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//===--- CodeGenFunction.h - Per-Function state for LLVM CodeGen ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This is the internal per-function state used for llvm translation.
//
//===----------------------------------------------------------------------===//
#ifndef CODEGEN_CODEGENFUNCTION_H
#define CODEGEN_CODEGENFUNCTION_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/LLVMBuilder.h"
#include <vector>
namespace llvm {
class Module;
}
namespace clang {
class ASTContext;
class Decl;
class FunctionDecl;
class TargetInfo;
class QualType;
class FunctionTypeProto;
class Stmt;
class CompoundStmt;
class LabelStmt;
class GotoStmt;
class IfStmt;
class WhileStmt;
class DoStmt;
class ForStmt;
class ReturnStmt;
class DeclStmt;
class Expr;
class DeclRefExpr;
class StringLiteral;
class IntegerLiteral;
class FloatingLiteral;
class CharacterLiteral;
class TypesCompatibleExpr;
class ImplicitCastExpr;
class CastExpr;
class CallExpr;
class UnaryOperator;
class BinaryOperator;
class CompoundAssignOperator;
class ArraySubscriptExpr;
class OCUVectorElementExpr;
class ConditionalOperator;
class ChooseExpr;
class PreDefinedExpr;
class ObjCStringLiteral;
class BlockVarDecl;
class EnumConstantDecl;
class ParmVarDecl;
namespace CodeGen {
class CodeGenModule;
/// RValue - This trivial value class is used to represent the result of an
/// expression that is evaluated. It can be one of two things: either a simple
/// LLVM SSA value, or the address of an aggregate value in memory. These two
/// possibilities are discriminated by isAggregate/isScalar.
class RValue {
llvm::Value *V;
// TODO: Encode this into the low bit of pointer for more efficient
// return-by-value.
bool IsAggregate;
// FIXME: Aggregate rvalues need to retain information about whether they are
// volatile or not.
public:
bool isAggregate() const { return IsAggregate; }
bool isScalar() const { return !IsAggregate; }
/// getVal() - Return the Value* of this scalar value.
llvm::Value *getVal() const {
assert(!isAggregate() && "Not a scalar!");
return V;
}
/// getAggregateAddr() - Return the Value* of the address of the aggregate.
llvm::Value *getAggregateAddr() const {
assert(isAggregate() && "Not an aggregate!");
return V;
}
static RValue get(llvm::Value *V) {
RValue ER;
ER.V = V;
ER.IsAggregate = false;
return ER;
}
static RValue getAggregate(llvm::Value *V) {
RValue ER;
ER.V = V;
ER.IsAggregate = true;
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: Volatility. Restrict?
// 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*.
OCUVectorElt // This is an ocu vector subset, use getOCUVectorComp
} LVType;
llvm::Value *V;
union {
llvm::Value *VectorIdx; // Index into a vector subscript: V[i]
unsigned VectorElts; // Encoded OCUVector element subset: V.xyx
};
public:
bool isSimple() const { return LVType == Simple; }
bool isVectorElt() const { return LVType == VectorElt; }
bool isBitfield() const { return LVType == BitField; }
bool isOCUVectorElt() const { return LVType == OCUVectorElt; }
// 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; }
// ocu vector elements.
llvm::Value *getOCUVectorAddr() const { assert(isOCUVectorElt()); return V; }
unsigned getOCUVectorElts() const {
assert(isOCUVectorElt());
return VectorElts;
}
static LValue MakeAddr(llvm::Value *V) {
LValue R;
R.LVType = Simple;
R.V = V;
return R;
}
static LValue MakeVectorElt(llvm::Value *Vec, llvm::Value *Idx) {
LValue R;
R.LVType = VectorElt;
R.V = Vec;
R.VectorIdx = Idx;
return R;
}
static LValue MakeOCUVectorElt(llvm::Value *Vec, unsigned Elements) {
LValue R;
R.LVType = OCUVectorElt;
R.V = Vec;
R.VectorElts = Elements;
return R;
}
};
/// CodeGenFunction - This class organizes the per-function state that is used
/// while generating LLVM code.
class CodeGenFunction {
public:
CodeGenModule &CGM; // Per-module state.
TargetInfo &Target;
typedef std::pair<llvm::Value *, llvm::Value *> ComplexPairTy;
llvm::LLVMBuilder Builder;
const FunctionDecl *CurFuncDecl;
llvm::Function *CurFn;
/// AllocaInsertPoint - This is an instruction in the entry block before which
/// we prefer to insert allocas.
llvm::Instruction *AllocaInsertPt;
const llvm::Type *LLVMIntTy;
unsigned LLVMPointerWidth;
private:
/// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
/// decls.
llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap;
/// LabelMap - This keeps track of the LLVM basic block for each C label.
llvm::DenseMap<const LabelStmt*, llvm::BasicBlock*> LabelMap;
// BreakContinueStack - This keeps track of where break and continue
// statements should jump to.
struct BreakContinue {
BreakContinue(llvm::BasicBlock *bb, llvm::BasicBlock *cb)
: BreakBlock(bb), ContinueBlock(cb) {}
llvm::BasicBlock *BreakBlock;
llvm::BasicBlock *ContinueBlock;
};
llvm::SmallVector<BreakContinue, 8> BreakContinueStack;
public:
CodeGenFunction(CodeGenModule &cgm);
ASTContext &getContext() const;
void GenerateCode(const FunctionDecl *FD);
const llvm::Type *ConvertType(QualType T);
/// hasAggregateLLVMType - Return true if the specified AST type will map into
/// an aggregate LLVM type or is void.
static bool hasAggregateLLVMType(QualType T);
/// getBasicBlockForLabel - Return the LLVM basicblock that the specified
/// label maps to.
llvm::BasicBlock *getBasicBlockForLabel(const LabelStmt *S);
void EmitBlock(llvm::BasicBlock *BB);
//===--------------------------------------------------------------------===//
// Helpers
//===--------------------------------------------------------------------===//
/// CreateTempAlloca - This creates a alloca and inserts it into the entry
/// block.
llvm::AllocaInst *CreateTempAlloca(const llvm::Type *Ty,
const char *Name = "tmp");
/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
/// expression and compare the result against zero, returning an Int1Ty value.
llvm::Value *EvaluateExprAsBool(const Expr *E);
//===--------------------------------------------------------------------===//
// Declaration Emission
//===--------------------------------------------------------------------===//
void EmitDecl(const Decl &D);
void EmitEnumConstantDecl(const EnumConstantDecl &D);
void EmitBlockVarDecl(const BlockVarDecl &D);
void EmitLocalBlockVarDecl(const BlockVarDecl &D);
void EmitParmDecl(const ParmVarDecl &D, llvm::Value *Arg);
//===--------------------------------------------------------------------===//
// Statement Emission
//===--------------------------------------------------------------------===//
void EmitStmt(const Stmt *S);
void EmitCompoundStmt(const CompoundStmt &S);
void EmitLabelStmt(const LabelStmt &S);
void EmitGotoStmt(const GotoStmt &S);
void EmitIfStmt(const IfStmt &S);
void EmitWhileStmt(const WhileStmt &S);
void EmitDoStmt(const DoStmt &S);
void EmitForStmt(const ForStmt &S);
void EmitReturnStmt(const ReturnStmt &S);
void EmitDeclStmt(const DeclStmt &S);
void EmitBreakStmt();
void EmitContinueStmt();
//===--------------------------------------------------------------------===//
// LValue Expression Emission
//===--------------------------------------------------------------------===//
/// EmitLValue - Emit code to compute a designator that specifies the location
/// of the expression.
///
/// This can return one of two things: a simple address or a bitfield
/// reference. In either case, the LLVM Value* in the LValue structure is
/// guaranteed to be an LLVM pointer type.
///
/// If this returns a bitfield reference, nothing about the pointee type of
/// the LLVM value is known: For example, it may not be a pointer to an
/// integer.
///
/// If this returns a normal address, and if the lvalue's C type is fixed
/// size, this method guarantees that the returned pointer type will point to
/// an LLVM type of the same size of the lvalue's type. If the lvalue has a
/// variable length type, this is not possible.
///
LValue EmitLValue(const Expr *E);
/// EmitLoadOfLValue - Given an expression that represents a value lvalue,
/// this method emits the address of the lvalue, then loads the result as an
/// rvalue, returning the rvalue.
RValue EmitLoadOfLValue(LValue V, QualType LVType);
RValue EmitLoadOfOCUElementLValue(LValue V, QualType LVType);
/// EmitStoreThroughLValue - Store the specified rvalue into the specified
/// lvalue, where both are guaranteed to the have the same type, and that type
/// is 'Ty'.
void EmitStoreThroughLValue(RValue Src, LValue Dst, QualType Ty);
void EmitStoreThroughOCUComponentLValue(RValue Src, LValue Dst, QualType Ty);
LValue EmitDeclRefLValue(const DeclRefExpr *E);
LValue EmitStringLiteralLValue(const StringLiteral *E);
LValue EmitPreDefinedLValue(const PreDefinedExpr *E);
LValue EmitUnaryOpLValue(const UnaryOperator *E);
LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E);
LValue EmitOCUVectorElementExpr(const OCUVectorElementExpr *E);
//===--------------------------------------------------------------------===//
// Scalar Expression Emission
//===--------------------------------------------------------------------===//
RValue EmitCallExpr(const CallExpr *E);
RValue EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
llvm::Value *EmitObjCStringLiteral(const ObjCStringLiteral *E);
//===--------------------------------------------------------------------===//
// Expression Emission
//===--------------------------------------------------------------------===//
// Expressions are broken into three classes: scalar, complex, aggregate.
/// EmitScalarExpr - Emit the computation of the specified expression of
/// LLVM scalar type, returning the result.
llvm::Value *EmitScalarExpr(const Expr *E);
/// EmitScalarConversion - Emit a conversion from the specified type to the
/// specified destination type, both of which are LLVM scalar types.
llvm::Value *EmitScalarConversion(llvm::Value *Src, QualType SrcTy,
QualType DstTy);
/// EmitComplexToScalarConversion - Emit a conversion from the specified
/// complex type to the specified destination type, where the destination
/// type is an LLVM scalar type.
llvm::Value *EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy,
QualType DstTy);
/// EmitAggExpr - Emit the computation of the specified expression of
/// aggregate type. The result is computed into DestPtr. Note that if
/// DestPtr is null, the value of the aggregate expression is not needed.
void EmitAggExpr(const Expr *E, llvm::Value *DestPtr, bool VolatileDest);
/// EmitComplexExpr - Emit the computation of the specified expression of
/// complex type, returning the result.
ComplexPairTy EmitComplexExpr(const Expr *E);
/// EmitComplexExprIntoAddr - Emit the computation of the specified expression
/// of complex type, storing into the specified Value*.
void EmitComplexExprIntoAddr(const Expr *E, llvm::Value *DestAddr,
bool DestIsVolatile);
};
} // end namespace CodeGen
} // end namespace clang
#endif