r361328 - Refactor: split Uninitialized state on APValue into an "Absent" state
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Tue May 21 16:15:18 PDT 2019
Author: rsmith
Date: Tue May 21 16:15:18 2019
New Revision: 361328
URL: http://llvm.org/viewvc/llvm-project?rev=361328&view=rev
Log:
Refactor: split Uninitialized state on APValue into an "Absent" state
representing no such object, and an "Indeterminate" state representing
an uninitialized object. The latter is not yet used, but soon will be.
Modified:
cfe/trunk/include/clang/AST/APValue.h
cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td
cfe/trunk/lib/AST/APValue.cpp
cfe/trunk/lib/AST/Decl.cpp
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/lib/CodeGen/CGExprConstant.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.cpp
cfe/trunk/lib/Sema/SemaTemplate.cpp
Modified: cfe/trunk/include/clang/AST/APValue.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/APValue.h?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/APValue.h (original)
+++ cfe/trunk/include/clang/AST/APValue.h Tue May 21 16:15:18 2019
@@ -78,7 +78,10 @@ class APValue {
typedef llvm::APFloat APFloat;
public:
enum ValueKind {
- Uninitialized,
+ /// There is no such object (it's outside its lifetime).
+ None,
+ /// This object has an indeterminate value (C++ [basic.indet]).
+ Indeterminate,
Int,
Float,
FixedPoint,
@@ -231,58 +234,59 @@ private:
DataType Data;
public:
- APValue() : Kind(Uninitialized) {}
- explicit APValue(APSInt I) : Kind(Uninitialized) {
+ APValue() : Kind(None) {}
+ explicit APValue(APSInt I) : Kind(None) {
MakeInt(); setInt(std::move(I));
}
- explicit APValue(APFloat F) : Kind(Uninitialized) {
+ explicit APValue(APFloat F) : Kind(None) {
MakeFloat(); setFloat(std::move(F));
}
- explicit APValue(APFixedPoint FX) : Kind(Uninitialized) {
+ explicit APValue(APFixedPoint FX) : Kind(None) {
MakeFixedPoint(std::move(FX));
}
- explicit APValue(const APValue *E, unsigned N) : Kind(Uninitialized) {
+ explicit APValue(const APValue *E, unsigned N) : Kind(None) {
MakeVector(); setVector(E, N);
}
- APValue(APSInt R, APSInt I) : Kind(Uninitialized) {
+ APValue(APSInt R, APSInt I) : Kind(None) {
MakeComplexInt(); setComplexInt(std::move(R), std::move(I));
}
- APValue(APFloat R, APFloat I) : Kind(Uninitialized) {
+ APValue(APFloat R, APFloat I) : Kind(None) {
MakeComplexFloat(); setComplexFloat(std::move(R), std::move(I));
}
APValue(const APValue &RHS);
- APValue(APValue &&RHS) : Kind(Uninitialized) { swap(RHS); }
+ APValue(APValue &&RHS) : Kind(None) { swap(RHS); }
APValue(LValueBase B, const CharUnits &O, NoLValuePath N,
bool IsNullPtr = false)
- : Kind(Uninitialized) {
+ : Kind(None) {
MakeLValue(); setLValue(B, O, N, IsNullPtr);
}
APValue(LValueBase B, const CharUnits &O, ArrayRef<LValuePathEntry> Path,
bool OnePastTheEnd, bool IsNullPtr = false)
- : Kind(Uninitialized) {
+ : Kind(None) {
MakeLValue(); setLValue(B, O, Path, OnePastTheEnd, IsNullPtr);
}
- APValue(UninitArray, unsigned InitElts, unsigned Size) : Kind(Uninitialized) {
+ APValue(UninitArray, unsigned InitElts, unsigned Size) : Kind(None) {
MakeArray(InitElts, Size);
}
- APValue(UninitStruct, unsigned B, unsigned M) : Kind(Uninitialized) {
+ APValue(UninitStruct, unsigned B, unsigned M) : Kind(None) {
MakeStruct(B, M);
}
explicit APValue(const FieldDecl *D, const APValue &V = APValue())
- : Kind(Uninitialized) {
+ : Kind(None) {
MakeUnion(); setUnion(D, V);
}
APValue(const ValueDecl *Member, bool IsDerivedMember,
- ArrayRef<const CXXRecordDecl*> Path) : Kind(Uninitialized) {
+ ArrayRef<const CXXRecordDecl*> Path) : Kind(None) {
MakeMemberPointer(Member, IsDerivedMember, Path);
}
APValue(const AddrLabelExpr* LHSExpr, const AddrLabelExpr* RHSExpr)
- : Kind(Uninitialized) {
+ : Kind(None) {
MakeAddrLabelDiff(); setAddrLabelDiff(LHSExpr, RHSExpr);
}
~APValue() {
- MakeUninit();
+ if (Kind != None && Kind != Indeterminate)
+ DestroyDataAndMakeUninit();
}
/// Returns whether the object performed allocations.
@@ -296,7 +300,11 @@ public:
void swap(APValue &RHS);
ValueKind getKind() const { return Kind; }
- bool isUninit() const { return Kind == Uninitialized; }
+
+ bool isAbsent() const { return Kind == None; }
+ bool isIndeterminate() const { return Kind == Indeterminate; }
+ bool hasValue() const { return Kind != None && Kind != Indeterminate; }
+
bool isInt() const { return Kind == Int; }
bool isFloat() const { return Kind == Float; }
bool isFixedPoint() const { return Kind == FixedPoint; }
@@ -536,56 +544,52 @@ public:
private:
void DestroyDataAndMakeUninit();
- void MakeUninit() {
- if (Kind != Uninitialized)
- DestroyDataAndMakeUninit();
- }
void MakeInt() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)Data.buffer) APSInt(1);
Kind = Int;
}
void MakeFloat() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) APFloat(0.0);
Kind = Float;
}
void MakeFixedPoint(APFixedPoint &&FX) {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void *)(char *)Data.buffer) APFixedPoint(std::move(FX));
Kind = FixedPoint;
}
void MakeVector() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) Vec();
Kind = Vector;
}
void MakeComplexInt() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) ComplexAPSInt();
Kind = ComplexInt;
}
void MakeComplexFloat() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) ComplexAPFloat();
Kind = ComplexFloat;
}
void MakeLValue();
void MakeArray(unsigned InitElts, unsigned Size);
void MakeStruct(unsigned B, unsigned M) {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) StructData(B, M);
Kind = Struct;
}
void MakeUnion() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) UnionData();
Kind = Union;
}
void MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
ArrayRef<const CXXRecordDecl*> Path);
void MakeAddrLabelDiff() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) AddrLabelDiffData();
Kind = AddrLabelDiff;
}
Modified: cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td Tue May 21 16:15:18 2019
@@ -115,7 +115,8 @@ def note_constexpr_lifetime_ended : Note
def note_constexpr_access_uninit : Note<
"%select{read of|assignment to|increment of|decrement of|member call on|"
"dynamic_cast of|typeid applied to}0 "
- "object outside its lifetime is not allowed in a constant expression">;
+ "%select{object outside its lifetime|uninitialized object}1 "
+ "is not allowed in a constant expression">;
def note_constexpr_use_uninit_reference : Note<
"use of reference outside its lifetime "
"is not allowed in a constant expression">;
Modified: cfe/trunk/lib/AST/APValue.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/APValue.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/AST/APValue.cpp (original)
+++ cfe/trunk/lib/AST/APValue.cpp Tue May 21 16:15:18 2019
@@ -219,9 +219,11 @@ APValue::UnionData::~UnionData () {
delete Value;
}
-APValue::APValue(const APValue &RHS) : Kind(Uninitialized) {
+APValue::APValue(const APValue &RHS) : Kind(None) {
switch (RHS.getKind()) {
- case Uninitialized:
+ case None:
+ case Indeterminate:
+ Kind = RHS.getKind();
break;
case Int:
MakeInt();
@@ -313,12 +315,13 @@ void APValue::DestroyDataAndMakeUninit()
((MemberPointerData*)(char*)Data.buffer)->~MemberPointerData();
else if (Kind == AddrLabelDiff)
((AddrLabelDiffData*)(char*)Data.buffer)->~AddrLabelDiffData();
- Kind = Uninitialized;
+ Kind = None;
}
bool APValue::needsCleanup() const {
switch (getKind()) {
- case Uninitialized:
+ case None:
+ case Indeterminate:
case AddrLabelDiff:
return false;
case Struct:
@@ -376,8 +379,11 @@ static double GetApproxValue(const llvm:
void APValue::dump(raw_ostream &OS) const {
switch (getKind()) {
- case Uninitialized:
- OS << "Uninitialized";
+ case None:
+ OS << "None";
+ return;
+ case Indeterminate:
+ OS << "Indeterminate";
return;
case Int:
OS << "Int: " << getInt();
@@ -452,7 +458,10 @@ void APValue::dump(raw_ostream &OS) cons
void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
switch (getKind()) {
- case APValue::Uninitialized:
+ case APValue::None:
+ Out << "<out of lifetime>";
+ return;
+ case APValue::Indeterminate:
Out << "<uninitialized>";
return;
case APValue::Int:
@@ -781,21 +790,21 @@ ArrayRef<const CXXRecordDecl*> APValue::
}
void APValue::MakeLValue() {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
static_assert(sizeof(LV) <= DataSize, "LV too big");
new ((void*)(char*)Data.buffer) LV();
Kind = LValue;
}
void APValue::MakeArray(unsigned InitElts, unsigned Size) {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
new ((void*)(char*)Data.buffer) Arr(InitElts, Size);
Kind = Array;
}
void APValue::MakeMemberPointer(const ValueDecl *Member, bool IsDerivedMember,
ArrayRef<const CXXRecordDecl*> Path) {
- assert(isUninit() && "Bad state change");
+ assert(isAbsent() && "Bad state change");
MemberPointerData *MPD = new ((void*)(char*)Data.buffer) MemberPointerData;
Kind = MemberPointer;
MPD->MemberAndIsDerivedMember.setPointer(Member);
Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Tue May 21 16:15:18 2019
@@ -2302,7 +2302,7 @@ APValue *VarDecl::evaluateValue(
// first time it is evaluated. FIXME: The notes won't always be emitted the
// first time we try evaluation, so might not be produced at all.
if (Eval->WasEvaluated)
- return Eval->Evaluated.isUninit() ? nullptr : &Eval->Evaluated;
+ return Eval->Evaluated.isAbsent() ? nullptr : &Eval->Evaluated;
const auto *Init = cast<Expr>(Eval->Value);
assert(!Init->isValueDependent());
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Tue May 21 16:15:18 2019
@@ -1291,7 +1291,7 @@ APValue &CallStackFrame::createTemporary
bool IsLifetimeExtended) {
unsigned Version = Info.CurrentCall->getTempVersion();
APValue &Result = Temporaries[MapKeyTy(Key, Version)];
- assert(Result.isUninit() && "temporary created multiple times");
+ assert(Result.isAbsent() && "temporary created multiple times");
Info.CleanupStack.push_back(Cleanup(&Result, IsLifetimeExtended));
return Result;
}
@@ -2025,7 +2025,7 @@ static bool
CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc, QualType Type,
const APValue &Value,
Expr::ConstExprUsage Usage = Expr::EvaluateForCodeGen) {
- if (Value.isUninit()) {
+ if (!Value.hasValue()) {
Info.FFDiag(DiagLoc, diag::note_constexpr_uninitialized)
<< true << Type;
return false;
@@ -2108,7 +2108,8 @@ static bool EvalPointerValueAsBool(const
static bool HandleConversionToBool(const APValue &Val, bool &Result) {
switch (Val.getKind()) {
- case APValue::Uninitialized:
+ case APValue::None:
+ case APValue::Indeterminate:
return false;
case APValue::Int:
Result = Val.getInt().getBoolValue();
@@ -2971,10 +2972,10 @@ findSubobject(EvalInfo &Info, const Expr
// Walk the designator's path to find the subobject.
for (unsigned I = 0, N = Sub.Entries.size(); /**/; ++I) {
- if (O->isUninit()) {
+ if (!O->hasValue()) {
if (!Info.checkingPotentialConstantExpression())
Info.FFDiag(E, diag::note_constexpr_access_uninit)
- << handler.AccessKind;
+ << handler.AccessKind << O->isIndeterminate();
return handler.failed();
}
@@ -5040,7 +5041,7 @@ static bool HandleConstructorCall(const
}
// Reserve space for the struct members.
- if (!RD->isUnion() && Result.isUninit())
+ if (!RD->isUnion() && !Result.hasValue())
Result = APValue(APValue::UninitStruct(), RD->getNumBases(),
std::distance(RD->field_begin(), RD->field_end()));
@@ -5097,7 +5098,7 @@ static bool HandleConstructorCall(const
// subobject other than the first.
// FIXME: In this case, the values of the other subobjects are
// specified, since zero-initialization sets all padding bits to zero.
- if (Value->isUninit() ||
+ if (!Value->hasValue() ||
(Value->isUnion() && Value->getUnionField() != FD)) {
if (CD->isUnion())
*Value = APValue(FD);
@@ -5953,7 +5954,9 @@ bool LValueExprEvaluator::VisitVarDecl(c
APValue *V;
if (!evaluateVarDeclInit(Info, E, VD, Frame, V, nullptr))
return false;
- if (V->isUninit()) {
+ if (!V->hasValue()) {
+ // FIXME: Is it possible for V to be indeterminate here? If so, we should
+ // adjust the diagnostic to say that.
if (!Info.checkingPotentialConstantExpression())
Info.FFDiag(E, diag::note_constexpr_use_uninit_reference);
return false;
@@ -7217,7 +7220,7 @@ bool RecordExprEvaluator::VisitInitListE
return EvaluateInPlace(Result.getUnionValue(), Info, Subobject, InitExpr);
}
- if (Result.isUninit())
+ if (!Result.hasValue())
Result = APValue(APValue::UninitStruct(), CXXRD ? CXXRD->getNumBases() : 0,
std::distance(RD->field_begin(), RD->field_end()));
unsigned ElementNo = 0;
@@ -7294,7 +7297,7 @@ bool RecordExprEvaluator::VisitCXXConstr
bool ZeroInit = E->requiresZeroInitialization();
if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
// If we've already performed zero-initialization, we're already done.
- if (!Result.isUninit())
+ if (Result.hasValue())
return true;
// We can get here in two different ways:
@@ -7794,7 +7797,7 @@ bool ArrayExprEvaluator::VisitInitListEx
// If the array was previously zero-initialized, preserve the
// zero-initialized values.
- if (!Filler.isUninit()) {
+ if (Filler.hasValue()) {
for (unsigned I = 0, E = Result.getArrayInitializedElts(); I != E; ++I)
Result.getArrayInitializedElt(I) = Filler;
if (Result.hasArrayFiller())
@@ -7863,7 +7866,7 @@ bool ArrayExprEvaluator::VisitCXXConstru
const LValue &Subobject,
APValue *Value,
QualType Type) {
- bool HadZeroInit = !Value->isUninit();
+ bool HadZeroInit = Value->hasValue();
if (const ConstantArrayType *CAT = Info.Ctx.getAsConstantArrayType(Type)) {
unsigned N = CAT->getSize().getZExtValue();
@@ -8427,7 +8430,7 @@ static bool EvaluateBuiltinConstantP(Eva
return EvaluateBuiltinConstantPForLValue(V);
// Otherwise, any constant value is good enough.
- return V.getKind() != APValue::Uninitialized;
+ return V.hasValue();
}
// Anything else isn't considered to be sufficiently constant.
Modified: cfe/trunk/lib/CodeGen/CGExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprConstant.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprConstant.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprConstant.cpp Tue May 21 16:15:18 2019
@@ -1860,8 +1860,10 @@ ConstantLValueEmitter::VisitMaterializeT
llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
QualType DestType) {
switch (Value.getKind()) {
- case APValue::Uninitialized:
- llvm_unreachable("Constant expressions should be initialized.");
+ case APValue::None:
+ case APValue::Indeterminate:
+ // Out-of-lifetime and indeterminate values can be modeled as 'undef'.
+ return llvm::UndefValue::get(CGM.getTypes().ConvertType(DestType));
case APValue::LValue:
return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
case APValue::Int:
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Tue May 21 16:15:18 2019
@@ -1990,7 +1990,7 @@ Address CodeGenFunction::EmitMSVAListRef
void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E,
const APValue &Init) {
- assert(!Init.isUninit() && "Invalid DeclRefExpr initializer!");
+ assert(Init.hasValue() && "Invalid DeclRefExpr initializer!");
if (CGDebugInfo *Dbg = getDebugInfo())
if (CGM.getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
Dbg->EmitGlobalVariable(E->getDecl(), Init);
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Tue May 21 16:15:18 2019
@@ -4886,7 +4886,7 @@ ConstantAddress CodeGenModule::GetAddrOf
// evaluating the initializer if the surrounding constant expression
// modifies the temporary.
Value = getContext().getMaterializedTemporaryValue(E, false);
- if (Value && Value->isUninit())
+ if (Value && Value->isAbsent())
Value = nullptr;
}
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=361328&r1=361327&r2=361328&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Tue May 21 16:15:18 2019
@@ -6390,10 +6390,13 @@ ExprResult Sema::CheckTemplateArgument(N
// Convert the APValue to a TemplateArgument.
switch (Value.getKind()) {
- case APValue::Uninitialized:
+ case APValue::None:
assert(ParamType->isNullPtrType());
Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
break;
+ case APValue::Indeterminate:
+ llvm_unreachable("result of constant evaluation should be initialized");
+ break;
case APValue::Int:
assert(ParamType->isIntegralOrEnumerationType());
Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
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