Remove bogus comment.
http://reviews.llvm.org/D5635
Files:
projects/compiler-rt/lib/ubsan/ubsan_handlers.cc
tools/clang/lib/CodeGen/CGClass.cpp
tools/clang/lib/CodeGen/CGExpr.cpp
tools/clang/lib/CodeGen/CGExprScalar.cpp
tools/clang/lib/CodeGen/CodeGenFunction.h
tools/clang/test/CodeGenCXX/catch-undef-behavior.cpp
Index: tools/clang/lib/CodeGen/CGClass.cpp
===================================================================
--- tools/clang/lib/CodeGen/CGClass.cpp
+++ tools/clang/lib/CodeGen/CGClass.cpp
@@ -134,12 +134,11 @@
return ptr;
}
-llvm::Value *
-CodeGenFunction::GetAddressOfBaseClass(llvm::Value *Value,
- const CXXRecordDecl *Derived,
- CastExpr::path_const_iterator PathBegin,
- CastExpr::path_const_iterator PathEnd,
- bool NullCheckValue) {
+llvm::Value *CodeGenFunction::GetAddressOfBaseClass(
+ llvm::Value *Value, const CXXRecordDecl *Derived,
+ CastExpr::path_const_iterator PathBegin,
+ CastExpr::path_const_iterator PathEnd, bool NullCheckValue,
+ SourceLocation Loc) {
assert(PathBegin != PathEnd && "Base path should not be empty!");
CastExpr::path_const_iterator Start = PathBegin;
@@ -176,9 +175,16 @@
llvm::Type *BasePtrTy =
ConvertType((PathEnd[-1])->getType())->getPointerTo();
+ QualType DerivedTy = getContext().getRecordType(Derived);
+ CharUnits DerivedAlign = getContext().getTypeAlignInChars(DerivedTy);
+
// If the static offset is zero and we don't have a virtual step,
// just do a bitcast; null checks are unnecessary.
if (NonVirtualOffset.isZero() && !VBase) {
+ if (sanitizePerformTypeCheck()) {
+ EmitTypeCheck(TCK_Upcast, Loc, Value, DerivedTy, DerivedAlign,
+ !NullCheckValue);
+ }
return Builder.CreateBitCast(Value, BasePtrTy);
}
@@ -197,6 +203,11 @@
EmitBlock(notNullBB);
}
+ if (sanitizePerformTypeCheck()) {
+ EmitTypeCheck(VBase ? TCK_UpcastToVirtualBase : TCK_Upcast, Loc, Value,
+ DerivedTy, DerivedAlign, true);
+ }
+
// Compute the virtual offset.
llvm::Value *VirtualOffset = nullptr;
if (VBase) {
Index: tools/clang/lib/CodeGen/CGExpr.cpp
===================================================================
--- tools/clang/lib/CodeGen/CGExpr.cpp
+++ tools/clang/lib/CodeGen/CGExpr.cpp
@@ -376,7 +376,7 @@
GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
Adjustment.DerivedToBase.BasePath->path_begin(),
Adjustment.DerivedToBase.BasePath->path_end(),
- /*NullCheckValue=*/ false);
+ /*NullCheckValue=*/ false, E->getExprLoc());
break;
case SubobjectAdjustment::FieldAdjustment: {
@@ -447,8 +447,8 @@
}
void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
- llvm::Value *Address,
- QualType Ty, CharUnits Alignment) {
+ llvm::Value *Address, QualType Ty,
+ CharUnits Alignment, bool SkipNullCheck) {
if (!sanitizePerformTypeCheck())
return;
@@ -463,13 +463,15 @@
llvm::Value *Cond = nullptr;
llvm::BasicBlock *Done = nullptr;
- if (SanOpts->Null || TCK == TCK_DowncastPointer) {
+ bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
+ TCK == TCK_UpcastToVirtualBase;
+ if ((SanOpts->Null || AllowNullPointers) && !SkipNullCheck) {
// The glvalue must not be an empty glvalue.
Cond = Builder.CreateICmpNE(
Address, llvm::Constant::getNullValue(Address->getType()));
- if (TCK == TCK_DowncastPointer) {
- // When performing a pointer downcast, it's OK if the value is null.
+ if (AllowNullPointers) {
+ // When performing pointer casts, it's OK if the value is null.
// Skip the remaining checks in that case.
Done = createBasicBlock("null");
llvm::BasicBlock *Rest = createBasicBlock("not.null");
@@ -535,7 +537,8 @@
CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
if (SanOpts->Vptr &&
(TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
- TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference) &&
+ TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
+ TCK == TCK_UpcastToVirtualBase) &&
RD && RD->hasDefinition() && RD->isDynamicClass()) {
// Compute a hash of the mangled name of the type.
//
@@ -2939,10 +2942,9 @@
llvm::Value *This = LV.getAddress();
// Perform the derived-to-base conversion
- llvm::Value *Base =
- GetAddressOfBaseClass(This, DerivedClassDecl,
- E->path_begin(), E->path_end(),
- /*NullCheckValue=*/false);
+ llvm::Value *Base = GetAddressOfBaseClass(
+ This, DerivedClassDecl, E->path_begin(), E->path_end(),
+ /*NullCheckValue=*/false, E->getExprLoc());
return MakeAddrLValue(Base, E->getType());
}
Index: tools/clang/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- tools/clang/lib/CodeGen/CGExprScalar.cpp
+++ tools/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1350,9 +1350,9 @@
E->getType()->getPointeeCXXRecordDecl();
assert(DerivedClassDecl && "DerivedToBase arg isn't a C++ object pointer!");
- return CGF.GetAddressOfBaseClass(Visit(E), DerivedClassDecl,
- CE->path_begin(), CE->path_end(),
- ShouldNullCheckClassCastValue(CE));
+ return CGF.GetAddressOfBaseClass(
+ Visit(E), DerivedClassDecl, CE->path_begin(), CE->path_end(),
+ ShouldNullCheckClassCastValue(CE), CE->getExprLoc());
}
case CK_Dynamic: {
Value *V = Visit(const_cast<Expr*>(E));
Index: tools/clang/lib/CodeGen/CodeGenFunction.h
===================================================================
--- tools/clang/lib/CodeGen/CodeGenFunction.h
+++ tools/clang/lib/CodeGen/CodeGenFunction.h
@@ -1657,7 +1657,7 @@
const CXXRecordDecl *Derived,
CastExpr::path_const_iterator PathBegin,
CastExpr::path_const_iterator PathEnd,
- bool NullCheckValue);
+ bool NullCheckValue, SourceLocation Loc);
llvm::Value *GetAddressOfDerivedClass(llvm::Value *Value,
const CXXRecordDecl *Derived,
@@ -1752,7 +1752,13 @@
TCK_DowncastPointer,
/// Checking the operand of a static_cast to a derived reference type. Must
/// be an object within its lifetime.
- TCK_DowncastReference
+ TCK_DowncastReference,
+ /// Checking the operand of a cast to a base object. Must be suitably sized
+ /// and aligned.
+ TCK_Upcast,
+ /// Checking the operand of a cast to a virtual base object. Must be an
+ /// object within its lifetime.
+ TCK_UpcastToVirtualBase,
};
/// \brief Whether any type-checking sanitizers are enabled. If \c false,
@@ -1762,7 +1768,8 @@
/// \brief Emit a check that \p V is the address of storage of the
/// appropriate size and alignment for an object of type \p Type.
void EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *V,
- QualType Type, CharUnits Alignment = CharUnits::Zero());
+ QualType Type, CharUnits Alignment = CharUnits::Zero(),
+ bool SkipNullCheck = false);
/// \brief Emit a check that \p Base points into an array object, which
/// we can access at index \p Index. \p Accessed should be \c false if we
Index: tools/clang/test/CodeGenCXX/catch-undef-behavior.cpp
===================================================================
--- tools/clang/test/CodeGenCXX/catch-undef-behavior.cpp
+++ tools/clang/test/CodeGenCXX/catch-undef-behavior.cpp
@@ -404,6 +404,40 @@
p(42);
}
+namespace UpcastPointerTest {
+struct S {};
+struct T : S { double d; };
+struct V : virtual S {};
+
+// CHECK-LABEL: upcast_pointer
+S* upcast_pointer(T* t) {
+ // Check for null pointer
+ // CHECK: %[[NONNULL:.*]] = icmp ne {{.*}}, null
+ // CHECK: br i1 %[[NONNULL]]
+
+ // Check alignment
+ // CHECK: %[[MISALIGN:.*]] = and i64 %{{.*}}, 7
+ // CHECK: icmp eq i64 %[[MISALIGN]], 0
+
+ // CHECK: call void @__ubsan_handle_type_mismatch
+ return t;
+}
+
+V getV();
+
+// CHECK-LABEL: upcast_to_vbase
+void upcast_to_vbase() {
+ // No need to check for null here, as we have a temporary here.
+
+ // CHECK-NOT: br i1
+
+ // CHECK: call i64 @llvm.objectsize
+ // CHECK: call void @__ubsan_handle_type_mismatch
+ // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss
+ const S& s = getV();
+}
+}
+
namespace CopyValueRepresentation {
// CHECK-LABEL: define {{.*}} @_ZN23CopyValueRepresentation2S3aSERKS0_
// CHECK-NOT: call {{.*}} @__ubsan_handle_load_invalid_value
Index: projects/compiler-rt/lib/ubsan/ubsan_handlers.cc
===================================================================
--- projects/compiler-rt/lib/ubsan/ubsan_handlers.cc
+++ projects/compiler-rt/lib/ubsan/ubsan_handlers.cc
@@ -30,10 +30,10 @@
}
namespace __ubsan {
- const char *TypeCheckKinds[] = {
+const char *TypeCheckKinds[] = {
"load of", "store to", "reference binding to", "member access within",
- "member call on", "constructor call on", "downcast of", "downcast of"
- };
+ "member call on", "constructor call on", "downcast of", "downcast of",
+ "upcast of", "cast to virtual base of"};
}
static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer,
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