/*

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of SourcePawn.

  *

  * SourcePawn is free software: you can redistribute it and/or modify it under

  * the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option)

  * any later version.

  * 

  * SourcePawn is distributed in the hope that it will be useful, but WITHOUT ANY

  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License along with

  * SourcePawn. If not, see http://www.gnu.org/licenses/.

  */

 #ifndef _include_sp2_hir_h_

 #define _include_sp2_hir_h_

 #include "../Types.h"

 #include "../PoolAllocator.h"

 #include "../Opcodes.h"

 #include "Symbols.h"

 namespace ke {

 #define HIR_OPS(_)                      \

     _(Call)                             \

     _(Integer)                          \

     _(Float)                            \

     _(Store)                            \

     _(ToRef)                            \

     /* Special LValue types */          \

     _(Index)                            \

     _(Local)                            \

     _(Global)                           \

     /* End LValues */                   \

     _(Binary)                           \

     _(Convert)                          \

     _(PostIncDec)

 // Forward declarations.

 #define _(name)    class H##name;

 HIR_OPS(_)

 #undef _

 class HIRVisitor;

 class AstNode;

 class HLValue;

 class HIR : public PoolObject

 {

   public:

     enum HOp {

 #define _(name) k##name,

         HIR_OPS(_)

 #undef _

         kTotalOps

     };

   public:

     HIR(AstNode *node, Type *type)

       : node_(node),

         type_(type)

     {

     }

     Handle<Type> type() {

         return type_;

     }

     AstNode *node() const {

         return node_;

     }

     virtual bool isLValue() const {

         return false;

     }

     virtual HOp op() const = 0;

     virtual void accept(HIRVisitor *visitor) = 0;

 #define _(name)                                         \

     bool is##name() const {                             \

         return op() == k##name;                         \

     }                                                   \

     H##name *to##name() {                               \

         assert(is##name());                             \

         return reinterpret_cast<H##name *>(this);       \

     }

     HIR_OPS(_)

 #undef _

     HLValue *toLValue() {

         assert(isLValue());

         return reinterpret_cast<HLValue *>(this);

     }

   private:

     AstNode *node_;

     ScopedRoot<Type> type_;

 };

 class BytecodeEmitter;

 class HIRVisitor

 {

   public:

 #define _(name)                                 \

     virtual void visit##name(H##name *hir) {    \

         assert(false);                          \

     }

     HIR_OPS(_)

 #undef _

 };

 typedef PoolList<HIR *> HIRList;

 #define DEFINE_HIR(name)                        \

     virtual HOp op() const {                    \

         return k##name;                         \

     }                                           \

     virtual void accept(HIRVisitor *visitor) {  \

         visitor->visit##name(this);             \

     }

 class HInteger : public HIR

 {

   public:

     HInteger(AstNode *node, Type *type, int value)

       : HIR(node, type),

         value_(value)

     {

     }

     DEFINE_HIR(Integer);

     int value() const {

         return value_;

     }

   private:

     int value_;

 };

 class HConvert : public HIR

 {

   public:

     HConvert(AstNode *node, Type *type, Opcode op, HIR *in)

       : HIR(node, type),

         op_(op),

         in_(in)

     {

     }

     DEFINE_HIR(Convert);

     Opcode opcode() const {

         return op_;

     }

     HIR *in() const {

         return in_;

     }

   private:

     Opcode op_;

     HIR *in_;

 };

 class HLValue : public HIR

 {

   public:

     HLValue(AstNode *node, Type *type)

       : HIR(node, type)

     {

     }

     // Pushes a reference to the LValue on the stack.

     virtual void bind(HIRVisitor *visitor, BytecodeEmitter &emitter_) = 0;

     // Duplicates a stack reference.

     virtual void hold(BytecodeEmitter &emitter_) = 0;

     // Reorders the stack for a post-increment operation:

     //   REF VAL -> VAL REF VAL

     virtual void swapAndPick(BytecodeEmitter &emitter_) = 0;

     // Given a stack layout of the form:

     //  [-1]    value

     //  [-2..n] ref

     //

     // Emits a store to the reference.

     virtual void store(BytecodeEmitter &emitter_) = 0;

     virtual void load(BytecodeEmitter &emitter_) = 0;

     // Try to make a direct reference, if semantics allow it. False if the

     // caller must allocate a reference to the stack.

     virtual bool ref(BytecodeEmitter &emitter_) = 0;

     bool isLValue() const {

         return true;

     }

 };

 class HLocal : public HLValue

 {

   public:

     HLocal(AstNode *node, VariableSymbol *sym);

     DEFINE_HIR(Local);

     // Pushes a reference to the LValue on the stack.

     void bind(HIRVisitor *visitor, BytecodeEmitter &emitter_);

     void hold(BytecodeEmitter &emitter_);

     void swapAndPick(BytecodeEmitter &emitter_);

     void store(BytecodeEmitter &emitter_);

     void load(BytecodeEmitter &emitter_);

     bool ref(BytecodeEmitter &emitter_);

     VariableSymbol *sym() const {

         return sym_;

     }

   private:

     VariableSymbol *sym_;

 };

 class HIndex : public HLValue

 {

   public:

     HIndex(AstNode *node, Type *type, HIR *left, HIR *right)

       : HLValue(node, type),

         left_(left),

         right_(right)

     {

     }

     DEFINE_HIR(Index);

     void bind(HIRVisitor *visitor, BytecodeEmitter &emitter_);

     void hold(BytecodeEmitter &emitter_);

     void swapAndPick(BytecodeEmitter &emitter_);

     void store(BytecodeEmitter &emitter_);

     void load(BytecodeEmitter &emitter_);

     bool ref(BytecodeEmitter &emitter_);

   private:

     HIR *left_;

     HIR *right_;

 };

 class HGlobal : public HLValue

 {

   public:

     HGlobal(AstNode *node, Symbol *sym)

       : HLValue(node, sym->type()),

         sym_(sym)

     {

     }

     DEFINE_HIR(Global);

     void bind(HIRVisitor *visitor, BytecodeEmitter &emitter_);

     void hold(BytecodeEmitter &emitter_);

     void swapAndPick(BytecodeEmitter &emitter_);

     void store(BytecodeEmitter &emitter_);

     void load(BytecodeEmitter &emitter_);

     bool ref(BytecodeEmitter &emitter_);

     Symbol *sym() const {

         return sym_;

     }

   private:

     Symbol *sym_;

 };

 class HBinary : public HIR

 {

   public:

     HBinary(AstNode *node, Type *type, TokenKind token, HIR *left, HIR *right)

       : HIR(node, type),

         token_(token),

         left_(left),

         right_(right)

     {

     }

     DEFINE_HIR(Binary);

     TokenKind token() const {

         return token_;

     }

     HIR *left() const {

         return left_;

     }

     HIR *right() const {

         return right_;

     }

   private:

     TokenKind token_;

     HIR *left_;

     HIR *right_;

 };

 class HFloat : public HIR

 {

   public:

     HFloat(AstNode *node, Type *type, float value)

       : HIR(node, type),

         value_(value)

     {

     }

     DEFINE_HIR(Float);

     float value() const {

         return value_;

     }

   private:

     float value_;

 };

 class HStore : public HIR

 {

   public:

     HStore(AstNode *node, HLValue *lval, HIR *rval)

       : HIR(node, lval->type()),

         kind_(TOK_ASSIGN),

         lval_(lval),

         rval_(rval)

     {

     }

     HStore(AstNode *node, TokenKind kind, HLValue *lval, HIR *rval)

       : HIR(node, lval->type()),

         kind_(kind),

         lval_(lval),

         rval_(rval)

     {

     }

     DEFINE_HIR(Store);

     HLValue *lval() const {

         return lval_;

     }

     HIR *rval() const {

         return rval_;

     }

     TokenKind kind() const {

         return kind_;

     }

   private:

     TokenKind kind_;

     HLValue *lval_;

     HIR *rval_;

 };

 class HPostIncDec : public HIR

 {

   public:

     HPostIncDec(AstNode *node, TokenKind kind, HLValue *lval, HIR *rval)

       : HIR(node, lval->type()),

         kind_(kind),

         lval_(lval),

         rval_(rval)

     {

     }

     DEFINE_HIR(PostIncDec);

     HLValue *lval() const {

         return lval_;

     }

     HIR *rval() const {

         return rval_;

     }

     TokenKind kind() const {

         return kind_;

     }

   private:

     TokenKind kind_;

     HLValue *lval_;

     HIR *rval_;

 };

 class HCall : public HIR

 {

   public:

     HCall(AstNode *node, Type *type, HIR *callee, HIRList *args)

       : HIR(node, type),

         callee_(callee),

         args_(args)

     {

     }

     DEFINE_HIR(Call);

     HIR *callee() const {

         return callee_;

     }

     HIRList *args() const {

         return args_;

     }

   private:

     HIR *callee_;

     HIRList *args_;

 };

 class HToRef : public HIR

 {

   public:

     HToRef(AstNode *node, Type *type, HIR *in)

       : HIR(node, type),

         in_(in)

     {

     }

     DEFINE_HIR(ToRef);

     HIR *in() const {

         return in_;

     }

   private:

     HIR *in_;

 };

 #undef DEFINE_HIR

 void EmitHIR(Zone *zone, BytecodeEmitter &emitter, HIR *hir);

 }

 #endif // _include_sp2_hir_h_