = addr;
@@ -386,15 +400,18 @@
AV.ObjCGCFlag = needsGC;
AV.ZeroedFlag = isZeroed;
AV.AliasedFlag = isAliased;
+ AV.CompleteObjectFlag = isCompleteObject;
return AV;
}
static AggValueSlot forLValue(LValue LV, IsDestructed_t isDestructed,
NeedsGCBarriers_t needsGC,
IsAliased_t isAliased,
+ IsCompleteObject_t isCompleteObject,
IsZeroed_t isZeroed = IsNotZeroed) {
return forAddr(LV.getAddress(), LV.getAlignment(),
- LV.getQuals(), isDestructed, needsGC, isAliased, isZeroed);
+ LV.getQuals(), isDestructed, needsGC, isAliased,
+ isCompleteObject, isZeroed);
}
IsDestructed_t isExternallyDestructed() const {
@@ -434,6 +451,10 @@
return IsAliased_t(AliasedFlag);
}
+ IsCompleteObject_t isCompleteObject() const {
+ return IsCompleteObject_t(CompleteObjectFlag);
+ }
+
// FIXME: Alignment?
RValue asRValue() const {
return RValue::getAggregate(getAddr(), isVolatile());
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 85cbd14..9acfc5e 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1596,7 +1596,9 @@
T.getQualifiers(),
AggValueSlot::IsNotDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
- AggValueSlot::IsNotAliased);
+ AggValueSlot::IsNotAliased,
+ AggValueSlot::IsCompleteObject,
+ AggValueSlot::IsNotZeroed);
}
/// Emit a cast to void* in the appropriate address space.
@@ -1628,9 +1630,10 @@
RValue EmitAnyExprToTemp(const Expr *E);
/// EmitAnyExprToMem - Emits the code necessary to evaluate an
- /// arbitrary expression into the given memory location.
+ /// arbitrary expression as an initialization of the given memory
+ /// location.
void EmitAnyExprToMem(const Expr *E, llvm::Value *Location,
- Qualifiers Quals, bool IsInitializer);
+ Qualifiers Quals);
/// EmitExprAsInit - Emits the code necessary to initialize a
/// location in memory with the given initializer.
@@ -1641,9 +1644,12 @@
///
/// \param isVolatile - True iff either the source or the destination is
/// volatile.
+ /// \param destIsCompleteObject - True if the destination is known to be
+ /// a complete object.
void EmitAggregateCopy(llvm::Value *DestPtr, llvm::Value *SrcPtr,
QualType EltTy, bool isVolatile=false,
- unsigned Alignment = 0);
+ unsigned alignment = 0,
+ bool destIsCompleteObject = false);
/// StartBlock - Start new block named N. If insert block is a dummy block
/// then reuse it.
diff --git a/test/CodeGenCXX/assign-operator.cpp b/test/CodeGenCXX/assign-operator.cpp
index e19df27..00058a2 100644
--- a/test/CodeGenCXX/assign-operator.cpp
+++ b/test/CodeGenCXX/assign-operator.cpp
@@ -28,3 +28,24 @@
A<int> a;
}
+
+// PR12204
+namespace test2 {
+ struct A {
+ A() {} // make this non-POD to enable tail layout
+ void *ptr;
+ char c;
+ };
+
+ void test(A &out) {
+ out = A();
+ }
+}
+// CHECK: define void @_ZN5test24testERNS_1AE(
+// CHECK: [[OUT:%.*]] = alloca [[A:%.*]]*, align 8
+// CHECK-NEXT: [[TMP:%.*]] = alloca [[A]], align 8
+// CHECK: [[REF:%.*]] = load [[A]]** [[OUT]], align 8
+// CHECK-NEXT: call void @_ZN5test21AC1Ev([[A]]* [[TMP]])
+// CHECK-NEXT: [[T0:%.*]] = bitcast [[A]]* [[REF]] to i8*
+// CHECK-NEXT: [[T1:%.*]] = bitcast [[A]]* [[TMP]] to i8*
+// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[T0]], i8* [[T1]], i64 9, i32 8, i1 false)
