--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/lib/CodeGen/CGValue.h	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,632 @@
+//===-- CGValue.h - LLVM CodeGen wrappers for llvm::Value* ------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// These classes implement wrappers around llvm::Value in order to
+// fully represent the range of values for C L- and R- values.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_CODEGEN_CGVALUE_H
+#define LLVM_CLANG_LIB_CODEGEN_CGVALUE_H
+
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Type.h"
+#include "llvm/IR/Value.h"
+#include "llvm/IR/Type.h"
+#include "Address.h"
+#include "CodeGenTBAA.h"
+
+namespace llvm {
+  class Constant;
+  class MDNode;
+}
+
+namespace clang {
+namespace CodeGen {
+  class AggValueSlot;
+  class CodeGenFunction;
+  struct CGBitFieldInfo;
+
+/// RValue - This trivial value class is used to represent the result of an
+/// expression that is evaluated.  It can be one of three things: either a
+/// simple LLVM SSA value, a pair of SSA values for complex numbers, or the
+/// address of an aggregate value in memory.
+class RValue {
+  enum Flavor { Scalar, Complex, Aggregate };
+
+  // The shift to make to an aggregate's alignment to make it look
+  // like a pointer.
+  enum { AggAlignShift = 4 };
+
+  // Stores first value and flavor.
+  llvm::PointerIntPair<llvm::Value *, 2, Flavor> V1;
+  // Stores second value and volatility.
+  llvm::PointerIntPair<llvm::Value *, 1, bool> V2;
+
+public:
+  bool isScalar() const { return V1.getInt() == Scalar; }
+  bool isComplex() const { return V1.getInt() == Complex; }
+  bool isAggregate() const { return V1.getInt() == Aggregate; }
+
+  bool isVolatileQualified() const { return V2.getInt(); }
+
+  /// getScalarVal() - Return the Value* of this scalar value.
+  llvm::Value *getScalarVal() const {
+    assert(isScalar() && "Not a scalar!");
+    return V1.getPointer();
+  }
+
+  /// getComplexVal - Return the real/imag components of this complex value.
+  ///
+  std::pair<llvm::Value *, llvm::Value *> getComplexVal() const {
+    return std::make_pair(V1.getPointer(), V2.getPointer());
+  }
+
+  /// getAggregateAddr() - Return the Value* of the address of the aggregate.
+  Address getAggregateAddress() const {
+    assert(isAggregate() && "Not an aggregate!");
+    auto align = reinterpret_cast<uintptr_t>(V2.getPointer()) >> AggAlignShift;
+    return Address(V1.getPointer(), CharUnits::fromQuantity(align));
+  }
+  llvm::Value *getAggregatePointer() const {
+    assert(isAggregate() && "Not an aggregate!");
+    return V1.getPointer();
+  }
+
+  static RValue getIgnored() {
+    // FIXME: should we make this a more explicit state?
+    return get(nullptr);
+  }
+
+  static RValue get(llvm::Value *V) {
+    RValue ER;
+    ER.V1.setPointer(V);
+    ER.V1.setInt(Scalar);
+    ER.V2.setInt(false);
+    return ER;
+  }
+  static RValue getComplex(llvm::Value *V1, llvm::Value *V2) {
+    RValue ER;
+    ER.V1.setPointer(V1);
+    ER.V2.setPointer(V2);
+    ER.V1.setInt(Complex);
+    ER.V2.setInt(false);
+    return ER;
+  }
+  static RValue getComplex(const std::pair<llvm::Value *, llvm::Value *> &C) {
+    return getComplex(C.first, C.second);
+  }
+  // FIXME: Aggregate rvalues need to retain information about whether they are
+  // volatile or not.  Remove default to find all places that probably get this
+  // wrong.
+  static RValue getAggregate(Address addr, bool isVolatile = false) {
+    RValue ER;
+    ER.V1.setPointer(addr.getPointer());
+    ER.V1.setInt(Aggregate);
+
+    auto align = static_cast<uintptr_t>(addr.getAlignment().getQuantity());
+    ER.V2.setPointer(reinterpret_cast<llvm::Value*>(align << AggAlignShift));
+    ER.V2.setInt(isVolatile);
+    return ER;
+  }
+};
+
+/// Does an ARC strong l-value have precise lifetime?
+enum ARCPreciseLifetime_t {
+  ARCImpreciseLifetime, ARCPreciseLifetime
+};
+
+/// The source of the alignment of an l-value; an expression of
+/// confidence in the alignment actually matching the estimate.
+enum class AlignmentSource {
+  /// The l-value was an access to a declared entity or something
+  /// equivalently strong, like the address of an array allocated by a
+  /// language runtime.
+  Decl,
+
+  /// The l-value was considered opaque, so the alignment was
+  /// determined from a type, but that type was an explicitly-aligned
+  /// typedef.
+  AttributedType,
+
+  /// The l-value was considered opaque, so the alignment was
+  /// determined from a type.
+  Type
+};
+
+/// Given that the base address has the given alignment source, what's
+/// our confidence in the alignment of the field?
+static inline AlignmentSource getFieldAlignmentSource(AlignmentSource Source) {
+  // For now, we don't distinguish fields of opaque pointers from
+  // top-level declarations, but maybe we should.
+  return AlignmentSource::Decl;
+}
+
+class LValueBaseInfo {
+  AlignmentSource AlignSource;
+
+public:
+  explicit LValueBaseInfo(AlignmentSource Source = AlignmentSource::Type)
+    : AlignSource(Source) {}
+  AlignmentSource getAlignmentSource() const { return AlignSource; }
+  void setAlignmentSource(AlignmentSource Source) { AlignSource = Source; }
+
+  void mergeForCast(const LValueBaseInfo &Info) {
+    setAlignmentSource(Info.getAlignmentSource());
+  }
+};
+
+/// LValue - This represents an lvalue references.  Because C/C++ allow
+/// bitfields, this is not a simple LLVM pointer, it may be a pointer plus a
+/// bitrange.
+class LValue {
+  enum {
+    Simple,       // This is a normal l-value, use getAddress().
+    VectorElt,    // This is a vector element l-value (V[i]), use getVector*
+    BitField,     // This is a bitfield l-value, use getBitfield*.
+    ExtVectorElt, // This is an extended vector subset, use getExtVectorComp
+    GlobalReg     // This is a register l-value, use getGlobalReg()
+  } LVType;
+
+  llvm::Value *V;
+
+  union {
+    // Index into a vector subscript: V[i]
+    llvm::Value *VectorIdx;
+
+    // ExtVector element subset: V.xyx
+    llvm::Constant *VectorElts;
+
+    // BitField start bit and size
+    const CGBitFieldInfo *BitFieldInfo;
+  };
+
+  QualType Type;
+
+  // 'const' is unused here
+  Qualifiers Quals;
+
+  // The alignment to use when accessing this lvalue.  (For vector elements,
+  // this is the alignment of the whole vector.)
+  unsigned Alignment;
+
+  // objective-c's ivar
+  bool Ivar:1;
+
+  // objective-c's ivar is an array
+  bool ObjIsArray:1;
+
+  // LValue is non-gc'able for any reason, including being a parameter or local
+  // variable.
+  bool NonGC: 1;
+
+  // Lvalue is a global reference of an objective-c object
+  bool GlobalObjCRef : 1;
+
+  // Lvalue is a thread local reference
+  bool ThreadLocalRef : 1;
+
+  // Lvalue has ARC imprecise lifetime.  We store this inverted to try
+  // to make the default bitfield pattern all-zeroes.
+  bool ImpreciseLifetime : 1;
+
+  // This flag shows if a nontemporal load/stores should be used when accessing
+  // this lvalue.
+  bool Nontemporal : 1;
+
+  LValueBaseInfo BaseInfo;
+  TBAAAccessInfo TBAAInfo;
+
+  Expr *BaseIvarExp;
+
+private:
+  void Initialize(QualType Type, Qualifiers Quals, CharUnits Alignment,
+                  LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo) {
+    assert((!Alignment.isZero() || Type->isIncompleteType()) &&
+           "initializing l-value with zero alignment!");
+    this->Type = Type;
+    this->Quals = Quals;
+    const unsigned MaxAlign = 1U << 31;
+    this->Alignment = Alignment.getQuantity() <= MaxAlign
+                          ? Alignment.getQuantity()
+                          : MaxAlign;
+    assert(this->Alignment == Alignment.getQuantity() &&
+           "Alignment exceeds allowed max!");
+    this->BaseInfo = BaseInfo;
+    this->TBAAInfo = TBAAInfo;
+
+    // Initialize Objective-C flags.
+    this->Ivar = this->ObjIsArray = this->NonGC = this->GlobalObjCRef = false;
+    this->ImpreciseLifetime = false;
+    this->Nontemporal = false;
+    this->ThreadLocalRef = false;
+    this->BaseIvarExp = nullptr;
+  }
+
+public:
+  bool isSimple() const { return LVType == Simple; }
+  bool isVectorElt() const { return LVType == VectorElt; }
+  bool isBitField() const { return LVType == BitField; }
+  bool isExtVectorElt() const { return LVType == ExtVectorElt; }
+  bool isGlobalReg() const { return LVType == GlobalReg; }
+
+  bool isVolatileQualified() const { return Quals.hasVolatile(); }
+  bool isRestrictQualified() const { return Quals.hasRestrict(); }
+  unsigned getVRQualifiers() const {
+    return Quals.getCVRQualifiers() & ~Qualifiers::Const;
+  }
+
+  QualType getType() const { return Type; }
+
+  Qualifiers::ObjCLifetime getObjCLifetime() const {
+    return Quals.getObjCLifetime();
+  }
+
+  bool isObjCIvar() const { return Ivar; }
+  void setObjCIvar(bool Value) { Ivar = Value; }
+
+  bool isObjCArray() const { return ObjIsArray; }
+  void setObjCArray(bool Value) { ObjIsArray = Value; }
+
+  bool isNonGC () const { return NonGC; }
+  void setNonGC(bool Value) { NonGC = Value; }
+
+  bool isGlobalObjCRef() const { return GlobalObjCRef; }
+  void setGlobalObjCRef(bool Value) { GlobalObjCRef = Value; }
+
+  bool isThreadLocalRef() const { return ThreadLocalRef; }
+  void setThreadLocalRef(bool Value) { ThreadLocalRef = Value;}
+
+  ARCPreciseLifetime_t isARCPreciseLifetime() const {
+    return ARCPreciseLifetime_t(!ImpreciseLifetime);
+  }
+  void setARCPreciseLifetime(ARCPreciseLifetime_t value) {
+    ImpreciseLifetime = (value == ARCImpreciseLifetime);
+  }
+  bool isNontemporal() const { return Nontemporal; }
+  void setNontemporal(bool Value) { Nontemporal = Value; }
+
+  bool isObjCWeak() const {
+    return Quals.getObjCGCAttr() == Qualifiers::Weak;
+  }
+  bool isObjCStrong() const {
+    return Quals.getObjCGCAttr() == Qualifiers::Strong;
+  }
+
+  bool isVolatile() const {
+    return Quals.hasVolatile();
+  }
+
+  Expr *getBaseIvarExp() const { return BaseIvarExp; }
+  void setBaseIvarExp(Expr *V) { BaseIvarExp = V; }
+
+  TBAAAccessInfo getTBAAInfo() const { return TBAAInfo; }
+  void setTBAAInfo(TBAAAccessInfo Info) { TBAAInfo = Info; }
+
+  const Qualifiers &getQuals() const { return Quals; }
+  Qualifiers &getQuals() { return Quals; }
+
+  LangAS getAddressSpace() const { return Quals.getAddressSpace(); }
+
+  CharUnits getAlignment() const { return CharUnits::fromQuantity(Alignment); }
+  void setAlignment(CharUnits A) { Alignment = A.getQuantity(); }
+
+  LValueBaseInfo getBaseInfo() const { return BaseInfo; }
+  void setBaseInfo(LValueBaseInfo Info) { BaseInfo = Info; }
+
+  // simple lvalue
+  llvm::Value *getPointer(CodeGenFunction &CGF) const {
+    assert(isSimple());
+    return V;
+  }
+  Address getAddress(CodeGenFunction &CGF) const {
+    return Address(getPointer(CGF), getAlignment());
+  }
+  void setAddress(Address address) {
+    assert(isSimple());
+    V = address.getPointer();
+    Alignment = address.getAlignment().getQuantity();
+  }
+
+  // vector elt lvalue
+  Address getVectorAddress() const {
+    return Address(getVectorPointer(), getAlignment());
+  }
+  llvm::Value *getVectorPointer() const { assert(isVectorElt()); return V; }
+  llvm::Value *getVectorIdx() const { assert(isVectorElt()); return VectorIdx; }
+
+  // extended vector elements.
+  Address getExtVectorAddress() const {
+    return Address(getExtVectorPointer(), getAlignment());
+  }
+  llvm::Value *getExtVectorPointer() const {
+    assert(isExtVectorElt());
+    return V;
+  }
+  llvm::Constant *getExtVectorElts() const {
+    assert(isExtVectorElt());
+    return VectorElts;
+  }
+
+  // bitfield lvalue
+  Address getBitFieldAddress() const {
+    return Address(getBitFieldPointer(), getAlignment());
+  }
+  llvm::Value *getBitFieldPointer() const { assert(isBitField()); return V; }
+  const CGBitFieldInfo &getBitFieldInfo() const {
+    assert(isBitField());
+    return *BitFieldInfo;
+  }
+
+  // global register lvalue
+  llvm::Value *getGlobalReg() const { assert(isGlobalReg()); return V; }
+
+  static LValue MakeAddr(Address address, QualType type, ASTContext &Context,
+                         LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo) {
+    Qualifiers qs = type.getQualifiers();
+    qs.setObjCGCAttr(Context.getObjCGCAttrKind(type));
+
+    LValue R;
+    R.LVType = Simple;
+    assert(address.getPointer()->getType()->isPointerTy());
+    R.V = address.getPointer();
+    R.Initialize(type, qs, address.getAlignment(), BaseInfo, TBAAInfo);
+    return R;
+  }
+
+  static LValue MakeVectorElt(Address vecAddress, llvm::Value *Idx,
+                              QualType type, LValueBaseInfo BaseInfo,
+                              TBAAAccessInfo TBAAInfo) {
+    LValue R;
+    R.LVType = VectorElt;
+    R.V = vecAddress.getPointer();
+    R.VectorIdx = Idx;
+    R.Initialize(type, type.getQualifiers(), vecAddress.getAlignment(),
+                 BaseInfo, TBAAInfo);
+    return R;
+  }
+
+  static LValue MakeExtVectorElt(Address vecAddress, llvm::Constant *Elts,
+                                 QualType type, LValueBaseInfo BaseInfo,
+                                 TBAAAccessInfo TBAAInfo) {
+    LValue R;
+    R.LVType = ExtVectorElt;
+    R.V = vecAddress.getPointer();
+    R.VectorElts = Elts;
+    R.Initialize(type, type.getQualifiers(), vecAddress.getAlignment(),
+                 BaseInfo, TBAAInfo);
+    return R;
+  }
+
+  /// Create a new object to represent a bit-field access.
+  ///
+  /// \param Addr - The base address of the bit-field sequence this
+  /// bit-field refers to.
+  /// \param Info - The information describing how to perform the bit-field
+  /// access.
+  static LValue MakeBitfield(Address Addr, const CGBitFieldInfo &Info,
+                             QualType type, LValueBaseInfo BaseInfo,
+                             TBAAAccessInfo TBAAInfo) {
+    LValue R;
+    R.LVType = BitField;
+    R.V = Addr.getPointer();
+    R.BitFieldInfo = &Info;
+    R.Initialize(type, type.getQualifiers(), Addr.getAlignment(), BaseInfo,
+                 TBAAInfo);
+    return R;
+  }
+
+  static LValue MakeGlobalReg(Address Reg, QualType type) {
+    LValue R;
+    R.LVType = GlobalReg;
+    R.V = Reg.getPointer();
+    R.Initialize(type, type.getQualifiers(), Reg.getAlignment(),
+                 LValueBaseInfo(AlignmentSource::Decl), TBAAAccessInfo());
+    return R;
+  }
+
+  RValue asAggregateRValue(CodeGenFunction &CGF) const {
+    return RValue::getAggregate(getAddress(CGF), isVolatileQualified());
+  }
+};
+
+/// An aggregate value slot.
+class AggValueSlot {
+  /// The address.
+  llvm::Value *Addr;
+
+  // Qualifiers
+  Qualifiers Quals;
+
+  unsigned Alignment;
+
+  /// 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;
+
+  /// 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;
+
+  /// 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;
+
+  /// AliasedFlag - This is set to true if the slot might be aliased
+  /// and it's not undefined behavior to access it through such an
+  /// alias.  Note that it's always undefined behavior to access a C++
+  /// object that's under construction through an alias derived from
+  /// outside the construction process.
+  ///
+  /// This flag controls whether calls that produce the aggregate
+  /// value may be evaluated directly into the slot, or whether they
+  /// must be evaluated into an unaliased temporary and then memcpy'ed
+  /// 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;
+
+  /// This is set to true if the tail padding of this slot might overlap
+  /// another object that may have already been initialized (and whose
+  /// value must be preserved by this initialization). If so, we may only
+  /// store up to the dsize of the type. Otherwise we can widen stores to
+  /// the size of the type.
+  bool OverlapFlag : 1;
+
+  /// If is set to true, sanitizer checks are already generated for this address
+  /// or not required. For instance, if this address represents an object
+  /// created in 'new' expression, sanitizer checks for memory is made as a part
+  /// of 'operator new' emission and object constructor should not generate
+  /// them.
+  bool SanitizerCheckedFlag : 1;
+
+public:
+  enum IsAliased_t { IsNotAliased, IsAliased };
+  enum IsDestructed_t { IsNotDestructed, IsDestructed };
+  enum IsZeroed_t { IsNotZeroed, IsZeroed };
+  enum Overlap_t { DoesNotOverlap, MayOverlap };
+  enum NeedsGCBarriers_t { DoesNotNeedGCBarriers, NeedsGCBarriers };
+  enum IsSanitizerChecked_t { IsNotSanitizerChecked, IsSanitizerChecked };
+
+  /// ignored - Returns an aggregate value slot indicating that the
+  /// aggregate value is being ignored.
+  static AggValueSlot ignored() {
+    return forAddr(Address::invalid(), Qualifiers(), IsNotDestructed,
+                   DoesNotNeedGCBarriers, IsNotAliased, DoesNotOverlap);
+  }
+
+  /// forAddr - Make a slot for an aggregate value.
+  ///
+  /// \param quals - The qualifiers that dictate how the slot should
+  /// be initialied. Only 'volatile' and the Objective-C lifetime
+  /// qualifiers matter.
+  ///
+  /// \param isDestructed - true if something else is responsible
+  ///   for calling destructors on this object
+  /// \param needsGC - true if the slot is potentially located
+  ///   somewhere that ObjC GC calls should be emitted for
+  static AggValueSlot forAddr(Address addr,
+                              Qualifiers quals,
+                              IsDestructed_t isDestructed,
+                              NeedsGCBarriers_t needsGC,
+                              IsAliased_t isAliased,
+                              Overlap_t mayOverlap,
+                              IsZeroed_t isZeroed = IsNotZeroed,
+                       IsSanitizerChecked_t isChecked = IsNotSanitizerChecked) {
+    AggValueSlot AV;
+    if (addr.isValid()) {
+      AV.Addr = addr.getPointer();
+      AV.Alignment = addr.getAlignment().getQuantity();
+    } else {
+      AV.Addr = nullptr;
+      AV.Alignment = 0;
+    }
+    AV.Quals = quals;
+    AV.DestructedFlag = isDestructed;
+    AV.ObjCGCFlag = needsGC;
+    AV.ZeroedFlag = isZeroed;
+    AV.AliasedFlag = isAliased;
+    AV.OverlapFlag = mayOverlap;
+    AV.SanitizerCheckedFlag = isChecked;
+    return AV;
+  }
+
+  static AggValueSlot
+  forLValue(const LValue &LV, CodeGenFunction &CGF, IsDestructed_t isDestructed,
+            NeedsGCBarriers_t needsGC, IsAliased_t isAliased,
+            Overlap_t mayOverlap, IsZeroed_t isZeroed = IsNotZeroed,
+            IsSanitizerChecked_t isChecked = IsNotSanitizerChecked) {
+    return forAddr(LV.getAddress(CGF), LV.getQuals(), isDestructed, needsGC,
+                   isAliased, mayOverlap, isZeroed, isChecked);
+  }
+
+  IsDestructed_t isExternallyDestructed() const {
+    return IsDestructed_t(DestructedFlag);
+  }
+  void setExternallyDestructed(bool destructed = true) {
+    DestructedFlag = destructed;
+  }
+
+  Qualifiers getQualifiers() const { return Quals; }
+
+  bool isVolatile() const {
+    return Quals.hasVolatile();
+  }
+
+  void setVolatile(bool flag) {
+    if (flag)
+      Quals.addVolatile();
+    else
+      Quals.removeVolatile();
+  }
+
+  Qualifiers::ObjCLifetime getObjCLifetime() const {
+    return Quals.getObjCLifetime();
+  }
+
+  NeedsGCBarriers_t requiresGCollection() const {
+    return NeedsGCBarriers_t(ObjCGCFlag);
+  }
+
+  llvm::Value *getPointer() const {
+    return Addr;
+  }
+
+  Address getAddress() const {
+    return Address(Addr, getAlignment());
+  }
+
+  bool isIgnored() const {
+    return Addr == nullptr;
+  }
+
+  CharUnits getAlignment() const {
+    return CharUnits::fromQuantity(Alignment);
+  }
+
+  IsAliased_t isPotentiallyAliased() const {
+    return IsAliased_t(AliasedFlag);
+  }
+
+  Overlap_t mayOverlap() const {
+    return Overlap_t(OverlapFlag);
+  }
+
+  bool isSanitizerChecked() const {
+    return SanitizerCheckedFlag;
+  }
+
+  RValue asRValue() const {
+    if (isIgnored()) {
+      return RValue::getIgnored();
+    } else {
+      return RValue::getAggregate(getAddress(), isVolatile());
+    }
+  }
+
+  void setZeroed(bool V = true) { ZeroedFlag = V; }
+  IsZeroed_t isZeroed() const {
+    return IsZeroed_t(ZeroedFlag);
+  }
+
+  /// Get the preferred size to use when storing a value to this slot. This
+  /// is the type size unless that might overlap another object, in which
+  /// case it's the dsize.
+  CharUnits getPreferredSize(ASTContext &Ctx, QualType Type) const {
+    return mayOverlap() ? Ctx.getTypeInfoDataSizeInChars(Type).first
+                        : Ctx.getTypeSizeInChars(Type);
+  }
+};
+
+}  // end namespace CodeGen
+}  // end namespace clang
+
+#endif