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Merged
zherczeg merged 1 commit into from
Nov 8, 2018
Merged

Use binary search for keyword checking #2584

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123 changes: 71 additions & 52 deletions jerry-core/parser/js/js-lexer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -309,37 +309,35 @@ typedef struct
* Keyword defines
*/
#define LEXER_KEYWORD(name, type) { (const uint8_t *) (name), (type) }
#define LEXER_KEYWORD_END() { (const uint8_t *) NULL, LEXER_EOS }
#define LEXER_KEYWORD_LIST_LENGTH(name) (const uint8_t) (sizeof ((name)) / sizeof ((name)[0]))
/** @} */

/**
* Keywords with 2 characters.
*/
static const keyword_string_t keyword_length_2[4] =
static const keyword_string_t keywords_with_length_2[] =
{
LEXER_KEYWORD ("do", LEXER_KEYW_DO),
LEXER_KEYWORD ("if", LEXER_KEYW_IF),
LEXER_KEYWORD ("in", LEXER_KEYW_IN),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 3 characters.
*/
static const keyword_string_t keyword_length_3[6] =
static const keyword_string_t keywords_with_length_3[] =
{
LEXER_KEYWORD ("for", LEXER_KEYW_FOR),
LEXER_KEYWORD ("let", LEXER_KEYW_LET),
LEXER_KEYWORD ("new", LEXER_KEYW_NEW),
LEXER_KEYWORD ("try", LEXER_KEYW_TRY),
LEXER_KEYWORD ("var", LEXER_KEYW_VAR),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 4 characters.
*/
static const keyword_string_t keyword_length_4[9] =
static const keyword_string_t keywords_with_length_4[] =
{
LEXER_KEYWORD ("case", LEXER_KEYW_CASE),
LEXER_KEYWORD ("else", LEXER_KEYW_ELSE),
Expand All @@ -349,22 +347,12 @@ static const keyword_string_t keyword_length_4[9] =
LEXER_KEYWORD ("true", LEXER_LIT_TRUE),
LEXER_KEYWORD ("void", LEXER_KEYW_VOID),
LEXER_KEYWORD ("with", LEXER_KEYW_WITH),
LEXER_KEYWORD_END ()
};

#ifndef CONFIG_DISABLE_ES2015
/**
* Number of keywords with 5 characters.
*/
#define KEYWORD_LENGTH_COUNT 11
#else /* CONFIG_DISABLE_ES2015 */
#define KEYWORD_LENGTH_COUNT 10
#endif /* !CONFIG_DISABLE_ES2015 */

/**
* Keywords with 5 characters.
*/
static const keyword_string_t keyword_length_5[KEYWORD_LENGTH_COUNT] =
static const keyword_string_t keywords_with_length_5[] =
{
#ifndef CONFIG_DISABLE_ES2015
LEXER_KEYWORD ("await", LEXER_KEYW_AWAIT),
Expand All @@ -378,13 +366,12 @@ static const keyword_string_t keyword_length_5[KEYWORD_LENGTH_COUNT] =
LEXER_KEYWORD ("throw", LEXER_KEYW_THROW),
LEXER_KEYWORD ("while", LEXER_KEYW_WHILE),
LEXER_KEYWORD ("yield", LEXER_KEYW_YIELD),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 6 characters.
*/
static const keyword_string_t keyword_length_6[9] =
static const keyword_string_t keywords_with_length_6[] =
{
LEXER_KEYWORD ("delete", LEXER_KEYW_DELETE),
LEXER_KEYWORD ("export", LEXER_KEYW_EXPORT),
Expand All @@ -394,71 +381,82 @@ static const keyword_string_t keyword_length_6[9] =
LEXER_KEYWORD ("static", LEXER_KEYW_STATIC),
LEXER_KEYWORD ("switch", LEXER_KEYW_SWITCH),
LEXER_KEYWORD ("typeof", LEXER_KEYW_TYPEOF),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 7 characters.
*/
static const keyword_string_t keyword_length_7[6] =
static const keyword_string_t keywords_with_length_7[] =
{
LEXER_KEYWORD ("default", LEXER_KEYW_DEFAULT),
LEXER_KEYWORD ("extends", LEXER_KEYW_EXTENDS),
LEXER_KEYWORD ("finally", LEXER_KEYW_FINALLY),
LEXER_KEYWORD ("package", LEXER_KEYW_PACKAGE),
LEXER_KEYWORD ("private", LEXER_KEYW_PRIVATE),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 8 characters.
*/
static const keyword_string_t keyword_length_8[4] =
static const keyword_string_t keywords_with_length_8[] =
{
LEXER_KEYWORD ("continue", LEXER_KEYW_CONTINUE),
LEXER_KEYWORD ("debugger", LEXER_KEYW_DEBUGGER),
LEXER_KEYWORD ("function", LEXER_KEYW_FUNCTION),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 9 characters.
*/
static const keyword_string_t keyword_length_9[3] =
static const keyword_string_t keywords_with_length_9[] =
{
LEXER_KEYWORD ("interface", LEXER_KEYW_INTERFACE),
LEXER_KEYWORD ("protected", LEXER_KEYW_PROTECTED),
LEXER_KEYWORD_END ()
};

/**
* Keywords with 10 characters.
*/
static const keyword_string_t keyword_length_10[3] =
static const keyword_string_t keywords_with_length_10[] =
{
LEXER_KEYWORD ("implements", LEXER_KEYW_IMPLEMENTS),
LEXER_KEYWORD ("instanceof", LEXER_KEYW_INSTANCEOF),
LEXER_KEYWORD_END ()
};

/**
* List to the keywords.
* List of the keyword groups.
*/
static const keyword_string_t * const keyword_strings_list[] =
{
keywords_with_length_2,
keywords_with_length_3,
keywords_with_length_4,
keywords_with_length_5,
keywords_with_length_6,
keywords_with_length_7,
keywords_with_length_8,
keywords_with_length_9,
keywords_with_length_10
};

/**
* List of the keyword groups length.
*/
static const keyword_string_t * const keyword_string_list[9] =
static const uint8_t keyword_lengths_list[] =
{
keyword_length_2,
keyword_length_3,
keyword_length_4,
keyword_length_5,
keyword_length_6,
keyword_length_7,
keyword_length_8,
keyword_length_9,
keyword_length_10
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_2),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_3),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_4),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_5),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_6),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_7),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_8),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_9),
LEXER_KEYWORD_LIST_LENGTH (keywords_with_length_10)
};

#undef LEXER_KEYWORD
#undef LEXER_KEYWORD_END
#undef LEXER_KEYWORD_LIST_LENGTH

/**
* Parse identifier.
Expand Down Expand Up @@ -551,31 +549,52 @@ lexer_parse_identifier (parser_context_t *context_p, /**< context */
&& !context_p->token.lit_location.has_escape
&& (length >= 2 && length <= 10))
{
const keyword_string_t *keyword_p = keyword_string_list[length - 2];
const keyword_string_t *keyword_list_p = keyword_strings_list[length - 2];

int start = 0;
int end = keyword_lengths_list[length - 2];
int middle = end / 2;

do
{
if (ident_start_p[0] == keyword_p->keyword_p[0]
&& ident_start_p[1] == keyword_p->keyword_p[1]
&& memcmp (ident_start_p, keyword_p->keyword_p, length) == 0)
const keyword_string_t *keyword_p = keyword_list_p + middle;
int compare_result = ident_start_p[0] - keyword_p->keyword_p[0];

if (compare_result == 0)
{
if (keyword_p->type >= LEXER_FIRST_FUTURE_STRICT_RESERVED_WORD)
compare_result = memcmp (ident_start_p, keyword_p->keyword_p, length);

if (compare_result == 0)
{
if (context_p->status_flags & PARSER_IS_STRICT)
if (JERRY_UNLIKELY (keyword_p->type >= LEXER_FIRST_FUTURE_STRICT_RESERVED_WORD))
{
parser_raise_error (context_p, PARSER_ERR_STRICT_IDENT_NOT_ALLOWED);
if (context_p->status_flags & PARSER_IS_STRICT)
{
parser_raise_error (context_p, PARSER_ERR_STRICT_IDENT_NOT_ALLOWED);
}

context_p->token.literal_is_reserved = true;
break;
}

context_p->token.literal_is_reserved = true;
context_p->token.type = (uint8_t) keyword_p->type;
break;
}
}

context_p->token.type = (uint8_t) keyword_p->type;
break;
if (compare_result > 0)
{
start = middle + 1;
}
else
{
JERRY_ASSERT (compare_result < 0);
end = middle;
}
keyword_p++;

middle = (start + end) / 2;
}
while (keyword_p->type != LEXER_EOS);
while (start < end);
}

if (context_p->token.type == LEXER_LITERAL)
Expand Down