blob: bf437507f270b76055c2c4f3f5bf428bc937b21c [file] [log] [blame]
/*
* String built-ins
*/
/* XXX: There are several limitations in the current implementation for
* strings with >= 0x80000000UL characters. In some cases one would need
* to be able to represent the range [-0xffffffff,0xffffffff] and so on.
* Generally character and byte length are assumed to fit into signed 32
* bits (< 0x80000000UL). Places with issues are not marked explicitly
* below in all cases, look for signed type usage (duk_int_t etc) for
* offsets/lengths.
*/
#include "duk_internal.h"
/*
* Constructor
*/
DUK_INTERNAL duk_ret_t duk_bi_string_constructor(duk_context *ctx) {
/* String constructor needs to distinguish between an argument not given at all
* vs. given as 'undefined'. We're a vararg function to handle this properly.
*/
if (duk_get_top(ctx) == 0) {
duk_push_hstring_stridx(ctx, DUK_STRIDX_EMPTY_STRING);
} else {
duk_to_string(ctx, 0);
}
DUK_ASSERT(duk_is_string(ctx, 0));
duk_set_top(ctx, 1);
if (duk_is_constructor_call(ctx)) {
duk_push_object_helper(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_EXOTIC_STRINGOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_STRING),
DUK_BIDX_STRING_PROTOTYPE);
/* String object internal value is immutable */
duk_dup(ctx, 0);
duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_VALUE, DUK_PROPDESC_FLAGS_NONE);
}
/* Note: unbalanced stack on purpose */
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_string_constructor_from_char_code(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_bufwriter_ctx bw_alloc;
duk_bufwriter_ctx *bw;
duk_idx_t i, n;
duk_ucodepoint_t cp;
/* XXX: It would be nice to build the string directly but ToUint16()
* coercion is needed so a generic helper would not be very
* helpful (perhaps coerce the value stack first here and then
* build a string from a duk_tval number sequence in one go?).
*/
n = duk_get_top(ctx);
bw = &bw_alloc;
DUK_BW_INIT_PUSHBUF(thr, bw, n); /* initial estimate for ASCII only codepoints */
for (i = 0; i < n; i++) {
/* XXX: could improve bufwriter handling to write multiple codepoints
* with one ensure call but the relative benefit would be quite small.
*/
#if defined(DUK_USE_NONSTD_STRING_FROMCHARCODE_32BIT)
/* ToUint16() coercion is mandatory in the E5.1 specification, but
* this non-compliant behavior makes more sense because we support
* non-BMP codepoints. Don't use CESU-8 because that'd create
* surrogate pairs.
*/
cp = (duk_ucodepoint_t) duk_to_uint32(ctx, i);
DUK_BW_WRITE_ENSURE_XUTF8(thr, bw, cp);
#else
cp = (duk_ucodepoint_t) duk_to_uint16(ctx, i);
DUK_BW_WRITE_ENSURE_CESU8(thr, bw, cp);
#endif
}
DUK_BW_COMPACT(thr, bw);
duk_to_string(ctx, -1);
return 1;
}
/*
* toString(), valueOf()
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_to_string(duk_context *ctx) {
duk_tval *tv;
duk_push_this(ctx);
tv = duk_require_tval(ctx, -1);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_STRING(tv)) {
/* return as is */
return 1;
} else if (DUK_TVAL_IS_OBJECT(tv)) {
duk_hobject *h = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h != NULL);
/* Must be a "string object", i.e. class "String" */
if (DUK_HOBJECT_GET_CLASS_NUMBER(h) != DUK_HOBJECT_CLASS_STRING) {
goto type_error;
}
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INT_VALUE);
DUK_ASSERT(duk_is_string(ctx, -1));
return 1;
} else {
goto type_error;
}
/* never here, but fall through */
type_error:
return DUK_RET_TYPE_ERROR;
}
/*
* Character and charcode access
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_char_at(duk_context *ctx) {
duk_int_t pos;
/* XXX: faster implementation */
(void) duk_push_this_coercible_to_string(ctx);
pos = duk_to_int(ctx, 0);
duk_substring(ctx, -1, pos, pos + 1);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_char_code_at(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_int_t pos;
duk_hstring *h;
duk_bool_t clamped;
/* XXX: faster implementation */
DUK_DDD(DUK_DDDPRINT("arg=%!T", (duk_tval *) duk_get_tval(ctx, 0)));
h = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h != NULL);
pos = duk_to_int_clamped_raw(ctx,
0 /*index*/,
0 /*min(incl)*/,
DUK_HSTRING_GET_CHARLEN(h) - 1 /*max(incl)*/,
&clamped /*out_clamped*/);
if (clamped) {
duk_push_number(ctx, DUK_DOUBLE_NAN);
return 1;
}
duk_push_u32(ctx, (duk_uint32_t) duk_hstring_char_code_at_raw(thr, h, pos));
return 1;
}
/*
* substring(), substr(), slice()
*/
/* XXX: any chance of merging these three similar but still slightly
* different algorithms so that footprint would be reduced?
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_substring(duk_context *ctx) {
duk_hstring *h;
duk_int_t start_pos, end_pos;
duk_int_t len;
h = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h != NULL);
len = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h);
/* [ start end str ] */
start_pos = duk_to_int_clamped(ctx, 0, 0, len);
if (duk_is_undefined(ctx, 1)) {
end_pos = len;
} else {
end_pos = duk_to_int_clamped(ctx, 1, 0, len);
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
DUK_ASSERT(end_pos >= 0 && end_pos <= len);
if (start_pos > end_pos) {
duk_int_t tmp = start_pos;
start_pos = end_pos;
end_pos = tmp;
}
DUK_ASSERT(end_pos >= start_pos);
duk_substring(ctx, -1, (duk_size_t) start_pos, (duk_size_t) end_pos);
return 1;
}
#ifdef DUK_USE_SECTION_B
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_substr(duk_context *ctx) {
duk_hstring *h;
duk_int_t start_pos, end_pos;
duk_int_t len;
/* Unlike non-obsolete String calls, substr() algorithm in E5.1
* specification will happily coerce undefined and null to strings
* ("undefined" and "null").
*/
duk_push_this(ctx);
h = duk_to_hstring(ctx, -1);
DUK_ASSERT(h != NULL);
len = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h);
/* [ start length str ] */
/* The implementation for computing of start_pos and end_pos differs
* from the standard algorithm, but is intended to result in the exactly
* same behavior. This is not always obvious.
*/
/* combines steps 2 and 5; -len ensures max() not needed for step 5 */
start_pos = duk_to_int_clamped(ctx, 0, -len, len);
if (start_pos < 0) {
start_pos = len + start_pos;
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
/* combines steps 3, 6; step 7 is not needed */
if (duk_is_undefined(ctx, 1)) {
end_pos = len;
} else {
DUK_ASSERT(start_pos <= len);
end_pos = start_pos + duk_to_int_clamped(ctx, 1, 0, len - start_pos);
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
DUK_ASSERT(end_pos >= 0 && end_pos <= len);
DUK_ASSERT(end_pos >= start_pos);
duk_substring(ctx, -1, (duk_size_t) start_pos, (duk_size_t) end_pos);
return 1;
}
#else /* DUK_USE_SECTION_B */
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_substr(duk_context *ctx) {
DUK_UNREF(ctx);
return DUK_RET_UNSUPPORTED_ERROR;
}
#endif /* DUK_USE_SECTION_B */
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_slice(duk_context *ctx) {
duk_hstring *h;
duk_int_t start_pos, end_pos;
duk_int_t len;
h = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h != NULL);
len = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h);
/* [ start end str ] */
start_pos = duk_to_int_clamped(ctx, 0, -len, len);
if (start_pos < 0) {
start_pos = len + start_pos;
}
if (duk_is_undefined(ctx, 1)) {
end_pos = len;
} else {
end_pos = duk_to_int_clamped(ctx, 1, -len, len);
if (end_pos < 0) {
end_pos = len + end_pos;
}
}
DUK_ASSERT(start_pos >= 0 && start_pos <= len);
DUK_ASSERT(end_pos >= 0 && end_pos <= len);
if (end_pos < start_pos) {
end_pos = start_pos;
}
DUK_ASSERT(end_pos >= start_pos);
duk_substring(ctx, -1, (duk_size_t) start_pos, (duk_size_t) end_pos);
return 1;
}
/*
* Case conversion
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_caseconv_shared(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_small_int_t uppercase = duk_get_current_magic(ctx);
(void) duk_push_this_coercible_to_string(ctx);
duk_unicode_case_convert_string(thr, (duk_bool_t) uppercase);
return 1;
}
/*
* indexOf() and lastIndexOf()
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_indexof_shared(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_hstring *h_this;
duk_hstring *h_search;
duk_int_t clen_this;
duk_int_t cpos;
duk_int_t bpos;
const duk_uint8_t *p_start, *p_end, *p;
const duk_uint8_t *q_start;
duk_int_t q_blen;
duk_uint8_t firstbyte;
duk_uint8_t t;
duk_small_int_t is_lastindexof = duk_get_current_magic(ctx); /* 0=indexOf, 1=lastIndexOf */
h_this = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h_this != NULL);
clen_this = (duk_int_t) DUK_HSTRING_GET_CHARLEN(h_this);
h_search = duk_to_hstring(ctx, 0);
DUK_ASSERT(h_search != NULL);
q_start = DUK_HSTRING_GET_DATA(h_search);
q_blen = (duk_int_t) DUK_HSTRING_GET_BYTELEN(h_search);
duk_to_number(ctx, 1);
if (duk_is_nan(ctx, 1) && is_lastindexof) {
/* indexOf: NaN should cause pos to be zero.
* lastIndexOf: NaN should cause pos to be +Infinity
* (and later be clamped to len).
*/
cpos = clen_this;
} else {
cpos = duk_to_int_clamped(ctx, 1, 0, clen_this);
}
/* Empty searchstring always matches; cpos must be clamped here.
* (If q_blen were < 0 due to clamped coercion, it would also be
* caught here.)
*/
if (q_blen <= 0) {
duk_push_int(ctx, cpos);
return 1;
}
DUK_ASSERT(q_blen > 0);
bpos = (duk_int_t) duk_heap_strcache_offset_char2byte(thr, h_this, (duk_uint32_t) cpos);
p_start = DUK_HSTRING_GET_DATA(h_this);
p_end = p_start + DUK_HSTRING_GET_BYTELEN(h_this);
p = p_start + bpos;
/* This loop is optimized for size. For speed, there should be
* two separate loops, and we should ensure that memcmp() can be
* used without an extra "will searchstring fit" check. Doing
* the preconditioning for 'p' and 'p_end' is easy but cpos
* must be updated if 'p' is wound back (backward scanning).
*/
firstbyte = q_start[0]; /* leading byte of match string */
while (p <= p_end && p >= p_start) {
t = *p;
/* For Ecmascript strings, this check can only match for
* initial UTF-8 bytes (not continuation bytes). For other
* strings all bets are off.
*/
if ((t == firstbyte) && ((duk_size_t) (p_end - p) >= (duk_size_t) q_blen)) {
DUK_ASSERT(q_blen > 0); /* no issues with memcmp() zero size, even if broken */
if (DUK_MEMCMP((const void *) p, (const void *) q_start, (size_t) q_blen) == 0) {
duk_push_int(ctx, cpos);
return 1;
}
}
/* track cpos while scanning */
if (is_lastindexof) {
/* when going backwards, we decrement cpos 'early';
* 'p' may point to a continuation byte of the char
* at offset 'cpos', but that's OK because we'll
* backtrack all the way to the initial byte.
*/
if ((t & 0xc0) != 0x80) {
cpos--;
}
p--;
} else {
if ((t & 0xc0) != 0x80) {
cpos++;
}
p++;
}
}
/* Not found. Empty string case is handled specially above. */
duk_push_int(ctx, -1);
return 1;
}
/*
* replace()
*/
/* XXX: the current implementation works but is quite clunky; it compiles
* to almost 1,4kB of x86 code so it needs to be simplified (better approach,
* shared helpers, etc). Some ideas for refactoring:
*
* - a primitive to convert a string into a regexp matcher (reduces matching
* code at the cost of making matching much slower)
* - use replace() as a basic helper for match() and split(), which are both
* much simpler
* - API call to get_prop and to_boolean
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_replace(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_hstring *h_input;
duk_hstring *h_match;
duk_hstring *h_search;
duk_hobject *h_re;
duk_bufwriter_ctx bw_alloc;
duk_bufwriter_ctx *bw;
#ifdef DUK_USE_REGEXP_SUPPORT
duk_bool_t is_regexp;
duk_bool_t is_global;
#endif
duk_bool_t is_repl_func;
duk_uint32_t match_start_coff, match_start_boff;
#ifdef DUK_USE_REGEXP_SUPPORT
duk_int_t match_caps;
#endif
duk_uint32_t prev_match_end_boff;
const duk_uint8_t *r_start, *r_end, *r; /* repl string scan */
duk_size_t tmp_sz;
DUK_ASSERT_TOP(ctx, 2);
h_input = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h_input != NULL);
bw = &bw_alloc;
DUK_BW_INIT_PUSHBUF(thr, bw, DUK_HSTRING_GET_BYTELEN(h_input)); /* input size is good output starting point */
DUK_ASSERT_TOP(ctx, 4);
/* stack[0] = search value
* stack[1] = replace value
* stack[2] = input string
* stack[3] = result buffer
*/
h_re = duk_get_hobject_with_class(ctx, 0, DUK_HOBJECT_CLASS_REGEXP);
if (h_re) {
#ifdef DUK_USE_REGEXP_SUPPORT
is_regexp = 1;
is_global = duk_get_prop_stridx_boolean(ctx, 0, DUK_STRIDX_GLOBAL, NULL);
if (is_global) {
/* start match from beginning */
duk_push_int(ctx, 0);
duk_put_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
}
#else /* DUK_USE_REGEXP_SUPPORT */
return DUK_RET_UNSUPPORTED_ERROR;
#endif /* DUK_USE_REGEXP_SUPPORT */
} else {
duk_to_string(ctx, 0);
#ifdef DUK_USE_REGEXP_SUPPORT
is_regexp = 0;
is_global = 0;
#endif
}
if (duk_is_function(ctx, 1)) {
is_repl_func = 1;
r_start = NULL;
r_end = NULL;
} else {
duk_hstring *h_repl;
is_repl_func = 0;
h_repl = duk_to_hstring(ctx, 1);
DUK_ASSERT(h_repl != NULL);
r_start = DUK_HSTRING_GET_DATA(h_repl);
r_end = r_start + DUK_HSTRING_GET_BYTELEN(h_repl);
}
prev_match_end_boff = 0;
for (;;) {
/*
* If matching with a regexp:
* - non-global RegExp: lastIndex not touched on a match, zeroed
* on a non-match
* - global RegExp: on match, lastIndex will be updated by regexp
* executor to point to next char after the matching part (so that
* characters in the matching part are not matched again)
*
* If matching with a string:
* - always non-global match, find first occurrence
*
* We need:
* - The character offset of start-of-match for the replacer function
* - The byte offsets for start-of-match and end-of-match to implement
* the replacement values $&, $`, and $', and to copy non-matching
* input string portions (including header and trailer) verbatim.
*
* NOTE: the E5.1 specification is a bit vague how the RegExp should
* behave in the replacement process; e.g. is matching done first for
* all matches (in the global RegExp case) before any replacer calls
* are made? See: test-bi-string-proto-replace.js for discussion.
*/
DUK_ASSERT_TOP(ctx, 4);
#ifdef DUK_USE_REGEXP_SUPPORT
if (is_regexp) {
duk_dup(ctx, 0);
duk_dup(ctx, 2);
duk_regexp_match(thr); /* [ ... regexp input ] -> [ res_obj ] */
if (!duk_is_object(ctx, -1)) {
duk_pop(ctx);
break;
}
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INDEX);
DUK_ASSERT(duk_is_number(ctx, -1));
match_start_coff = duk_get_int(ctx, -1);
duk_pop(ctx);
duk_get_prop_index(ctx, -1, 0);
DUK_ASSERT(duk_is_string(ctx, -1));
h_match = duk_get_hstring(ctx, -1);
DUK_ASSERT(h_match != NULL);
duk_pop(ctx); /* h_match is borrowed, remains reachable through match_obj */
if (DUK_HSTRING_GET_BYTELEN(h_match) == 0) {
/* This should be equivalent to match() algorithm step 8.f.iii.2:
* detect an empty match and allow it, but don't allow it twice.
*/
duk_uint32_t last_index;
duk_get_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
last_index = (duk_uint32_t) duk_get_uint(ctx, -1);
DUK_DDD(DUK_DDDPRINT("empty match, bump lastIndex: %ld -> %ld",
(long) last_index, (long) (last_index + 1)));
duk_pop(ctx);
duk_push_int(ctx, last_index + 1);
duk_put_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
}
DUK_ASSERT(duk_get_length(ctx, -1) <= DUK_INT_MAX); /* string limits */
match_caps = (duk_int_t) duk_get_length(ctx, -1);
} else {
#else /* DUK_USE_REGEXP_SUPPORT */
{ /* unconditionally */
#endif /* DUK_USE_REGEXP_SUPPORT */
const duk_uint8_t *p_start, *p_end, *p; /* input string scan */
const duk_uint8_t *q_start; /* match string */
duk_size_t q_blen;
#ifdef DUK_USE_REGEXP_SUPPORT
DUK_ASSERT(!is_global); /* single match always */
#endif
p_start = DUK_HSTRING_GET_DATA(h_input);
p_end = p_start + DUK_HSTRING_GET_BYTELEN(h_input);
p = p_start;
h_search = duk_get_hstring(ctx, 0);
DUK_ASSERT(h_search != NULL);
q_start = DUK_HSTRING_GET_DATA(h_search);
q_blen = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h_search);
p_end -= q_blen; /* ensure full memcmp() fits in while */
match_start_coff = 0;
while (p <= p_end) {
DUK_ASSERT(p + q_blen <= DUK_HSTRING_GET_DATA(h_input) + DUK_HSTRING_GET_BYTELEN(h_input));
if (DUK_MEMCMP((const void *) p, (const void *) q_start, (size_t) q_blen) == 0) {
duk_dup(ctx, 0);
h_match = duk_get_hstring(ctx, -1);
DUK_ASSERT(h_match != NULL);
#ifdef DUK_USE_REGEXP_SUPPORT
match_caps = 0;
#endif
goto found;
}
/* track utf-8 non-continuation bytes */
if ((p[0] & 0xc0) != 0x80) {
match_start_coff++;
}
p++;
}
/* not found */
break;
}
found:
/* stack[0] = search value
* stack[1] = replace value
* stack[2] = input string
* stack[3] = result buffer
* stack[4] = regexp match OR match string
*/
match_start_boff = duk_heap_strcache_offset_char2byte(thr, h_input, match_start_coff);
tmp_sz = (duk_size_t) (match_start_boff - prev_match_end_boff);
DUK_BW_WRITE_ENSURE_BYTES(thr, bw, DUK_HSTRING_GET_DATA(h_input) + prev_match_end_boff, tmp_sz);
prev_match_end_boff = match_start_boff + DUK_HSTRING_GET_BYTELEN(h_match);
if (is_repl_func) {
duk_idx_t idx_args;
duk_hstring *h_repl;
/* regexp res_obj is at index 4 */
duk_dup(ctx, 1);
idx_args = duk_get_top(ctx);
#ifdef DUK_USE_REGEXP_SUPPORT
if (is_regexp) {
duk_int_t idx;
duk_require_stack(ctx, match_caps + 2);
for (idx = 0; idx < match_caps; idx++) {
/* match followed by capture(s) */
duk_get_prop_index(ctx, 4, idx);
}
} else {
#else /* DUK_USE_REGEXP_SUPPORT */
{ /* unconditionally */
#endif /* DUK_USE_REGEXP_SUPPORT */
/* match == search string, by definition */
duk_dup(ctx, 0);
}
duk_push_int(ctx, match_start_coff);
duk_dup(ctx, 2);
/* [ ... replacer match [captures] match_char_offset input ] */
duk_call(ctx, duk_get_top(ctx) - idx_args);
h_repl = duk_to_hstring(ctx, -1); /* -> [ ... repl_value ] */
DUK_ASSERT(h_repl != NULL);
DUK_BW_WRITE_ENSURE_HSTRING(thr, bw, h_repl);
duk_pop(ctx); /* repl_value */
} else {
r = r_start;
while (r < r_end) {
duk_int_t ch1;
duk_int_t ch2;
#ifdef DUK_USE_REGEXP_SUPPORT
duk_int_t ch3;
#endif
duk_size_t left;
ch1 = *r++;
if (ch1 != DUK_ASC_DOLLAR) {
goto repl_write;
}
left = r_end - r;
if (left <= 0) {
goto repl_write;
}
ch2 = r[0];
switch ((int) ch2) {
case DUK_ASC_DOLLAR: {
ch1 = (1 << 8) + DUK_ASC_DOLLAR;
goto repl_write;
}
case DUK_ASC_AMP: {
DUK_BW_WRITE_ENSURE_HSTRING(thr, bw, h_match);
r++;
continue;
}
case DUK_ASC_GRAVE: {
tmp_sz = (duk_size_t) match_start_boff;
DUK_BW_WRITE_ENSURE_BYTES(thr, bw, DUK_HSTRING_GET_DATA(h_input), tmp_sz);
r++;
continue;
}
case DUK_ASC_SINGLEQUOTE: {
duk_uint32_t match_end_boff;
/* Use match charlen instead of bytelen, just in case the input and
* match codepoint encodings would have different lengths.
*/
match_end_boff = duk_heap_strcache_offset_char2byte(thr,
h_input,
match_start_coff + DUK_HSTRING_GET_CHARLEN(h_match));
tmp_sz = (duk_size_t) (DUK_HSTRING_GET_BYTELEN(h_input) - match_end_boff);
DUK_BW_WRITE_ENSURE_BYTES(thr, bw, DUK_HSTRING_GET_DATA(h_input) + match_end_boff, tmp_sz);
r++;
continue;
}
default: {
#ifdef DUK_USE_REGEXP_SUPPORT
duk_int_t capnum, captmp, capadv;
/* XXX: optional check, match_caps is zero if no regexp,
* so dollar will be interpreted literally anyway.
*/
if (!is_regexp) {
goto repl_write;
}
if (!(ch2 >= DUK_ASC_0 && ch2 <= DUK_ASC_9)) {
goto repl_write;
}
capnum = ch2 - DUK_ASC_0;
capadv = 1;
if (left >= 2) {
ch3 = r[1];
if (ch3 >= DUK_ASC_0 && ch3 <= DUK_ASC_9) {
captmp = capnum * 10 + (ch3 - DUK_ASC_0);
if (captmp < match_caps) {
capnum = captmp;
capadv = 2;
}
}
}
if (capnum > 0 && capnum < match_caps) {
DUK_ASSERT(is_regexp != 0); /* match_caps == 0 without regexps */
/* regexp res_obj is at offset 4 */
duk_get_prop_index(ctx, 4, (duk_uarridx_t) capnum);
if (duk_is_string(ctx, -1)) {
duk_hstring *h_tmp_str;
h_tmp_str = duk_get_hstring(ctx, -1);
DUK_ASSERT(h_tmp_str != NULL);
DUK_BW_WRITE_ENSURE_HSTRING(thr, bw, h_tmp_str);
} else {
/* undefined -> skip (replaced with empty) */
}
duk_pop(ctx);
r += capadv;
continue;
} else {
goto repl_write;
}
#else /* DUK_USE_REGEXP_SUPPORT */
goto repl_write; /* unconditionally */
#endif /* DUK_USE_REGEXP_SUPPORT */
} /* default case */
} /* switch (ch2) */
repl_write:
/* ch1 = (r_increment << 8) + byte */
DUK_BW_WRITE_ENSURE_U8(thr, bw, (duk_uint8_t) (ch1 & 0xff));
r += ch1 >> 8;
} /* while repl */
} /* if (is_repl_func) */
duk_pop(ctx); /* pop regexp res_obj or match string */
#ifdef DUK_USE_REGEXP_SUPPORT
if (!is_global) {
#else
{ /* unconditionally; is_global==0 */
#endif
break;
}
}
/* trailer */
tmp_sz = (duk_size_t) (DUK_HSTRING_GET_BYTELEN(h_input) - prev_match_end_boff);
DUK_BW_WRITE_ENSURE_BYTES(thr, bw, DUK_HSTRING_GET_DATA(h_input) + prev_match_end_boff, tmp_sz);
DUK_ASSERT_TOP(ctx, 4);
DUK_BW_COMPACT(thr, bw);
duk_to_string(ctx, -1);
return 1;
}
/*
* split()
*/
/* XXX: very messy now, but works; clean up, remove unused variables (nomimally
* used so compiler doesn't complain).
*/
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_split(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_hstring *h_input;
duk_hstring *h_sep;
duk_uint32_t limit;
duk_uint32_t arr_idx;
#ifdef DUK_USE_REGEXP_SUPPORT
duk_bool_t is_regexp;
#endif
duk_bool_t matched; /* set to 1 if any match exists (needed for empty input special case) */
duk_uint32_t prev_match_end_coff, prev_match_end_boff;
duk_uint32_t match_start_boff, match_start_coff;
duk_uint32_t match_end_boff, match_end_coff;
DUK_UNREF(thr);
h_input = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h_input != NULL);
duk_push_array(ctx);
if (duk_is_undefined(ctx, 1)) {
limit = 0xffffffffUL;
} else {
limit = duk_to_uint32(ctx, 1);
}
if (limit == 0) {
return 1;
}
/* If the separator is a RegExp, make a "clone" of it. The specification
* algorithm calls [[Match]] directly for specific indices; we emulate this
* by tweaking lastIndex and using a "force global" variant of duk_regexp_match()
* which will use global-style matching even when the RegExp itself is non-global.
*/
if (duk_is_undefined(ctx, 0)) {
/* The spec algorithm first does "R = ToString(separator)" before checking
* whether separator is undefined. Since this is side effect free, we can
* skip the ToString() here.
*/
duk_dup(ctx, 2);
duk_put_prop_index(ctx, 3, 0);
return 1;
} else if (duk_get_hobject_with_class(ctx, 0, DUK_HOBJECT_CLASS_REGEXP) != NULL) {
#ifdef DUK_USE_REGEXP_SUPPORT
duk_push_hobject_bidx(ctx, DUK_BIDX_REGEXP_CONSTRUCTOR);
duk_dup(ctx, 0);
duk_new(ctx, 1); /* [ ... RegExp val ] -> [ ... res ] */
duk_replace(ctx, 0);
/* lastIndex is initialized to zero by new RegExp() */
is_regexp = 1;
#else
return DUK_RET_UNSUPPORTED_ERROR;
#endif
} else {
duk_to_string(ctx, 0);
#ifdef DUK_USE_REGEXP_SUPPORT
is_regexp = 0;
#endif
}
/* stack[0] = separator (string or regexp)
* stack[1] = limit
* stack[2] = input string
* stack[3] = result array
*/
prev_match_end_boff = 0;
prev_match_end_coff = 0;
arr_idx = 0;
matched = 0;
for (;;) {
/*
* The specification uses RegExp [[Match]] to attempt match at specific
* offsets. We don't have such a primitive, so we use an actual RegExp
* and tweak lastIndex. Since the RegExp may be non-global, we use a
* special variant which forces global-like behavior for matching.
*/
DUK_ASSERT_TOP(ctx, 4);
#ifdef DUK_USE_REGEXP_SUPPORT
if (is_regexp) {
duk_dup(ctx, 0);
duk_dup(ctx, 2);
duk_regexp_match_force_global(thr); /* [ ... regexp input ] -> [ res_obj ] */
if (!duk_is_object(ctx, -1)) {
duk_pop(ctx);
break;
}
matched = 1;
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INDEX);
DUK_ASSERT(duk_is_number(ctx, -1));
match_start_coff = duk_get_int(ctx, -1);
match_start_boff = duk_heap_strcache_offset_char2byte(thr, h_input, match_start_coff);
duk_pop(ctx);
if (match_start_coff == DUK_HSTRING_GET_CHARLEN(h_input)) {
/* don't allow an empty match at the end of the string */
duk_pop(ctx);
break;
}
duk_get_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
DUK_ASSERT(duk_is_number(ctx, -1));
match_end_coff = duk_get_int(ctx, -1);
match_end_boff = duk_heap_strcache_offset_char2byte(thr, h_input, match_end_coff);
duk_pop(ctx);
/* empty match -> bump and continue */
if (prev_match_end_boff == match_end_boff) {
duk_push_int(ctx, match_end_coff + 1);
duk_put_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
duk_pop(ctx);
continue;
}
} else {
#else /* DUK_USE_REGEXP_SUPPORT */
{ /* unconditionally */
#endif /* DUK_USE_REGEXP_SUPPORT */
const duk_uint8_t *p_start, *p_end, *p; /* input string scan */
const duk_uint8_t *q_start; /* match string */
duk_size_t q_blen, q_clen;
p_start = DUK_HSTRING_GET_DATA(h_input);
p_end = p_start + DUK_HSTRING_GET_BYTELEN(h_input);
p = p_start + prev_match_end_boff;
h_sep = duk_get_hstring(ctx, 0);
DUK_ASSERT(h_sep != NULL);
q_start = DUK_HSTRING_GET_DATA(h_sep);
q_blen = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h_sep);
q_clen = (duk_size_t) DUK_HSTRING_GET_CHARLEN(h_sep);
p_end -= q_blen; /* ensure full memcmp() fits in while */
match_start_coff = prev_match_end_coff;
if (q_blen == 0) {
/* Handle empty separator case: it will always match, and always
* triggers the check in step 13.c.iii initially. Note that we
* must skip to either end of string or start of first codepoint,
* skipping over any continuation bytes!
*
* Don't allow an empty string to match at the end of the input.
*/
matched = 1; /* empty separator can always match */
match_start_coff++;
p++;
while (p < p_end) {
if ((p[0] & 0xc0) != 0x80) {
goto found;
}
p++;
}
goto not_found;
}
DUK_ASSERT(q_blen > 0 && q_clen > 0);
while (p <= p_end) {
DUK_ASSERT(p + q_blen <= DUK_HSTRING_GET_DATA(h_input) + DUK_HSTRING_GET_BYTELEN(h_input));
DUK_ASSERT(q_blen > 0); /* no issues with empty memcmp() */
if (DUK_MEMCMP((const void *) p, (const void *) q_start, (size_t) q_blen) == 0) {
/* never an empty match, so step 13.c.iii can't be triggered */
goto found;
}
/* track utf-8 non-continuation bytes */
if ((p[0] & 0xc0) != 0x80) {
match_start_coff++;
}
p++;
}
not_found:
/* not found */
break;
found:
matched = 1;
match_start_boff = (duk_uint32_t) (p - p_start);
match_end_coff = (duk_uint32_t) (match_start_coff + q_clen); /* constrained by string length */
match_end_boff = (duk_uint32_t) (match_start_boff + q_blen); /* ditto */
/* empty match (may happen with empty separator) -> bump and continue */
if (prev_match_end_boff == match_end_boff) {
prev_match_end_boff++;
prev_match_end_coff++;
continue;
}
} /* if (is_regexp) */
/* stack[0] = separator (string or regexp)
* stack[1] = limit
* stack[2] = input string
* stack[3] = result array
* stack[4] = regexp res_obj (if is_regexp)
*/
DUK_DDD(DUK_DDDPRINT("split; match_start b=%ld,c=%ld, match_end b=%ld,c=%ld, prev_end b=%ld,c=%ld",
(long) match_start_boff, (long) match_start_coff,
(long) match_end_boff, (long) match_end_coff,
(long) prev_match_end_boff, (long) prev_match_end_coff));
duk_push_lstring(ctx,
(const char *) (DUK_HSTRING_GET_DATA(h_input) + prev_match_end_boff),
(duk_size_t) (match_start_boff - prev_match_end_boff));
duk_put_prop_index(ctx, 3, arr_idx);
arr_idx++;
if (arr_idx >= limit) {
goto hit_limit;
}
#ifdef DUK_USE_REGEXP_SUPPORT
if (is_regexp) {
duk_size_t i, len;
len = duk_get_length(ctx, 4);
for (i = 1; i < len; i++) {
DUK_ASSERT(i <= DUK_UARRIDX_MAX); /* cannot have >4G captures */
duk_get_prop_index(ctx, 4, (duk_uarridx_t) i);
duk_put_prop_index(ctx, 3, arr_idx);
arr_idx++;
if (arr_idx >= limit) {
goto hit_limit;
}
}
duk_pop(ctx);
/* lastIndex already set up for next match */
} else {
#else /* DUK_USE_REGEXP_SUPPORT */
{ /* unconditionally */
#endif /* DUK_USE_REGEXP_SUPPORT */
/* no action */
}
prev_match_end_boff = match_end_boff;
prev_match_end_coff = match_end_coff;
continue;
} /* for */
/* Combined step 11 (empty string special case) and 14-15. */
DUK_DDD(DUK_DDDPRINT("split trailer; prev_end b=%ld,c=%ld",
(long) prev_match_end_boff, (long) prev_match_end_coff));
if (DUK_HSTRING_GET_CHARLEN(h_input) > 0 || !matched) {
/* Add trailer if:
* a) non-empty input
* b) empty input and no (zero size) match found (step 11)
*/
duk_push_lstring(ctx,
(const char *) DUK_HSTRING_GET_DATA(h_input) + prev_match_end_boff,
(duk_size_t) (DUK_HSTRING_GET_BYTELEN(h_input) - prev_match_end_boff));
duk_put_prop_index(ctx, 3, arr_idx);
/* No arr_idx update or limit check */
}
return 1;
hit_limit:
#ifdef DUK_USE_REGEXP_SUPPORT
if (is_regexp) {
duk_pop(ctx);
}
#endif
return 1;
}
/*
* Various
*/
#ifdef DUK_USE_REGEXP_SUPPORT
DUK_LOCAL void duk__to_regexp_helper(duk_context *ctx, duk_idx_t index, duk_bool_t force_new) {
duk_hobject *h;
/* Shared helper for match() steps 3-4, search() steps 3-4. */
DUK_ASSERT(index >= 0);
if (force_new) {
goto do_new;
}
h = duk_get_hobject_with_class(ctx, index, DUK_HOBJECT_CLASS_REGEXP);
if (!h) {
goto do_new;
}
return;
do_new:
duk_push_hobject_bidx(ctx, DUK_BIDX_REGEXP_CONSTRUCTOR);
duk_dup(ctx, index);
duk_new(ctx, 1); /* [ ... RegExp val ] -> [ ... res ] */
duk_replace(ctx, index);
}
#endif /* DUK_USE_REGEXP_SUPPORT */
#ifdef DUK_USE_REGEXP_SUPPORT
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_search(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
/* Easiest way to implement the search required by the specification
* is to do a RegExp test() with lastIndex forced to zero. To avoid
* side effects on the argument, "clone" the RegExp if a RegExp was
* given as input.
*
* The global flag of the RegExp should be ignored; setting lastIndex
* to zero (which happens when "cloning" the RegExp) should have an
* equivalent effect.
*/
DUK_ASSERT_TOP(ctx, 1);
(void) duk_push_this_coercible_to_string(ctx); /* at index 1 */
duk__to_regexp_helper(ctx, 0 /*index*/, 1 /*force_new*/);
/* stack[0] = regexp
* stack[1] = string
*/
/* Avoid using RegExp.prototype methods, as they're writable and
* configurable and may have been changed.
*/
duk_dup(ctx, 0);
duk_dup(ctx, 1); /* [ ... re_obj input ] */
duk_regexp_match(thr); /* -> [ ... res_obj ] */
if (!duk_is_object(ctx, -1)) {
duk_push_int(ctx, -1);
return 1;
}
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INDEX);
DUK_ASSERT(duk_is_number(ctx, -1));
return 1;
}
#else /* DUK_USE_REGEXP_SUPPORT */
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_search(duk_context *ctx) {
DUK_UNREF(ctx);
return DUK_RET_UNSUPPORTED_ERROR;
}
#endif /* DUK_USE_REGEXP_SUPPORT */
#ifdef DUK_USE_REGEXP_SUPPORT
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_match(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_bool_t global;
duk_int_t prev_last_index;
duk_int_t this_index;
duk_int_t arr_idx;
DUK_ASSERT_TOP(ctx, 1);
(void) duk_push_this_coercible_to_string(ctx);
duk__to_regexp_helper(ctx, 0 /*index*/, 0 /*force_new*/);
global = duk_get_prop_stridx_boolean(ctx, 0, DUK_STRIDX_GLOBAL, NULL);
DUK_ASSERT_TOP(ctx, 2);
/* stack[0] = regexp
* stack[1] = string
*/
if (!global) {
duk_regexp_match(thr); /* -> [ res_obj ] */
return 1; /* return 'res_obj' */
}
/* Global case is more complex. */
/* [ regexp string ] */
duk_push_int(ctx, 0);
duk_put_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
duk_push_array(ctx);
/* [ regexp string res_arr ] */
prev_last_index = 0;
arr_idx = 0;
for (;;) {
DUK_ASSERT_TOP(ctx, 3);
duk_dup(ctx, 0);
duk_dup(ctx, 1);
duk_regexp_match(thr); /* -> [ ... regexp string ] -> [ ... res_obj ] */
if (!duk_is_object(ctx, -1)) {
duk_pop(ctx);
break;
}
duk_get_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
DUK_ASSERT(duk_is_number(ctx, -1));
this_index = duk_get_int(ctx, -1);
duk_pop(ctx);
if (this_index == prev_last_index) {
this_index++;
duk_push_int(ctx, this_index);
duk_put_prop_stridx(ctx, 0, DUK_STRIDX_LAST_INDEX);
}
prev_last_index = this_index;
duk_get_prop_index(ctx, -1, 0); /* match string */
duk_put_prop_index(ctx, 2, arr_idx);
arr_idx++;
duk_pop(ctx); /* res_obj */
}
if (arr_idx == 0) {
duk_push_null(ctx);
}
return 1; /* return 'res_arr' or 'null' */
}
#else /* DUK_USE_REGEXP_SUPPORT */
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_match(duk_context *ctx) {
DUK_UNREF(ctx);
return DUK_RET_UNSUPPORTED_ERROR;
}
#endif /* DUK_USE_REGEXP_SUPPORT */
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_concat(duk_context *ctx) {
/* duk_concat() coerces arguments with ToString() in correct order */
(void) duk_push_this_coercible_to_string(ctx);
duk_insert(ctx, 0); /* this is relatively expensive */
duk_concat(ctx, duk_get_top(ctx));
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_trim(duk_context *ctx) {
DUK_ASSERT_TOP(ctx, 0);
(void) duk_push_this_coercible_to_string(ctx);
duk_trim(ctx, 0);
DUK_ASSERT_TOP(ctx, 1);
return 1;
}
DUK_INTERNAL duk_ret_t duk_bi_string_prototype_locale_compare(duk_context *ctx) {
duk_hstring *h1;
duk_hstring *h2;
duk_size_t h1_len, h2_len, prefix_len;
duk_small_int_t ret = 0;
duk_small_int_t rc;
/* The current implementation of localeCompare() is simply a codepoint
* by codepoint comparison, implemented with a simple string compare
* because UTF-8 should preserve codepoint ordering (assuming valid
* shortest UTF-8 encoding).
*
* The specification requires that the return value must be related
* to the sort order: e.g. negative means that 'this' comes before
* 'that' in sort order. We assume an ascending sort order.
*/
/* XXX: could share code with duk_js_ops.c, duk_js_compare_helper */
h1 = duk_push_this_coercible_to_string(ctx);
DUK_ASSERT(h1 != NULL);
h2 = duk_to_hstring(ctx, 0);
DUK_ASSERT(h2 != NULL);
h1_len = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h1);
h2_len = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h2);
prefix_len = (h1_len <= h2_len ? h1_len : h2_len);
/* Zero size compare not an issue with DUK_MEMCMP. */
rc = (duk_small_int_t) DUK_MEMCMP((const void *) DUK_HSTRING_GET_DATA(h1),
(const void *) DUK_HSTRING_GET_DATA(h2),
(size_t) prefix_len);
if (rc < 0) {
ret = -1;
goto done;
} else if (rc > 0) {
ret = 1;
goto done;
}
/* prefix matches, lengths matter now */
if (h1_len > h2_len) {
ret = 1;
goto done;
} else if (h1_len == h2_len) {
DUK_ASSERT(ret == 0);
goto done;
}
ret = -1;
goto done;
done:
duk_push_int(ctx, (duk_int_t) ret);
return 1;
}