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-rw-r--r--clang/lib/CodeGen/CGClass.cpp119
1 files changed, 76 insertions, 43 deletions
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index ea943c2986d..cd397498890 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -1806,12 +1806,14 @@ void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
bool ForVirtualBase,
bool Delegating, llvm::Value *This,
const CXXConstructExpr *E) {
+ const CXXRecordDecl *ClassDecl = D->getParent();
+
// C++11 [class.mfct.non-static]p2:
// If a non-static member function of a class X is called for an object that
// is not of type X, or of a type derived from X, the behavior is undefined.
// FIXME: Provide a source location here.
EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall, SourceLocation(), This,
- getContext().getRecordType(D->getParent()));
+ getContext().getRecordType(ClassDecl));
if (D->isTrivial() && D->isDefaultConstructor()) {
assert(E->getNumArgs() == 0 && "trivial default ctor with args");
@@ -1827,7 +1829,7 @@ void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
const Expr *Arg = E->getArg(0);
QualType SrcTy = Arg->getType();
llvm::Value *Src = EmitLValue(Arg).getAddress();
- QualType DestTy = getContext().getTypeDeclType(D->getParent());
+ QualType DestTy = getContext().getTypeDeclType(ClassDecl);
EmitAggregateCopyCtor(This, Src, DestTy, SrcTy);
return;
}
@@ -1850,6 +1852,41 @@ void CodeGenFunction::EmitCXXConstructorCall(const CXXConstructorDecl *D,
const CGFunctionInfo &Info =
CGM.getTypes().arrangeCXXConstructorCall(Args, D, Type, ExtraArgs);
EmitCall(Info, Callee, ReturnValueSlot(), Args, D);
+
+ // Generate vtable assumptions if we're constructing a complete object
+ // with a vtable. We don't do this for base subobjects for two reasons:
+ // first, it's incorrect for classes with virtual bases, and second, we're
+ // about to overwrite the vptrs anyway.
+ if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
+ ClassDecl->isDynamicClass() && Type != Ctor_Base)
+ EmitVTableAssumptionLoads(ClassDecl, This);
+}
+
+void CodeGenFunction::EmitVTableAssumptionLoad(const VPtr &Vptr,
+ llvm::Value *This) {
+ llvm::Value *VTableGlobal =
+ CGM.getCXXABI().getVTableAddressPoint(Vptr.Base, Vptr.VTableClass);
+ if (!VTableGlobal)
+ return;
+
+ // We can just use the base offset in the complete class.
+ CharUnits NonVirtualOffset = Vptr.Base.getBaseOffset();
+
+ if (!NonVirtualOffset.isZero())
+ This =
+ ApplyNonVirtualAndVirtualOffset(*this, This, NonVirtualOffset, nullptr);
+
+ llvm::Value *VPtrValue = GetVTablePtr(This, VTableGlobal->getType());
+ llvm::Value *Cmp =
+ Builder.CreateICmpEQ(VPtrValue, VTableGlobal, "cmp.vtables");
+ Builder.CreateAssumption(Cmp);
+}
+
+void CodeGenFunction::EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl,
+ llvm::Value *This) {
+ if (CGM.getCXXABI().doStructorsInitializeVPtrs(ClassDecl))
+ for (const VPtr &Vptr : getVTablePointers(ClassDecl))
+ EmitVTableAssumptionLoad(Vptr, This);
}
void
@@ -2017,24 +2054,12 @@ void CodeGenFunction::PushDestructorCleanup(QualType T, llvm::Value *Addr) {
PushDestructorCleanup(D, Addr);
}
-void
-CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
- const CXXRecordDecl *NearestVBase,
- CharUnits OffsetFromNearestVBase,
- const CXXRecordDecl *VTableClass) {
- const CXXRecordDecl *RD = Base.getBase();
-
- // Don't initialize the vtable pointer if the class is marked with the
- // 'novtable' attribute.
- if ((RD == VTableClass || RD == NearestVBase) &&
- VTableClass->hasAttr<MSNoVTableAttr>())
- return;
-
+void CodeGenFunction::InitializeVTablePointer(const VPtr &Vptr) {
// Compute the address point.
- bool NeedsVirtualOffset;
llvm::Value *VTableAddressPoint =
CGM.getCXXABI().getVTableAddressPointInStructor(
- *this, VTableClass, Base, NearestVBase, NeedsVirtualOffset);
+ *this, Vptr.VTableClass, Vptr.Base, Vptr.NearestVBase);
+
if (!VTableAddressPoint)
return;
@@ -2042,17 +2067,15 @@ CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
llvm::Value *VirtualOffset = nullptr;
CharUnits NonVirtualOffset = CharUnits::Zero();
- if (NeedsVirtualOffset) {
+ if (CGM.getCXXABI().isVirtualOffsetNeededForVTableField(*this, Vptr)) {
// We need to use the virtual base offset offset because the virtual base
// might have a different offset in the most derived class.
- VirtualOffset = CGM.getCXXABI().GetVirtualBaseClassOffset(*this,
- LoadCXXThis(),
- VTableClass,
- NearestVBase);
- NonVirtualOffset = OffsetFromNearestVBase;
+ VirtualOffset = CGM.getCXXABI().GetVirtualBaseClassOffset(
+ *this, LoadCXXThis(), Vptr.VTableClass, Vptr.NearestVBase);
+ NonVirtualOffset = Vptr.OffsetFromNearestVBase;
} else {
// We can just use the base offset in the complete class.
- NonVirtualOffset = Base.getBaseOffset();
+ NonVirtualOffset = Vptr.Base.getBaseOffset();
}
// Apply the offsets.
@@ -2071,23 +2094,36 @@ CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
->getPointerTo();
VTableField = Builder.CreateBitCast(VTableField, VTablePtrTy->getPointerTo());
VTableAddressPoint = Builder.CreateBitCast(VTableAddressPoint, VTablePtrTy);
+
llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);
CGM.DecorateInstruction(Store, CGM.getTBAAInfoForVTablePtr());
}
-void
-CodeGenFunction::InitializeVTablePointers(BaseSubobject Base,
- const CXXRecordDecl *NearestVBase,
- CharUnits OffsetFromNearestVBase,
- bool BaseIsNonVirtualPrimaryBase,
- const CXXRecordDecl *VTableClass,
- VisitedVirtualBasesSetTy& VBases) {
+CodeGenFunction::VPtrsVector
+CodeGenFunction::getVTablePointers(const CXXRecordDecl *VTableClass) {
+ CodeGenFunction::VPtrsVector VPtrsResult;
+ VisitedVirtualBasesSetTy VBases;
+ getVTablePointers(BaseSubobject(VTableClass, CharUnits::Zero()),
+ /*NearestVBase=*/nullptr,
+ /*OffsetFromNearestVBase=*/CharUnits::Zero(),
+ /*BaseIsNonVirtualPrimaryBase=*/false, VTableClass, VBases,
+ VPtrsResult);
+ return VPtrsResult;
+}
+
+void CodeGenFunction::getVTablePointers(BaseSubobject Base,
+ const CXXRecordDecl *NearestVBase,
+ CharUnits OffsetFromNearestVBase,
+ bool BaseIsNonVirtualPrimaryBase,
+ const CXXRecordDecl *VTableClass,
+ VisitedVirtualBasesSetTy &VBases,
+ VPtrsVector &Vptrs) {
// If this base is a non-virtual primary base the address point has already
// been set.
if (!BaseIsNonVirtualPrimaryBase) {
// Initialize the vtable pointer for this base.
- InitializeVTablePointer(Base, NearestVBase, OffsetFromNearestVBase,
- VTableClass);
+ VPtr Vptr = {Base, NearestVBase, OffsetFromNearestVBase, VTableClass};
+ Vptrs.push_back(Vptr);
}
const CXXRecordDecl *RD = Base.getBase();
@@ -2125,11 +2161,10 @@ CodeGenFunction::InitializeVTablePointers(BaseSubobject Base,
BaseDeclIsNonVirtualPrimaryBase = Layout.getPrimaryBase() == BaseDecl;
}
- InitializeVTablePointers(BaseSubobject(BaseDecl, BaseOffset),
- I.isVirtual() ? BaseDecl : NearestVBase,
- BaseOffsetFromNearestVBase,
- BaseDeclIsNonVirtualPrimaryBase,
- VTableClass, VBases);
+ getVTablePointers(
+ BaseSubobject(BaseDecl, BaseOffset),
+ I.isVirtual() ? BaseDecl : NearestVBase, BaseOffsetFromNearestVBase,
+ BaseDeclIsNonVirtualPrimaryBase, VTableClass, VBases, Vptrs);
}
}
@@ -2139,11 +2174,9 @@ void CodeGenFunction::InitializeVTablePointers(const CXXRecordDecl *RD) {
return;
// Initialize the vtable pointers for this class and all of its bases.
- VisitedVirtualBasesSetTy VBases;
- InitializeVTablePointers(BaseSubobject(RD, CharUnits::Zero()),
- /*NearestVBase=*/nullptr,
- /*OffsetFromNearestVBase=*/CharUnits::Zero(),
- /*BaseIsNonVirtualPrimaryBase=*/false, RD, VBases);
+ if (CGM.getCXXABI().doStructorsInitializeVPtrs(RD))
+ for (const VPtr &Vptr : getVTablePointers(RD))
+ InitializeVTablePointer(Vptr);
if (RD->getNumVBases())
CGM.getCXXABI().initializeHiddenVirtualInheritanceMembers(*this, RD);
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