/* * 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; }