pebble/third_party/jerryscript/jerry-core/lit/lit-char-helpers.c
2025-01-27 11:38:16 -08:00

514 lines
16 KiB
C

/* Copyright 2015-2016 Samsung Electronics Co., Ltd.
* Copyright 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.
*/
#include "lit-char-helpers.h"
#include "lit/lit-unicode-ranges.inc.h"
#include "lit-strings.h"
#define NUM_OF_ELEMENTS(array) (sizeof (array) / sizeof ((array)[0]))
/**
* Binary search algorithm that searches the a
* character in the given char array.
*
* @return true - if the character is in the given array
* false - otherwise
*/
static bool
search_char_in_char_array (ecma_char_t c, /**< code unit */
const ecma_char_t *array, /**< array */
int size_of_array) /**< length of the array */
{
int bottom = 0;
int top = size_of_array - 1;
while (bottom <= top)
{
int middle = (bottom + top) / 2;
ecma_char_t current = array[middle];
if (current == c)
{
return true;
}
if (c < current)
{
top = middle - 1;
}
else
{
bottom = middle + 1;
}
}
return false;
} /* search_char_in_char_array */
/**
* Binary search algorithm that searches a character in the given intervals.
* Intervals specifed by two arrays. The first one contains the starting points
* of the intervals, the second one contains the length of them.
*
* @return true - if the the character is included (inclusively) in one of the intervals in the given array
* false - otherwise
*/
static bool
search_char_in_interval_array (ecma_char_t c, /**< code unit */
const ecma_char_t *array_sp, /**< array of interval starting points */
const uint8_t *lengths, /**< array of interval lengths */
int size_of_array) /**< length of the array */
{
int bottom = 0;
int top = size_of_array - 1;
while (bottom <= top)
{
int middle = (bottom + top) / 2;
ecma_char_t current_sp = array_sp[middle];
if (current_sp <= c && c <= current_sp + lengths[middle])
{
return true;
}
if (c > current_sp)
{
bottom = middle + 1;
}
else
{
top = middle - 1;
}
}
return false;
} /* search_char_in_interval_array */
/**
* Check if specified character is one of the Format-Control characters
*
* @return true - if the character is one of characters, listed in ECMA-262 v5, Table 1,
* false - otherwise.
*/
bool
lit_char_is_format_control (ecma_char_t c) /**< code unit */
{
return (c == LIT_CHAR_ZWNJ
|| c == LIT_CHAR_ZWJ
|| c == LIT_CHAR_BOM);
} /* lit_char_is_format_control */
/**
* Check if specified character is one of the Whitespace characters including those
* that fall into "Space, Separator" ("Zs") Unicode character category.
*
* @return true - if the character is one of characters, listed in ECMA-262 v5, Table 2,
* false - otherwise.
*/
bool
lit_char_is_white_space (ecma_char_t c) /**< code unit */
{
if (c <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
{
return (c == LIT_CHAR_TAB
|| c == LIT_CHAR_VTAB
|| c == LIT_CHAR_FF
|| c == LIT_CHAR_SP);
}
else
{
return (c == LIT_CHAR_NBSP
|| c == LIT_CHAR_BOM
|| (c >= unicode_separator_char_interv_sps[0]
&& c <= unicode_separator_char_interv_sps[0] + unicode_separator_char_interv_lens[0])
|| search_char_in_char_array (c, unicode_separator_chars, NUM_OF_ELEMENTS (unicode_separator_chars)));
}
} /* lit_char_is_white_space */
/**
* Check if specified character is one of LineTerminator characters
*
* @return true - if the character is one of characters, listed in ECMA-262 v5, Table 3,
* false - otherwise.
*/
bool
lit_char_is_line_terminator (ecma_char_t c) /**< code unit */
{
return (c == LIT_CHAR_LF
|| c == LIT_CHAR_CR
|| c == LIT_CHAR_LS
|| c == LIT_CHAR_PS);
} /* lit_char_is_line_terminator */
/**
* Check if specified character is a unicode letter
*
* Note:
* Unicode letter is a character, included into one of the following categories:
* - Uppercase letter (Lu);
* - Lowercase letter (Ll);
* - Titlecase letter (Lt);
* - Modifier letter (Lm);
* - Other letter (Lo);
* - Letter number (Nl).
*
* See also:
* ECMA-262 v5, 7.6
*
* @return true - if specified character falls into one of the listed categories,
* false - otherwise.
*/
static bool
lit_char_is_unicode_letter (ecma_char_t c) /**< code unit */
{
return (search_char_in_interval_array (c, unicode_letter_interv_sps, unicode_letter_interv_lens,
NUM_OF_ELEMENTS (unicode_letter_interv_sps))
|| search_char_in_char_array (c, unicode_letter_chars, NUM_OF_ELEMENTS (unicode_letter_chars)));
} /* lit_char_is_unicode_letter */
/**
* Check if specified character is a non-letter character and can be used as a
* non-first character of an identifier.
* These characters coverd by the following unicode categories:
* - digit (Nd)
* - punctuation mark (Mn, Mc)
* - connector punctuation (Pc)
*
* See also:
* ECMA-262 v5, 7.6
*
* @return true - if specified character falls into one of the listed categories,
* false - otherwise.
*/
static bool
lit_char_is_unicode_non_letter_ident_part (ecma_char_t c) /**< code unit */
{
return (search_char_in_interval_array (c, unicode_non_letter_ident_part_interv_sps,
unicode_non_letter_ident_part_interv_lens,
NUM_OF_ELEMENTS (unicode_non_letter_ident_part_interv_sps))
|| search_char_in_char_array (c, unicode_non_letter_ident_part_chars,
NUM_OF_ELEMENTS (unicode_non_letter_ident_part_chars)));
} /* lit_char_is_unicode_non_letter_ident_part */
/**
* Checks whether the next UTF8 character is a valid identifier start.
*
* @return true if it is.
*/
bool
lit_char_is_identifier_start (const uint8_t *src_p) /**< pointer to a vaild UTF8 character */
{
if (*src_p <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
{
return lit_char_is_identifier_start_character (*src_p);
}
return lit_char_is_identifier_start_character (lit_utf8_peek_next (src_p));
} /* lit_char_is_identifier_start */
/**
* Checks whether the character is a valid identifier start.
*
* @return true if it is.
*/
bool
lit_char_is_identifier_start_character (uint16_t chr) /**< EcmaScript character */
{
// Fast path for ASCII-defined letters
if (chr <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
{
return ((LEXER_TO_ASCII_LOWERCASE (chr) >= LIT_CHAR_LOWERCASE_A
&& LEXER_TO_ASCII_LOWERCASE (chr) <= LIT_CHAR_LOWERCASE_Z)
|| chr == LIT_CHAR_DOLLAR_SIGN
|| chr == LIT_CHAR_UNDERSCORE);
}
return lit_char_is_unicode_letter (chr);
} /* lit_char_is_identifier_start_character */
/**
* Checks whether the next UTF8 character is a valid identifier part.
*
* @return true if it is.
*/
bool
lit_char_is_identifier_part (const uint8_t *src_p) /**< pointer to a vaild UTF8 character */
{
if (*src_p <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
{
return lit_char_is_identifier_part_character (*src_p);
}
return lit_char_is_identifier_part_character (lit_utf8_peek_next (src_p));
} /* lit_char_is_identifier_part */
/**
* Checks whether the character is a valid identifier part.
*
* @return true if it is.
*/
bool
lit_char_is_identifier_part_character (uint16_t chr) /**< EcmaScript character */
{
// Fast path for ASCII-defined letters
if (chr <= LIT_UTF8_1_BYTE_CODE_POINT_MAX)
{
return ((LEXER_TO_ASCII_LOWERCASE (chr) >= LIT_CHAR_LOWERCASE_A
&& LEXER_TO_ASCII_LOWERCASE (chr) <= LIT_CHAR_LOWERCASE_Z)
|| (chr >= LIT_CHAR_0 && chr <= LIT_CHAR_9)
|| chr == LIT_CHAR_DOLLAR_SIGN
|| chr == LIT_CHAR_UNDERSCORE);
}
return (lit_char_is_unicode_letter (chr)
|| lit_char_is_unicode_non_letter_ident_part (chr));
} /* lit_char_is_identifier_part_character */
/**
* Check if specified character is one of OctalDigit characters (ECMA-262 v5, B.1.2)
*
* @return true / false
*/
bool
lit_char_is_octal_digit (ecma_char_t c) /**< code unit */
{
return (c >= LIT_CHAR_ASCII_OCTAL_DIGITS_BEGIN && c <= LIT_CHAR_ASCII_OCTAL_DIGITS_END);
} /* lit_char_is_octal_digit */
/**
* Check if specified character is one of DecimalDigit characters (ECMA-262 v5, 7.8.3)
*
* @return true / false
*/
bool
lit_char_is_decimal_digit (ecma_char_t c) /**< code unit */
{
return (c >= LIT_CHAR_ASCII_DIGITS_BEGIN && c <= LIT_CHAR_ASCII_DIGITS_END);
} /* lit_char_is_decimal_digit */
/**
* Check if specified character is one of HexDigit characters (ECMA-262 v5, 7.8.3)
*
* @return true / false
*/
bool
lit_char_is_hex_digit (ecma_char_t c) /**< code unit */
{
return ((c >= LIT_CHAR_ASCII_DIGITS_BEGIN && c <= LIT_CHAR_ASCII_DIGITS_END)
|| (LEXER_TO_ASCII_LOWERCASE (c) >= LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_BEGIN
&& LEXER_TO_ASCII_LOWERCASE (c) <= LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_END));
} /* lit_char_is_hex_digit */
/**
* Convert a HexDigit character to its numeric value, as defined in ECMA-262 v5, 7.8.3
*
* @return digit value, corresponding to the hex char
*/
uint32_t
lit_char_hex_to_int (ecma_char_t c) /**< code unit, corresponding to
* one of HexDigit characters */
{
JERRY_ASSERT (lit_char_is_hex_digit (c));
if (c >= LIT_CHAR_ASCII_DIGITS_BEGIN && c <= LIT_CHAR_ASCII_DIGITS_END)
{
return (uint32_t) (c - LIT_CHAR_ASCII_DIGITS_BEGIN);
}
else if (c >= LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_BEGIN && c <= LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_END)
{
return (uint32_t) (c - LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_BEGIN + 10);
}
else
{
return (uint32_t) (c - LIT_CHAR_ASCII_UPPERCASE_LETTERS_HEX_BEGIN + 10);
}
} /* lit_char_hex_to_int */
/**
* Converts a character to UTF8 bytes.
*
* @return length of the UTF8 representation.
*/
size_t
lit_char_to_utf8_bytes (uint8_t *dst_p, /**< destination buffer */
ecma_char_t chr) /**< EcmaScript character */
{
if (!(chr & ~LIT_UTF8_1_BYTE_CODE_POINT_MAX))
{
/* 00000000 0xxxxxxx -> 0xxxxxxx */
*dst_p = (uint8_t) chr;
return 1;
}
if (!(chr & ~LIT_UTF8_2_BYTE_CODE_POINT_MAX))
{
/* 00000yyy yyxxxxxx -> 110yyyyy 10xxxxxx */
*(dst_p++) = (uint8_t) (LIT_UTF8_2_BYTE_MARKER | ((chr >> 6) & LIT_UTF8_LAST_5_BITS_MASK));
*dst_p = (uint8_t) (LIT_UTF8_EXTRA_BYTE_MARKER | (chr & LIT_UTF8_LAST_6_BITS_MASK));
return 2;
}
JERRY_ASSERT (!(chr & ~LIT_UTF8_3_BYTE_CODE_POINT_MAX));
/* zzzzyyyy yyxxxxxx -> 1110zzzz 10yyyyyy 10xxxxxx */
*(dst_p++) = (uint8_t) (LIT_UTF8_3_BYTE_MARKER | ((chr >> 12) & LIT_UTF8_LAST_4_BITS_MASK));
*(dst_p++) = (uint8_t) (LIT_UTF8_EXTRA_BYTE_MARKER | ((chr >> 6) & LIT_UTF8_LAST_6_BITS_MASK));
*dst_p = (uint8_t) (LIT_UTF8_EXTRA_BYTE_MARKER | (chr & LIT_UTF8_LAST_6_BITS_MASK));
return 3;
} /* lit_char_to_utf8_bytes */
/**
* Returns the length of the UTF8 representation of a character.
*
* @return length of the UTF8 representation.
*/
size_t
lit_char_get_utf8_length (ecma_char_t chr) /**< EcmaScript character */
{
if (!(chr & ~LIT_UTF8_1_BYTE_CODE_POINT_MAX))
{
/* 00000000 0xxxxxxx */
return 1;
}
if (!(chr & ~LIT_UTF8_2_BYTE_CODE_POINT_MAX))
{
/* 00000yyy yyxxxxxx */
return 2;
}
/* zzzzyyyy yyxxxxxx */
JERRY_ASSERT (!(chr & ~LIT_UTF8_3_BYTE_CODE_POINT_MAX));
return 3;
} /* lit_char_get_utf8_length */
/**
* Parse the next number_of_characters hexadecimal character,
* and construct a code unit from them. The buffer must
* be zero terminated.
*
* @return true if decoding was successful, false otherwise
*/
bool
lit_read_code_unit_from_hex (const lit_utf8_byte_t *buf_p, /**< buffer with characters */
lit_utf8_size_t number_of_characters, /**< number of characters to be read */
ecma_char_ptr_t out_code_unit_p) /**< [out] decoded result */
{
ecma_char_t code_unit = LIT_CHAR_NULL;
JERRY_ASSERT (number_of_characters >= 2 && number_of_characters <= 4);
for (lit_utf8_size_t i = 0; i < number_of_characters; i++)
{
code_unit = (ecma_char_t) (code_unit << 4u);
if (*buf_p >= LIT_CHAR_ASCII_DIGITS_BEGIN
&& *buf_p <= LIT_CHAR_ASCII_DIGITS_END)
{
code_unit |= (ecma_char_t) (*buf_p - LIT_CHAR_ASCII_DIGITS_BEGIN);
}
else if (*buf_p >= LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_BEGIN
&& *buf_p <= LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_END)
{
code_unit |= (ecma_char_t) (*buf_p - (LIT_CHAR_ASCII_LOWERCASE_LETTERS_HEX_BEGIN - 10));
}
else if (*buf_p >= LIT_CHAR_ASCII_UPPERCASE_LETTERS_HEX_BEGIN
&& *buf_p <= LIT_CHAR_ASCII_UPPERCASE_LETTERS_HEX_END)
{
code_unit |= (ecma_char_t) (*buf_p - (LIT_CHAR_ASCII_UPPERCASE_LETTERS_HEX_BEGIN - 10));
}
else
{
return false;
}
buf_p++;
}
*out_code_unit_p = code_unit;
return true;
} /* lit_read_code_unit_from_hex */
/**
* Check if specified character is a word character (part of IsWordChar abstract operation)
*
* See also: ECMA-262 v5, 15.10.2.6 (IsWordChar)
*
* @return true - if the character is a word character
* false - otherwise.
*/
bool
lit_char_is_word_char (ecma_char_t c) /**< code unit */
{
return ((c >= LIT_CHAR_ASCII_LOWERCASE_LETTERS_BEGIN && c <= LIT_CHAR_ASCII_LOWERCASE_LETTERS_END)
|| (c >= LIT_CHAR_ASCII_UPPERCASE_LETTERS_BEGIN && c <= LIT_CHAR_ASCII_UPPERCASE_LETTERS_END)
|| (c >= LIT_CHAR_ASCII_DIGITS_BEGIN && c <= LIT_CHAR_ASCII_DIGITS_END)
|| c == LIT_CHAR_UNDERSCORE);
} /* lit_char_is_word_char */
/**
* Returns the lowercase character sequence of an ecma character.
*
* Note: output_buffer_p must be able to hold at least LIT_MAXIMUM_OTHER_CASE_LENGTH characters.
*
* @return the length of the lowercase character sequence
* which is always between 1 and LIT_MAXIMUM_OTHER_CASE_LENGTH.
*/
ecma_length_t
lit_char_to_lower_case (ecma_char_t character, /**< input character value */
ecma_char_t *output_buffer_p, /**< [out] buffer for the result characters */
ecma_length_t buffer_size) /**< buffer size */
{
/* TODO: Needs a proper lower case implementation. See issue #323. */
JERRY_ASSERT (buffer_size >= LIT_MAXIMUM_OTHER_CASE_LENGTH);
if (character >= LIT_CHAR_UPPERCASE_A && character <= LIT_CHAR_UPPERCASE_Z)
{
output_buffer_p[0] = (ecma_char_t) (character + (LIT_CHAR_LOWERCASE_A - LIT_CHAR_UPPERCASE_A));
return 1;
}
output_buffer_p[0] = character;
return 1;
} /* lit_char_to_lower_case */
/**
* Returns the uppercase character sequence of an ecma character.
*
* Note: output_buffer_p must be able to hold at least LIT_MAXIMUM_OTHER_CASE_LENGTH characters.
*
* @return the length of the uppercase character sequence
* which is always between 1 and LIT_MAXIMUM_OTHER_CASE_LENGTH.
*/
ecma_length_t
lit_char_to_upper_case (ecma_char_t character, /**< input character value */
ecma_char_t *output_buffer_p, /**< buffer for the result characters */
ecma_length_t buffer_size) /**< buffer size */
{
/* TODO: Needs a proper upper case implementation. See issue #323. */
JERRY_ASSERT (buffer_size >= LIT_MAXIMUM_OTHER_CASE_LENGTH);
if (character >= LIT_CHAR_LOWERCASE_A && character <= LIT_CHAR_LOWERCASE_Z)
{
output_buffer_p[0] = (ecma_char_t) (character - (LIT_CHAR_LOWERCASE_A - LIT_CHAR_UPPERCASE_A));
return 1;
}
output_buffer_p[0] = character;
return 1;
} /* lit_char_to_upper_case */