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Diffstat (limited to 'js/src/builtin/String.cpp')
| -rw-r--r-- | js/src/builtin/String.cpp | 4617 |
1 files changed, 4617 insertions, 0 deletions
diff --git a/js/src/builtin/String.cpp b/js/src/builtin/String.cpp new file mode 100644 index 0000000000..5cee7a68bf --- /dev/null +++ b/js/src/builtin/String.cpp @@ -0,0 +1,4617 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "builtin/String.h" + +#include "mozilla/Attributes.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/FloatingPoint.h" +#if JS_HAS_INTL_API +# include "mozilla/intl/String.h" +#endif +#include "mozilla/PodOperations.h" +#include "mozilla/Range.h" +#include "mozilla/SIMD.h" +#include "mozilla/TextUtils.h" + +#include <algorithm> +#include <limits> +#include <string.h> +#include <type_traits> + +#include "jsnum.h" +#include "jstypes.h" + +#include "builtin/Array.h" +#if JS_HAS_INTL_API +# include "builtin/intl/CommonFunctions.h" +# include "builtin/intl/FormatBuffer.h" +#endif +#include "builtin/RegExp.h" +#include "jit/InlinableNatives.h" +#include "js/Conversions.h" +#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_* +#if !JS_HAS_INTL_API +# include "js/LocaleSensitive.h" +#endif +#include "js/Printer.h" +#include "js/PropertyAndElement.h" // JS_DefineFunctions +#include "js/PropertySpec.h" +#include "js/StableStringChars.h" +#include "js/UniquePtr.h" +#include "util/StringBuffer.h" +#include "util/Unicode.h" +#include "vm/GlobalObject.h" +#include "vm/JSContext.h" +#include "vm/JSObject.h" +#include "vm/RegExpObject.h" +#include "vm/SelfHosting.h" +#include "vm/StaticStrings.h" +#include "vm/ToSource.h" // js::ValueToSource +#include "vm/WellKnownAtom.h" // js_*_str + +#include "vm/GeckoProfiler-inl.h" +#include "vm/InlineCharBuffer-inl.h" +#include "vm/NativeObject-inl.h" +#include "vm/StringObject-inl.h" +#include "vm/StringType-inl.h" + +using namespace js; + +using JS::Symbol; +using JS::SymbolCode; + +using mozilla::AsciiAlphanumericToNumber; +using mozilla::CheckedInt; +using mozilla::EnsureUtf16ValiditySpan; +using mozilla::IsAsciiHexDigit; +using mozilla::PodCopy; +using mozilla::RangedPtr; +using mozilla::SIMD; +using mozilla::Span; +using mozilla::Utf16ValidUpTo; + +using JS::AutoCheckCannotGC; +using JS::AutoStableStringChars; + +static JSLinearString* ArgToLinearString(JSContext* cx, const CallArgs& args, + unsigned argno) { + if (argno >= args.length()) { + return cx->names().undefined; + } + + JSString* str = ToString<CanGC>(cx, args[argno]); + if (!str) { + return nullptr; + } + + return str->ensureLinear(cx); +} + +/* + * Forward declarations for URI encode/decode and helper routines + */ +static bool str_decodeURI(JSContext* cx, unsigned argc, Value* vp); + +static bool str_decodeURI_Component(JSContext* cx, unsigned argc, Value* vp); + +static bool str_encodeURI(JSContext* cx, unsigned argc, Value* vp); + +static bool str_encodeURI_Component(JSContext* cx, unsigned argc, Value* vp); + +/* + * Global string methods + */ + +/* ES5 B.2.1 */ +template <typename CharT> +static bool Escape(JSContext* cx, const CharT* chars, uint32_t length, + InlineCharBuffer<Latin1Char>& newChars, + uint32_t* newLengthOut) { + // clang-format off + static const uint8_t shouldPassThrough[128] = { + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,1,1,0,1,1,1, /* !"#$%&'()*+,-./ */ + 1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0, /* 0123456789:;<=>? */ + 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* @ABCDEFGHIJKLMNO */ + 1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,1, /* PQRSTUVWXYZ[\]^_ */ + 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* `abcdefghijklmno */ + 1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0, /* pqrstuvwxyz{\}~ DEL */ + }; + // clang-format on + + /* Take a first pass and see how big the result string will need to be. */ + uint32_t newLength = length; + for (size_t i = 0; i < length; i++) { + char16_t ch = chars[i]; + if (ch < 128 && shouldPassThrough[ch]) { + continue; + } + + /* + * newlength is incremented below by at most 5 and at this point it must + * be a valid string length, so this should never overflow uint32_t. + */ + static_assert(JSString::MAX_LENGTH < UINT32_MAX - 5, + "Adding 5 to valid string length should not overflow"); + + MOZ_ASSERT(newLength <= JSString::MAX_LENGTH); + + /* The character will be encoded as %XX or %uXXXX. */ + newLength += (ch < 256) ? 2 : 5; + + if (MOZ_UNLIKELY(newLength > JSString::MAX_LENGTH)) { + ReportAllocationOverflow(cx); + return false; + } + } + + if (newLength == length) { + *newLengthOut = newLength; + return true; + } + + if (!newChars.maybeAlloc(cx, newLength)) { + return false; + } + + static const char digits[] = "0123456789ABCDEF"; + + Latin1Char* rawNewChars = newChars.get(); + size_t i, ni; + for (i = 0, ni = 0; i < length; i++) { + char16_t ch = chars[i]; + if (ch < 128 && shouldPassThrough[ch]) { + rawNewChars[ni++] = ch; + } else if (ch < 256) { + rawNewChars[ni++] = '%'; + rawNewChars[ni++] = digits[ch >> 4]; + rawNewChars[ni++] = digits[ch & 0xF]; + } else { + rawNewChars[ni++] = '%'; + rawNewChars[ni++] = 'u'; + rawNewChars[ni++] = digits[ch >> 12]; + rawNewChars[ni++] = digits[(ch & 0xF00) >> 8]; + rawNewChars[ni++] = digits[(ch & 0xF0) >> 4]; + rawNewChars[ni++] = digits[ch & 0xF]; + } + } + MOZ_ASSERT(ni == newLength); + + *newLengthOut = newLength; + return true; +} + +static bool str_escape(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "escape"); + CallArgs args = CallArgsFromVp(argc, vp); + + Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0)); + if (!str) { + return false; + } + + InlineCharBuffer<Latin1Char> newChars; + uint32_t newLength = 0; // initialize to silence GCC warning + if (str->hasLatin1Chars()) { + AutoCheckCannotGC nogc; + if (!Escape(cx, str->latin1Chars(nogc), str->length(), newChars, + &newLength)) { + return false; + } + } else { + AutoCheckCannotGC nogc; + if (!Escape(cx, str->twoByteChars(nogc), str->length(), newChars, + &newLength)) { + return false; + } + } + + // Return input if no characters need to be escaped. + if (newLength == str->length()) { + args.rval().setString(str); + return true; + } + + JSString* res = newChars.toString(cx, newLength); + if (!res) { + return false; + } + + args.rval().setString(res); + return true; +} + +template <typename CharT> +static inline bool Unhex4(const RangedPtr<const CharT> chars, + char16_t* result) { + CharT a = chars[0], b = chars[1], c = chars[2], d = chars[3]; + + if (!(IsAsciiHexDigit(a) && IsAsciiHexDigit(b) && IsAsciiHexDigit(c) && + IsAsciiHexDigit(d))) { + return false; + } + + char16_t unhex = AsciiAlphanumericToNumber(a); + unhex = (unhex << 4) + AsciiAlphanumericToNumber(b); + unhex = (unhex << 4) + AsciiAlphanumericToNumber(c); + unhex = (unhex << 4) + AsciiAlphanumericToNumber(d); + *result = unhex; + return true; +} + +template <typename CharT> +static inline bool Unhex2(const RangedPtr<const CharT> chars, + char16_t* result) { + CharT a = chars[0], b = chars[1]; + + if (!(IsAsciiHexDigit(a) && IsAsciiHexDigit(b))) { + return false; + } + + *result = (AsciiAlphanumericToNumber(a) << 4) + AsciiAlphanumericToNumber(b); + return true; +} + +template <typename CharT> +static bool Unescape(StringBuffer& sb, + const mozilla::Range<const CharT> chars) { + // Step 2. + uint32_t length = chars.length(); + + /* + * Note that the spec algorithm has been optimized to avoid building + * a string in the case where no escapes are present. + */ + bool building = false; + +#define ENSURE_BUILDING \ + do { \ + if (!building) { \ + building = true; \ + if (!sb.reserve(length)) return false; \ + sb.infallibleAppend(chars.begin().get(), k); \ + } \ + } while (false); + + // Step 4. + uint32_t k = 0; + + // Step 5. + while (k < length) { + // Step 5.a. + char16_t c = chars[k]; + + // Step 5.b. + if (c == '%') { + static_assert(JSString::MAX_LENGTH < UINT32_MAX - 6, + "String length is not near UINT32_MAX"); + + // Steps 5.b.i-ii. + if (k + 6 <= length && chars[k + 1] == 'u') { + if (Unhex4(chars.begin() + k + 2, &c)) { + ENSURE_BUILDING + k += 5; + } + } else if (k + 3 <= length) { + if (Unhex2(chars.begin() + k + 1, &c)) { + ENSURE_BUILDING + k += 2; + } + } + } + + // Step 5.c. + if (building && !sb.append(c)) { + return false; + } + + // Step 5.d. + k += 1; + } + + return true; +#undef ENSURE_BUILDING +} + +// ES2018 draft rev f83aa38282c2a60c6916ebc410bfdf105a0f6a54 +// B.2.1.2 unescape ( string ) +static bool str_unescape(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "unescape"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Step 1. + Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0)); + if (!str) { + return false; + } + + // Step 3. + JSStringBuilder sb(cx); + if (str->hasTwoByteChars() && !sb.ensureTwoByteChars()) { + return false; + } + + // Steps 2, 4-5. + bool unescapeFailed = false; + if (str->hasLatin1Chars()) { + AutoCheckCannotGC nogc; + unescapeFailed = !Unescape(sb, str->latin1Range(nogc)); + } else { + AutoCheckCannotGC nogc; + unescapeFailed = !Unescape(sb, str->twoByteRange(nogc)); + } + if (unescapeFailed) { + return false; + } + + // Step 6. + JSLinearString* result; + if (!sb.empty()) { + result = sb.finishString(); + if (!result) { + return false; + } + } else { + result = str; + } + + args.rval().setString(result); + return true; +} + +static bool str_uneval(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + JSString* str = ValueToSource(cx, args.get(0)); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; +} + +static const JSFunctionSpec string_functions[] = { + JS_FN(js_escape_str, str_escape, 1, JSPROP_RESOLVING), + JS_FN(js_unescape_str, str_unescape, 1, JSPROP_RESOLVING), + JS_FN(js_uneval_str, str_uneval, 1, JSPROP_RESOLVING), + JS_FN(js_decodeURI_str, str_decodeURI, 1, JSPROP_RESOLVING), + JS_FN(js_encodeURI_str, str_encodeURI, 1, JSPROP_RESOLVING), + JS_FN(js_decodeURIComponent_str, str_decodeURI_Component, 1, + JSPROP_RESOLVING), + JS_FN(js_encodeURIComponent_str, str_encodeURI_Component, 1, + JSPROP_RESOLVING), + + JS_FS_END}; + +static const unsigned STRING_ELEMENT_ATTRS = + JSPROP_ENUMERATE | JSPROP_READONLY | JSPROP_PERMANENT; + +static bool str_enumerate(JSContext* cx, HandleObject obj) { + RootedString str(cx, obj->as<StringObject>().unbox()); + js::StaticStrings& staticStrings = cx->staticStrings(); + + RootedValue value(cx); + for (size_t i = 0, length = str->length(); i < length; i++) { + JSString* str1 = staticStrings.getUnitStringForElement(cx, str, i); + if (!str1) { + return false; + } + value.setString(str1); + if (!DefineDataElement(cx, obj, i, value, + STRING_ELEMENT_ATTRS | JSPROP_RESOLVING)) { + return false; + } + } + + return true; +} + +static bool str_mayResolve(const JSAtomState&, jsid id, JSObject*) { + // str_resolve ignores non-integer ids. + return id.isInt(); +} + +static bool str_resolve(JSContext* cx, HandleObject obj, HandleId id, + bool* resolvedp) { + if (!id.isInt()) { + return true; + } + + RootedString str(cx, obj->as<StringObject>().unbox()); + + int32_t slot = id.toInt(); + if ((size_t)slot < str->length()) { + JSString* str1 = + cx->staticStrings().getUnitStringForElement(cx, str, size_t(slot)); + if (!str1) { + return false; + } + RootedValue value(cx, StringValue(str1)); + if (!DefineDataElement(cx, obj, uint32_t(slot), value, + STRING_ELEMENT_ATTRS | JSPROP_RESOLVING)) { + return false; + } + *resolvedp = true; + } + return true; +} + +static const JSClassOps StringObjectClassOps = { + nullptr, // addProperty + nullptr, // delProperty + str_enumerate, // enumerate + nullptr, // newEnumerate + str_resolve, // resolve + str_mayResolve, // mayResolve + nullptr, // finalize + nullptr, // call + nullptr, // construct + nullptr, // trace +}; + +const JSClass StringObject::class_ = { + js_String_str, + JSCLASS_HAS_RESERVED_SLOTS(StringObject::RESERVED_SLOTS) | + JSCLASS_HAS_CACHED_PROTO(JSProto_String), + &StringObjectClassOps, &StringObject::classSpec_}; + +/* + * Perform the initial |RequireObjectCoercible(thisv)| and |ToString(thisv)| + * from nearly all String.prototype.* functions. + */ +static MOZ_ALWAYS_INLINE JSString* ToStringForStringFunction( + JSContext* cx, const char* funName, HandleValue thisv) { + if (thisv.isString()) { + return thisv.toString(); + } + + if (thisv.isObject()) { + if (thisv.toObject().is<StringObject>()) { + StringObject* nobj = &thisv.toObject().as<StringObject>(); + // We have to make sure that the ToPrimitive call from ToString + // would be unobservable. + if (HasNoToPrimitiveMethodPure(nobj, cx) && + HasNativeMethodPure(nobj, cx->names().toString, str_toString, cx)) { + return nobj->unbox(); + } + } + } else if (thisv.isNullOrUndefined()) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_INCOMPATIBLE_PROTO, "String", funName, + thisv.isNull() ? "null" : "undefined"); + return nullptr; + } + + return ToStringSlow<CanGC>(cx, thisv); +} + +MOZ_ALWAYS_INLINE bool IsString(HandleValue v) { + return v.isString() || (v.isObject() && v.toObject().is<StringObject>()); +} + +MOZ_ALWAYS_INLINE bool str_toSource_impl(JSContext* cx, const CallArgs& args) { + MOZ_ASSERT(IsString(args.thisv())); + + JSString* str = ToString<CanGC>(cx, args.thisv()); + if (!str) { + return false; + } + + UniqueChars quoted = QuoteString(cx, str, '"'); + if (!quoted) { + return false; + } + + JSStringBuilder sb(cx); + if (!sb.append("(new String(") || + !sb.append(quoted.get(), strlen(quoted.get())) || !sb.append("))")) { + return false; + } + + JSString* result = sb.finishString(); + if (!result) { + return false; + } + args.rval().setString(result); + return true; +} + +static bool str_toSource(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + return CallNonGenericMethod<IsString, str_toSource_impl>(cx, args); +} + +MOZ_ALWAYS_INLINE bool str_toString_impl(JSContext* cx, const CallArgs& args) { + MOZ_ASSERT(IsString(args.thisv())); + + args.rval().setString( + args.thisv().isString() + ? args.thisv().toString() + : args.thisv().toObject().as<StringObject>().unbox()); + return true; +} + +bool js::str_toString(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + return CallNonGenericMethod<IsString, str_toString_impl>(cx, args); +} + +/* + * Java-like string native methods. + */ + +JSString* js::SubstringKernel(JSContext* cx, HandleString str, int32_t beginInt, + int32_t lengthInt) { + MOZ_ASSERT(0 <= beginInt); + MOZ_ASSERT(0 <= lengthInt); + MOZ_ASSERT(uint32_t(beginInt) <= str->length()); + MOZ_ASSERT(uint32_t(lengthInt) <= str->length() - beginInt); + + uint32_t begin = beginInt; + uint32_t len = lengthInt; + + /* + * Optimization for one level deep ropes. + * This is common for the following pattern: + * + * while() { + * text = text.substr(0, x) + "bla" + text.substr(x) + * test.charCodeAt(x + 1) + * } + */ + if (str->isRope()) { + JSRope* rope = &str->asRope(); + + /* Substring is totally in leftChild of rope. */ + if (begin + len <= rope->leftChild()->length()) { + return NewDependentString(cx, rope->leftChild(), begin, len); + } + + /* Substring is totally in rightChild of rope. */ + if (begin >= rope->leftChild()->length()) { + begin -= rope->leftChild()->length(); + return NewDependentString(cx, rope->rightChild(), begin, len); + } + + /* + * Requested substring is partly in the left and partly in right child. + * Create a rope of substrings for both childs. + */ + MOZ_ASSERT(begin < rope->leftChild()->length() && + begin + len > rope->leftChild()->length()); + + size_t lhsLength = rope->leftChild()->length() - begin; + size_t rhsLength = begin + len - rope->leftChild()->length(); + + Rooted<JSRope*> ropeRoot(cx, rope); + RootedString lhs( + cx, NewDependentString(cx, ropeRoot->leftChild(), begin, lhsLength)); + if (!lhs) { + return nullptr; + } + + RootedString rhs( + cx, NewDependentString(cx, ropeRoot->rightChild(), 0, rhsLength)); + if (!rhs) { + return nullptr; + } + + return JSRope::new_<CanGC>(cx, lhs, rhs, len); + } + + return NewDependentString(cx, str, begin, len); +} + +/** + * U+03A3 GREEK CAPITAL LETTER SIGMA has two different lower case mappings + * depending on its context: + * When it's preceded by a cased character and not followed by another cased + * character, its lower case form is U+03C2 GREEK SMALL LETTER FINAL SIGMA. + * Otherwise its lower case mapping is U+03C3 GREEK SMALL LETTER SIGMA. + * + * Unicode 9.0, §3.13 Default Case Algorithms + */ +static char16_t Final_Sigma(const char16_t* chars, size_t length, + size_t index) { + MOZ_ASSERT(index < length); + MOZ_ASSERT(chars[index] == unicode::GREEK_CAPITAL_LETTER_SIGMA); + MOZ_ASSERT(unicode::ToLowerCase(unicode::GREEK_CAPITAL_LETTER_SIGMA) == + unicode::GREEK_SMALL_LETTER_SIGMA); + +#if JS_HAS_INTL_API + // Tell the analysis the BinaryProperty.contains function pointer called by + // mozilla::intl::String::Is{CaseIgnorable, Cased} cannot GC. + JS::AutoSuppressGCAnalysis nogc; + + bool precededByCased = false; + for (size_t i = index; i > 0;) { + char16_t c = chars[--i]; + char32_t codePoint = c; + if (unicode::IsTrailSurrogate(c) && i > 0) { + char16_t lead = chars[i - 1]; + if (unicode::IsLeadSurrogate(lead)) { + codePoint = unicode::UTF16Decode(lead, c); + i--; + } + } + + // Ignore any characters with the property Case_Ignorable. + // NB: We need to skip over all Case_Ignorable characters, even when + // they also have the Cased binary property. + if (mozilla::intl::String::IsCaseIgnorable(codePoint)) { + continue; + } + + precededByCased = mozilla::intl::String::IsCased(codePoint); + break; + } + if (!precededByCased) { + return unicode::GREEK_SMALL_LETTER_SIGMA; + } + + bool followedByCased = false; + for (size_t i = index + 1; i < length;) { + char16_t c = chars[i++]; + char32_t codePoint = c; + if (unicode::IsLeadSurrogate(c) && i < length) { + char16_t trail = chars[i]; + if (unicode::IsTrailSurrogate(trail)) { + codePoint = unicode::UTF16Decode(c, trail); + i++; + } + } + + // Ignore any characters with the property Case_Ignorable. + // NB: We need to skip over all Case_Ignorable characters, even when + // they also have the Cased binary property. + if (mozilla::intl::String::IsCaseIgnorable(codePoint)) { + continue; + } + + followedByCased = mozilla::intl::String::IsCased(codePoint); + break; + } + if (!followedByCased) { + return unicode::GREEK_SMALL_LETTER_FINAL_SIGMA; + } +#endif + + return unicode::GREEK_SMALL_LETTER_SIGMA; +} + +// If |srcLength == destLength| is true, the destination buffer was allocated +// with the same size as the source buffer. When we append characters which +// have special casing mappings, we test |srcLength == destLength| to decide +// if we need to back out and reallocate a sufficiently large destination +// buffer. Otherwise the destination buffer was allocated with the correct +// size to hold all lower case mapped characters, i.e. +// |destLength == ToLowerCaseLength(srcChars, 0, srcLength)| is true. +template <typename CharT> +static size_t ToLowerCaseImpl(CharT* destChars, const CharT* srcChars, + size_t startIndex, size_t srcLength, + size_t destLength) { + MOZ_ASSERT(startIndex < srcLength); + MOZ_ASSERT(srcLength <= destLength); + if constexpr (std::is_same_v<CharT, Latin1Char>) { + MOZ_ASSERT(srcLength == destLength); + } + + size_t j = startIndex; + for (size_t i = startIndex; i < srcLength; i++) { + CharT c = srcChars[i]; + if constexpr (!std::is_same_v<CharT, Latin1Char>) { + if (unicode::IsLeadSurrogate(c) && i + 1 < srcLength) { + char16_t trail = srcChars[i + 1]; + if (unicode::IsTrailSurrogate(trail)) { + trail = unicode::ToLowerCaseNonBMPTrail(c, trail); + destChars[j++] = c; + destChars[j++] = trail; + i++; + continue; + } + } + + // Special case: U+0130 LATIN CAPITAL LETTER I WITH DOT ABOVE + // lowercases to <U+0069 U+0307>. + if (c == unicode::LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE) { + // Return if the output buffer is too small. + if (srcLength == destLength) { + return i; + } + + destChars[j++] = CharT('i'); + destChars[j++] = CharT(unicode::COMBINING_DOT_ABOVE); + continue; + } + + // Special case: U+03A3 GREEK CAPITAL LETTER SIGMA lowercases to + // one of two codepoints depending on context. + if (c == unicode::GREEK_CAPITAL_LETTER_SIGMA) { + destChars[j++] = Final_Sigma(srcChars, srcLength, i); + continue; + } + } + + c = unicode::ToLowerCase(c); + destChars[j++] = c; + } + + MOZ_ASSERT(j == destLength); + return srcLength; +} + +static size_t ToLowerCaseLength(const char16_t* chars, size_t startIndex, + size_t length) { + size_t lowerLength = length; + for (size_t i = startIndex; i < length; i++) { + char16_t c = chars[i]; + + // U+0130 is lowercased to the two-element sequence <U+0069 U+0307>. + if (c == unicode::LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE) { + lowerLength += 1; + } + } + return lowerLength; +} + +template <typename CharT> +static JSString* ToLowerCase(JSContext* cx, JSLinearString* str) { + // Unlike toUpperCase, toLowerCase has the nice invariant that if the + // input is a Latin-1 string, the output is also a Latin-1 string. + + InlineCharBuffer<CharT> newChars; + + const size_t length = str->length(); + size_t resultLength; + { + AutoCheckCannotGC nogc; + const CharT* chars = str->chars<CharT>(nogc); + + // We don't need extra special casing checks in the loop below, + // because U+0130 LATIN CAPITAL LETTER I WITH DOT ABOVE and U+03A3 + // GREEK CAPITAL LETTER SIGMA already have simple lower case mappings. + MOZ_ASSERT(unicode::ChangesWhenLowerCased( + unicode::LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE), + "U+0130 has a simple lower case mapping"); + MOZ_ASSERT( + unicode::ChangesWhenLowerCased(unicode::GREEK_CAPITAL_LETTER_SIGMA), + "U+03A3 has a simple lower case mapping"); + + // One element Latin-1 strings can be directly retrieved from the + // static strings cache. + if constexpr (std::is_same_v<CharT, Latin1Char>) { + if (length == 1) { + CharT lower = unicode::ToLowerCase(chars[0]); + MOZ_ASSERT(StaticStrings::hasUnit(lower)); + + return cx->staticStrings().getUnit(lower); + } + } + + // Look for the first character that changes when lowercased. + size_t i = 0; + for (; i < length; i++) { + CharT c = chars[i]; + if constexpr (!std::is_same_v<CharT, Latin1Char>) { + if (unicode::IsLeadSurrogate(c) && i + 1 < length) { + CharT trail = chars[i + 1]; + if (unicode::IsTrailSurrogate(trail)) { + if (unicode::ChangesWhenLowerCasedNonBMP(c, trail)) { + break; + } + + i++; + continue; + } + } + } + if (unicode::ChangesWhenLowerCased(c)) { + break; + } + } + + // If no character needs to change, return the input string. + if (i == length) { + return str; + } + + resultLength = length; + if (!newChars.maybeAlloc(cx, resultLength)) { + return nullptr; + } + + PodCopy(newChars.get(), chars, i); + + size_t readChars = + ToLowerCaseImpl(newChars.get(), chars, i, length, resultLength); + if constexpr (!std::is_same_v<CharT, Latin1Char>) { + if (readChars < length) { + resultLength = ToLowerCaseLength(chars, readChars, length); + + if (!newChars.maybeRealloc(cx, length, resultLength)) { + return nullptr; + } + + MOZ_ALWAYS_TRUE(length == ToLowerCaseImpl(newChars.get(), chars, + readChars, length, + resultLength)); + } + } else { + MOZ_ASSERT(readChars == length, + "Latin-1 strings don't have special lower case mappings"); + } + } + + return newChars.toStringDontDeflate(cx, resultLength); +} + +JSString* js::StringToLowerCase(JSContext* cx, HandleString string) { + JSLinearString* linear = string->ensureLinear(cx); + if (!linear) { + return nullptr; + } + + if (linear->hasLatin1Chars()) { + return ToLowerCase<Latin1Char>(cx, linear); + } + return ToLowerCase<char16_t>(cx, linear); +} + +static bool str_toLowerCase(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "toLowerCase"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str(cx, + ToStringForStringFunction(cx, "toLowerCase", args.thisv())); + if (!str) { + return false; + } + + JSString* result = StringToLowerCase(cx, str); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +#if JS_HAS_INTL_API +// String.prototype.toLocaleLowerCase is self-hosted when Intl is exposed, +// with core functionality performed by the intrinsic below. + +static const char* CaseMappingLocale(JSContext* cx, JSString* str) { + JSLinearString* locale = str->ensureLinear(cx); + if (!locale) { + return nullptr; + } + + MOZ_ASSERT(locale->length() >= 2, "locale is a valid language tag"); + + // Lithuanian, Turkish, and Azeri have language dependent case mappings. + static const char languagesWithSpecialCasing[][3] = {"lt", "tr", "az"}; + + // All strings in |languagesWithSpecialCasing| are of length two, so we + // only need to compare the first two characters to find a matching locale. + // ES2017 Intl, §9.2.2 BestAvailableLocale + if (locale->length() == 2 || locale->latin1OrTwoByteChar(2) == '-') { + for (const auto& language : languagesWithSpecialCasing) { + if (locale->latin1OrTwoByteChar(0) == language[0] && + locale->latin1OrTwoByteChar(1) == language[1]) { + return language; + } + } + } + + return ""; // ICU root locale +} + +static bool HasDefaultCasing(const char* locale) { return !strcmp(locale, ""); } + +bool js::intl_toLocaleLowerCase(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + MOZ_ASSERT(args.length() == 2); + MOZ_ASSERT(args[0].isString()); + MOZ_ASSERT(args[1].isString()); + + RootedString string(cx, args[0].toString()); + + const char* locale = CaseMappingLocale(cx, args[1].toString()); + if (!locale) { + return false; + } + + // Call String.prototype.toLowerCase() for language independent casing. + if (HasDefaultCasing(locale)) { + JSString* str = StringToLowerCase(cx, string); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; + } + + AutoStableStringChars inputChars(cx); + if (!inputChars.initTwoByte(cx, string)) { + return false; + } + mozilla::Range<const char16_t> input = inputChars.twoByteRange(); + + // Note: maximum case mapping length is three characters, so the result + // length might be > INT32_MAX. ICU will fail in this case. + static_assert(JSString::MAX_LENGTH <= INT32_MAX, + "String length must fit in int32_t for ICU"); + + static const size_t INLINE_CAPACITY = js::intl::INITIAL_CHAR_BUFFER_SIZE; + + intl::FormatBuffer<char16_t, INLINE_CAPACITY> buffer(cx); + + auto ok = mozilla::intl::String::ToLocaleLowerCase(locale, input, buffer); + if (ok.isErr()) { + intl::ReportInternalError(cx, ok.unwrapErr()); + return false; + } + + JSString* result = buffer.toString(cx); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +#else + +// When the Intl API is not exposed, String.prototype.toLowerCase is implemented +// in C++. +static bool str_toLocaleLowerCase(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", + "toLocaleLowerCase"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str( + cx, ToStringForStringFunction(cx, "toLocaleLowerCase", args.thisv())); + if (!str) { + return false; + } + + /* + * Forcefully ignore the first (or any) argument and return toLowerCase(), + * ECMA has reserved that argument, presumably for defining the locale. + */ + if (cx->runtime()->localeCallbacks && + cx->runtime()->localeCallbacks->localeToLowerCase) { + RootedValue result(cx); + if (!cx->runtime()->localeCallbacks->localeToLowerCase(cx, str, &result)) { + return false; + } + + args.rval().set(result); + return true; + } + + Rooted<JSLinearString*> linear(cx, str->ensureLinear(cx)); + if (!linear) { + return false; + } + + JSString* result = StringToLowerCase(cx, linear); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +#endif // JS_HAS_INTL_API + +static inline bool ToUpperCaseHasSpecialCasing(Latin1Char charCode) { + // U+00DF LATIN SMALL LETTER SHARP S is the only Latin-1 code point with + // special casing rules, so detect it inline. + bool hasUpperCaseSpecialCasing = + charCode == unicode::LATIN_SMALL_LETTER_SHARP_S; + MOZ_ASSERT(hasUpperCaseSpecialCasing == + unicode::ChangesWhenUpperCasedSpecialCasing(charCode)); + + return hasUpperCaseSpecialCasing; +} + +static inline bool ToUpperCaseHasSpecialCasing(char16_t charCode) { + return unicode::ChangesWhenUpperCasedSpecialCasing(charCode); +} + +static inline size_t ToUpperCaseLengthSpecialCasing(Latin1Char charCode) { + // U+00DF LATIN SMALL LETTER SHARP S is uppercased to two 'S'. + MOZ_ASSERT(charCode == unicode::LATIN_SMALL_LETTER_SHARP_S); + + return 2; +} + +static inline size_t ToUpperCaseLengthSpecialCasing(char16_t charCode) { + MOZ_ASSERT(ToUpperCaseHasSpecialCasing(charCode)); + + return unicode::LengthUpperCaseSpecialCasing(charCode); +} + +static inline void ToUpperCaseAppendUpperCaseSpecialCasing(char16_t charCode, + Latin1Char* elements, + size_t* index) { + // U+00DF LATIN SMALL LETTER SHARP S is uppercased to two 'S'. + MOZ_ASSERT(charCode == unicode::LATIN_SMALL_LETTER_SHARP_S); + static_assert('S' <= JSString::MAX_LATIN1_CHAR, "'S' is a Latin-1 character"); + + elements[(*index)++] = 'S'; + elements[(*index)++] = 'S'; +} + +static inline void ToUpperCaseAppendUpperCaseSpecialCasing(char16_t charCode, + char16_t* elements, + size_t* index) { + unicode::AppendUpperCaseSpecialCasing(charCode, elements, index); +} + +// See ToLowerCaseImpl for an explanation of the parameters. +template <typename DestChar, typename SrcChar> +static size_t ToUpperCaseImpl(DestChar* destChars, const SrcChar* srcChars, + size_t startIndex, size_t srcLength, + size_t destLength) { + static_assert(std::is_same_v<SrcChar, Latin1Char> || + !std::is_same_v<DestChar, Latin1Char>, + "cannot write non-Latin-1 characters into Latin-1 string"); + MOZ_ASSERT(startIndex < srcLength); + MOZ_ASSERT(srcLength <= destLength); + + size_t j = startIndex; + for (size_t i = startIndex; i < srcLength; i++) { + char16_t c = srcChars[i]; + if constexpr (!std::is_same_v<DestChar, Latin1Char>) { + if (unicode::IsLeadSurrogate(c) && i + 1 < srcLength) { + char16_t trail = srcChars[i + 1]; + if (unicode::IsTrailSurrogate(trail)) { + trail = unicode::ToUpperCaseNonBMPTrail(c, trail); + destChars[j++] = c; + destChars[j++] = trail; + i++; + continue; + } + } + } + + if (MOZ_UNLIKELY(c > 0x7f && + ToUpperCaseHasSpecialCasing(static_cast<SrcChar>(c)))) { + // Return if the output buffer is too small. + if (srcLength == destLength) { + return i; + } + + ToUpperCaseAppendUpperCaseSpecialCasing(c, destChars, &j); + continue; + } + + c = unicode::ToUpperCase(c); + if constexpr (std::is_same_v<DestChar, Latin1Char>) { + MOZ_ASSERT(c <= JSString::MAX_LATIN1_CHAR); + } + destChars[j++] = c; + } + + MOZ_ASSERT(j == destLength); + return srcLength; +} + +template <typename CharT> +static size_t ToUpperCaseLength(const CharT* chars, size_t startIndex, + size_t length) { + size_t upperLength = length; + for (size_t i = startIndex; i < length; i++) { + char16_t c = chars[i]; + + if (c > 0x7f && ToUpperCaseHasSpecialCasing(static_cast<CharT>(c))) { + upperLength += ToUpperCaseLengthSpecialCasing(static_cast<CharT>(c)) - 1; + } + } + return upperLength; +} + +template <typename DestChar, typename SrcChar> +static inline void CopyChars(DestChar* destChars, const SrcChar* srcChars, + size_t length) { + static_assert(!std::is_same_v<DestChar, SrcChar>, + "PodCopy is used for the same type case"); + for (size_t i = 0; i < length; i++) { + destChars[i] = srcChars[i]; + } +} + +template <typename CharT> +static inline void CopyChars(CharT* destChars, const CharT* srcChars, + size_t length) { + PodCopy(destChars, srcChars, length); +} + +template <typename DestChar, typename SrcChar> +static inline bool ToUpperCase(JSContext* cx, + InlineCharBuffer<DestChar>& newChars, + const SrcChar* chars, size_t startIndex, + size_t length, size_t* resultLength) { + MOZ_ASSERT(startIndex < length); + + *resultLength = length; + if (!newChars.maybeAlloc(cx, length)) { + return false; + } + + CopyChars(newChars.get(), chars, startIndex); + + size_t readChars = + ToUpperCaseImpl(newChars.get(), chars, startIndex, length, length); + if (readChars < length) { + size_t actualLength = ToUpperCaseLength(chars, readChars, length); + + *resultLength = actualLength; + if (!newChars.maybeRealloc(cx, length, actualLength)) { + return false; + } + + MOZ_ALWAYS_TRUE(length == ToUpperCaseImpl(newChars.get(), chars, readChars, + length, actualLength)); + } + + return true; +} + +template <typename CharT> +static JSString* ToUpperCase(JSContext* cx, JSLinearString* str) { + using Latin1Buffer = InlineCharBuffer<Latin1Char>; + using TwoByteBuffer = InlineCharBuffer<char16_t>; + + mozilla::MaybeOneOf<Latin1Buffer, TwoByteBuffer> newChars; + const size_t length = str->length(); + size_t resultLength; + { + AutoCheckCannotGC nogc; + const CharT* chars = str->chars<CharT>(nogc); + + // Most one element Latin-1 strings can be directly retrieved from the + // static strings cache. + if constexpr (std::is_same_v<CharT, Latin1Char>) { + if (length == 1) { + Latin1Char c = chars[0]; + if (c != unicode::MICRO_SIGN && + c != unicode::LATIN_SMALL_LETTER_Y_WITH_DIAERESIS && + c != unicode::LATIN_SMALL_LETTER_SHARP_S) { + char16_t upper = unicode::ToUpperCase(c); + MOZ_ASSERT(upper <= JSString::MAX_LATIN1_CHAR); + MOZ_ASSERT(StaticStrings::hasUnit(upper)); + + return cx->staticStrings().getUnit(upper); + } + + MOZ_ASSERT(unicode::ToUpperCase(c) > JSString::MAX_LATIN1_CHAR || + ToUpperCaseHasSpecialCasing(c)); + } + } + + // Look for the first character that changes when uppercased. + size_t i = 0; + for (; i < length; i++) { + CharT c = chars[i]; + if constexpr (!std::is_same_v<CharT, Latin1Char>) { + if (unicode::IsLeadSurrogate(c) && i + 1 < length) { + CharT trail = chars[i + 1]; + if (unicode::IsTrailSurrogate(trail)) { + if (unicode::ChangesWhenUpperCasedNonBMP(c, trail)) { + break; + } + + i++; + continue; + } + } + } + if (unicode::ChangesWhenUpperCased(c)) { + break; + } + if (MOZ_UNLIKELY(c > 0x7f && ToUpperCaseHasSpecialCasing(c))) { + break; + } + } + + // If no character needs to change, return the input string. + if (i == length) { + return str; + } + + // The string changes when uppercased, so we must create a new string. + // Can it be Latin-1? + // + // If the original string is Latin-1, it can -- unless the string + // contains U+00B5 MICRO SIGN or U+00FF SMALL LETTER Y WITH DIAERESIS, + // the only Latin-1 codepoints that don't uppercase within Latin-1. + // Search for those codepoints to decide whether the new string can be + // Latin-1. + // If the original string is a two-byte string, its uppercase form is + // so rarely Latin-1 that we don't even consider creating a new + // Latin-1 string. + if constexpr (std::is_same_v<CharT, Latin1Char>) { + bool resultIsLatin1 = true; + for (size_t j = i; j < length; j++) { + Latin1Char c = chars[j]; + if (c == unicode::MICRO_SIGN || + c == unicode::LATIN_SMALL_LETTER_Y_WITH_DIAERESIS) { + MOZ_ASSERT(unicode::ToUpperCase(c) > JSString::MAX_LATIN1_CHAR); + resultIsLatin1 = false; + break; + } else { + MOZ_ASSERT(unicode::ToUpperCase(c) <= JSString::MAX_LATIN1_CHAR); + } + } + + if (resultIsLatin1) { + newChars.construct<Latin1Buffer>(); + + if (!ToUpperCase(cx, newChars.ref<Latin1Buffer>(), chars, i, length, + &resultLength)) { + return nullptr; + } + } else { + newChars.construct<TwoByteBuffer>(); + + if (!ToUpperCase(cx, newChars.ref<TwoByteBuffer>(), chars, i, length, + &resultLength)) { + return nullptr; + } + } + } else { + newChars.construct<TwoByteBuffer>(); + + if (!ToUpperCase(cx, newChars.ref<TwoByteBuffer>(), chars, i, length, + &resultLength)) { + return nullptr; + } + } + } + + auto toString = [&](auto& chars) { + return chars.toStringDontDeflate(cx, resultLength); + }; + + return newChars.mapNonEmpty(toString); +} + +JSString* js::StringToUpperCase(JSContext* cx, HandleString string) { + JSLinearString* linear = string->ensureLinear(cx); + if (!linear) { + return nullptr; + } + + if (linear->hasLatin1Chars()) { + return ToUpperCase<Latin1Char>(cx, linear); + } + return ToUpperCase<char16_t>(cx, linear); +} + +static bool str_toUpperCase(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "toUpperCase"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str(cx, + ToStringForStringFunction(cx, "toUpperCase", args.thisv())); + if (!str) { + return false; + } + + JSString* result = StringToUpperCase(cx, str); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +#if JS_HAS_INTL_API +// String.prototype.toLocaleUpperCase is self-hosted when Intl is exposed, +// with core functionality performed by the intrinsic below. + +bool js::intl_toLocaleUpperCase(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + MOZ_ASSERT(args.length() == 2); + MOZ_ASSERT(args[0].isString()); + MOZ_ASSERT(args[1].isString()); + + RootedString string(cx, args[0].toString()); + + const char* locale = CaseMappingLocale(cx, args[1].toString()); + if (!locale) { + return false; + } + + // Call String.prototype.toUpperCase() for language independent casing. + if (HasDefaultCasing(locale)) { + JSString* str = js::StringToUpperCase(cx, string); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; + } + + AutoStableStringChars inputChars(cx); + if (!inputChars.initTwoByte(cx, string)) { + return false; + } + mozilla::Range<const char16_t> input = inputChars.twoByteRange(); + + // Note: maximum case mapping length is three characters, so the result + // length might be > INT32_MAX. ICU will fail in this case. + static_assert(JSString::MAX_LENGTH <= INT32_MAX, + "String length must fit in int32_t for ICU"); + + static const size_t INLINE_CAPACITY = js::intl::INITIAL_CHAR_BUFFER_SIZE; + + intl::FormatBuffer<char16_t, INLINE_CAPACITY> buffer(cx); + + auto ok = mozilla::intl::String::ToLocaleUpperCase(locale, input, buffer); + if (ok.isErr()) { + intl::ReportInternalError(cx, ok.unwrapErr()); + return false; + } + + JSString* result = buffer.toString(cx); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +#else + +// When the Intl API is not exposed, String.prototype.toUpperCase is implemented +// in C++. +static bool str_toLocaleUpperCase(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", + "toLocaleUpperCase"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str( + cx, ToStringForStringFunction(cx, "toLocaleUpperCase", args.thisv())); + if (!str) { + return false; + } + + /* + * Forcefully ignore the first (or any) argument and return toUpperCase(), + * ECMA has reserved that argument, presumably for defining the locale. + */ + if (cx->runtime()->localeCallbacks && + cx->runtime()->localeCallbacks->localeToUpperCase) { + RootedValue result(cx); + if (!cx->runtime()->localeCallbacks->localeToUpperCase(cx, str, &result)) { + return false; + } + + args.rval().set(result); + return true; + } + + Rooted<JSLinearString*> linear(cx, str->ensureLinear(cx)); + if (!linear) { + return false; + } + + JSString* result = StringToUpperCase(cx, linear); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +#endif // JS_HAS_INTL_API + +#if JS_HAS_INTL_API + +// String.prototype.localeCompare is self-hosted when Intl functionality is +// exposed, and the only intrinsics it requires are provided in the +// implementation of Intl.Collator. + +#else + +// String.prototype.localeCompare is implemented in C++ (delegating to +// JSLocaleCallbacks) when Intl functionality is not exposed. +static bool str_localeCompare(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", + "localeCompare"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str( + cx, ToStringForStringFunction(cx, "localeCompare", args.thisv())); + if (!str) { + return false; + } + + RootedString thatStr(cx, ToString<CanGC>(cx, args.get(0))); + if (!thatStr) { + return false; + } + + if (cx->runtime()->localeCallbacks && + cx->runtime()->localeCallbacks->localeCompare) { + RootedValue result(cx); + if (!cx->runtime()->localeCallbacks->localeCompare(cx, str, thatStr, + &result)) { + return false; + } + + args.rval().set(result); + return true; + } + + int32_t result; + if (!CompareStrings(cx, str, thatStr, &result)) { + return false; + } + + args.rval().setInt32(result); + return true; +} + +#endif // JS_HAS_INTL_API + +#if JS_HAS_INTL_API + +// ES2017 draft rev 45e890512fd77add72cc0ee742785f9f6f6482de +// 21.1.3.12 String.prototype.normalize ( [ form ] ) +// +// String.prototype.normalize is only implementable if ICU's normalization +// functionality is available. +static bool str_normalize(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "normalize"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Steps 1-2. + RootedString str(cx, + ToStringForStringFunction(cx, "normalize", args.thisv())); + if (!str) { + return false; + } + + using NormalizationForm = mozilla::intl::String::NormalizationForm; + + NormalizationForm form; + if (!args.hasDefined(0)) { + // Step 3. + form = NormalizationForm::NFC; + } else { + // Step 4. + JSLinearString* formStr = ArgToLinearString(cx, args, 0); + if (!formStr) { + return false; + } + + // Step 5. + if (EqualStrings(formStr, cx->names().NFC)) { + form = NormalizationForm::NFC; + } else if (EqualStrings(formStr, cx->names().NFD)) { + form = NormalizationForm::NFD; + } else if (EqualStrings(formStr, cx->names().NFKC)) { + form = NormalizationForm::NFKC; + } else if (EqualStrings(formStr, cx->names().NFKD)) { + form = NormalizationForm::NFKD; + } else { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_INVALID_NORMALIZE_FORM); + return false; + } + } + + // Latin-1 strings are already in Normalization Form C. + if (form == NormalizationForm::NFC && str->hasLatin1Chars()) { + // Step 7. + args.rval().setString(str); + return true; + } + + // Step 6. + AutoStableStringChars stableChars(cx); + if (!stableChars.initTwoByte(cx, str)) { + return false; + } + + mozilla::Range<const char16_t> srcChars = stableChars.twoByteRange(); + + static const size_t INLINE_CAPACITY = js::intl::INITIAL_CHAR_BUFFER_SIZE; + + intl::FormatBuffer<char16_t, INLINE_CAPACITY> buffer(cx); + + auto alreadyNormalized = + mozilla::intl::String::Normalize(form, srcChars, buffer); + if (alreadyNormalized.isErr()) { + intl::ReportInternalError(cx, alreadyNormalized.unwrapErr()); + return false; + } + + using AlreadyNormalized = mozilla::intl::String::AlreadyNormalized; + + // Return if the input string is already normalized. + if (alreadyNormalized.unwrap() == AlreadyNormalized::Yes) { + // Step 7. + args.rval().setString(str); + return true; + } + + JSString* ns = buffer.toString(cx); + if (!ns) { + return false; + } + + // Step 7. + args.rval().setString(ns); + return true; +} + +#endif // JS_HAS_INTL_API + +#ifdef NIGHTLY_BUILD +/** + * IsStringWellFormedUnicode ( string ) + * https://tc39.es/ecma262/#sec-isstringwellformedunicode + */ +static bool IsStringWellFormedUnicode(JSContext* cx, HandleString str, + bool* isWellFormedOut) { + MOZ_ASSERT(isWellFormedOut); + *isWellFormedOut = false; + + JSLinearString* linear = str->ensureLinear(cx); + if (!linear) { + return false; + } + + // Latin1 chars are well-formed. + if (linear->hasLatin1Chars()) { + *isWellFormedOut = true; + return true; + } + + { + AutoCheckCannotGC nogc; + size_t len = linear->length(); + *isWellFormedOut = + Utf16ValidUpTo(Span{linear->twoByteChars(nogc), len}) == len; + } + return true; +} + +/** + * Well-Formed Unicode Strings (Stage 3 proposal) + * + * String.prototype.isWellFormed + * https://tc39.es/proposal-is-usv-string/#sec-string.prototype.iswellformed + */ +static bool str_isWellFormed(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "isWellFormed"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Step 1. Let O be ? RequireObjectCoercible(this value). + // Step 2. Let S be ? ToString(O). + RootedString str(cx, + ToStringForStringFunction(cx, "isWellFormed", args.thisv())); + if (!str) { + return false; + } + + // Step 3. Return IsStringWellFormedUnicode(S). + bool isWellFormed; + if (!IsStringWellFormedUnicode(cx, str, &isWellFormed)) { + return false; + } + + args.rval().setBoolean(isWellFormed); + return true; +} + +/** + * Well-Formed Unicode Strings (Stage 3 proposal) + * + * String.prototype.toWellFormed + * https://tc39.es/proposal-is-usv-string/#sec-string.prototype.towellformed + */ +static bool str_toWellFormed(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "toWellFormed"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Step 1. Let O be ? RequireObjectCoercible(this value). + // Step 2. Let S be ? ToString(O). + RootedString str(cx, + ToStringForStringFunction(cx, "toWellFormed", args.thisv())); + if (!str) { + return false; + } + + // If the string itself is well-formed, return it. + bool isWellFormed; + if (!IsStringWellFormedUnicode(cx, str, &isWellFormed)) { + return false; + } + if (isWellFormed) { + args.rval().setString(str); + return true; + } + + // Step 3. Let strLen be the length of S. + size_t len = str->length(); + + // Step 4-6 + auto buffer = cx->make_pod_arena_array<char16_t>(js::StringBufferArena, len); + if (!buffer) { + return false; + } + + { + AutoCheckCannotGC nogc; + JSLinearString* linear = str->ensureLinear(cx); + PodCopy(buffer.get(), linear->twoByteChars(nogc), len); + EnsureUtf16ValiditySpan(Span{buffer.get(), len}); + } + + JSString* result = NewString<CanGC>(cx, std::move(buffer), len); + if (!result) { + return false; + } + + // Step 7. Return result. + args.rval().setString(result); + return true; +} +#endif // NIGHTLY_BUILD + +static bool str_charAt(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "charAt"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str(cx); + size_t i; + if (args.thisv().isString() && args.length() != 0 && args[0].isInt32()) { + str = args.thisv().toString(); + i = size_t(args[0].toInt32()); + if (i >= str->length()) { + goto out_of_range; + } + } else { + str = ToStringForStringFunction(cx, "charAt", args.thisv()); + if (!str) { + return false; + } + + double d = 0.0; + if (args.length() > 0 && !ToInteger(cx, args[0], &d)) { + return false; + } + + if (d < 0 || str->length() <= d) { + goto out_of_range; + } + i = size_t(d); + } + + str = cx->staticStrings().getUnitStringForElement(cx, str, i); + if (!str) { + return false; + } + args.rval().setString(str); + return true; + +out_of_range: + args.rval().setString(cx->runtime()->emptyString); + return true; +} + +bool js::str_charCodeAt_impl(JSContext* cx, HandleString string, + HandleValue index, MutableHandleValue res) { + size_t i; + if (index.isInt32()) { + i = index.toInt32(); + if (i >= string->length()) { + goto out_of_range; + } + } else { + double d = 0.0; + if (!ToInteger(cx, index, &d)) { + return false; + } + // check whether d is negative as size_t is unsigned + if (d < 0 || string->length() <= d) { + goto out_of_range; + } + i = size_t(d); + } + char16_t c; + if (!string->getChar(cx, i, &c)) { + return false; + } + res.setInt32(c); + return true; + +out_of_range: + res.setNaN(); + return true; +} + +bool js::str_charCodeAt(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "charCodeAt"); + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str(cx); + RootedValue index(cx); + if (args.thisv().isString()) { + str = args.thisv().toString(); + } else { + str = ToStringForStringFunction(cx, "charCodeAt", args.thisv()); + if (!str) { + return false; + } + } + if (args.length() != 0) { + index = args[0]; + } else { + index.setInt32(0); + } + + return js::str_charCodeAt_impl(cx, str, index, args.rval()); +} + +/* + * Boyer-Moore-Horspool superlinear search for pat:patlen in text:textlen. + * The patlen argument must be positive and no greater than sBMHPatLenMax. + * + * Return the index of pat in text, or -1 if not found. + */ +static const uint32_t sBMHCharSetSize = 256; /* ISO-Latin-1 */ +static const uint32_t sBMHPatLenMax = 255; /* skip table element is uint8_t */ +static const int sBMHBadPattern = + -2; /* return value if pat is not ISO-Latin-1 */ + +template <typename TextChar, typename PatChar> +static int BoyerMooreHorspool(const TextChar* text, uint32_t textLen, + const PatChar* pat, uint32_t patLen) { + MOZ_ASSERT(0 < patLen && patLen <= sBMHPatLenMax); + + uint8_t skip[sBMHCharSetSize]; + for (uint32_t i = 0; i < sBMHCharSetSize; i++) { + skip[i] = uint8_t(patLen); + } + + uint32_t patLast = patLen - 1; + for (uint32_t i = 0; i < patLast; i++) { + char16_t c = pat[i]; + if (c >= sBMHCharSetSize) { + return sBMHBadPattern; + } + skip[c] = uint8_t(patLast - i); + } + + for (uint32_t k = patLast; k < textLen;) { + for (uint32_t i = k, j = patLast;; i--, j--) { + if (text[i] != pat[j]) { + break; + } + if (j == 0) { + return static_cast<int>(i); /* safe: max string size */ + } + } + + char16_t c = text[k]; + k += (c >= sBMHCharSetSize) ? patLen : skip[c]; + } + return -1; +} + +template <typename TextChar, typename PatChar> +struct MemCmp { + using Extent = uint32_t; + static MOZ_ALWAYS_INLINE Extent computeExtent(const PatChar*, + uint32_t patLen) { + return (patLen - 2) * sizeof(PatChar); + } + static MOZ_ALWAYS_INLINE bool match(const PatChar* p, const TextChar* t, + Extent extent) { + MOZ_ASSERT(sizeof(TextChar) == sizeof(PatChar)); + return memcmp(p, t, extent) == 0; + } +}; + +template <typename TextChar, typename PatChar> +struct ManualCmp { + using Extent = const PatChar*; + static MOZ_ALWAYS_INLINE Extent computeExtent(const PatChar* pat, + uint32_t patLen) { + return pat + patLen; + } + static MOZ_ALWAYS_INLINE bool match(const PatChar* p, const TextChar* t, + Extent extent) { + for (; p != extent; ++p, ++t) { + if (*p != *t) { + return false; + } + } + return true; + } +}; + +template <class InnerMatch, typename TextChar, typename PatChar> +static int Matcher(const TextChar* text, uint32_t textlen, const PatChar* pat, + uint32_t patlen) { + MOZ_ASSERT(patlen > 1); + + const typename InnerMatch::Extent extent = + InnerMatch::computeExtent(pat, patlen); + + uint32_t i = 0; + uint32_t n = textlen - patlen + 1; + + while (i < n) { + const TextChar* pos; + + // This is a bit awkward. Consider the case where we're searching "abcdef" + // for "def". n will be 4, because we know in advance that the last place we + // can *start* a successful search will be at 'd'. However, if we just use n + // - i, then our first search will be looking through "abcd" for "de", + // because our memchr2xN functions search for two characters at a time. So + // we just have to compensate by adding 1. This will never exceed textlen + // because we know patlen is at least two. + size_t searchLen = n - i + 1; + if (sizeof(TextChar) == 1) { + MOZ_ASSERT(pat[0] <= 0xff); + pos = (TextChar*)SIMD::memchr2x8((char*)text + i, pat[0], pat[1], + searchLen); + } else { + pos = (TextChar*)SIMD::memchr2x16((char16_t*)(text + i), char16_t(pat[0]), + char16_t(pat[1]), searchLen); + } + + if (pos == nullptr) { + return -1; + } + + i = static_cast<uint32_t>(pos - text); + const uint32_t inlineLookaheadChars = 2; + if (InnerMatch::match(pat + inlineLookaheadChars, + text + i + inlineLookaheadChars, extent)) { + return i; + } + + i += 1; + } + return -1; +} + +template <typename TextChar, typename PatChar> +static MOZ_ALWAYS_INLINE int StringMatch(const TextChar* text, uint32_t textLen, + const PatChar* pat, uint32_t patLen) { + if (patLen == 0) { + return 0; + } + if (textLen < patLen) { + return -1; + } + + if (sizeof(TextChar) == 1 && sizeof(PatChar) > 1 && pat[0] > 0xff) { + return -1; + } + + if (patLen == 1) { + const TextChar* pos; + if (sizeof(TextChar) == 1) { + MOZ_ASSERT(pat[0] <= 0xff); + pos = (TextChar*)SIMD::memchr8((char*)text, pat[0], textLen); + } else { + pos = + (TextChar*)SIMD::memchr16((char16_t*)text, char16_t(pat[0]), textLen); + } + + if (pos == nullptr) { + return -1; + } + + return pos - text; + } + + // We use a fast two-character-wide search in Matcher below, so we need to + // validate that pat[1] isn't outside the latin1 range up front if the + // sizes are different. + if (sizeof(TextChar) == 1 && sizeof(PatChar) > 1 && pat[1] > 0xff) { + return -1; + } + + /* + * If the text or pattern string is short, BMH will be more expensive than + * the basic linear scan due to initialization cost and a more complex loop + * body. While the correct threshold is input-dependent, we can make a few + * conservative observations: + * - When |textLen| is "big enough", the initialization time will be + * proportionally small, so the worst-case slowdown is minimized. + * - When |patLen| is "too small", even the best case for BMH will be + * slower than a simple scan for large |textLen| due to the more complex + * loop body of BMH. + * From this, the values for "big enough" and "too small" are determined + * empirically. See bug 526348. + */ + if (textLen >= 512 && patLen >= 11 && patLen <= sBMHPatLenMax) { + int index = BoyerMooreHorspool(text, textLen, pat, patLen); + if (index != sBMHBadPattern) { + return index; + } + } + + /* + * For big patterns with large potential overlap we want the SIMD-optimized + * speed of memcmp. For small patterns, a simple loop is faster. We also can't + * use memcmp if one of the strings is TwoByte and the other is Latin-1. + */ + return (patLen > 128 && std::is_same_v<TextChar, PatChar>) + ? Matcher<MemCmp<TextChar, PatChar>, TextChar, PatChar>( + text, textLen, pat, patLen) + : Matcher<ManualCmp<TextChar, PatChar>, TextChar, PatChar>( + text, textLen, pat, patLen); +} + +static int32_t StringMatch(JSLinearString* text, JSLinearString* pat, + uint32_t start = 0) { + MOZ_ASSERT(start <= text->length()); + uint32_t textLen = text->length() - start; + uint32_t patLen = pat->length(); + + int match; + AutoCheckCannotGC nogc; + if (text->hasLatin1Chars()) { + const Latin1Char* textChars = text->latin1Chars(nogc) + start; + if (pat->hasLatin1Chars()) { + match = StringMatch(textChars, textLen, pat->latin1Chars(nogc), patLen); + } else { + match = StringMatch(textChars, textLen, pat->twoByteChars(nogc), patLen); + } + } else { + const char16_t* textChars = text->twoByteChars(nogc) + start; + if (pat->hasLatin1Chars()) { + match = StringMatch(textChars, textLen, pat->latin1Chars(nogc), patLen); + } else { + match = StringMatch(textChars, textLen, pat->twoByteChars(nogc), patLen); + } + } + + return (match == -1) ? -1 : start + match; +} + +static const size_t sRopeMatchThresholdRatioLog2 = 4; + +int js::StringFindPattern(JSLinearString* text, JSLinearString* pat, + size_t start) { + return StringMatch(text, pat, start); +} + +typedef Vector<JSLinearString*, 16, SystemAllocPolicy> LinearStringVector; + +template <typename TextChar, typename PatChar> +static int RopeMatchImpl(const AutoCheckCannotGC& nogc, + LinearStringVector& strings, const PatChar* pat, + size_t patLen) { + /* Absolute offset from the beginning of the logical text string. */ + int pos = 0; + + for (JSLinearString** outerp = strings.begin(); outerp != strings.end(); + ++outerp) { + /* Try to find a match within 'outer'. */ + JSLinearString* outer = *outerp; + const TextChar* chars = outer->chars<TextChar>(nogc); + size_t len = outer->length(); + int matchResult = StringMatch(chars, len, pat, patLen); + if (matchResult != -1) { + /* Matched! */ + return pos + matchResult; + } + + /* Try to find a match starting in 'outer' and running into other nodes. */ + const TextChar* const text = chars + (patLen > len ? 0 : len - patLen + 1); + const TextChar* const textend = chars + len; + const PatChar p0 = *pat; + const PatChar* const p1 = pat + 1; + const PatChar* const patend = pat + patLen; + for (const TextChar* t = text; t != textend;) { + if (*t++ != p0) { + continue; + } + + JSLinearString** innerp = outerp; + const TextChar* ttend = textend; + const TextChar* tt = t; + for (const PatChar* pp = p1; pp != patend; ++pp, ++tt) { + while (tt == ttend) { + if (++innerp == strings.end()) { + return -1; + } + + JSLinearString* inner = *innerp; + tt = inner->chars<TextChar>(nogc); + ttend = tt + inner->length(); + } + if (*pp != *tt) { + goto break_continue; + } + } + + /* Matched! */ + return pos + (t - chars) - 1; /* -1 because of *t++ above */ + + break_continue:; + } + + pos += len; + } + + return -1; +} + +/* + * RopeMatch takes the text to search and the pattern to search for in the text. + * RopeMatch returns false on OOM and otherwise returns the match index through + * the 'match' outparam (-1 for not found). + */ +static bool RopeMatch(JSContext* cx, JSRope* text, JSLinearString* pat, + int* match) { + uint32_t patLen = pat->length(); + if (patLen == 0) { + *match = 0; + return true; + } + if (text->length() < patLen) { + *match = -1; + return true; + } + + /* + * List of leaf nodes in the rope. If we run out of memory when trying to + * append to this list, we can still fall back to StringMatch, so use the + * system allocator so we don't report OOM in that case. + */ + LinearStringVector strings; + + /* + * We don't want to do rope matching if there is a poor node-to-char ratio, + * since this means spending a lot of time in the match loop below. We also + * need to build the list of leaf nodes. Do both here: iterate over the + * nodes so long as there are not too many. + * + * We also don't use rope matching if the rope contains both Latin-1 and + * TwoByte nodes, to simplify the match algorithm. + */ + { + size_t threshold = text->length() >> sRopeMatchThresholdRatioLog2; + StringSegmentRange r(cx); + if (!r.init(text)) { + return false; + } + + bool textIsLatin1 = text->hasLatin1Chars(); + while (!r.empty()) { + if (threshold-- == 0 || r.front()->hasLatin1Chars() != textIsLatin1 || + !strings.append(r.front())) { + JSLinearString* linear = text->ensureLinear(cx); + if (!linear) { + return false; + } + + *match = StringMatch(linear, pat); + return true; + } + if (!r.popFront()) { + return false; + } + } + } + + AutoCheckCannotGC nogc; + if (text->hasLatin1Chars()) { + if (pat->hasLatin1Chars()) { + *match = RopeMatchImpl<Latin1Char>(nogc, strings, pat->latin1Chars(nogc), + patLen); + } else { + *match = RopeMatchImpl<Latin1Char>(nogc, strings, pat->twoByteChars(nogc), + patLen); + } + } else { + if (pat->hasLatin1Chars()) { + *match = RopeMatchImpl<char16_t>(nogc, strings, pat->latin1Chars(nogc), + patLen); + } else { + *match = RopeMatchImpl<char16_t>(nogc, strings, pat->twoByteChars(nogc), + patLen); + } + } + + return true; +} + +static MOZ_ALWAYS_INLINE bool ReportErrorIfFirstArgIsRegExp( + JSContext* cx, const CallArgs& args) { + // Only call IsRegExp if the first argument is definitely an object, so we + // don't pay the cost of an additional function call in the common case. + if (args.length() == 0 || !args[0].isObject()) { + return true; + } + + bool isRegExp; + if (!IsRegExp(cx, args[0], &isRegExp)) { + return false; + } + + if (isRegExp) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_INVALID_ARG_TYPE, "first", "", + "Regular Expression"); + return false; + } + return true; +} + +// ES2018 draft rev de77aaeffce115deaf948ed30c7dbe4c60983c0c +// 21.1.3.7 String.prototype.includes ( searchString [ , position ] ) +bool js::str_includes(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "includes"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Steps 1-2. + RootedString str(cx, ToStringForStringFunction(cx, "includes", args.thisv())); + if (!str) { + return false; + } + + // Steps 3-4. + if (!ReportErrorIfFirstArgIsRegExp(cx, args)) { + return false; + } + + // Step 5. + Rooted<JSLinearString*> searchStr(cx, ArgToLinearString(cx, args, 0)); + if (!searchStr) { + return false; + } + + // Step 6. + uint32_t pos = 0; + if (args.hasDefined(1)) { + if (args[1].isInt32()) { + int i = args[1].toInt32(); + pos = (i < 0) ? 0U : uint32_t(i); + } else { + double d; + if (!ToInteger(cx, args[1], &d)) { + return false; + } + pos = uint32_t(std::min(std::max(d, 0.0), double(UINT32_MAX))); + } + } + + // Step 7. + uint32_t textLen = str->length(); + + // Step 8. + uint32_t start = std::min(pos, textLen); + + // Steps 9-10. + JSLinearString* text = str->ensureLinear(cx); + if (!text) { + return false; + } + + args.rval().setBoolean(StringMatch(text, searchStr, start) != -1); + return true; +} + +/* ES6 20120927 draft 15.5.4.7. */ +bool js::str_indexOf(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "indexOf"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Steps 1, 2, and 3 + RootedString str(cx, ToStringForStringFunction(cx, "indexOf", args.thisv())); + if (!str) { + return false; + } + + // Steps 4 and 5 + Rooted<JSLinearString*> searchStr(cx, ArgToLinearString(cx, args, 0)); + if (!searchStr) { + return false; + } + + // Steps 6 and 7 + uint32_t pos = 0; + if (args.hasDefined(1)) { + if (args[1].isInt32()) { + int i = args[1].toInt32(); + pos = (i < 0) ? 0U : uint32_t(i); + } else { + double d; + if (!ToInteger(cx, args[1], &d)) { + return false; + } + pos = uint32_t(std::min(std::max(d, 0.0), double(UINT32_MAX))); + } + } + + // Step 8 + uint32_t textLen = str->length(); + + // Step 9 + uint32_t start = std::min(pos, textLen); + + if (str == searchStr) { + // AngularJS often invokes "false".indexOf("false"). This check should + // be cheap enough to not hurt anything else. + args.rval().setInt32(start == 0 ? 0 : -1); + return true; + } + + // Steps 10 and 11 + JSLinearString* text = str->ensureLinear(cx); + if (!text) { + return false; + } + + args.rval().setInt32(StringMatch(text, searchStr, start)); + return true; +} + +bool js::StringIndexOf(JSContext* cx, HandleString string, + HandleString searchString, int32_t* result) { + if (string == searchString) { + *result = 0; + return true; + } + + JSLinearString* text = string->ensureLinear(cx); + if (!text) { + return false; + } + + JSLinearString* searchStr = searchString->ensureLinear(cx); + if (!searchStr) { + return false; + } + + *result = StringMatch(text, searchStr, 0); + return true; +} + +template <typename TextChar, typename PatChar> +static int32_t LastIndexOfImpl(const TextChar* text, size_t textLen, + const PatChar* pat, size_t patLen, + size_t start) { + MOZ_ASSERT(patLen > 0); + MOZ_ASSERT(patLen <= textLen); + MOZ_ASSERT(start <= textLen - patLen); + + const PatChar p0 = *pat; + const PatChar* patNext = pat + 1; + const PatChar* patEnd = pat + patLen; + + for (const TextChar* t = text + start; t >= text; --t) { + if (*t == p0) { + const TextChar* t1 = t + 1; + for (const PatChar* p1 = patNext; p1 < patEnd; ++p1, ++t1) { + if (*t1 != *p1) { + goto break_continue; + } + } + + return static_cast<int32_t>(t - text); + } + break_continue:; + } + + return -1; +} + +// ES2017 draft rev 6859bb9ccaea9c6ede81d71e5320e3833b92cb3e +// 21.1.3.9 String.prototype.lastIndexOf ( searchString [ , position ] ) +static bool str_lastIndexOf(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "lastIndexOf"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Steps 1-2. + RootedString str(cx, + ToStringForStringFunction(cx, "lastIndexOf", args.thisv())); + if (!str) { + return false; + } + + // Step 3. + Rooted<JSLinearString*> searchStr(cx, ArgToLinearString(cx, args, 0)); + if (!searchStr) { + return false; + } + + // Step 6. + size_t len = str->length(); + + // Step 8. + size_t searchLen = searchStr->length(); + + // Steps 4-5, 7. + int start = len - searchLen; // Start searching here + if (args.hasDefined(1)) { + if (args[1].isInt32()) { + int i = args[1].toInt32(); + if (i <= 0) { + start = 0; + } else if (i < start) { + start = i; + } + } else { + double d; + if (!ToNumber(cx, args[1], &d)) { + return false; + } + if (!std::isnan(d)) { + d = JS::ToInteger(d); + if (d <= 0) { + start = 0; + } else if (d < start) { + start = int(d); + } + } + } + } + + if (str == searchStr) { + args.rval().setInt32(0); + return true; + } + + if (searchLen > len) { + args.rval().setInt32(-1); + return true; + } + + if (searchLen == 0) { + args.rval().setInt32(start); + return true; + } + MOZ_ASSERT(0 <= start && size_t(start) < len); + + JSLinearString* text = str->ensureLinear(cx); + if (!text) { + return false; + } + + // Step 9. + int32_t res; + AutoCheckCannotGC nogc; + if (text->hasLatin1Chars()) { + const Latin1Char* textChars = text->latin1Chars(nogc); + if (searchStr->hasLatin1Chars()) { + res = LastIndexOfImpl(textChars, len, searchStr->latin1Chars(nogc), + searchLen, start); + } else { + res = LastIndexOfImpl(textChars, len, searchStr->twoByteChars(nogc), + searchLen, start); + } + } else { + const char16_t* textChars = text->twoByteChars(nogc); + if (searchStr->hasLatin1Chars()) { + res = LastIndexOfImpl(textChars, len, searchStr->latin1Chars(nogc), + searchLen, start); + } else { + res = LastIndexOfImpl(textChars, len, searchStr->twoByteChars(nogc), + searchLen, start); + } + } + + args.rval().setInt32(res); + return true; +} + +// ES2018 draft rev de77aaeffce115deaf948ed30c7dbe4c60983c0c +// 21.1.3.20 String.prototype.startsWith ( searchString [ , position ] ) +bool js::str_startsWith(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "startsWith"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Steps 1-2. + RootedString str(cx, + ToStringForStringFunction(cx, "startsWith", args.thisv())); + if (!str) { + return false; + } + + // Steps 3-4. + if (!ReportErrorIfFirstArgIsRegExp(cx, args)) { + return false; + } + + // Step 5. + Rooted<JSLinearString*> searchStr(cx, ArgToLinearString(cx, args, 0)); + if (!searchStr) { + return false; + } + + // Step 6. + uint32_t pos = 0; + if (args.hasDefined(1)) { + if (args[1].isInt32()) { + int i = args[1].toInt32(); + pos = (i < 0) ? 0U : uint32_t(i); + } else { + double d; + if (!ToInteger(cx, args[1], &d)) { + return false; + } + pos = uint32_t(std::min(std::max(d, 0.0), double(UINT32_MAX))); + } + } + + // Step 7. + uint32_t textLen = str->length(); + + // Step 8. + uint32_t start = std::min(pos, textLen); + + // Step 9. + uint32_t searchLen = searchStr->length(); + + // Step 10. + if (searchLen + start < searchLen || searchLen + start > textLen) { + args.rval().setBoolean(false); + return true; + } + + // Steps 11-12. + JSLinearString* text = str->ensureLinear(cx); + if (!text) { + return false; + } + + args.rval().setBoolean(HasSubstringAt(text, searchStr, start)); + return true; +} + +bool js::StringStartsWith(JSContext* cx, HandleString string, + HandleString searchString, bool* result) { + if (searchString->length() > string->length()) { + *result = false; + return true; + } + + JSLinearString* str = string->ensureLinear(cx); + if (!str) { + return false; + } + + JSLinearString* searchStr = searchString->ensureLinear(cx); + if (!searchStr) { + return false; + } + + *result = HasSubstringAt(str, searchStr, 0); + return true; +} + +// ES2018 draft rev de77aaeffce115deaf948ed30c7dbe4c60983c0c +// 21.1.3.6 String.prototype.endsWith ( searchString [ , endPosition ] ) +bool js::str_endsWith(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "endsWith"); + CallArgs args = CallArgsFromVp(argc, vp); + + // Steps 1-2. + RootedString str(cx, ToStringForStringFunction(cx, "endsWith", args.thisv())); + if (!str) { + return false; + } + + // Steps 3-4. + if (!ReportErrorIfFirstArgIsRegExp(cx, args)) { + return false; + } + + // Step 5. + Rooted<JSLinearString*> searchStr(cx, ArgToLinearString(cx, args, 0)); + if (!searchStr) { + return false; + } + + // Step 6. + uint32_t textLen = str->length(); + + // Step 7. + uint32_t pos = textLen; + if (args.hasDefined(1)) { + if (args[1].isInt32()) { + int i = args[1].toInt32(); + pos = (i < 0) ? 0U : uint32_t(i); + } else { + double d; + if (!ToInteger(cx, args[1], &d)) { + return false; + } + pos = uint32_t(std::min(std::max(d, 0.0), double(UINT32_MAX))); + } + } + + // Step 8. + uint32_t end = std::min(pos, textLen); + + // Step 9. + uint32_t searchLen = searchStr->length(); + + // Step 11 (reordered). + if (searchLen > end) { + args.rval().setBoolean(false); + return true; + } + + // Step 10. + uint32_t start = end - searchLen; + + // Steps 12-13. + JSLinearString* text = str->ensureLinear(cx); + if (!text) { + return false; + } + + args.rval().setBoolean(HasSubstringAt(text, searchStr, start)); + return true; +} + +bool js::StringEndsWith(JSContext* cx, HandleString string, + HandleString searchString, bool* result) { + if (searchString->length() > string->length()) { + *result = false; + return true; + } + + JSLinearString* str = string->ensureLinear(cx); + if (!str) { + return false; + } + + JSLinearString* searchStr = searchString->ensureLinear(cx); + if (!searchStr) { + return false; + } + + uint32_t start = str->length() - searchStr->length(); + + *result = HasSubstringAt(str, searchStr, start); + return true; +} + +template <typename CharT> +static void TrimString(const CharT* chars, bool trimStart, bool trimEnd, + size_t length, size_t* pBegin, size_t* pEnd) { + size_t begin = 0, end = length; + + if (trimStart) { + while (begin < length && unicode::IsSpace(chars[begin])) { + ++begin; + } + } + + if (trimEnd) { + while (end > begin && unicode::IsSpace(chars[end - 1])) { + --end; + } + } + + *pBegin = begin; + *pEnd = end; +} + +static bool TrimString(JSContext* cx, const CallArgs& args, const char* funName, + bool trimStart, bool trimEnd) { + JSString* str = ToStringForStringFunction(cx, funName, args.thisv()); + if (!str) { + return false; + } + + JSLinearString* linear = str->ensureLinear(cx); + if (!linear) { + return false; + } + + size_t length = linear->length(); + size_t begin, end; + if (linear->hasLatin1Chars()) { + AutoCheckCannotGC nogc; + TrimString(linear->latin1Chars(nogc), trimStart, trimEnd, length, &begin, + &end); + } else { + AutoCheckCannotGC nogc; + TrimString(linear->twoByteChars(nogc), trimStart, trimEnd, length, &begin, + &end); + } + + JSLinearString* result = NewDependentString(cx, linear, begin, end - begin); + if (!result) { + return false; + } + + args.rval().setString(result); + return true; +} + +static bool str_trim(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "trim"); + CallArgs args = CallArgsFromVp(argc, vp); + return TrimString(cx, args, "trim", true, true); +} + +static bool str_trimStart(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "trimStart"); + CallArgs args = CallArgsFromVp(argc, vp); + return TrimString(cx, args, "trimStart", true, false); +} + +static bool str_trimEnd(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "String.prototype", "trimEnd"); + CallArgs args = CallArgsFromVp(argc, vp); + return TrimString(cx, args, "trimEnd", false, true); +} + +// Utility for building a rope (lazy concatenation) of strings. +class RopeBuilder { + JSContext* cx; + RootedString res; + + RopeBuilder(const RopeBuilder& other) = delete; + void operator=(const RopeBuilder& other) = delete; + + public: + explicit RopeBuilder(JSContext* cx) + : cx(cx), res(cx, cx->runtime()->emptyString) {} + + inline bool append(HandleString str) { + res = ConcatStrings<CanGC>(cx, res, str); + return !!res; + } + + inline JSString* result() { return res; } +}; + +namespace { + +template <typename CharT> +static uint32_t FindDollarIndex(const CharT* chars, size_t length) { + if (const CharT* p = js_strchr_limit(chars, '$', chars + length)) { + uint32_t dollarIndex = p - chars; + MOZ_ASSERT(dollarIndex < length); + return dollarIndex; + } + return UINT32_MAX; +} + +} /* anonymous namespace */ + +/* + * Constructs a result string that looks like: + * + * newstring = string[:matchStart] + repstr + string[matchEnd:] + */ +static JSString* BuildFlatReplacement(JSContext* cx, HandleString textstr, + Handle<JSLinearString*> repstr, + size_t matchStart, size_t patternLength) { + size_t matchEnd = matchStart + patternLength; + + RootedString resultStr(cx, NewDependentString(cx, textstr, 0, matchStart)); + if (!resultStr) { + return nullptr; + } + + resultStr = ConcatStrings<CanGC>(cx, resultStr, repstr); + if (!resultStr) { + return nullptr; + } + + MOZ_ASSERT(textstr->length() >= matchEnd); + RootedString rest(cx, NewDependentString(cx, textstr, matchEnd, + textstr->length() - matchEnd)); + if (!rest) { + return nullptr; + } + + return ConcatStrings<CanGC>(cx, resultStr, rest); +} + +static JSString* BuildFlatRopeReplacement(JSContext* cx, HandleString textstr, + Handle<JSLinearString*> repstr, + size_t match, size_t patternLength) { + MOZ_ASSERT(textstr->isRope()); + + size_t matchEnd = match + patternLength; + + /* + * If we are replacing over a rope, avoid flattening it by iterating + * through it, building a new rope. + */ + StringSegmentRange r(cx); + if (!r.init(textstr)) { + return nullptr; + } + + RopeBuilder builder(cx); + + /* + * Special case when the pattern string is '', which matches to the + * head of the string and doesn't overlap with any component of the rope. + */ + if (patternLength == 0) { + MOZ_ASSERT(match == 0); + if (!builder.append(repstr)) { + return nullptr; + } + } + + size_t pos = 0; + while (!r.empty()) { + RootedString str(cx, r.front()); + size_t len = str->length(); + size_t strEnd = pos + len; + if (pos < matchEnd && strEnd > match) { + /* + * We need to special-case any part of the rope that overlaps + * with the replacement string. + */ + if (match >= pos) { + /* + * If this part of the rope overlaps with the left side of + * the pattern, then it must be the only one to overlap with + * the first character in the pattern, so we include the + * replacement string here. + */ + RootedString leftSide(cx, NewDependentString(cx, str, 0, match - pos)); + if (!leftSide || !builder.append(leftSide) || !builder.append(repstr)) { + return nullptr; + } + } + + /* + * If str runs off the end of the matched string, append the + * last part of str. + */ + if (strEnd > matchEnd) { + RootedString rightSide( + cx, NewDependentString(cx, str, matchEnd - pos, strEnd - matchEnd)); + if (!rightSide || !builder.append(rightSide)) { + return nullptr; + } + } + } else { + if (!builder.append(str)) { + return nullptr; + } + } + pos += str->length(); + if (!r.popFront()) { + return nullptr; + } + } + + return builder.result(); +} + +template <typename CharT> +static bool AppendDollarReplacement(StringBuffer& newReplaceChars, + size_t firstDollarIndex, size_t matchStart, + size_t matchLimit, JSLinearString* text, + const CharT* repChars, size_t repLength) { + MOZ_ASSERT(firstDollarIndex < repLength); + MOZ_ASSERT(matchStart <= matchLimit); + MOZ_ASSERT(matchLimit <= text->length()); + + // Move the pre-dollar chunk in bulk. + if (!newReplaceChars.append(repChars, firstDollarIndex)) { + return false; + } + + // Move the rest char-by-char, interpreting dollars as we encounter them. + const CharT* repLimit = repChars + repLength; + for (const CharT* it = repChars + firstDollarIndex; it < repLimit; ++it) { + if (*it != '$' || it == repLimit - 1) { + if (!newReplaceChars.append(*it)) { + return false; + } + continue; + } + + switch (*(it + 1)) { + case '$': + // Eat one of the dollars. + if (!newReplaceChars.append(*it)) { + return false; + } + break; + case '&': + if (!newReplaceChars.appendSubstring(text, matchStart, + matchLimit - matchStart)) { + return false; + } + break; + case '`': + if (!newReplaceChars.appendSubstring(text, 0, matchStart)) { + return false; + } + break; + case '\'': + if (!newReplaceChars.appendSubstring(text, matchLimit, + text->length() - matchLimit)) { + return false; + } + break; + default: + // The dollar we saw was not special (no matter what its mother told + // it). + if (!newReplaceChars.append(*it)) { + return false; + } + continue; + } + ++it; // We always eat an extra char in the above switch. + } + + return true; +} + +/* + * Perform a linear-scan dollar substitution on the replacement text. + */ +static JSLinearString* InterpretDollarReplacement( + JSContext* cx, HandleString textstrArg, Handle<JSLinearString*> repstr, + uint32_t firstDollarIndex, size_t matchStart, size_t patternLength) { + Rooted<JSLinearString*> textstr(cx, textstrArg->ensureLinear(cx)); + if (!textstr) { + return nullptr; + } + + size_t matchLimit = matchStart + patternLength; + + /* + * Most probably: + * + * len(newstr) >= len(orig) - len(match) + len(replacement) + * + * Note that dollar vars _could_ make the resulting text smaller than this. + */ + JSStringBuilder newReplaceChars(cx); + if (repstr->hasTwoByteChars() && !newReplaceChars.ensureTwoByteChars()) { + return nullptr; + } + + if (!newReplaceChars.reserve(textstr->length() - patternLength + + repstr->length())) { + return nullptr; + } + + bool res; + if (repstr->hasLatin1Chars()) { + AutoCheckCannotGC nogc; + res = AppendDollarReplacement(newReplaceChars, firstDollarIndex, matchStart, + matchLimit, textstr, + repstr->latin1Chars(nogc), repstr->length()); + } else { + AutoCheckCannotGC nogc; + res = AppendDollarReplacement(newReplaceChars, firstDollarIndex, matchStart, + matchLimit, textstr, + repstr->twoByteChars(nogc), repstr->length()); + } + if (!res) { + return nullptr; + } + + return newReplaceChars.finishString(); +} + +template <typename StrChar, typename RepChar> +static bool StrFlatReplaceGlobal(JSContext* cx, JSLinearString* str, + JSLinearString* pat, JSLinearString* rep, + StringBuffer& sb) { + MOZ_ASSERT(str->length() > 0); + + AutoCheckCannotGC nogc; + const StrChar* strChars = str->chars<StrChar>(nogc); + const RepChar* repChars = rep->chars<RepChar>(nogc); + + // The pattern is empty, so we interleave the replacement string in-between + // each character. + if (!pat->length()) { + CheckedInt<uint32_t> strLength(str->length()); + CheckedInt<uint32_t> repLength(rep->length()); + CheckedInt<uint32_t> length = repLength * (strLength - 1) + strLength; + if (!length.isValid()) { + ReportAllocationOverflow(cx); + return false; + } + + if (!sb.reserve(length.value())) { + return false; + } + + for (unsigned i = 0; i < str->length() - 1; ++i, ++strChars) { + sb.infallibleAppend(*strChars); + sb.infallibleAppend(repChars, rep->length()); + } + sb.infallibleAppend(*strChars); + return true; + } + + // If it's true, we are sure that the result's length is, at least, the same + // length as |str->length()|. + if (rep->length() >= pat->length()) { + if (!sb.reserve(str->length())) { + return false; + } + } + + uint32_t start = 0; + for (;;) { + int match = StringMatch(str, pat, start); + if (match < 0) { + break; + } + if (!sb.append(strChars + start, match - start)) { + return false; + } + if (!sb.append(repChars, rep->length())) { + return false; + } + start = match + pat->length(); + } + + if (!sb.append(strChars + start, str->length() - start)) { + return false; + } + + return true; +} + +// This is identical to "str.split(pattern).join(replacement)" except that we +// do some deforestation optimization in Ion. +JSString* js::StringFlatReplaceString(JSContext* cx, HandleString string, + HandleString pattern, + HandleString replacement) { + MOZ_ASSERT(string); + MOZ_ASSERT(pattern); + MOZ_ASSERT(replacement); + + if (!string->length()) { + return string; + } + + Rooted<JSLinearString*> linearRepl(cx, replacement->ensureLinear(cx)); + if (!linearRepl) { + return nullptr; + } + + Rooted<JSLinearString*> linearPat(cx, pattern->ensureLinear(cx)); + if (!linearPat) { + return nullptr; + } + + Rooted<JSLinearString*> linearStr(cx, string->ensureLinear(cx)); + if (!linearStr) { + return nullptr; + } + + JSStringBuilder sb(cx); + if (linearStr->hasTwoByteChars()) { + if (!sb.ensureTwoByteChars()) { + return nullptr; + } + if (linearRepl->hasTwoByteChars()) { + if (!StrFlatReplaceGlobal<char16_t, char16_t>(cx, linearStr, linearPat, + linearRepl, sb)) { + return nullptr; + } + } else { + if (!StrFlatReplaceGlobal<char16_t, Latin1Char>(cx, linearStr, linearPat, + linearRepl, sb)) { + return nullptr; + } + } + } else { + if (linearRepl->hasTwoByteChars()) { + if (!sb.ensureTwoByteChars()) { + return nullptr; + } + if (!StrFlatReplaceGlobal<Latin1Char, char16_t>(cx, linearStr, linearPat, + linearRepl, sb)) { + return nullptr; + } + } else { + if (!StrFlatReplaceGlobal<Latin1Char, Latin1Char>( + cx, linearStr, linearPat, linearRepl, sb)) { + return nullptr; + } + } + } + + return sb.finishString(); +} + +JSString* js::str_replace_string_raw(JSContext* cx, HandleString string, + HandleString pattern, + HandleString replacement) { + Rooted<JSLinearString*> repl(cx, replacement->ensureLinear(cx)); + if (!repl) { + return nullptr; + } + + Rooted<JSLinearString*> pat(cx, pattern->ensureLinear(cx)); + if (!pat) { + return nullptr; + } + + size_t patternLength = pat->length(); + int32_t match; + uint32_t dollarIndex; + + { + AutoCheckCannotGC nogc; + dollarIndex = + repl->hasLatin1Chars() + ? FindDollarIndex(repl->latin1Chars(nogc), repl->length()) + : FindDollarIndex(repl->twoByteChars(nogc), repl->length()); + } + + /* + * |string| could be a rope, so we want to avoid flattening it for as + * long as possible. + */ + if (string->isRope()) { + if (!RopeMatch(cx, &string->asRope(), pat, &match)) { + return nullptr; + } + } else { + match = StringMatch(&string->asLinear(), pat, 0); + } + + if (match < 0) { + return string; + } + + if (dollarIndex != UINT32_MAX) { + repl = InterpretDollarReplacement(cx, string, repl, dollarIndex, match, + patternLength); + if (!repl) { + return nullptr; + } + } else if (string->isRope()) { + return BuildFlatRopeReplacement(cx, string, repl, match, patternLength); + } + return BuildFlatReplacement(cx, string, repl, match, patternLength); +} + +template <typename StrChar, typename RepChar> +static bool ReplaceAllInternal(const AutoCheckCannotGC& nogc, + JSLinearString* string, + JSLinearString* searchString, + JSLinearString* replaceString, + const int32_t startPosition, + JSStringBuilder& result) { + // Step 7. + const size_t stringLength = string->length(); + const size_t searchLength = searchString->length(); + const size_t replaceLength = replaceString->length(); + + MOZ_ASSERT(stringLength > 0); + MOZ_ASSERT(searchLength > 0); + MOZ_ASSERT(stringLength >= searchLength); + + // Step 12. + uint32_t endOfLastMatch = 0; + + const StrChar* strChars = string->chars<StrChar>(nogc); + const RepChar* repChars = replaceString->chars<RepChar>(nogc); + + uint32_t dollarIndex = FindDollarIndex(repChars, replaceLength); + + // If it's true, we are sure that the result's length is, at least, the same + // length as |str->length()|. + if (replaceLength >= searchLength) { + if (!result.reserve(stringLength)) { + return false; + } + } + + int32_t position = startPosition; + do { + // Step 14.c. + // Append the substring before the current match. + if (!result.append(strChars + endOfLastMatch, position - endOfLastMatch)) { + return false; + } + + // Steps 14.a-b and 14.d. + // Append the replacement. + if (dollarIndex != UINT32_MAX) { + size_t matchLimit = position + searchLength; + if (!AppendDollarReplacement(result, dollarIndex, position, matchLimit, + string, repChars, replaceLength)) { + return false; + } + } else { + if (!result.append(repChars, replaceLength)) { + return false; + } + } + + // Step 14.e. + endOfLastMatch = position + searchLength; + + // Step 11. + // Find the next match. + position = StringMatch(string, searchString, endOfLastMatch); + } while (position >= 0); + + // Step 15. + // Append the substring after the last match. + return result.append(strChars + endOfLastMatch, + stringLength - endOfLastMatch); +} + +// https://tc39.es/proposal-string-replaceall/#sec-string.prototype.replaceall +// Steps 7-16 when functionalReplace is false and searchString is not empty. +// +// The steps are quite different, for performance. Loops in steps 11 and 14 +// are fused. GetSubstitution is optimized away when possible. +template <typename StrChar, typename RepChar> +static JSString* ReplaceAll(JSContext* cx, JSLinearString* string, + JSLinearString* searchString, + JSLinearString* replaceString) { + // Step 7 moved into ReplaceAll_internal. + + // Step 8 (advanceBy is equal to searchLength when searchLength > 0). + + // Step 9 (not needed in this implementation). + + // Step 10. + // Find the first match. + int32_t position = StringMatch(string, searchString, 0); + + // Nothing to replace, so return early. + if (position < 0) { + return string; + } + + // Steps 11, 12 moved into ReplaceAll_internal. + + // Step 13. + JSStringBuilder result(cx); + if constexpr (std::is_same_v<StrChar, char16_t> || + std::is_same_v<RepChar, char16_t>) { + if (!result.ensureTwoByteChars()) { + return nullptr; + } + } + + bool internalFailure = false; + { + AutoCheckCannotGC nogc; + internalFailure = !ReplaceAllInternal<StrChar, RepChar>( + nogc, string, searchString, replaceString, position, result); + } + if (internalFailure) { + return nullptr; + } + + // Step 16. + return result.finishString(); +} + +template <typename StrChar, typename RepChar> +static bool ReplaceAllInterleaveInternal(const AutoCheckCannotGC& nogc, + JSContext* cx, JSLinearString* string, + JSLinearString* replaceString, + JSStringBuilder& result) { + // Step 7. + const size_t stringLength = string->length(); + const size_t replaceLength = replaceString->length(); + + const StrChar* strChars = string->chars<StrChar>(nogc); + const RepChar* repChars = replaceString->chars<RepChar>(nogc); + + uint32_t dollarIndex = FindDollarIndex(repChars, replaceLength); + + if (dollarIndex != UINT32_MAX) { + if (!result.reserve(stringLength)) { + return false; + } + } else { + // Compute the exact result length when no substitutions take place. + CheckedInt<uint32_t> strLength(stringLength); + CheckedInt<uint32_t> repLength(replaceLength); + CheckedInt<uint32_t> length = strLength + (strLength + 1) * repLength; + if (!length.isValid()) { + ReportAllocationOverflow(cx); + return false; + } + + if (!result.reserve(length.value())) { + return false; + } + } + + auto appendReplacement = [&](size_t match) { + if (dollarIndex != UINT32_MAX) { + return AppendDollarReplacement(result, dollarIndex, match, match, string, + repChars, replaceLength); + } + return result.append(repChars, replaceLength); + }; + + for (size_t index = 0; index < stringLength; index++) { + // Steps 11, 14.a-b and 14.d. + // The empty string matches before each character. + if (!appendReplacement(index)) { + return false; + } + + // Step 14.c. + if (!result.append(strChars[index])) { + return false; + } + } + + // Steps 11, 14.a-b and 14.d. + // The empty string also matches at the end of the string. + return appendReplacement(stringLength); + + // Step 15 (not applicable when searchString is the empty string). +} + +// https://tc39.es/proposal-string-replaceall/#sec-string.prototype.replaceall +// Steps 7-16 when functionalReplace is false and searchString is the empty +// string. +// +// The steps are quite different, for performance. Loops in steps 11 and 14 +// are fused. GetSubstitution is optimized away when possible. +template <typename StrChar, typename RepChar> +static JSString* ReplaceAllInterleave(JSContext* cx, JSLinearString* string, + JSLinearString* replaceString) { + // Step 7 moved into ReplaceAllInterleavedInternal. + + // Step 8 (advanceBy is 1 when searchString is the empty string). + + // Steps 9-12 (trivial when searchString is the empty string). + + // Step 13. + JSStringBuilder result(cx); + if constexpr (std::is_same_v<StrChar, char16_t> || + std::is_same_v<RepChar, char16_t>) { + if (!result.ensureTwoByteChars()) { + return nullptr; + } + } + + bool internalFailure = false; + { + AutoCheckCannotGC nogc; + internalFailure = !ReplaceAllInterleaveInternal<StrChar, RepChar>( + nogc, cx, string, replaceString, result); + } + if (internalFailure) { + return nullptr; + } + + // Step 16. + return result.finishString(); +} + +// String.prototype.replaceAll (Stage 3 proposal) +// https://tc39.es/proposal-string-replaceall/ +// +// String.prototype.replaceAll ( searchValue, replaceValue ) +// +// Steps 7-16 when functionalReplace is false. +JSString* js::str_replaceAll_string_raw(JSContext* cx, HandleString string, + HandleString searchString, + HandleString replaceString) { + const size_t stringLength = string->length(); + const size_t searchLength = searchString->length(); + + // Directly return when we're guaranteed to find no match. + if (searchLength > stringLength) { + return string; + } + + Rooted<JSLinearString*> str(cx, string->ensureLinear(cx)); + if (!str) { + return nullptr; + } + + Rooted<JSLinearString*> repl(cx, replaceString->ensureLinear(cx)); + if (!repl) { + return nullptr; + } + + Rooted<JSLinearString*> search(cx, searchString->ensureLinear(cx)); + if (!search) { + return nullptr; + } + + // The pattern is empty, so we interleave the replacement string in-between + // each character. + if (searchLength == 0) { + if (str->hasTwoByteChars()) { + if (repl->hasTwoByteChars()) { + return ReplaceAllInterleave<char16_t, char16_t>(cx, str, repl); + } + return ReplaceAllInterleave<char16_t, Latin1Char>(cx, str, repl); + } + if (repl->hasTwoByteChars()) { + return ReplaceAllInterleave<Latin1Char, char16_t>(cx, str, repl); + } + return ReplaceAllInterleave<Latin1Char, Latin1Char>(cx, str, repl); + } + + MOZ_ASSERT(stringLength > 0); + + if (str->hasTwoByteChars()) { + if (repl->hasTwoByteChars()) { + return ReplaceAll<char16_t, char16_t>(cx, str, search, repl); + } + return ReplaceAll<char16_t, Latin1Char>(cx, str, search, repl); + } + if (repl->hasTwoByteChars()) { + return ReplaceAll<Latin1Char, char16_t>(cx, str, search, repl); + } + return ReplaceAll<Latin1Char, Latin1Char>(cx, str, search, repl); +} + +static ArrayObject* SingleElementStringArray(JSContext* cx, + Handle<JSLinearString*> str) { + ArrayObject* array = NewDenseFullyAllocatedArray(cx, 1); + if (!array) { + return nullptr; + } + array->setDenseInitializedLength(1); + array->initDenseElement(0, StringValue(str)); + return array; +} + +// ES 2016 draft Mar 25, 2016 21.1.3.17 steps 4, 8, 12-18. +static ArrayObject* SplitHelper(JSContext* cx, Handle<JSLinearString*> str, + uint32_t limit, Handle<JSLinearString*> sep) { + size_t strLength = str->length(); + size_t sepLength = sep->length(); + MOZ_ASSERT(sepLength != 0); + + // Step 12. + if (strLength == 0) { + // Step 12.a. + int match = StringMatch(str, sep, 0); + + // Step 12.b. + if (match != -1) { + return NewDenseEmptyArray(cx); + } + + // Steps 12.c-e. + return SingleElementStringArray(cx, str); + } + + // Step 3 (reordered). + RootedValueVector splits(cx); + + // Step 8 (reordered). + size_t lastEndIndex = 0; + + // Step 13. + size_t index = 0; + + // Step 14. + while (index != strLength) { + // Step 14.a. + int match = StringMatch(str, sep, index); + + // Step 14.b. + // + // Our match algorithm differs from the spec in that it returns the + // next index at which a match happens. If no match happens we're + // done. + // + // But what if the match is at the end of the string (and the string is + // not empty)? Per 14.c.i this shouldn't be a match, so we have to + // specially exclude it. Thus this case should hold: + // + // var a = "abc".split(/\b/); + // assertEq(a.length, 1); + // assertEq(a[0], "abc"); + if (match == -1) { + break; + } + + // Step 14.c. + size_t endIndex = match + sepLength; + + // Step 14.c.i. + if (endIndex == lastEndIndex) { + index++; + continue; + } + + // Step 14.c.ii. + MOZ_ASSERT(lastEndIndex < endIndex); + MOZ_ASSERT(sepLength <= strLength); + MOZ_ASSERT(lastEndIndex + sepLength <= endIndex); + + // Step 14.c.ii.1. + size_t subLength = size_t(endIndex - sepLength - lastEndIndex); + JSString* sub = NewDependentString(cx, str, lastEndIndex, subLength); + + // Steps 14.c.ii.2-4. + if (!sub || !splits.append(StringValue(sub))) { + return nullptr; + } + + // Step 14.c.ii.5. + if (splits.length() == limit) { + return NewDenseCopiedArray(cx, splits.length(), splits.begin()); + } + + // Step 14.c.ii.6. + index = endIndex; + + // Step 14.c.ii.7. + lastEndIndex = index; + } + + // Step 15. + JSString* sub = + NewDependentString(cx, str, lastEndIndex, strLength - lastEndIndex); + + // Steps 16-17. + if (!sub || !splits.append(StringValue(sub))) { + return nullptr; + } + + // Step 18. + return NewDenseCopiedArray(cx, splits.length(), splits.begin()); +} + +// Fast-path for splitting a string into a character array via split(""). +static ArrayObject* CharSplitHelper(JSContext* cx, Handle<JSLinearString*> str, + uint32_t limit) { + size_t strLength = str->length(); + if (strLength == 0) { + return NewDenseEmptyArray(cx); + } + + js::StaticStrings& staticStrings = cx->staticStrings(); + uint32_t resultlen = (limit < strLength ? limit : strLength); + MOZ_ASSERT(limit > 0 && resultlen > 0, + "Neither limit nor strLength is zero, so resultlen is greater " + "than zero."); + + Rooted<ArrayObject*> splits(cx, NewDenseFullyAllocatedArray(cx, resultlen)); + if (!splits) { + return nullptr; + } + + if (str->hasLatin1Chars()) { + splits->setDenseInitializedLength(resultlen); + + JS::AutoCheckCannotGC nogc; + const Latin1Char* latin1Chars = str->latin1Chars(nogc); + for (size_t i = 0; i < resultlen; ++i) { + Latin1Char c = latin1Chars[i]; + MOZ_ASSERT(staticStrings.hasUnit(c)); + splits->initDenseElement(i, StringValue(staticStrings.getUnit(c))); + } + } else { + splits->ensureDenseInitializedLength(0, resultlen); + + for (size_t i = 0; i < resultlen; ++i) { + JSString* sub = staticStrings.getUnitStringForElement(cx, str, i); + if (!sub) { + return nullptr; + } + splits->initDenseElement(i, StringValue(sub)); + } + } + + return splits; +} + +template <typename TextChar> +static MOZ_ALWAYS_INLINE ArrayObject* SplitSingleCharHelper( + JSContext* cx, Handle<JSLinearString*> str, const TextChar* text, + uint32_t textLen, char16_t patCh) { + // Count the number of occurrences of patCh within text. + uint32_t count = 0; + for (size_t index = 0; index < textLen; index++) { + if (static_cast<char16_t>(text[index]) == patCh) { + count++; + } + } + + // Handle zero-occurrence case - return input string in an array. + if (count == 0) { + return SingleElementStringArray(cx, str); + } + + // Create the result array for the substring values. + Rooted<ArrayObject*> splits(cx, NewDenseFullyAllocatedArray(cx, count + 1)); + if (!splits) { + return nullptr; + } + splits->ensureDenseInitializedLength(0, count + 1); + + // Add substrings. + uint32_t splitsIndex = 0; + size_t lastEndIndex = 0; + for (size_t index = 0; index < textLen; index++) { + if (static_cast<char16_t>(text[index]) == patCh) { + size_t subLength = size_t(index - lastEndIndex); + JSString* sub = NewDependentString(cx, str, lastEndIndex, subLength); + if (!sub) { + return nullptr; + } + splits->initDenseElement(splitsIndex++, StringValue(sub)); + lastEndIndex = index + 1; + } + } + + // Add substring for tail of string (after last match). + JSString* sub = + NewDependentString(cx, str, lastEndIndex, textLen - lastEndIndex); + if (!sub) { + return nullptr; + } + splits->initDenseElement(splitsIndex++, StringValue(sub)); + + return splits; +} + +// ES 2016 draft Mar 25, 2016 21.1.3.17 steps 4, 8, 12-18. +static ArrayObject* SplitSingleCharHelper(JSContext* cx, + Handle<JSLinearString*> str, + char16_t ch) { + // Step 12. + size_t strLength = str->length(); + + AutoStableStringChars linearChars(cx); + if (!linearChars.init(cx, str)) { + return nullptr; + } + + if (linearChars.isLatin1()) { + return SplitSingleCharHelper(cx, str, linearChars.latin1Chars(), strLength, + ch); + } + + return SplitSingleCharHelper(cx, str, linearChars.twoByteChars(), strLength, + ch); +} + +// ES 2016 draft Mar 25, 2016 21.1.3.17 steps 4, 8, 12-18. +ArrayObject* js::StringSplitString(JSContext* cx, HandleString str, + HandleString sep, uint32_t limit) { + MOZ_ASSERT(limit > 0, "Only called for strictly positive limit."); + + Rooted<JSLinearString*> linearStr(cx, str->ensureLinear(cx)); + if (!linearStr) { + return nullptr; + } + + Rooted<JSLinearString*> linearSep(cx, sep->ensureLinear(cx)); + if (!linearSep) { + return nullptr; + } + + if (linearSep->length() == 0) { + return CharSplitHelper(cx, linearStr, limit); + } + + if (linearSep->length() == 1 && limit >= static_cast<uint32_t>(INT32_MAX)) { + char16_t ch = linearSep->latin1OrTwoByteChar(0); + return SplitSingleCharHelper(cx, linearStr, ch); + } + + return SplitHelper(cx, linearStr, limit, linearSep); +} + +static const JSFunctionSpec string_methods[] = { + JS_FN(js_toSource_str, str_toSource, 0, 0), + + /* Java-like methods. */ + JS_INLINABLE_FN(js_toString_str, str_toString, 0, 0, StringToString), + JS_INLINABLE_FN(js_valueOf_str, str_toString, 0, 0, StringValueOf), + JS_INLINABLE_FN("toLowerCase", str_toLowerCase, 0, 0, StringToLowerCase), + JS_INLINABLE_FN("toUpperCase", str_toUpperCase, 0, 0, StringToUpperCase), + JS_INLINABLE_FN("charAt", str_charAt, 1, 0, StringCharAt), + JS_INLINABLE_FN("charCodeAt", str_charCodeAt, 1, 0, StringCharCodeAt), + JS_SELF_HOSTED_FN("substring", "String_substring", 2, 0), + JS_SELF_HOSTED_FN("padStart", "String_pad_start", 2, 0), + JS_SELF_HOSTED_FN("padEnd", "String_pad_end", 2, 0), + JS_SELF_HOSTED_FN("codePointAt", "String_codePointAt", 1, 0), + JS_FN("includes", str_includes, 1, 0), + JS_INLINABLE_FN("indexOf", str_indexOf, 1, 0, StringIndexOf), + JS_FN("lastIndexOf", str_lastIndexOf, 1, 0), + JS_INLINABLE_FN("startsWith", str_startsWith, 1, 0, StringStartsWith), + JS_INLINABLE_FN("endsWith", str_endsWith, 1, 0, StringEndsWith), + JS_FN("trim", str_trim, 0, 0), + JS_FN("trimStart", str_trimStart, 0, 0), + JS_FN("trimEnd", str_trimEnd, 0, 0), +#if JS_HAS_INTL_API + JS_SELF_HOSTED_FN("toLocaleLowerCase", "String_toLocaleLowerCase", 0, 0), + JS_SELF_HOSTED_FN("toLocaleUpperCase", "String_toLocaleUpperCase", 0, 0), + JS_SELF_HOSTED_FN("localeCompare", "String_localeCompare", 1, 0), +#else + JS_FN("toLocaleLowerCase", str_toLocaleLowerCase, 0, 0), + JS_FN("toLocaleUpperCase", str_toLocaleUpperCase, 0, 0), + JS_FN("localeCompare", str_localeCompare, 1, 0), +#endif + JS_SELF_HOSTED_FN("repeat", "String_repeat", 1, 0), +#if JS_HAS_INTL_API + JS_FN("normalize", str_normalize, 0, 0), +#endif +#ifdef NIGHTLY_BUILD + JS_FN("isWellFormed", str_isWellFormed, 0, 0), + JS_FN("toWellFormed", str_toWellFormed, 0, 0), +#endif + + /* Perl-ish methods (search is actually Python-esque). */ + JS_SELF_HOSTED_FN("match", "String_match", 1, 0), + JS_SELF_HOSTED_FN("matchAll", "String_matchAll", 1, 0), + JS_SELF_HOSTED_FN("search", "String_search", 1, 0), + JS_SELF_HOSTED_FN("replace", "String_replace", 2, 0), + JS_SELF_HOSTED_FN("replaceAll", "String_replaceAll", 2, 0), + JS_SELF_HOSTED_FN("split", "String_split", 2, 0), + JS_SELF_HOSTED_FN("substr", "String_substr", 2, 0), + + /* Python-esque sequence methods. */ + JS_SELF_HOSTED_FN("concat", "String_concat", 1, 0), + JS_SELF_HOSTED_FN("slice", "String_slice", 2, 0), + + JS_SELF_HOSTED_FN("at", "String_at", 1, 0), + + /* HTML string methods. */ + JS_SELF_HOSTED_FN("bold", "String_bold", 0, 0), + JS_SELF_HOSTED_FN("italics", "String_italics", 0, 0), + JS_SELF_HOSTED_FN("fixed", "String_fixed", 0, 0), + JS_SELF_HOSTED_FN("strike", "String_strike", 0, 0), + JS_SELF_HOSTED_FN("small", "String_small", 0, 0), + JS_SELF_HOSTED_FN("big", "String_big", 0, 0), + JS_SELF_HOSTED_FN("blink", "String_blink", 0, 0), + JS_SELF_HOSTED_FN("sup", "String_sup", 0, 0), + JS_SELF_HOSTED_FN("sub", "String_sub", 0, 0), + JS_SELF_HOSTED_FN("anchor", "String_anchor", 1, 0), + JS_SELF_HOSTED_FN("link", "String_link", 1, 0), + JS_SELF_HOSTED_FN("fontcolor", "String_fontcolor", 1, 0), + JS_SELF_HOSTED_FN("fontsize", "String_fontsize", 1, 0), + + JS_SELF_HOSTED_SYM_FN(iterator, "String_iterator", 0, 0), + JS_FS_END, +}; + +// ES6 rev 27 (2014 Aug 24) 21.1.1 +bool js::StringConstructor(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + RootedString str(cx); + if (args.length() > 0) { + if (!args.isConstructing() && args[0].isSymbol()) { + return js::SymbolDescriptiveString(cx, args[0].toSymbol(), args.rval()); + } + + str = ToString<CanGC>(cx, args[0]); + if (!str) { + return false; + } + } else { + str = cx->runtime()->emptyString; + } + + if (args.isConstructing()) { + RootedObject proto(cx); + if (!GetPrototypeFromBuiltinConstructor(cx, args, JSProto_String, &proto)) { + return false; + } + + StringObject* strobj = StringObject::create(cx, str, proto); + if (!strobj) { + return false; + } + args.rval().setObject(*strobj); + return true; + } + + args.rval().setString(str); + return true; +} + +bool js::str_fromCharCode(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + MOZ_ASSERT(args.length() <= ARGS_LENGTH_MAX); + + // Optimize the single-char case. + if (args.length() == 1) { + return str_fromCharCode_one_arg(cx, args[0], args.rval()); + } + + // Optimize the case where the result will definitely fit in an inline + // string (thin or fat) and so we don't need to malloc the chars. (We could + // cover some cases where args.length() goes up to + // JSFatInlineString::MAX_LENGTH_LATIN1 if we also checked if the chars are + // all Latin-1, but it doesn't seem worth the effort.) + InlineCharBuffer<char16_t> chars; + if (!chars.maybeAlloc(cx, args.length())) { + return false; + } + + char16_t* rawChars = chars.get(); + for (unsigned i = 0; i < args.length(); i++) { + uint16_t code; + if (!ToUint16(cx, args[i], &code)) { + return false; + } + + rawChars[i] = char16_t(code); + } + + JSString* str = chars.toString(cx, args.length()); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; +} + +static inline bool CodeUnitToString(JSContext* cx, uint16_t ucode, + MutableHandleValue rval) { + if (StaticStrings::hasUnit(ucode)) { + rval.setString(cx->staticStrings().getUnit(ucode)); + return true; + } + + char16_t c = char16_t(ucode); + JSString* str = NewStringCopyNDontDeflate<CanGC>(cx, &c, 1); + if (!str) { + return false; + } + + rval.setString(str); + return true; +} + +bool js::str_fromCharCode_one_arg(JSContext* cx, HandleValue code, + MutableHandleValue rval) { + uint16_t ucode; + + if (!ToUint16(cx, code, &ucode)) { + return false; + } + + return CodeUnitToString(cx, ucode, rval); +} + +static MOZ_ALWAYS_INLINE bool ToCodePoint(JSContext* cx, HandleValue code, + char32_t* codePoint) { + // String.fromCodePoint, Steps 5.a-b. + + // Fast path for the common case - the input is already an int32. + if (code.isInt32()) { + int32_t nextCP = code.toInt32(); + if (nextCP >= 0 && nextCP <= int32_t(unicode::NonBMPMax)) { + *codePoint = char32_t(nextCP); + return true; + } + } + + double nextCP; + if (!ToNumber(cx, code, &nextCP)) { + return false; + } + + // String.fromCodePoint, Steps 5.c-d. + if (JS::ToInteger(nextCP) != nextCP || nextCP < 0 || + nextCP > unicode::NonBMPMax) { + ToCStringBuf cbuf; + const char* numStr = NumberToCString(&cbuf, nextCP); + MOZ_ASSERT(numStr); + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_NOT_A_CODEPOINT, numStr); + return false; + } + + *codePoint = char32_t(nextCP); + return true; +} + +bool js::str_fromCodePoint_one_arg(JSContext* cx, HandleValue code, + MutableHandleValue rval) { + // Steps 1-4 (omitted). + + // Steps 5.a-d. + char32_t codePoint; + if (!ToCodePoint(cx, code, &codePoint)) { + return false; + } + + // Steps 5.e, 6. + if (!unicode::IsSupplementary(codePoint)) { + return CodeUnitToString(cx, uint16_t(codePoint), rval); + } + + char16_t chars[] = {unicode::LeadSurrogate(codePoint), + unicode::TrailSurrogate(codePoint)}; + JSString* str = NewStringCopyNDontDeflate<CanGC>(cx, chars, 2); + if (!str) { + return false; + } + + rval.setString(str); + return true; +} + +static bool str_fromCodePoint_few_args(JSContext* cx, const CallArgs& args) { + MOZ_ASSERT(args.length() <= JSFatInlineString::MAX_LENGTH_TWO_BYTE / 2); + + // Steps 1-2 (omitted). + + // Step 3. + char16_t elements[JSFatInlineString::MAX_LENGTH_TWO_BYTE]; + + // Steps 4-5. + unsigned length = 0; + for (unsigned nextIndex = 0; nextIndex < args.length(); nextIndex++) { + // Steps 5.a-d. + char32_t codePoint; + if (!ToCodePoint(cx, args[nextIndex], &codePoint)) { + return false; + } + + // Step 5.e. + unicode::UTF16Encode(codePoint, elements, &length); + } + + // Step 6. + JSString* str = NewStringCopyN<CanGC>(cx, elements, length); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; +} + +// ES2017 draft rev 40edb3a95a475c1b251141ac681b8793129d9a6d +// 21.1.2.2 String.fromCodePoint(...codePoints) +bool js::str_fromCodePoint(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + + // Optimize the single code-point case. + if (args.length() == 1) { + return str_fromCodePoint_one_arg(cx, args[0], args.rval()); + } + + // Optimize the case where the result will definitely fit in an inline + // string (thin or fat) and so we don't need to malloc the chars. (We could + // cover some cases where |args.length()| goes up to + // JSFatInlineString::MAX_LENGTH_LATIN1 / 2 if we also checked if the chars + // are all Latin-1, but it doesn't seem worth the effort.) + if (args.length() <= JSFatInlineString::MAX_LENGTH_TWO_BYTE / 2) { + return str_fromCodePoint_few_args(cx, args); + } + + // Steps 1-2 (omitted). + + // Step 3. + static_assert( + ARGS_LENGTH_MAX < std::numeric_limits<decltype(args.length())>::max() / 2, + "|args.length() * 2| does not overflow"); + auto elements = cx->make_pod_arena_array<char16_t>(js::StringBufferArena, + args.length() * 2); + if (!elements) { + return false; + } + + // Steps 4-5. + unsigned length = 0; + for (unsigned nextIndex = 0; nextIndex < args.length(); nextIndex++) { + // Steps 5.a-d. + char32_t codePoint; + if (!ToCodePoint(cx, args[nextIndex], &codePoint)) { + return false; + } + + // Step 5.e. + unicode::UTF16Encode(codePoint, elements.get(), &length); + } + + // Step 6. + JSString* str = NewString<CanGC>(cx, std::move(elements), length); + if (!str) { + return false; + } + + args.rval().setString(str); + return true; +} + +static const JSFunctionSpec string_static_methods[] = { + JS_INLINABLE_FN("fromCharCode", js::str_fromCharCode, 1, 0, + StringFromCharCode), + JS_INLINABLE_FN("fromCodePoint", js::str_fromCodePoint, 1, 0, + StringFromCodePoint), + + JS_SELF_HOSTED_FN("raw", "String_static_raw", 1, 0), JS_FS_END}; + +/* static */ +SharedShape* StringObject::assignInitialShape(JSContext* cx, + Handle<StringObject*> obj) { + MOZ_ASSERT(obj->empty()); + + if (!NativeObject::addPropertyInReservedSlot(cx, obj, cx->names().length, + LENGTH_SLOT, {})) { + return nullptr; + } + + return obj->sharedShape(); +} + +JSObject* StringObject::createPrototype(JSContext* cx, JSProtoKey key) { + Rooted<JSString*> empty(cx, cx->runtime()->emptyString); + Rooted<StringObject*> proto( + cx, GlobalObject::createBlankPrototype<StringObject>(cx, cx->global())); + if (!proto) { + return nullptr; + } + if (!StringObject::init(cx, proto, empty)) { + return nullptr; + } + return proto; +} + +static bool StringClassFinish(JSContext* cx, HandleObject ctor, + HandleObject proto) { + Handle<NativeObject*> nativeProto = proto.as<NativeObject>(); + + // Create "trimLeft" as an alias for "trimStart". + RootedValue trimFn(cx); + RootedId trimId(cx, NameToId(cx->names().trimStart)); + RootedId trimAliasId(cx, NameToId(cx->names().trimLeft)); + if (!NativeGetProperty(cx, nativeProto, trimId, &trimFn) || + !NativeDefineDataProperty(cx, nativeProto, trimAliasId, trimFn, 0)) { + return false; + } + + // Create "trimRight" as an alias for "trimEnd". + trimId = NameToId(cx->names().trimEnd); + trimAliasId = NameToId(cx->names().trimRight); + if (!NativeGetProperty(cx, nativeProto, trimId, &trimFn) || + !NativeDefineDataProperty(cx, nativeProto, trimAliasId, trimFn, 0)) { + return false; + } + + /* + * Define escape/unescape, the URI encode/decode functions, and maybe + * uneval on the global object. + */ + if (!JS_DefineFunctions(cx, cx->global(), string_functions)) { + return false; + } + + return true; +} + +const ClassSpec StringObject::classSpec_ = { + GenericCreateConstructor<StringConstructor, 1, gc::AllocKind::FUNCTION, + &jit::JitInfo_String>, + StringObject::createPrototype, + string_static_methods, + nullptr, + string_methods, + nullptr, + StringClassFinish}; + +#define ____ false + +/* + * Uri reserved chars + #: + * - 35: # + * - 36: $ + * - 38: & + * - 43: + + * - 44: , + * - 47: / + * - 58: : + * - 59: ; + * - 61: = + * - 63: ? + * - 64: @ + */ +static const bool js_isUriReservedPlusPound[] = { + // clang-format off +/* 0 1 2 3 4 5 6 7 8 9 */ +/* 0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 1 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 3 */ ____, ____, ____, ____, ____, true, true, ____, true, ____, +/* 4 */ ____, ____, ____, true, true, ____, ____, true, ____, ____, +/* 5 */ ____, ____, ____, ____, ____, ____, ____, ____, true, true, +/* 6 */ ____, true, ____, true, true, ____, ____, ____, ____, ____, +/* 7 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 8 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 9 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 10 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 11 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 12 */ ____, ____, ____, ____, ____, ____, ____, ____ + // clang-format on +}; + +/* + * Uri unescaped chars: + * - 33: ! + * - 39: ' + * - 40: ( + * - 41: ) + * - 42: * + * - 45: - + * - 46: . + * - 48..57: 0-9 + * - 65..90: A-Z + * - 95: _ + * - 97..122: a-z + * - 126: ~ + */ +static const bool js_isUriUnescaped[] = { + // clang-format off +/* 0 1 2 3 4 5 6 7 8 9 */ +/* 0 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 1 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 2 */ ____, ____, ____, ____, ____, ____, ____, ____, ____, ____, +/* 3 */ ____, ____, ____, true, ____, ____, ____, ____, ____, true, +/* 4 */ true, true, true, ____, ____, true, true, ____, true, true, +/* 5 */ true, true, true, true, true, true, true, true, ____, ____, +/* 6 */ ____, ____, ____, ____, ____, true, true, true, true, true, +/* 7 */ true, true, true, true, true, true, true, true, true, true, +/* 8 */ true, true, true, true, true, true, true, true, true, true, +/* 9 */ true, ____, ____, ____, ____, true, ____, true, true, true, +/* 10 */ true, true, true, true, true, true, true, true, true, true, +/* 11 */ true, true, true, true, true, true, true, true, true, true, +/* 12 */ true, true, true, ____, ____, ____, true, ____ + // clang-format on +}; + +#undef ____ + +static inline bool TransferBufferToString(JSStringBuilder& sb, JSString* str, + MutableHandleValue rval) { + if (!sb.empty()) { + str = sb.finishString(); + if (!str) { + return false; + } + } + rval.setString(str); + return true; +} + +/* + * ECMA 3, 15.1.3 URI Handling Function Properties + * + * The following are implementations of the algorithms + * given in the ECMA specification for the hidden functions + * 'Encode' and 'Decode'. + */ +enum EncodeResult { Encode_Failure, Encode_BadUri, Encode_Success }; + +// Bug 1403318: GCC sometimes inlines this Encode function rather than the +// caller Encode function. Annotate both functions with MOZ_NEVER_INLINE resp. +// MOZ_ALWAYS_INLINE to ensure we get the desired inlining behavior. +template <typename CharT> +static MOZ_NEVER_INLINE EncodeResult Encode(StringBuffer& sb, + const CharT* chars, size_t length, + const bool* unescapedSet) { + Latin1Char hexBuf[3]; + hexBuf[0] = '%'; + + auto appendEncoded = [&sb, &hexBuf](Latin1Char c) { + static const char HexDigits[] = "0123456789ABCDEF"; /* NB: uppercase */ + + hexBuf[1] = HexDigits[c >> 4]; + hexBuf[2] = HexDigits[c & 0xf]; + return sb.append(hexBuf, 3); + }; + + auto appendRange = [&sb, chars, length](size_t start, size_t end) { + MOZ_ASSERT(start <= end); + + if (start < end) { + if (start == 0) { + if (!sb.reserve(length)) { + return false; + } + } + return sb.append(chars + start, chars + end); + } + return true; + }; + + size_t startAppend = 0; + for (size_t k = 0; k < length; k++) { + CharT c = chars[k]; + if (c < 128 && + (js_isUriUnescaped[c] || (unescapedSet && unescapedSet[c]))) { + continue; + } else { + if (!appendRange(startAppend, k)) { + return Encode_Failure; + } + + if constexpr (std::is_same_v<CharT, Latin1Char>) { + if (c < 0x80) { + if (!appendEncoded(c)) { + return Encode_Failure; + } + } else { + if (!appendEncoded(0xC0 | (c >> 6)) || + !appendEncoded(0x80 | (c & 0x3F))) { + return Encode_Failure; + } + } + } else { + if (unicode::IsTrailSurrogate(c)) { + return Encode_BadUri; + } + + char32_t v; + if (!unicode::IsLeadSurrogate(c)) { + v = c; + } else { + k++; + if (k == length) { + return Encode_BadUri; + } + + char16_t c2 = chars[k]; + if (!unicode::IsTrailSurrogate(c2)) { + return Encode_BadUri; + } + + v = unicode::UTF16Decode(c, c2); + } + + uint8_t utf8buf[4]; + size_t L = OneUcs4ToUtf8Char(utf8buf, v); + for (size_t j = 0; j < L; j++) { + if (!appendEncoded(utf8buf[j])) { + return Encode_Failure; + } + } + } + + startAppend = k + 1; + } + } + + if (startAppend > 0) { + if (!appendRange(startAppend, length)) { + return Encode_Failure; + } + } + + return Encode_Success; +} + +static MOZ_ALWAYS_INLINE bool Encode(JSContext* cx, Handle<JSLinearString*> str, + const bool* unescapedSet, + MutableHandleValue rval) { + size_t length = str->length(); + if (length == 0) { + rval.setString(cx->runtime()->emptyString); + return true; + } + + JSStringBuilder sb(cx); + + EncodeResult res; + if (str->hasLatin1Chars()) { + AutoCheckCannotGC nogc; + res = Encode(sb, str->latin1Chars(nogc), str->length(), unescapedSet); + } else { + AutoCheckCannotGC nogc; + res = Encode(sb, str->twoByteChars(nogc), str->length(), unescapedSet); + } + + if (res == Encode_Failure) { + return false; + } + + if (res == Encode_BadUri) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_URI); + return false; + } + + MOZ_ASSERT(res == Encode_Success); + return TransferBufferToString(sb, str, rval); +} + +enum DecodeResult { Decode_Failure, Decode_BadUri, Decode_Success }; + +template <typename CharT> +static DecodeResult Decode(StringBuffer& sb, const CharT* chars, size_t length, + const bool* reservedSet) { + auto appendRange = [&sb, chars](size_t start, size_t end) { + MOZ_ASSERT(start <= end); + + if (start < end) { + return sb.append(chars + start, chars + end); + } + return true; + }; + + size_t startAppend = 0; + for (size_t k = 0; k < length; k++) { + CharT c = chars[k]; + if (c == '%') { + size_t start = k; + if ((k + 2) >= length) { + return Decode_BadUri; + } + + if (!IsAsciiHexDigit(chars[k + 1]) || !IsAsciiHexDigit(chars[k + 2])) { + return Decode_BadUri; + } + + uint32_t B = AsciiAlphanumericToNumber(chars[k + 1]) * 16 + + AsciiAlphanumericToNumber(chars[k + 2]); + k += 2; + if (B < 128) { + Latin1Char ch = Latin1Char(B); + if (reservedSet && reservedSet[ch]) { + continue; + } + + if (!appendRange(startAppend, start)) { + return Decode_Failure; + } + if (!sb.append(ch)) { + return Decode_Failure; + } + } else { + int n = 1; + while (B & (0x80 >> n)) { + n++; + } + + if (n == 1 || n > 4) { + return Decode_BadUri; + } + + uint8_t octets[4]; + octets[0] = (uint8_t)B; + if (k + 3 * (n - 1) >= length) { + return Decode_BadUri; + } + + for (int j = 1; j < n; j++) { + k++; + if (chars[k] != '%') { + return Decode_BadUri; + } + + if (!IsAsciiHexDigit(chars[k + 1]) || + !IsAsciiHexDigit(chars[k + 2])) { + return Decode_BadUri; + } + + B = AsciiAlphanumericToNumber(chars[k + 1]) * 16 + + AsciiAlphanumericToNumber(chars[k + 2]); + if ((B & 0xC0) != 0x80) { + return Decode_BadUri; + } + + k += 2; + octets[j] = char(B); + } + + if (!appendRange(startAppend, start)) { + return Decode_Failure; + } + + char32_t v = JS::Utf8ToOneUcs4Char(octets, n); + MOZ_ASSERT(v >= 128); + if (v >= unicode::NonBMPMin) { + if (v > unicode::NonBMPMax) { + return Decode_BadUri; + } + + if (!sb.append(unicode::LeadSurrogate(v))) { + return Decode_Failure; + } + if (!sb.append(unicode::TrailSurrogate(v))) { + return Decode_Failure; + } + } else { + if (!sb.append(char16_t(v))) { + return Decode_Failure; + } + } + } + + startAppend = k + 1; + } + } + + if (startAppend > 0) { + if (!appendRange(startAppend, length)) { + return Decode_Failure; + } + } + + return Decode_Success; +} + +static bool Decode(JSContext* cx, Handle<JSLinearString*> str, + const bool* reservedSet, MutableHandleValue rval) { + size_t length = str->length(); + if (length == 0) { + rval.setString(cx->runtime()->emptyString); + return true; + } + + JSStringBuilder sb(cx); + + DecodeResult res; + if (str->hasLatin1Chars()) { + AutoCheckCannotGC nogc; + res = Decode(sb, str->latin1Chars(nogc), str->length(), reservedSet); + } else { + AutoCheckCannotGC nogc; + res = Decode(sb, str->twoByteChars(nogc), str->length(), reservedSet); + } + + if (res == Decode_Failure) { + return false; + } + + if (res == Decode_BadUri) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_URI); + return false; + } + + MOZ_ASSERT(res == Decode_Success); + return TransferBufferToString(sb, str, rval); +} + +static bool str_decodeURI(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "decodeURI"); + CallArgs args = CallArgsFromVp(argc, vp); + Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0)); + if (!str) { + return false; + } + + return Decode(cx, str, js_isUriReservedPlusPound, args.rval()); +} + +static bool str_decodeURI_Component(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "decodeURIComponent"); + CallArgs args = CallArgsFromVp(argc, vp); + Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0)); + if (!str) { + return false; + } + + return Decode(cx, str, nullptr, args.rval()); +} + +static bool str_encodeURI(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "encodeURI"); + CallArgs args = CallArgsFromVp(argc, vp); + Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0)); + if (!str) { + return false; + } + + return Encode(cx, str, js_isUriReservedPlusPound, args.rval()); +} + +static bool str_encodeURI_Component(JSContext* cx, unsigned argc, Value* vp) { + AutoJSMethodProfilerEntry pseudoFrame(cx, "encodeURIComponent"); + CallArgs args = CallArgsFromVp(argc, vp); + Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0)); + if (!str) { + return false; + } + + return Encode(cx, str, nullptr, args.rval()); +} + +JSString* js::EncodeURI(JSContext* cx, const char* chars, size_t length) { + JSStringBuilder sb(cx); + EncodeResult result = Encode(sb, reinterpret_cast<const Latin1Char*>(chars), + length, js_isUriReservedPlusPound); + if (result == EncodeResult::Encode_Failure) { + return nullptr; + } + if (result == EncodeResult::Encode_BadUri) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_URI); + return nullptr; + } + if (sb.empty()) { + return NewStringCopyN<CanGC>(cx, chars, length); + } + return sb.finishString(); +} + +static bool FlatStringMatchHelper(JSContext* cx, HandleString str, + HandleString pattern, bool* isFlat, + int32_t* match) { + Rooted<JSLinearString*> linearPattern(cx, pattern->ensureLinear(cx)); + if (!linearPattern) { + return false; + } + + static const size_t MAX_FLAT_PAT_LEN = 256; + if (linearPattern->length() > MAX_FLAT_PAT_LEN || + StringHasRegExpMetaChars(linearPattern)) { + *isFlat = false; + return true; + } + + *isFlat = true; + if (str->isRope()) { + if (!RopeMatch(cx, &str->asRope(), linearPattern, match)) { + return false; + } + } else { + *match = StringMatch(&str->asLinear(), linearPattern); + } + + return true; +} + +static bool BuildFlatMatchArray(JSContext* cx, HandleString str, + HandleString pattern, int32_t match, + MutableHandleValue rval) { + if (match < 0) { + rval.setNull(); + return true; + } + + // Get the templateObject that defines the shape and type of the output + // object. + ArrayObject* templateObject = + cx->realm()->regExps.getOrCreateMatchResultTemplateObject(cx); + if (!templateObject) { + return false; + } + + Rooted<ArrayObject*> arr( + cx, NewDenseFullyAllocatedArrayWithTemplate(cx, 1, templateObject)); + if (!arr) { + return false; + } + + // Store a Value for each pair. + arr->setDenseInitializedLength(1); + arr->initDenseElement(0, StringValue(pattern)); + + // Set the |index| property. (TemplateObject positions it in slot 0). + arr->setSlot(0, Int32Value(match)); + + // Set the |input| property. (TemplateObject positions it in slot 1). + arr->setSlot(1, StringValue(str)); + +#ifdef DEBUG + RootedValue test(cx); + RootedId id(cx, NameToId(cx->names().index)); + if (!NativeGetProperty(cx, arr, id, &test)) { + return false; + } + MOZ_ASSERT(test == arr->getSlot(0)); + id = NameToId(cx->names().input); + if (!NativeGetProperty(cx, arr, id, &test)) { + return false; + } + MOZ_ASSERT(test == arr->getSlot(1)); +#endif + + rval.setObject(*arr); + return true; +} + +#ifdef DEBUG +static bool CallIsStringOptimizable(JSContext* cx, const char* name, + bool* result) { + FixedInvokeArgs<0> args(cx); + + RootedValue rval(cx); + if (!CallSelfHostedFunction(cx, name, UndefinedHandleValue, args, &rval)) { + return false; + } + + *result = rval.toBoolean(); + return true; +} +#endif + +bool js::FlatStringMatch(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + MOZ_ASSERT(args.length() == 2); + MOZ_ASSERT(args[0].isString()); + MOZ_ASSERT(args[1].isString()); +#ifdef DEBUG + bool isOptimizable = false; + if (!CallIsStringOptimizable(cx, "IsStringMatchOptimizable", + &isOptimizable)) { + return false; + } + MOZ_ASSERT(isOptimizable); +#endif + + RootedString str(cx, args[0].toString()); + RootedString pattern(cx, args[1].toString()); + + bool isFlat = false; + int32_t match = 0; + if (!FlatStringMatchHelper(cx, str, pattern, &isFlat, &match)) { + return false; + } + + if (!isFlat) { + args.rval().setUndefined(); + return true; + } + + return BuildFlatMatchArray(cx, str, pattern, match, args.rval()); +} + +bool js::FlatStringSearch(JSContext* cx, unsigned argc, Value* vp) { + CallArgs args = CallArgsFromVp(argc, vp); + MOZ_ASSERT(args.length() == 2); + MOZ_ASSERT(args[0].isString()); + MOZ_ASSERT(args[1].isString()); +#ifdef DEBUG + bool isOptimizable = false; + if (!CallIsStringOptimizable(cx, "IsStringSearchOptimizable", + &isOptimizable)) { + return false; + } + MOZ_ASSERT(isOptimizable); +#endif + + RootedString str(cx, args[0].toString()); + RootedString pattern(cx, args[1].toString()); + + bool isFlat = false; + int32_t match = 0; + if (!FlatStringMatchHelper(cx, str, pattern, &isFlat, &match)) { + return false; + } + + if (!isFlat) { + args.rval().setInt32(-2); + return true; + } + + args.rval().setInt32(match); + return true; +} |