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//===-- CGValue.h - LLVM CodeGen wrappers for llvm::Value* ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// These classes implement wrappers around llvm::Value in order to
// fully represent the range of values for C L- and R- values.
//
//===----------------------------------------------------------------------===//
#ifndef CLANG_CODEGEN_CGVALUE_H
#define CLANG_CODEGEN_CGVALUE_H
#include "clang/AST/Type.h"
namespace llvm {
class Constant;
class Value;
}
namespace clang {
class ObjCPropertyRefExpr;
class ObjCKVCRefExpr;
namespace CodeGen {
/// 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 {
llvm::Value *V1, *V2;
// TODO: Encode this into the low bit of pointer for more efficient
// return-by-value.
enum { Scalar, Complex, Aggregate } Flavor;
bool Volatile:1;
public:
bool isScalar() const { return Flavor == Scalar; }
bool isComplex() const { return Flavor == Complex; }
bool isAggregate() const { return Flavor == Aggregate; }
bool isVolatileQualified() const { return Volatile; }
/// getScalar() - Return the Value* of this scalar value.
llvm::Value *getScalarVal() const {
assert(isScalar() && "Not a scalar!");
return V1;
}
/// getComplexVal - Return the real/imag components of this complex value.
///
std::pair<llvm::Value *, llvm::Value *> getComplexVal() const {
return std::pair<llvm::Value *, llvm::Value *>(V1, V2);
}
/// getAggregateAddr() - Return the Value* of the address of the aggregate.
llvm::Value *getAggregateAddr() const {
assert(isAggregate() && "Not an aggregate!");
return V1;
}
static RValue get(llvm::Value *V) {
RValue ER;
ER.V1 = V;
ER.Flavor = Scalar;
ER.Volatile = false;
return ER;
}
static RValue getComplex(llvm::Value *V1, llvm::Value *V2) {
RValue ER;
ER.V1 = V1;
ER.V2 = V2;
ER.Flavor = Complex;
ER.Volatile = false;
return ER;
}
static RValue getComplex(const std::pair<llvm::Value *, llvm::Value *> &C) {
RValue ER;
ER.V1 = C.first;
ER.V2 = C.second;
ER.Flavor = Complex;
ER.Volatile = false;
return ER;
}
// 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(llvm::Value *V, bool Vol = false) {
RValue ER;
ER.V1 = V;
ER.Flavor = Aggregate;
ER.Volatile = Vol;
return ER;
}
};
/// 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 {
// FIXME: alignment?
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
PropertyRef, // This is an Objective-C property reference, use
// getPropertyRefExpr
KVCRef // This is an objective-c 'implicit' property ref,
// use getKVCRefExpr
} LVType;
enum ObjCType {
None = 0, // object with no gc attribute.
Weak, // __weak object expression
Strong // __strong object expression
};
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
struct {
unsigned short StartBit;
unsigned short Size;
bool IsSigned;
} BitfieldData;
// Obj-C property reference expression
const ObjCPropertyRefExpr *PropertyRefExpr;
// ObjC 'implicit' property reference expression
const ObjCKVCRefExpr *KVCRefExpr;
};
bool Volatile:1;
// FIXME: set but never used, what effect should it have?
bool Restrict:1;
// objective-c's ivar
bool Ivar: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;
// objective-c's gc attributes
unsigned ObjCType : 2;
// address space
unsigned AddressSpace;
private:
static void SetQualifiers(unsigned Qualifiers, LValue& R) {
R.Volatile = (Qualifiers&QualType::Volatile)!=0;
R.Restrict = (Qualifiers&QualType::Restrict)!=0;
// FIXME: Convenient place to set objc flags to 0. This should really be
// done in a user-defined constructor instead.
R.ObjCType = None;
R.Ivar = R.NonGC = R.GlobalObjCRef = false;
}
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 isPropertyRef() const { return LVType == PropertyRef; }
bool isKVCRef() const { return LVType == KVCRef; }
bool isVolatileQualified() const { return Volatile; }
bool isRestrictQualified() const { return Restrict; }
unsigned getQualifiers() const {
return (Volatile ? QualType::Volatile : 0) |
(Restrict ? QualType::Restrict : 0);
}
bool isObjCIvar() const { return Ivar; }
bool isNonGC () const { return NonGC; }
bool isGlobalObjCRef() const { return GlobalObjCRef; }
bool isObjCWeak() const { return ObjCType == Weak; }
bool isObjCStrong() const { return ObjCType == Strong; }
unsigned getAddressSpace() const { return AddressSpace; }
static void SetObjCIvar(LValue& R, bool iValue) {
R.Ivar = iValue;
}
static void SetGlobalObjCRef(LValue& R, bool iValue) {
R.GlobalObjCRef = iValue;
}
static void SetObjCNonGC(LValue& R, bool iValue) {
R.NonGC = iValue;
}
static void SetObjCType(QualType::GCAttrTypes GCAttrs, LValue& R) {
if (GCAttrs == QualType::Weak)
R.ObjCType = Weak;
else if (GCAttrs == QualType::Strong)
R.ObjCType = Strong;
else
R.ObjCType = None;
}
// simple lvalue
llvm::Value *getAddress() const { assert(isSimple()); return V; }
// vector elt lvalue
llvm::Value *getVectorAddr() const { assert(isVectorElt()); return V; }
llvm::Value *getVectorIdx() const { assert(isVectorElt()); return VectorIdx; }
// extended vector elements.
llvm::Value *getExtVectorAddr() const { assert(isExtVectorElt()); return V; }
llvm::Constant *getExtVectorElts() const {
assert(isExtVectorElt());
return VectorElts;
}
// bitfield lvalue
llvm::Value *getBitfieldAddr() const { assert(isBitfield()); return V; }
unsigned short getBitfieldStartBit() const {
assert(isBitfield());
return BitfieldData.StartBit;
}
unsigned short getBitfieldSize() const {
assert(isBitfield());
return BitfieldData.Size;
}
bool isBitfieldSigned() const {
assert(isBitfield());
return BitfieldData.IsSigned;
}
// property ref lvalue
const ObjCPropertyRefExpr *getPropertyRefExpr() const {
assert(isPropertyRef());
return PropertyRefExpr;
}
// 'implicit' property ref lvalue
const ObjCKVCRefExpr *getKVCRefExpr() const {
assert(isKVCRef());
return KVCRefExpr;
}
static LValue MakeAddr(llvm::Value *V, unsigned Qualifiers,
QualType::GCAttrTypes GCAttrs = QualType::GCNone,
unsigned AddressSpace = 0) {
LValue R;
R.LVType = Simple;
R.V = V;
SetQualifiers(Qualifiers,R);
R.AddressSpace = AddressSpace;
SetObjCType(GCAttrs, R);
return R;
}
static LValue MakeVectorElt(llvm::Value *Vec, llvm::Value *Idx,
unsigned Qualifiers) {
LValue R;
R.LVType = VectorElt;
R.V = Vec;
R.VectorIdx = Idx;
SetQualifiers(Qualifiers,R);
return R;
}
static LValue MakeExtVectorElt(llvm::Value *Vec, llvm::Constant *Elts,
unsigned Qualifiers) {
LValue R;
R.LVType = ExtVectorElt;
R.V = Vec;
R.VectorElts = Elts;
SetQualifiers(Qualifiers,R);
return R;
}
static LValue MakeBitfield(llvm::Value *V, unsigned short StartBit,
unsigned short Size, bool IsSigned,
unsigned Qualifiers) {
LValue R;
R.LVType = BitField;
R.V = V;
R.BitfieldData.StartBit = StartBit;
R.BitfieldData.Size = Size;
R.BitfieldData.IsSigned = IsSigned;
SetQualifiers(Qualifiers,R);
return R;
}
// FIXME: It is probably bad that we aren't emitting the target when we build
// the lvalue. However, this complicates the code a bit, and I haven't figured
// out how to make it go wrong yet.
static LValue MakePropertyRef(const ObjCPropertyRefExpr *E,
unsigned Qualifiers) {
LValue R;
R.LVType = PropertyRef;
R.PropertyRefExpr = E;
SetQualifiers(Qualifiers,R);
return R;
}
static LValue MakeKVCRef(const ObjCKVCRefExpr *E, unsigned Qualifiers) {
LValue R;
R.LVType = KVCRef;
R.KVCRefExpr = E;
SetQualifiers(Qualifiers,R);
return R;
}
};
} // end namespace CodeGen
} // end namespace clang
#endif