/* Copyright 2015-2016 Samsung Electronics Co., Ltd.
 * Copyright 2015-2016 University of Szeged.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef JS_PARSER_INTERNAL_H
#define JS_PARSER_INTERNAL_H

#include "common.h"

#include "byte-code.h"
#include "js-parser.h"
#include "js-parser-limits.h"
#include "js-lexer.h"

/** \addtogroup parser Parser
 * @{
 *
 * \addtogroup jsparser JavaScript
 * @{
 *
 * \addtogroup jsparser_internals Internals
 * @{
 */

/* General parser flags. */
#define PARSER_IS_STRICT                      0x00001u
#define PARSER_IS_FUNCTION                    0x00002u
#define PARSER_IS_CLOSURE                     0x00004u
#define PARSER_IS_PROPERTY_GETTER             0x00008u
#define PARSER_IS_PROPERTY_SETTER             0x00010u
#define PARSER_IS_FUNC_EXPRESSION             0x00020u
#define PARSER_HAS_NON_STRICT_ARG             0x00040u
#define PARSER_INSIDE_WITH                    0x00080u
#define PARSER_RESOLVE_THIS_FOR_CALLS         0x00100u
#define PARSER_NAMED_FUNCTION_EXP             0x00200u
#define PARSER_HAS_INITIALIZED_VARS           0x00400u
#define PARSER_NO_END_LABEL                   0x00800u
#define PARSER_NO_REG_STORE                   0x01000u
#define PARSER_ARGUMENTS_NEEDED               0x02000u
#define PARSER_ARGUMENTS_NOT_NEEDED           0x04000u
#define PARSER_LEXICAL_ENV_NEEDED             0x08000u
#define PARSER_HAS_LATE_LIT_INIT              0x10000u

/* Expression parsing flags. */
#define PARSE_EXPR                            0x00
#define PARSE_EXPR_STATEMENT                  0x01
#define PARSE_EXPR_BLOCK                      0x02
#define PARSE_EXPR_NO_COMMA                   0x04
#define PARSE_EXPR_HAS_LITERAL                0x08

/* The maximum of PARSER_CBC_STREAM_PAGE_SIZE is 127. */
#define PARSER_CBC_STREAM_PAGE_SIZE \
  ((uint32_t) (64 - sizeof (void *)))

#define PARSER_STACK_PAGE_SIZE \
  ((uint32_t) (((sizeof (void *) > 4) ? 128 : 64) - sizeof (void *)))

/* Avoid compiler warnings for += operations. */
#define PARSER_PLUS_EQUAL_U16(base, value) (base) = (uint16_t) ((base) + (value))
#define PARSER_MINUS_EQUAL_U16(base, value) (base) = (uint16_t) ((base) - (value))
#define PARSER_PLUS_EQUAL_LC(base, value) (base) = (parser_line_counter_t) ((base) + (value))

/**
 * Parser boolean type.
 */
typedef enum
{
  PARSER_FALSE = 0,                           /**< false constant */
  PARSER_TRUE = 1                             /**< true constant */
} parser_boolean_t;

/**
 * Argument for a compact-byte code.
 */
typedef struct
{
  uint16_t literal_index;                     /**< literal index argument */
  uint16_t value;                             /**< other argument (second literal or byte). */
  uint16_t third_literal_index;               /**< literal index argument */
  uint8_t literal_type;                       /**< last literal type */
  uint8_t literal_object_type;                /**< last literal object type */
} cbc_argument_t;

/* Useful parser macros. */

#define PARSER_CBC_UNAVAILABLE CBC_EXT_OPCODE

#define PARSER_TO_EXT_OPCODE(opcode) ((uint16_t) ((opcode) + 256))
#define PARSER_GET_EXT_OPCODE(opcode) ((opcode) - 256)
#define PARSER_IS_BASIC_OPCODE(opcode) ((opcode) < 256)
#define PARSER_IS_PUSH_LITERAL(opcode) \
  ((opcode) == CBC_PUSH_LITERAL \
   || (opcode) == CBC_PUSH_TWO_LITERALS \
   || (opcode) == CBC_PUSH_THREE_LITERALS)

#define PARSER_GET_LITERAL(literal_index) \
  ((lexer_literal_t *) parser_list_get (&context_p->literal_pool, (literal_index)))

#define PARSER_TO_BINARY_OPERATION_WITH_RESULT(opcode) \
  (PARSER_TO_EXT_OPCODE(opcode) - CBC_ASSIGN_ADD + CBC_EXT_ASSIGN_ADD_PUSH_RESULT)

#define PARSER_TO_BINARY_OPERATION_WITH_BLOCK(opcode) \
  ((uint16_t) (PARSER_TO_EXT_OPCODE(opcode) - CBC_ASSIGN_ADD + CBC_EXT_ASSIGN_ADD_BLOCK))

#define PARSER_GET_FLAGS(op) \
  (PARSER_IS_BASIC_OPCODE (op) ? cbc_flags[(op)] : cbc_ext_flags[PARSER_GET_EXT_OPCODE (op)])

#define PARSER_OPCODE_IS_RETURN(op) \
  ((op) == CBC_RETURN || (op) == CBC_RETURN_WITH_BLOCK || (op) == CBC_RETURN_WITH_LITERAL)

#define PARSER_ARGS_EQ(op, types) \
  ((PARSER_GET_FLAGS (op) & CBC_ARG_TYPES) == (types))

/**
 * All data allocated by the parser is
 * stored in parser_data_pages in the memory.
 */
typedef struct parser_mem_page_t
{
  struct parser_mem_page_t *next_p;           /**< next page */
  uint8_t bytes[1];                           /**< memory bytes */
} parser_mem_page_t;

/**
 * Structure for managing parser memory.
 */
typedef struct
{
  parser_mem_page_t *first_p;                 /**< first allocated page */
  parser_mem_page_t *last_p;                  /**< last allocated page */
  uint32_t last_position;                     /**< position of the last allocated byte */
} parser_mem_data_t;

/**
 * Parser memory list.
 */
typedef struct
{
  parser_mem_data_t data;                     /**< storage space */
  uint32_t page_size;                         /**< size of each page */
  uint32_t item_size;                         /**< size of each item */
  uint32_t item_count;                        /**< number of items on each page */
} parser_list_t;

/**
 * Iterator for parser memory list.
 */
typedef struct
{
  parser_list_t *list_p;                      /**< parser list */
  parser_mem_page_t *current_p;               /**< currently processed page */
  size_t current_position;                    /**< current position on the page */
} parser_list_iterator_t;

/**
 * Parser memory stack.
 */
typedef struct
{
  parser_mem_data_t data;                     /**< storage space */
  parser_mem_page_t *free_page_p;             /**< space for fast allocation */
} parser_stack_t;

/**
 * Iterator for parser memory stack.
 */
typedef struct
{
  parser_mem_page_t *current_p;               /**< currently processed page */
  size_t current_position;                    /**< current position on the page */
} parser_stack_iterator_t;

/**
 * Branch type.
 */
typedef struct
{
  parser_mem_page_t *page_p;                  /**< branch location page */
  uint32_t offset;                            /**< branch location offset */
} parser_branch_t;

/**
 * Branch chain type.
 */
typedef struct parser_branch_node_t
{
  struct parser_branch_node_t *next_p;        /**< next linked list node */
  parser_branch_t branch;                     /**< branch */
} parser_branch_node_t;

/**
 * Those members of a context which needs
 * to be saved when a sub-function is parsed.
 */
typedef struct parser_saved_context_t
{
  /* Parser members. */
  uint32_t status_flags;                      /**< parsing options */
  uint16_t stack_depth;                       /**< current stack depth */
  uint16_t stack_limit;                       /**< maximum stack depth */
  struct parser_saved_context_t *prev_context_p; /**< last saved context */
  parser_stack_iterator_t last_statement;     /**< last statement position */

  /* Literal types */
  uint16_t argument_count;                    /**< number of function arguments */
  uint16_t register_count;                    /**< number of registers */
  uint16_t literal_count;                     /**< number of literals */

  /* Memory storage members. */
  parser_mem_data_t byte_code;                /**< byte code buffer */
  uint32_t byte_code_size;                    /**< byte code size for branches */
  parser_mem_data_t literal_pool_data;        /**< literal list */

#ifdef PARSER_DEBUG
  uint16_t context_stack_depth;               /**< current context stack depth */
#endif /* PARSER_DEBUG */
} parser_saved_context_t;

/**
 * Shared parser context.
 */
typedef struct
{
  PARSER_TRY_CONTEXT (try_buffer);            /**< try_buffer */
  parser_error_t error;                       /**< error code */
  void *allocated_buffer_p;                   /**< dinamically allocated buffer
                                               *   which needs to be freed on error */
  uint32_t allocated_buffer_size;             /**< size of the dinamically allocated buffer */

  /* Parser members. */
  uint32_t status_flags;                      /**< status flags */
  uint16_t stack_depth;                       /**< current stack depth */
  uint16_t stack_limit;                       /**< maximum stack depth */
  parser_saved_context_t *last_context_p;     /**< last saved context */
  parser_stack_iterator_t last_statement;     /**< last statement position */

  /* Lexer members. */
  lexer_token_t token;                        /**< current token */
  lexer_lit_object_t lit_object;              /**< current literal object */
  const uint8_t *source_p;                    /**< next source byte */
  const uint8_t *source_end_p;                /**< last source byte */
  parser_line_counter_t line;                 /**< current line */
  parser_line_counter_t column;               /**< current column */

  /* Compact byte code members. */
  cbc_argument_t last_cbc;                    /**< argument of the last cbc */
  uint16_t last_cbc_opcode;                   /**< opcode of the last cbc */

  /* Literal types */
  uint16_t argument_count;                    /**< number of function arguments */
  uint16_t register_count;                    /**< number of registers */
  uint16_t literal_count;                     /**< number of literals */

  /* Memory storage members. */
  parser_mem_data_t byte_code;                /**< byte code buffer */
  uint32_t byte_code_size;                    /**< current byte code size for branches */
  parser_list_t literal_pool;                 /**< literal list */
  parser_mem_data_t stack;                    /**< storage space */
  parser_mem_page_t *free_page_p;             /**< space for fast allocation */
  uint8_t stack_top_uint8;                    /**< top byte stored on the stack */

#ifdef PARSER_DEBUG
  /* Variables for debugging / logging. */
  uint16_t context_stack_depth;               /**< current context stack depth */
#endif /* PARSER_DEBUG */

#ifdef PARSER_DUMP_BYTE_CODE
  int is_show_opcodes;                        /**< show opcodes */
  uint32_t total_byte_code_size;              /**< total byte code size */
#endif /* PARSER_DUMP_BYTE_CODE */
} parser_context_t;

/* Memory management.
 * Note: throws an error if unsuccessful. */
void *parser_malloc (parser_context_t *, size_t);
void parser_free (void *, size_t);
void *parser_malloc_local (parser_context_t *, size_t);
void parser_free_local (void *, size_t);

/* Parser byte stream. */

void parser_cbc_stream_init (parser_mem_data_t *);
void parser_cbc_stream_free (parser_mem_data_t *);
void parser_cbc_stream_alloc_page (parser_context_t *, parser_mem_data_t *);

/* Parser list. Ensures pointer alignment. */

void parser_list_init (parser_list_t *, uint32_t, uint32_t);
void parser_list_free (parser_list_t *);
void parser_list_reset (parser_list_t *);
void *parser_list_append (parser_context_t *, parser_list_t *);
void *parser_list_get (parser_list_t *, size_t);
void parser_list_iterator_init (parser_list_t *, parser_list_iterator_t *);
void *parser_list_iterator_next (parser_list_iterator_t *);

/* Parser stack. Optimized for pushing bytes.
 * Pop functions never throws error. */

void parser_stack_init (parser_context_t *);
void parser_stack_free (parser_context_t *);
void parser_stack_push_uint8 (parser_context_t *, uint8_t);
void parser_stack_pop_uint8 (parser_context_t *);
void parser_stack_push_uint16 (parser_context_t *, uint16_t);
uint16_t parser_stack_pop_uint16 (parser_context_t *);
void parser_stack_push (parser_context_t *, const void *, uint32_t);
void parser_stack_pop (parser_context_t *, void *, uint32_t);
void parser_stack_iterator_skip (parser_stack_iterator_t *, size_t);
void parser_stack_iterator_read (parser_stack_iterator_t *, void *, size_t);
void parser_stack_iterator_write (parser_stack_iterator_t *, const void *, size_t);

/* Compact byte code emitting functions. */

void parser_flush_cbc (parser_context_t *);
void parser_emit_cbc (parser_context_t *, uint16_t);
void parser_emit_cbc_literal (parser_context_t *, uint16_t, uint16_t);
void parser_emit_cbc_literal_from_token (parser_context_t *, uint16_t);
void parser_emit_cbc_call (parser_context_t *, uint16_t, size_t);
void parser_emit_cbc_push_number (parser_context_t *, int);
void parser_emit_cbc_forward_branch (parser_context_t *, uint16_t, parser_branch_t *);
parser_branch_node_t *parser_emit_cbc_forward_branch_item (parser_context_t *, uint16_t, parser_branch_node_t *);
void parser_emit_cbc_backward_branch (parser_context_t *, uint16_t, uint32_t);
void parser_set_branch_to_current_position (parser_context_t *, parser_branch_t *);
void parser_set_breaks_to_current_position (parser_context_t *, parser_branch_node_t *);
void parser_set_continues_to_current_position (parser_context_t *, parser_branch_node_t *);

/* Convenience macros. */
#define parser_emit_cbc_ext(context_p, opcode) \
  parser_emit_cbc ((context_p), PARSER_TO_EXT_OPCODE (opcode))
#define parser_emit_cbc_ext_literal(context_p, opcode, literal_index) \
  parser_emit_cbc_literal ((context_p), PARSER_TO_EXT_OPCODE (opcode), (literal_index))
#define parser_emit_cbc_ext_call(context_p, opcode, call_arguments) \
  parser_emit_cbc_call ((context_p), PARSER_TO_EXT_OPCODE (opcode), (call_arguments))
#define parser_emit_cbc_ext_forward_branch(context_p, opcode, branch_p) \
  parser_emit_cbc_forward_branch ((context_p), PARSER_TO_EXT_OPCODE (opcode), (branch_p))
#define parser_emit_cbc_ext_backward_branch(context_p, opcode, offset) \
  parser_emit_cbc_backward_branch ((context_p), PARSER_TO_EXT_OPCODE (opcode), (offset))

/* Lexer functions */

void lexer_next_token (parser_context_t *);
void lexer_expect_identifier (parser_context_t *, uint8_t);
void lexer_scan_identifier (parser_context_t *, int);
ecma_char_t lexer_hex_to_character (parser_context_t *context_p, const uint8_t *source_p, int length);
void lexer_expect_object_literal_id (parser_context_t *, int);
void lexer_construct_literal_object (parser_context_t *, lexer_lit_location_t *, uint8_t);
int lexer_construct_number_object (parser_context_t *, int, int);
void lexer_construct_function_object (parser_context_t *, uint32_t);
void lexer_construct_regexp_object (parser_context_t *, int);
int lexer_compare_identifier_to_current (parser_context_t *, const lexer_lit_location_t *);

/* Parser functions. */

void parser_parse_expression (parser_context_t *, int);
void parser_parse_statements (parser_context_t *);
void parser_scan_until (parser_context_t *, lexer_range_t *, lexer_token_type_t);
ecma_compiled_code_t *parser_parse_function (parser_context_t *, uint32_t);
void parser_free_jumps (parser_stack_iterator_t);

/* Error management. */

void parser_raise_error (parser_context_t *, parser_error_t);

/**
 * @}
 * @}
 * @}
 */

#endif /* !JS_PARSER_INTERNAL_H */