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/*
* Heap string representation.
*
* Strings are byte sequences ordinarily stored in extended UTF-8 format,
* allowing values larger than the official UTF-8 range (used internally)
* and also allowing UTF-8 encoding of surrogate pairs (CESU-8 format).
* Strings may also be invalid UTF-8 altogether which is the case e.g. with
* strings used as internal property names and raw buffers converted to
* strings. In such cases the 'clen' field contains an inaccurate value.
*
* ECMAScript requires support for 32-bit long strings. However, since each
* 16-bit codepoint can take 3 bytes in CESU-8, this representation can only
* support about 1.4G codepoint long strings in extreme cases. This is not
* really a practical issue.
*/
#if !defined(DUK_HSTRING_H_INCLUDED)
#define DUK_HSTRING_H_INCLUDED
/* Impose a maximum string length for now. Restricted artificially to
* ensure adding a heap header length won't overflow size_t. The limit
* should be synchronized with DUK_HBUFFER_MAX_BYTELEN.
*
* E5.1 makes provisions to support strings longer than 4G characters.
* This limit should be eliminated on 64-bit platforms (and increased
* closer to maximum support on 32-bit platforms).
*/
#if defined(DUK_USE_STRLEN16)
#define DUK_HSTRING_MAX_BYTELEN (0x0000ffffUL)
#else
#define DUK_HSTRING_MAX_BYTELEN (0x7fffffffUL)
#endif
/* XXX: could add flags for "is valid CESU-8" (ECMAScript compatible strings),
* "is valid UTF-8", "is valid extended UTF-8" (internal strings are not,
* regexp bytecode is), and "contains non-BMP characters". These are not
* needed right now.
*/
/* With lowmem builds the high 16 bits of duk_heaphdr are used for other
* purposes, so this leaves 7 duk_heaphdr flags and 9 duk_hstring flags.
*/
#define DUK_HSTRING_FLAG_ASCII DUK_HEAPHDR_USER_FLAG(0) /* string is ASCII, clen == blen */
#define DUK_HSTRING_FLAG_ARRIDX DUK_HEAPHDR_USER_FLAG(1) /* string is a valid array index */
#define DUK_HSTRING_FLAG_SYMBOL DUK_HEAPHDR_USER_FLAG(2) /* string is a symbol (invalid utf-8) */
#define DUK_HSTRING_FLAG_HIDDEN \
DUK_HEAPHDR_USER_FLAG(3) /* string is a hidden symbol (implies symbol, Duktape 1.x internal string) */
#define DUK_HSTRING_FLAG_RESERVED_WORD DUK_HEAPHDR_USER_FLAG(4) /* string is a reserved word (non-strict) */
#define DUK_HSTRING_FLAG_STRICT_RESERVED_WORD DUK_HEAPHDR_USER_FLAG(5) /* string is a reserved word (strict) */
#define DUK_HSTRING_FLAG_EVAL_OR_ARGUMENTS DUK_HEAPHDR_USER_FLAG(6) /* string is 'eval' or 'arguments' */
#define DUK_HSTRING_FLAG_EXTDATA DUK_HEAPHDR_USER_FLAG(7) /* string data is external (duk_hstring_external) */
#define DUK_HSTRING_FLAG_PINNED_LITERAL DUK_HEAPHDR_USER_FLAG(8) /* string is a literal, and pinned */
#define DUK_HSTRING_HAS_ASCII(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_ASCII)
#define DUK_HSTRING_HAS_ARRIDX(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_ARRIDX)
#define DUK_HSTRING_HAS_SYMBOL(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_SYMBOL)
#define DUK_HSTRING_HAS_HIDDEN(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_HIDDEN)
#define DUK_HSTRING_HAS_RESERVED_WORD(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_RESERVED_WORD)
#define DUK_HSTRING_HAS_STRICT_RESERVED_WORD(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_STRICT_RESERVED_WORD)
#define DUK_HSTRING_HAS_EVAL_OR_ARGUMENTS(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_EVAL_OR_ARGUMENTS)
#define DUK_HSTRING_HAS_EXTDATA(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_EXTDATA)
#define DUK_HSTRING_HAS_PINNED_LITERAL(x) DUK_HEAPHDR_CHECK_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_PINNED_LITERAL)
#define DUK_HSTRING_SET_ASCII(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_ASCII)
#define DUK_HSTRING_SET_ARRIDX(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_ARRIDX)
#define DUK_HSTRING_SET_SYMBOL(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_SYMBOL)
#define DUK_HSTRING_SET_HIDDEN(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_HIDDEN)
#define DUK_HSTRING_SET_RESERVED_WORD(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_RESERVED_WORD)
#define DUK_HSTRING_SET_STRICT_RESERVED_WORD(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_STRICT_RESERVED_WORD)
#define DUK_HSTRING_SET_EVAL_OR_ARGUMENTS(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_EVAL_OR_ARGUMENTS)
#define DUK_HSTRING_SET_EXTDATA(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_EXTDATA)
#define DUK_HSTRING_SET_PINNED_LITERAL(x) DUK_HEAPHDR_SET_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_PINNED_LITERAL)
#define DUK_HSTRING_CLEAR_ASCII(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_ASCII)
#define DUK_HSTRING_CLEAR_ARRIDX(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_ARRIDX)
#define DUK_HSTRING_CLEAR_SYMBOL(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_SYMBOL)
#define DUK_HSTRING_CLEAR_HIDDEN(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_HIDDEN)
#define DUK_HSTRING_CLEAR_RESERVED_WORD(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_RESERVED_WORD)
#define DUK_HSTRING_CLEAR_STRICT_RESERVED_WORD(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_STRICT_RESERVED_WORD)
#define DUK_HSTRING_CLEAR_EVAL_OR_ARGUMENTS(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_EVAL_OR_ARGUMENTS)
#define DUK_HSTRING_CLEAR_EXTDATA(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_EXTDATA)
#define DUK_HSTRING_CLEAR_PINNED_LITERAL(x) DUK_HEAPHDR_CLEAR_FLAG_BITS(&(x)->hdr, DUK_HSTRING_FLAG_PINNED_LITERAL)
#if 0 /* Slightly smaller code without explicit flag, but explicit flag \
* is very useful when 'clen' is dropped. \
*/
#define DUK_HSTRING_IS_ASCII(x) (DUK_HSTRING_GET_BYTELEN((x)) == DUK_HSTRING_GET_CHARLEN((x)))
#endif
#define DUK_HSTRING_IS_ASCII(x) DUK_HSTRING_HAS_ASCII((x)) /* lazily set! */
#define DUK_HSTRING_IS_EMPTY(x) (DUK_HSTRING_GET_BYTELEN((x)) == 0)
#if defined(DUK_USE_STRHASH16)
#define DUK_HSTRING_GET_HASH(x) ((x)->hdr.h_flags >> 16)
#define DUK_HSTRING_SET_HASH(x, v) \
do { \
(x)->hdr.h_flags = ((x)->hdr.h_flags & 0x0000ffffUL) | ((v) << 16); \
} while (0)
#else
#define DUK_HSTRING_GET_HASH(x) ((x)->hash)
#define DUK_HSTRING_SET_HASH(x, v) \
do { \
(x)->hash = (v); \
} while (0)
#endif
#if defined(DUK_USE_STRLEN16)
#define DUK_HSTRING_GET_BYTELEN(x) ((x)->hdr.h_strextra16)
#define DUK_HSTRING_SET_BYTELEN(x, v) \
do { \
(x)->hdr.h_strextra16 = (v); \
} while (0)
#if defined(DUK_USE_HSTRING_CLEN)
#define DUK_HSTRING_GET_CHARLEN(x) duk_hstring_get_charlen((x))
#define DUK_HSTRING_SET_CHARLEN(x, v) \
do { \
(x)->clen16 = (v); \
} while (0)
#else
#define DUK_HSTRING_GET_CHARLEN(x) duk_hstring_get_charlen((x))
#define DUK_HSTRING_SET_CHARLEN(x, v) \
do { \
DUK_ASSERT(0); /* should never be called */ \
} while (0)
#endif
#else
#define DUK_HSTRING_GET_BYTELEN(x) ((x)->blen)
#define DUK_HSTRING_SET_BYTELEN(x, v) \
do { \
(x)->blen = (v); \
} while (0)
#define DUK_HSTRING_GET_CHARLEN(x) duk_hstring_get_charlen((x))
#define DUK_HSTRING_SET_CHARLEN(x, v) \
do { \
(x)->clen = (v); \
} while (0)
#endif
#if defined(DUK_USE_HSTRING_EXTDATA)
#define DUK_HSTRING_GET_EXTDATA(x) ((x)->extdata)
#define DUK_HSTRING_GET_DATA(x) \
(DUK_HSTRING_HAS_EXTDATA((x)) ? DUK_HSTRING_GET_EXTDATA((const duk_hstring_external *) (x)) : \
((const duk_uint8_t *) ((x) + 1)))
#else
#define DUK_HSTRING_GET_DATA(x) ((const duk_uint8_t *) ((x) + 1))
#endif
#define DUK_HSTRING_GET_DATA_END(x) (DUK_HSTRING_GET_DATA((x)) + (x)->blen)
/* Marker value; in E5 2^32-1 is not a valid array index (2^32-2 is highest
* valid).
*/
#define DUK_HSTRING_NO_ARRAY_INDEX (0xffffffffUL)
#if defined(DUK_USE_HSTRING_ARRIDX)
#define DUK_HSTRING_GET_ARRIDX_FAST(h) ((h)->arridx)
#define DUK_HSTRING_GET_ARRIDX_SLOW(h) ((h)->arridx)
#else
/* Get array index related to string (or return DUK_HSTRING_NO_ARRAY_INDEX);
* avoids helper call if string has no array index value.
*/
#define DUK_HSTRING_GET_ARRIDX_FAST(h) \
(DUK_HSTRING_HAS_ARRIDX((h)) ? duk_js_to_arrayindex_hstring_fast_known((h)) : DUK_HSTRING_NO_ARRAY_INDEX)
/* Slower but more compact variant. */
#define DUK_HSTRING_GET_ARRIDX_SLOW(h) (duk_js_to_arrayindex_hstring_fast((h)))
#endif
/* XXX: these actually fit into duk_hstring */
#define DUK_SYMBOL_TYPE_HIDDEN 0
#define DUK_SYMBOL_TYPE_GLOBAL 1
#define DUK_SYMBOL_TYPE_LOCAL 2
#define DUK_SYMBOL_TYPE_WELLKNOWN 3
/* Assertion for duk_hstring validity. */
#if defined(DUK_USE_ASSERTIONS)
DUK_INTERNAL_DECL void duk_hstring_assert_valid(duk_hstring *h);
#define DUK_HSTRING_ASSERT_VALID(h) \
do { \
duk_hstring_assert_valid((h)); \
} while (0)
#else
#define DUK_HSTRING_ASSERT_VALID(h) \
do { \
} while (0)
#endif
/*
* Misc
*/
struct duk_hstring {
/* Smaller heaphdr than for other objects, because strings are held
* in string intern table which requires no link pointers. Much of
* the 32-bit flags field is unused by flags, so we can stuff a 16-bit
* field in there.
*/
duk_heaphdr_string hdr;
/* String hash. */
#if defined(DUK_USE_STRHASH16)
/* If 16-bit hash is in use, stuff it into duk_heaphdr_string flags. */
#else
duk_uint32_t hash;
#endif
/* Precomputed array index (or DUK_HSTRING_NO_ARRAY_INDEX). */
#if defined(DUK_USE_HSTRING_ARRIDX)
duk_uarridx_t arridx;
#endif
/* Length in bytes (not counting NUL term). */
#if defined(DUK_USE_STRLEN16)
/* placed in duk_heaphdr_string */
#else
duk_uint32_t blen;
#endif
/* Length in codepoints (must be E5 compatible). */
#if defined(DUK_USE_STRLEN16)
#if defined(DUK_USE_HSTRING_CLEN)
duk_uint16_t clen16;
#else
/* computed live */
#endif
#else
duk_uint32_t clen;
#endif
/*
* String data of 'blen+1' bytes follows (+1 for NUL termination
* convenience for C API). No alignment needs to be guaranteed
* for strings, but fields above should guarantee alignment-by-4
* (but not alignment-by-8).
*/
};
/* The external string struct is defined even when the feature is inactive. */
struct duk_hstring_external {
duk_hstring str;
/*
* For an external string, the NUL-terminated string data is stored
* externally. The user must guarantee that data behind this pointer
* doesn't change while it's used.
*/
const duk_uint8_t *extdata;
};
/*
* Prototypes
*/
DUK_INTERNAL_DECL duk_ucodepoint_t duk_hstring_char_code_at_raw(duk_hthread *thr,
duk_hstring *h,
duk_uint_t pos,
duk_bool_t surrogate_aware);
DUK_INTERNAL_DECL duk_bool_t duk_hstring_equals_ascii_cstring(duk_hstring *h, const char *cstr);
DUK_INTERNAL_DECL duk_size_t duk_hstring_get_charlen(duk_hstring *h);
#if !defined(DUK_USE_HSTRING_LAZY_CLEN)
DUK_INTERNAL_DECL void duk_hstring_init_charlen(duk_hstring *h);
#endif
#endif /* DUK_HSTRING_H_INCLUDED */
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