r360988 - Revert Refactor constant evaluation of typeid(T) to track a symbolic type_info object rather than tracking the originating expression.
Chris Bieneman via cfe-commits
cfe-commits at lists.llvm.org
Thu May 16 22:46:03 PDT 2019
Author: cbieneman
Date: Thu May 16 22:46:03 2019
New Revision: 360988
URL: http://llvm.org/viewvc/llvm-project?rev=360988&view=rev
Log:
Revert Refactor constant evaluation of typeid(T) to track a symbolic type_info object rather than tracking the originating expression.
This reverts r360974 (git commit 7ee4307bd4450022c3c8777f43a40cc4f0ccc009)
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/ExprConstant.cpp
cfe/trunk/lib/CodeGen/CGExprConstant.cpp
cfe/trunk/lib/Sema/SemaTemplate.cpp
cfe/trunk/test/CXX/drs/dr19xx.cpp
cfe/trunk/test/Parser/MicrosoftExtensions.cpp
cfe/trunk/test/SemaCXX/builtin-constant-p.cpp
cfe/trunk/test/SemaCXX/typeid.cpp
cfe/trunk/www/cxx_dr_status.html
Modified: cfe/trunk/include/clang/AST/APValue.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/APValue.h?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/APValue.h (original)
+++ cfe/trunk/include/clang/AST/APValue.h Thu May 16 22:46:03 2019
@@ -24,52 +24,14 @@ namespace clang {
class AddrLabelExpr;
class ASTContext;
class CharUnits;
- class CXXRecordDecl;
- class Decl;
class DiagnosticBuilder;
class Expr;
class FieldDecl;
- struct PrintingPolicy;
- class Type;
+ class Decl;
class ValueDecl;
+ class CXXRecordDecl;
+ class QualType;
-/// Symbolic representation of typeid(T) for some type T.
-class TypeInfoLValue {
- const Type *T;
-
-public:
- TypeInfoLValue() : T() {}
- explicit TypeInfoLValue(const Type *T);
-
- const Type *getType() const { return T; }
- explicit operator bool() const { return T; }
-
- void *getOpaqueValue() { return const_cast<Type*>(T); }
- static TypeInfoLValue getFromOpaqueValue(void *Value) {
- TypeInfoLValue V;
- V.T = reinterpret_cast<const Type*>(Value);
- return V;
- }
-
- void print(llvm::raw_ostream &Out, const PrintingPolicy &Policy) const;
-};
-}
-
-namespace llvm {
-template<> struct PointerLikeTypeTraits<clang::TypeInfoLValue> {
- static void *getAsVoidPointer(clang::TypeInfoLValue V) {
- return V.getOpaqueValue();
- }
- static clang::TypeInfoLValue getFromVoidPointer(void *P) {
- return clang::TypeInfoLValue::getFromOpaqueValue(P);
- }
- // Validated by static_assert in APValue.cpp; hardcoded to avoid needing
- // to include Type.h.
- static constexpr int NumLowBitsAvailable = 3;
-};
-}
-
-namespace clang {
/// APValue - This class implements a discriminated union of [uninitialized]
/// [APSInt] [APFloat], [Complex APSInt] [Complex APFloat], [Expr + Offset],
/// [Vector: N * APValue], [Array: N * APValue]
@@ -95,18 +57,13 @@ public:
class LValueBase {
public:
- typedef llvm::PointerUnion<const ValueDecl *, const Expr *, TypeInfoLValue>
- PtrTy;
+ typedef llvm::PointerUnion<const ValueDecl *, const Expr *> PtrTy;
- LValueBase() : Local{} {}
+ LValueBase() : CallIndex(0), Version(0) {}
template <class T>
- LValueBase(T P, unsigned I = 0, unsigned V = 0) : Ptr(P), Local{I, V} {
- assert(!is<TypeInfoLValue>() &&
- "don't use this constructor to form a type_info lvalue");
- }
-
- static LValueBase getTypeInfo(TypeInfoLValue LV, QualType TypeInfo);
+ LValueBase(T P, unsigned I = 0, unsigned V = 0)
+ : Ptr(P), CallIndex(I), Version(V) {}
template <class T>
bool is() const { return Ptr.is<T>(); }
@@ -121,15 +78,28 @@ public:
bool isNull() const;
- explicit operator bool() const;
+ explicit operator bool () const;
- PtrTy getPointer() const { return Ptr; }
+ PtrTy getPointer() const {
+ return Ptr;
+ }
- unsigned getCallIndex() const;
- unsigned getVersion() const;
- QualType getTypeInfoType() const;
+ unsigned getCallIndex() const {
+ return CallIndex;
+ }
- friend bool operator==(const LValueBase &LHS, const LValueBase &RHS);
+ void setCallIndex(unsigned Index) {
+ CallIndex = Index;
+ }
+
+ unsigned getVersion() const {
+ return Version;
+ }
+
+ friend bool operator==(const LValueBase &LHS, const LValueBase &RHS) {
+ return LHS.Ptr == RHS.Ptr && LHS.CallIndex == RHS.CallIndex &&
+ LHS.Version == RHS.Version;
+ }
friend bool operator!=(const LValueBase &LHS, const LValueBase &RHS) {
return !(LHS == RHS);
}
@@ -137,14 +107,7 @@ public:
private:
PtrTy Ptr;
- struct LocalState {
- unsigned CallIndex, Version;
- };
- union {
- LocalState Local;
- /// The type std::type_info, if this is a TypeInfoLValue.
- void *TypeInfoType;
- };
+ unsigned CallIndex, Version;
};
/// A FieldDecl or CXXRecordDecl, along with a flag indicating whether we
Modified: cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticASTKinds.td Thu May 16 22:46:03 2019
@@ -160,9 +160,6 @@ def note_constexpr_access_static_tempora
"dynamic_cast of}0 temporary "
"is not allowed in a constant expression outside the expression that "
"created the temporary">;
-def note_constexpr_access_unreadable_object : Note<
- "%select{read of|assignment to|increment of|decrement of|member call on|"
- "dynamic_cast of}0 object '%1' whose value is not known">;
def note_constexpr_modify_global : Note<
"a constant expression cannot modify an object that is visible outside "
"that expression">;
Modified: cfe/trunk/lib/AST/APValue.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/APValue.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/lib/AST/APValue.cpp (original)
+++ cfe/trunk/lib/AST/APValue.cpp Thu May 16 22:46:03 2019
@@ -20,56 +20,6 @@
#include "llvm/Support/raw_ostream.h"
using namespace clang;
-/// The identity of a type_info object depends on the canonical unqualified
-/// type only.
-TypeInfoLValue::TypeInfoLValue(const Type *T)
- : T(T->getCanonicalTypeUnqualified().getTypePtr()) {}
-
-void TypeInfoLValue::print(llvm::raw_ostream &Out,
- const PrintingPolicy &Policy) const {
- Out << "typeid(";
- QualType(getType(), 0).print(Out, Policy);
- Out << ")";
-}
-
-static_assert(
- 1 << llvm::PointerLikeTypeTraits<TypeInfoLValue>::NumLowBitsAvailable <=
- alignof(const Type *),
- "Type is insufficiently aligned");
-
-APValue::LValueBase APValue::LValueBase::getTypeInfo(TypeInfoLValue LV,
- QualType TypeInfo) {
- LValueBase Base;
- Base.Ptr = LV;
- Base.TypeInfoType = TypeInfo.getAsOpaquePtr();
- return Base;
-}
-
-unsigned APValue::LValueBase::getCallIndex() const {
- return is<TypeInfoLValue>() ? 0 : Local.CallIndex;
-}
-
-unsigned APValue::LValueBase::getVersion() const {
- return is<TypeInfoLValue>() ? 0 : Local.Version;
-}
-
-QualType APValue::LValueBase::getTypeInfoType() const {
- assert(is<TypeInfoLValue>() && "not a type_info lvalue");
- return QualType::getFromOpaquePtr(TypeInfoType);
-}
-
-namespace clang {
-bool operator==(const APValue::LValueBase &LHS,
- const APValue::LValueBase &RHS) {
- if (LHS.Ptr != RHS.Ptr)
- return false;
- if (LHS.is<TypeInfoLValue>())
- return true;
- return LHS.Local.CallIndex == RHS.Local.CallIndex &&
- LHS.Local.Version == RHS.Local.Version;
-}
-}
-
namespace {
struct LVBase {
APValue::LValueBase Base;
@@ -110,8 +60,6 @@ llvm::DenseMapInfo<clang::APValue::LValu
namespace clang {
llvm::hash_code hash_value(const APValue::LValueBase &Base) {
- if (Base.is<TypeInfoLValue>())
- return llvm::hash_value(Base.getOpaqueValue());
return llvm::hash_combine(Base.getOpaqueValue(), Base.getCallIndex(),
Base.getVersion());
}
@@ -522,9 +470,7 @@ void APValue::printPretty(raw_ostream &O
if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
Out << *VD;
- else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
- TI.print(Out, Ctx.getPrintingPolicy());
- } else {
+ else {
assert(Base.get<const Expr *>() != nullptr &&
"Expecting non-null Expr");
Base.get<const Expr*>()->printPretty(Out, nullptr,
@@ -549,9 +495,6 @@ void APValue::printPretty(raw_ostream &O
if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
Out << *VD;
ElemTy = VD->getType();
- } else if (TypeInfoLValue TI = Base.dyn_cast<TypeInfoLValue>()) {
- TI.print(Out, Ctx.getPrintingPolicy());
- ElemTy = Base.getTypeInfoType();
} else {
const Expr *E = Base.get<const Expr*>();
assert(E != nullptr && "Expecting non-null Expr");
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Thu May 16 22:46:03 2019
@@ -87,9 +87,6 @@ namespace {
return D->getType();
}
- if (TypeInfoLValue TI = B.dyn_cast<TypeInfoLValue>())
- return B.getTypeInfoType();
-
const Expr *Base = B.get<const Expr*>();
// For a materialized temporary, the type of the temporary we materialized
@@ -1786,9 +1783,6 @@ static bool IsGlobalLValue(APValue::LVal
return isa<FunctionDecl>(D);
}
- if (B.is<TypeInfoLValue>())
- return true;
-
const Expr *E = B.get<const Expr*>();
switch (E->getStmtClass()) {
default:
@@ -1806,6 +1800,7 @@ static bool IsGlobalLValue(APValue::LVal
case Expr::PredefinedExprClass:
case Expr::ObjCStringLiteralClass:
case Expr::ObjCEncodeExprClass:
+ case Expr::CXXTypeidExprClass:
case Expr::CXXUuidofExprClass:
return true;
case Expr::ObjCBoxedExprClass:
@@ -1883,9 +1878,9 @@ static void NoteLValueLocation(EvalInfo
const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>();
if (VD)
Info.Note(VD->getLocation(), diag::note_declared_at);
- else if (const Expr *E = Base.dyn_cast<const Expr*>())
- Info.Note(E->getExprLoc(), diag::note_constexpr_temporary_here);
- // We have no information to show for a typeid(T) object.
+ else
+ Info.Note(Base.get<const Expr*>()->getExprLoc(),
+ diag::note_constexpr_temporary_here);
}
/// Check that this reference or pointer core constant expression is a valid
@@ -3409,7 +3404,7 @@ static CompleteObject findCompleteObject
if (!Frame) {
if (const MaterializeTemporaryExpr *MTE =
- dyn_cast_or_null<MaterializeTemporaryExpr>(Base)) {
+ dyn_cast<MaterializeTemporaryExpr>(Base)) {
assert(MTE->getStorageDuration() == SD_Static &&
"should have a frame for a non-global materialized temporary");
@@ -3444,13 +3439,7 @@ static CompleteObject findCompleteObject
} else {
if (!IsAccess)
return CompleteObject(LVal.getLValueBase(), nullptr, BaseType);
- APValue Val;
- LVal.moveInto(Val);
- Info.FFDiag(E, diag::note_constexpr_access_unreadable_object)
- << AK
- << Val.getAsString(Info.Ctx,
- Info.Ctx.getLValueReferenceType(LValType));
- NoteLValueLocation(Info, LVal.Base);
+ Info.FFDiag(E);
return CompleteObject();
}
} else {
@@ -5788,13 +5777,13 @@ public:
// - Literals
// * CompoundLiteralExpr in C (and in global scope in C++)
// * StringLiteral
+// * CXXTypeidExpr
// * PredefinedExpr
// * ObjCStringLiteralExpr
// * ObjCEncodeExpr
// * AddrLabelExpr
// * BlockExpr
// * CallExpr for a MakeStringConstant builtin
-// - typeid(T) expressions, as TypeInfoLValues
// - Locals and temporaries
// * MaterializeTemporaryExpr
// * Any Expr, with a CallIndex indicating the function in which the temporary
@@ -6029,14 +6018,8 @@ LValueExprEvaluator::VisitCompoundLitera
}
bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
- if (!E->isPotentiallyEvaluated()) {
- TypeInfoLValue TypeInfo;
- if (E->isTypeOperand())
- TypeInfo = TypeInfoLValue(E->getTypeOperand(Info.Ctx).getTypePtr());
- else
- TypeInfo = TypeInfoLValue(E->getExprOperand()->getType().getTypePtr());
- return Success(APValue::LValueBase::getTypeInfo(TypeInfo, E->getType()));
- }
+ if (!E->isPotentiallyEvaluated())
+ return Success(E);
Info.FFDiag(E, diag::note_constexpr_typeid_polymorphic)
<< E->getExprOperand()->getType()
@@ -6632,11 +6615,9 @@ bool PointerExprEvaluator::VisitBuiltinC
if (const ValueDecl *VD =
OffsetResult.Base.dyn_cast<const ValueDecl*>()) {
BaseAlignment = Info.Ctx.getDeclAlign(VD);
- } else if (const Expr *E = OffsetResult.Base.dyn_cast<const Expr *>()) {
- BaseAlignment = GetAlignOfExpr(Info, E, UETT_AlignOf);
} else {
- BaseAlignment = GetAlignOfType(
- Info, OffsetResult.Base.getTypeInfoType(), UETT_AlignOf);
+ BaseAlignment = GetAlignOfExpr(
+ Info, OffsetResult.Base.get<const Expr *>(), UETT_AlignOf);
}
if (BaseAlignment < Align) {
@@ -8354,10 +8335,6 @@ static bool EvaluateBuiltinConstantPForL
if (!isa<StringLiteral>(E))
return false;
return LV.getLValueOffset().isZero();
- } else if (Base.is<TypeInfoLValue>()) {
- // Surprisingly, GCC considers __builtin_constant_p(&typeid(int)) to
- // evaluate to true.
- return true;
} else {
// Any other base is not constant enough for GCC.
return false;
@@ -8422,8 +8399,6 @@ static QualType getObjectType(APValue::L
} else if (const Expr *E = B.get<const Expr*>()) {
if (isa<CompoundLiteralExpr>(E))
return E->getType();
- } else if (B.is<TypeInfoLValue>()) {
- return B.getTypeInfoType();
}
return QualType();
Modified: cfe/trunk/lib/CodeGen/CGExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprConstant.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprConstant.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprConstant.cpp Thu May 16 22:46:03 2019
@@ -1735,17 +1735,6 @@ ConstantLValueEmitter::tryEmitBase(const
return nullptr;
}
- // Handle typeid(T).
- if (TypeInfoLValue TI = base.dyn_cast<TypeInfoLValue>()) {
- llvm::Type *StdTypeInfoPtrTy =
- CGM.getTypes().ConvertType(base.getTypeInfoType())->getPointerTo();
- llvm::Constant *TypeInfo =
- CGM.GetAddrOfRTTIDescriptor(QualType(TI.getType(), 0));
- if (TypeInfo->getType() != StdTypeInfoPtrTy)
- TypeInfo = llvm::ConstantExpr::getBitCast(TypeInfo, StdTypeInfoPtrTy);
- return TypeInfo;
- }
-
// Otherwise, it must be an expression.
return Visit(base.get<const Expr*>());
}
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Thu May 16 22:46:03 2019
@@ -6424,11 +6424,8 @@ ExprResult Sema::CheckTemplateArgument(N
// -- a string literal
// -- the result of a typeid expression, or
// -- a predefined __func__ variable
- APValue::LValueBase Base = Value.getLValueBase();
- auto *VD = const_cast<ValueDecl *>(Base.dyn_cast<const ValueDecl *>());
- if (Base && !VD) {
- auto *E = Base.dyn_cast<const Expr *>();
- if (E && isa<CXXUuidofExpr>(E)) {
+ if (auto *E = Value.getLValueBase().dyn_cast<const Expr*>()) {
+ if (isa<CXXUuidofExpr>(E)) {
Converted = TemplateArgument(ArgResult.get()->IgnoreImpCasts());
break;
}
@@ -6436,6 +6433,8 @@ ExprResult Sema::CheckTemplateArgument(N
<< Arg->getSourceRange();
return ExprError();
}
+ auto *VD = const_cast<ValueDecl *>(
+ Value.getLValueBase().dyn_cast<const ValueDecl *>());
// -- a subobject
if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
VD && VD->getType()->isArrayType() &&
Modified: cfe/trunk/test/CXX/drs/dr19xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr19xx.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr19xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr19xx.cpp Thu May 16 22:46:03 2019
@@ -167,14 +167,9 @@ namespace dr1959 { // dr1959: 3.9
#endif
}
-namespace dr1968 { // dr1968: no
+namespace dr1968 { // dr1968: yes
#if __cplusplus >= 201103L
- // FIXME: According to DR1968, both of these should be considered
- // non-constant.
- static_assert(&typeid(int) == &typeid(int), "");
-
- constexpr const std::type_info *f() { return &typeid(int); }
- static_assert(f() == f(), "");
+ static_assert(&typeid(int) == &typeid(int), ""); // expected-error{{not an integral constant expression}}
#endif
}
Modified: cfe/trunk/test/Parser/MicrosoftExtensions.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/MicrosoftExtensions.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/test/Parser/MicrosoftExtensions.cpp (original)
+++ cfe/trunk/test/Parser/MicrosoftExtensions.cpp Thu May 16 22:46:03 2019
@@ -138,8 +138,6 @@ typedef COM_CLASS_TEMPLATE_REF<struct_wi
COM_CLASS_TEMPLATE_REF<int, __uuidof(struct_with_uuid)> good_template_arg;
COM_CLASS_TEMPLATE<int, __uuidof(struct_with_uuid)> bad_template_arg; // expected-error {{non-type template argument of type 'const _GUID' is not a constant expression}}
-// expected-note at -1 {{read of object '__uuidof(struct_with_uuid)' whose value is not known}}
-// expected-note at -2 {{temporary created here}}
namespace PR16911 {
struct __declspec(uuid("{12345678-1234-1234-1234-1234567890aB}")) uuid;
Modified: cfe/trunk/test/SemaCXX/builtin-constant-p.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/builtin-constant-p.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/builtin-constant-p.cpp (original)
+++ cfe/trunk/test/SemaCXX/builtin-constant-p.cpp Thu May 16 22:46:03 2019
@@ -130,8 +130,3 @@ constexpr int mutate6(bool mutate) {
static_assert(mutate6(false) == 11);
// Mutation of state outside __builtin_constant_p: evaluates to false.
static_assert(mutate6(true) == 10);
-
-// GCC strangely returns true for the address of a type_info object, despite it
-// not being a pointer to the start of a string literal.
-namespace std { struct type_info; }
-static_assert(__builtin_constant_p(&typeid(int)));
Modified: cfe/trunk/test/SemaCXX/typeid.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/typeid.cpp?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/typeid.cpp (original)
+++ cfe/trunk/test/SemaCXX/typeid.cpp Thu May 16 22:46:03 2019
@@ -6,7 +6,7 @@ void f()
}
namespace std {
- struct type_info { const char *name; };
+ class type_info;
}
void g()
@@ -27,6 +27,3 @@ void h(int i) {
typeid(V); // expected-error{{'typeid' of variably modified type 'char [i]'}}
typeid(char [i]); // expected-error{{'typeid' of variably modified type 'char [i]'}}
}
-
-// expected-note at +1 {{read of object 'typeid(int).name' whose value is not known}}
-constexpr const char *name = typeid(int).name; // expected-error {{constant expression}}
Modified: cfe/trunk/www/cxx_dr_status.html
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_dr_status.html?rev=360988&r1=360987&r2=360988&view=diff
==============================================================================
--- cfe/trunk/www/cxx_dr_status.html (original)
+++ cfe/trunk/www/cxx_dr_status.html Thu May 16 22:46:03 2019
@@ -11623,7 +11623,7 @@ and <I>POD class</I></td>
<td><a href="http://wg21.link/cwg1968">1968</a></td>
<td>NAD</td>
<td>Address of <TT>typeid</TT> in constant expressions</td>
- <td class="none" align="center">No</td>
+ <td class="full" align="center">Yes</td>
</tr>
<tr class="open" id="1969">
<td><a href="http://wg21.link/cwg1969">1969</a></td>
More information about the cfe-commits
mailing list