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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /js/public/shadow/String.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/public/shadow/String.h')
-rw-r--r-- | js/public/shadow/String.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/js/public/shadow/String.h b/js/public/shadow/String.h new file mode 100644 index 0000000000..570c9f189b --- /dev/null +++ b/js/public/shadow/String.h @@ -0,0 +1,120 @@ +/* -*- 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/. */ + +/* Shadow definition of |JSString| innards. Don't use this directly! */ + +#ifndef js_shadow_String_h +#define js_shadow_String_h + +#include <stdint.h> // uint32_t, uintptr_t + +#include "jstypes.h" // JS_PUBLIC_API, js::Bit, js::BitMask, JS_BITS_PER_WORD + +#include "js/TypeDecls.h" // JS::Latin1Char + +class JS_PUBLIC_API JSAtom; +struct JSExternalStringCallbacks; +class JSLinearString; +class JS_PUBLIC_API JSString; + +namespace js { +namespace gc { +struct Cell; +} // namespace gc +} // namespace js + +namespace JS { + +namespace shadow { + +struct String { + static constexpr uint32_t ATOM_BIT = js::Bit(3); + static constexpr uint32_t LINEAR_BIT = js::Bit(4); + static constexpr uint32_t INLINE_CHARS_BIT = js::Bit(6); + static constexpr uint32_t LATIN1_CHARS_BIT = js::Bit(9); + static constexpr uint32_t EXTERNAL_FLAGS = LINEAR_BIT | js::Bit(8); + static constexpr uint32_t TYPE_FLAGS_MASK = js::BitMask(9) - js::BitMask(3); + static constexpr uint32_t PERMANENT_ATOM_MASK = ATOM_BIT | js::Bit(8); + + uintptr_t flags_; +#if JS_BITS_PER_WORD == 32 + uint32_t length_; +#endif + + union { + const JS::Latin1Char* nonInlineCharsLatin1; + const char16_t* nonInlineCharsTwoByte; + JS::Latin1Char inlineStorageLatin1[1]; + char16_t inlineStorageTwoByte[1]; + }; + const JSExternalStringCallbacks* externalCallbacks; + + uint32_t flags() const { return static_cast<uint32_t>(flags_); } + uint32_t length() const { +#if JS_BITS_PER_WORD == 32 + return length_; +#else + return static_cast<uint32_t>(flags_ >> 32); +#endif + } + + static bool isPermanentAtom(const js::gc::Cell* cell) { + uint32_t flags = reinterpret_cast<const String*>(cell)->flags(); + return (flags & PERMANENT_ATOM_MASK) == PERMANENT_ATOM_MASK; + } + + bool isLinear() const { return flags() & LINEAR_BIT; } + bool hasLatin1Chars() const { return flags() & LATIN1_CHARS_BIT; } + + // For hot code, prefer other type queries. + bool isExternal() const { + return (flags() & TYPE_FLAGS_MASK) == EXTERNAL_FLAGS; + } + + const JS::Latin1Char* latin1LinearChars() const { + MOZ_ASSERT(isLinear()); + MOZ_ASSERT(hasLatin1Chars()); + return (flags() & String::INLINE_CHARS_BIT) ? inlineStorageLatin1 + : nonInlineCharsLatin1; + } + + const char16_t* twoByteLinearChars() const { + MOZ_ASSERT(isLinear()); + MOZ_ASSERT(!hasLatin1Chars()); + return (flags() & String::INLINE_CHARS_BIT) ? inlineStorageTwoByte + : nonInlineCharsTwoByte; + } +}; + +inline const String* AsShadowString(const JSString* str) { + return reinterpret_cast<const String*>(str); +} + +inline String* AsShadowString(JSString* str) { + return reinterpret_cast<String*>(str); +} + +inline const String* AsShadowString(const JSLinearString* str) { + return reinterpret_cast<const String*>(str); +} + +inline String* AsShadowString(JSLinearString* str) { + return reinterpret_cast<String*>(str); +} + +inline const String* AsShadowString(const JSAtom* str) { + return reinterpret_cast<const String*>(str); +} + +inline String* AsShadowString(JSAtom* str) { + return reinterpret_cast<String*>(str); +} + +} // namespace shadow + +} // namespace JS + +#endif // js_shadow_String_h |