js/src/jsatominlines.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sts=4 et sw=4 tw=99:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef jsatominlines_h
   8 #define jsatominlines_h
   9
  10 #include "jsatom.h"
  11
  12 #include "mozilla/PodOperations.h"
  13 #include "mozilla/RangedPtr.h"
  14
  15 #include "jscntxt.h"
  16 #include "jsnum.h"
  17
  18 #include "vm/String.h"
  19
  20 inline JSAtom *
  21 js::AtomStateEntry::asPtr() const
  22 {
  23     JS_ASSERT(bits != 0);
  24     JSAtom *atom = reinterpret_cast<JSAtom *>(bits & NO_TAG_MASK);
  25     JSString::readBarrier(atom);
  26     return atom;
  27 }
  28
  29 namespace js {
  30
  31 inline jsid
  32 AtomToId(JSAtom *atom)
  33 {
  34     JS_STATIC_ASSERT(JSID_INT_MIN == 0);
  35
  36     uint32_t index;
  37     if (atom->isIndex(&index) && index <= JSID_INT_MAX)
  38         return INT_TO_JSID(int32_t(index));
  39
  40     return JSID_FROM_BITS(size_t(atom));
  41 }
  42
  43 inline bool
  44 ValueToIdPure(const Value &v, jsid *id)
  45 {
  46     int32_t i;
  47     if (ValueFitsInInt32(v, &i) && INT_FITS_IN_JSID(i)) {
  48         *id = INT_TO_JSID(i);
  49         return true;
  50     }
  51
  52     if (v.isSymbol()) {
  53         *id = SYMBOL_TO_JSID(v.toSymbol());
  54         return true;
  55     }
  56
  57     if (!v.isString() || !v.toString()->isAtom())
  58         return false;
  59
  60     *id = AtomToId(&v.toString()->asAtom());
  61     return true;
  62 }
  63
  64 template <AllowGC allowGC>
  65 inline bool
  66 ValueToId(JSContext* cx, typename MaybeRooted<Value, allowGC>::HandleType v,
  67           typename MaybeRooted<jsid, allowGC>::MutableHandleType idp)
  68 {
  69     int32_t i;
  70     if (ValueFitsInInt32(v, &i) && INT_FITS_IN_JSID(i)) {
  71         idp.set(INT_TO_JSID(i));
  72         return true;
  73     }
  74
  75     if (v.isSymbol()) {
  76         idp.set(SYMBOL_TO_JSID(v.toSymbol()));
  77         return true;
  78     }
  79
  80     JSAtom *atom = ToAtom<allowGC>(cx, v);
  81     if (!atom)
  82         return false;
  83
  84     idp.set(AtomToId(atom));
  85     return true;
  86 }
  87
  88 /*
  89  * Write out character representing |index| to the memory just before |end|.
  90  * Thus |*end| is not touched, but |end[-1]| and earlier are modified as
  91  * appropriate.  There must be at least js::UINT32_CHAR_BUFFER_LENGTH elements
  92  * before |end| to avoid buffer underflow.  The start of the characters written
  93  * is returned and is necessarily before |end|.
  94  */
  95 template <typename T>
  96 inline mozilla::RangedPtr<T>
  97 BackfillIndexInCharBuffer(uint32_t index, mozilla::RangedPtr<T> end)
  98 {
  99 #ifdef DEBUG
 100     /*
 101      * Assert that the buffer we're filling will hold as many characters as we
 102      * could write out, by dereferencing the index that would hold the most
 103      * significant digit.
 104      */
 105     (void) *(end - UINT32_CHAR_BUFFER_LENGTH);
 106 #endif
 107
 108     do {
 109         uint32_t next = index / 10, digit = index % 10;
 110         *--end = '0' + digit;
 111         index = next;
 112     } while (index > 0);
 113
 114     return end;
 115 }
 116
 117 bool
 118 IndexToIdSlow(ExclusiveContext *cx, uint32_t index, MutableHandleId idp);
 119
 120 inline bool
 121 IndexToId(ExclusiveContext *cx, uint32_t index, MutableHandleId idp)
 122 {
 123     if (index <= JSID_INT_MAX) {
 124         idp.set(INT_TO_JSID(index));
 125         return true;
 126     }
 127
 128     return IndexToIdSlow(cx, index, idp);
 129 }
 130
 131 static MOZ_ALWAYS_INLINE JSFlatString *
 132 IdToString(JSContext *cx, jsid id)
 133 {
 134     if (JSID_IS_STRING(id))
 135         return JSID_TO_ATOM(id);
 136
 137     if (MOZ_LIKELY(JSID_IS_INT(id)))
 138         return Int32ToString<CanGC>(cx, JSID_TO_INT(id));
 139
 140     RootedValue idv(cx, IdToValue(id));
 141     JSString *str = ToStringSlow<CanGC>(cx, idv);
 142     if (!str)
 143         return nullptr;
 144
 145     return str->ensureFlat(cx);
 146 }
 147
 148 inline
 149 AtomHasher::Lookup::Lookup(const JSAtom *atom)
 150   : isLatin1(atom->hasLatin1Chars()), length(atom->length()), atom(atom)
 151 {
 152     if (isLatin1) {
 153         latin1Chars = atom->latin1Chars(nogc);
 154         hash = mozilla::HashString(latin1Chars, length);
 155     } else {
 156         twoByteChars = atom->twoByteChars(nogc);
 157         hash = mozilla::HashString(twoByteChars, length);
 158     }
 159 }
 160
 161 inline bool
 162 AtomHasher::match(const AtomStateEntry &entry, const Lookup &lookup)
 163 {
 164     JSAtom *key = entry.asPtr();
 165     if (lookup.atom)
 166         return lookup.atom == key;
 167     if (key->length() != lookup.length)
 168         return false;
 169
 170     if (key->hasLatin1Chars()) {
 171         const Latin1Char *keyChars = key->latin1Chars(lookup.nogc);
 172         if (lookup.isLatin1)
 173             return mozilla::PodEqual(keyChars, lookup.latin1Chars, lookup.length);
 174         return EqualChars(keyChars, lookup.twoByteChars, lookup.length);
 175     }
 176
 177     const jschar *keyChars = key->twoByteChars(lookup.nogc);
 178     if (lookup.isLatin1)
 179         return EqualChars(lookup.latin1Chars, keyChars, lookup.length);
 180     return mozilla::PodEqual(keyChars, lookup.twoByteChars, lookup.length);
 181 }
 182
 183 inline Handle<PropertyName*>
 184 TypeName(JSType type, const JSAtomState &names)
 185 {
 186     JS_ASSERT(type < JSTYPE_LIMIT);
 187     JS_STATIC_ASSERT(offsetof(JSAtomState, undefined) +
 188                      JSTYPE_LIMIT * sizeof(ImmutablePropertyNamePtr) <=
 189                      sizeof(JSAtomState));
 190     JS_STATIC_ASSERT(JSTYPE_VOID == 0);
 191     return (&names.undefined)[type];
 192 }
 193
 194 inline Handle<PropertyName*>
 195 ClassName(JSProtoKey key, JSAtomState &atomState)
 196 {
 197     JS_ASSERT(key < JSProto_LIMIT);
 198     JS_STATIC_ASSERT(offsetof(JSAtomState, Null) +
 199                      JSProto_LIMIT * sizeof(ImmutablePropertyNamePtr) <=
 200                      sizeof(JSAtomState));
 201     JS_STATIC_ASSERT(JSProto_Null == 0);
 202     return (&atomState.Null)[key];
 203 }
 204
 205 inline Handle<PropertyName*>
 206 ClassName(JSProtoKey key, JSRuntime *rt)
 207 {
 208     return ClassName(key, *rt->commonNames);
 209 }
 210
 211 inline Handle<PropertyName*>
 212 ClassName(JSProtoKey key, ExclusiveContext *cx)
 213 {
 214     return ClassName(key, cx->names());
 215 }
 216
 217 } // namespace js
 218
 219 #endif /* jsatominlines_h */