/* vim: set ts=4 sw=4 tw=99 et:

 *

 * Copyright (C) 2012 David Anderson

 *

 * This file is part of JITCraft.

 *

 * JITCraft 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.

 * 

 * Foobar 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

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

 */

#ifndef _include_jc_types_h_

#define _include_jc_types_h_

#include "Heap.h"

#include "Barriers.h"

#include "FixedArray.h"

#include "compiler/Token.h"

namespace ke {

class String;

class Descriptor;

class StructMap;

class ArrayMap;

#define MAX_ARRAY_DEPTH     5

enum PrimitiveType

{

    // A boolean type semantically represents 0 or 1. As an optimization, its

    // internal storage type is the same as int32, and any non-zero value

    // compares positively to "true".

    PrimitiveType_Bool,

    // A character is an arbitrary 8-bit value. Characters are not supported

    // as a normal storage class; they may only be used for arrays. When read

    // from an array, they are immediately sign extended to 32 bits. Integers

    // stored into an char array are truncated to 8 bits.

    PrimitiveType_Char,         // signed, 8-bit character

    // Enumerations and untyped variables are stored as signed, 32-bit integers.

    PrimitiveType_Int32,

    // Floating point values are 32-bit IEEE-754 floats. This is required ro

    // SourcePawn 1 compatibility.

    PrimitiveType_Float,

    // This is a native-sized integer type (32-bit on 32-bit systems, 64-bit

    // on 64-bit systems), and does not exist in language semantics.

    PrimitiveType_Native,

    PrimitiveTypes_Total

};

enum TypeQualifiers

{

    TypeQual_None           = 0,

    // Const qualifier that has not been determined yet.

    TypeQual_UnkConst       = (1 << 0),

    // For simplification, SP2 differentiates between two meanings of const.

    // "StoreConst" means that the value itself may not be changed. For

    // example,

    //     const a = 5;

    //

    // Specifies that the storage of "a" is immutable.

    //

    // In addition, "RefConst" means that the memory at a reference may not

    // be changed. For example,

    //

    //     const char:text[] = "asdfasdfasdf";

    //

    // Specifies a readonly view of a character array, however, |text| itself

    // may be repointed to another readonly character array.

    //

    // The meaning of "const" is inferred based on the scope and type:

    //

    //                   +---------+---------+-------+

    //                   | Array   | Struct  | Other |

    //   +---------------+---------+---------+-------+

    //   | GLOBAL/STATIC | Ref|Str | Ref|Str | Str   |

    //   | LOCAL         | Ref     | Ref|Str | Str   |

    //   +---------------+---------+---------+-------+

    TypeQual_StoreConst     = (1 << 1),

    TypeQual_RefConst       = (1 << 2)

};

class Type : public Object

{

  protected:

    enum Kind {

        // A primitive is a plain-old-data type.

        PRIMITIVE,

        // Void is an internal type used to specify that a function returns no

        // value.

        VOID,

        // Enums are plain-old-data with int32 storage. They allow for extra

        // type checking that would not be possible with integers.

        ENUM,

        // Unchecked is a magic type that has implicit, bitwise coercion to

        // int32, float, bool, or an enum.

        UNCHECKED,

        // ------ Add traceable types below -------

        // An immutable type that is a primitive in terms of language

        // semantics, but gets a special type here to make internal

        // logic easier.

        STRING,

        // An array is a fixed-length vector of any other type.

        ARRAY,

        EXTERNAL_ARRAY,

        // A reference type may only be specified on parameters, and

        // references may only be computed to primitives or enums.

        REFERENCE,

        // A function type encapsulates a function signature.

        FUNCTION,

        // Structs are composite records that may contain primitives, arrays,

        // functions, enums, and other structs.

        STRUCT,

        // Contains type qualifiers, and a back pointer to the actual

        // unqualified type.

        QUALTYPE

    };

    void init(Kind kind);

  private:

    Kind kind() {

        return root_->kind_;

    }

  public:   

    static Type *NewVoid(Zone *zone);

    static Type *NewUnchecked(Zone *zone);

    static Type *NewPrimitive(Zone *zone, PrimitiveType type);

    static Type *NewString(Zone *zone);

    static Type *cast(Object *obj) {

        assert(!obj ||

               obj->is(MapKind_Type) ||

               obj->is(MapKind_FunctionType) ||

               obj->is(MapKind_StructType) ||

               obj->is(MapKind_ArrayType) ||

               obj->is(MapKind_ReferenceType) ||

               obj->is(MapKind_EnumType));

        return (Type *)obj;

    }

    bool isPrimitive() {

        return kind() == PRIMITIVE;

    }

    bool isArray() {

        return kind() == ARRAY || kind() == EXTERNAL_ARRAY;

    }

    bool isReference() {

        return kind() == REFERENCE;

    }

    bool isFunction() {

        return kind() == FUNCTION;

    }

    bool isVoid() {

        return kind() == VOID;

    }

    bool isUnchecked() {

        return kind() == UNCHECKED;

    }

    bool isStruct() {

        return kind() == STRUCT;

    }

    PrimitiveType primitive() {

        assert(isPrimitive());

        return root_->primitive_;

    }

    bool isPod() {

        return (isPrimitive() && !isString()) || isEnum() || isUnchecked();

    }

    PrimitiveType pod() {

        assert(isPod());

        return isPrimitive()

               ? (primitive() == PrimitiveType_Bool)

                 ? PrimitiveType_Int32

                 : primitive()

               : PrimitiveType_Int32;

    }

    bool isChar() {

        return isPrimitive() && primitive() == PrimitiveType_Char;

    }

    bool isFloat() {

        return isPrimitive() && primitive() == PrimitiveType_Float;

    }

    bool isInt32() {

        return isPrimitive() && primitive() == PrimitiveType_Int32;

    }

    bool isInt32OrEnum() {

        return isInt32() || isEnum();

    }

    bool isBool() {

        return isPrimitive() && primitive() == PrimitiveType_Bool;

    }

    bool isString() {

        return kind() == STRING;

    }

    bool isExternalArray() {

        return kind() == EXTERNAL_ARRAY;

    }

    bool isTraceable() {

        return kind() >= STRING;

    }

    bool isEnum() {

        return kind() == ENUM;

    }

    bool hasTypeQualifiers() {

        return kind_ == QUALTYPE;

    }

    TypeQualifiers quals() {

        if (hasTypeQualifiers())

            return TypeQual_None;

        return quals_;

    }

    // GC Descriptor.

    static inline size_t offsetOfRoot() {

        return OFFSETOF(Type, root_);

    }

    // End GC Descriptor.

  protected:

    Kind kind_;

    PrimitiveType primitive_;

    TypeQualifiers quals_;

    // For unqualified types, this points to |this|. For qualified types, it

    // points to the unqualified original type.

    Barriered<Type> root_;

};

class EnumType : public Type

{

  public:

    static EnumType *New(Zone *Zone, Handle<String> name);

    String *name() {

        return name_;

    }

    // GC Descriptor.

    static inline size_t offsetOfName() {

        return OFFSETOF(EnumType, name_);

    }

    // End GC Descriptor.

    static EnumType *cast(Object *obj) {

        assert(!obj || obj->is(MapKind_EnumType));

        return (EnumType *)obj;

    }

  private:

    Barriered<String> name_;

};

class ReferenceType : public Type

{

  public:

    static ReferenceType *New(Zone *zone, Handle<Type> contained);

    Type *contained() {

        return contained_;

    }

    // GC Descriptor.

    static inline size_t offsetOfContained() {

        return OFFSETOF(ReferenceType, contained_);

    }

    // End GC Descriptor.

    static ReferenceType *cast(Object *obj) {

        assert(!obj || obj->is(MapKind_ReferenceType));

        return (ReferenceType *)obj;

    }

  private:

    Barriered<Type> contained_;

};

class ArrayType : public Type

{

  public:

    static const int DYNAMIC_ARRAY_SIZE = -1;

    static ArrayType *New(Zone *zone, Handle<Type> contained, int elements);

    static ArrayType *NewExternal(Zone *zone, Handle<Type> contained);

    Type *innermost() {

        Type *temp = contained();

        while (temp->isArray())

            temp = ArrayType::cast(temp)->contained();

        return temp;

    }

    Type *contained() {

        return contained_;

    }

    bool isFixedLength() {

        return elements_ > 0;

    }

    bool isCharArray() {

        return contained()->isPrimitive() &&

               contained()->primitive() == PrimitiveType_Char;

    }

    unsigned fixedLength() {

        assert(isFixedLength());

        return elements_;

    }

    unsigned levels() {

        return levels_;

    }

    bool hasInlineElements() {

        // We don't allocate traceable elements inline, since there's no

        // point to the optimization; we're going to be allocating lots of

        // objects anyway (in theory).

        return isFixedLength() && !contained()->isTraceable();

    }

    // Arrays of this type can be created with this cached map.

    ArrayMap *newMap() {

        return newMap_;

    }

    void setNewMap(ArrayMap *map) {

        assert(!newMap());

        newMap_ = map;

    }

    // GC Descriptor.

    static inline size_t offsetOfContained() {

        return OFFSETOF(ArrayType, contained_);

    }

    static inline size_t offsetOfNewMap() {

        return OFFSETOF(ArrayType, newMap_);

    }

    // End GC Descriptor.

    static ArrayType *cast(Object *obj) {

        assert(!obj || obj->is(MapKind_ArrayType));

        return (ArrayType *)obj;

    }

  private:

    int32 elements_;

    unsigned levels_;

    Barriered<Type> contained_;

    Barriered<ArrayMap> newMap_;

};

class StructType : public Type

{

  public:

    static StructType *New(Zone *zone, Handle<String> name, Handle<FixedArray> fields);

    FixedArray *fields() {

        assert(isStruct());

        return fields_;

    }

    Descriptor *lookupField(Handle<String> name, unsigned *index = NULL);

    // Objects of this type can be created with this cached map.

    StructMap *newMap() {

        return newMap_;

    }

    void setNewMap(StructMap *map) {

        assert(!newMap());

        newMap_ = map;

    }

    String *name() {

        return name_;

    }

    // GC Descriptor.

    static inline size_t offsetOfFields() {

        return OFFSETOF(StructType, fields_);

    }

    static inline size_t offsetOfNewMap() {

        return OFFSETOF(StructType, newMap_);

    }

    static inline size_t offsetOfName() {

        return OFFSETOF(StructType, name_);

    }

    // End GC Descriptor.

    static StructType *cast(Object *obj) {

        assert(!obj || obj->is(MapKind_StructType));

        return (StructType *)obj;

    }

  private:

    // Structs only.

    Barriered<FixedArray> fields_;

    Barriered<StructMap> newMap_;

    Barriered<String> name_;

};

class FunctionType : public Type

{

  public:

    static FunctionType *New(Zone *zone, Handle<String> name, TokenKind kind);

    Type *parameterAt(size_t i) {

        return Type::cast(parameters()->at(i));

    }

    Type *returnType() {

        assert(isFunction());

        return returnType_;

    }

    FixedArray *parameters() {

        assert(isFunction());

        return parameters_;

    }

    FixedArray *defaults() {

        assert(isFunction());

        return defaults_;

    }

    bool isNative() {

        return token_ == TOK_NATIVE;

    }

    bool isForward() {

        return token_ == TOK_FORWARD;

    }

    bool isNativeVariadic() {

        assert(isNative());

        return variadicNative_;

    }

    void setReturnType(Handle<Type> returnType) {

        assert(!returnType_);

        returnType_ = returnType;

    }

    void setParameterTypes(Handle<FixedArray> types) {

        assert(!parameters_);

        parameters_ = types;

    }

    TokenKind token() {

        return token_;

    }

    String *name() {

        return name_;

    }

    // GC Descriptor.

    static inline size_t offsetOfReturnType() {

        return OFFSETOF(FunctionType, returnType_);

    }

    static inline size_t offsetOfParameters() {

        return OFFSETOF(FunctionType, parameters_);

    }

    static inline size_t offsetOfDefaults() {

        return OFFSETOF(FunctionType, defaults_);

    }

    static inline size_t offsetOfName() {

        return OFFSETOF(FunctionType, name_);

    }

    // End GC Descriptor.

    static FunctionType *cast(Object *obj) {

        assert(!obj || obj->is(MapKind_FunctionType));

        return (FunctionType *)obj;

    }

  private:

    // Functions only.

    Barriered<Type> returnType_;

    Barriered<FixedArray> parameters_;

    Barriered<FixedArray> defaults_;

    Barriered<String> name_;

    TokenKind token_;

    bool variadicNative_;

};

class BoxedPrimitive

{

    PrimitiveType type_;

    union {

        int i_;

        float f_;

    };

  public:

    static BoxedPrimitive Int(int i) {

        BoxedPrimitive b;

        b.type_ = PrimitiveType_Int32;

        b.i_ = i;

        return b;

    }

    static BoxedPrimitive Float(float f) {

        BoxedPrimitive b;

        b.type_ = PrimitiveType_Float;

        b.f_ = f;

        return b;

    }

    PrimitiveType type() const {

        return type_;

    }

    int toInt() const {

        assert(type() == PrimitiveType_Int32);

        return i_;

    }

    float toFloat() const {

        assert(type() == PrimitiveType_Float);

        return f_;

    }

};

const char *GetTypeName(Type *type);

}

#endif // _include_jc_types_h_