runtime/objc-sel.mm

   1 /*
   2  * Copyright (c) 2012 Apple Inc.  All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #if __OBJC2__
  25
  26 #include "objc-private.h"
  27 #include "objc-cache.h"
  28 #include "DenseMapExtras.h"
  29
  30
  31 static objc::ExplicitInitDenseSet<const char *> namedSelectors;
  32 static SEL search_builtins(const char *key);
  33
  34
  35 /***********************************************************************
  36 * sel_init
  37 * Initialize selector tables and register selectors used internally.
  38 **********************************************************************/
  39 void sel_init(size_t selrefCount)
  40 {
  41 #if SUPPORT_PREOPT
  42     if (PrintPreopt) {
  43         _objc_inform("PREOPTIMIZATION: using dyld selector opt");
  44     }
  45 #endif
  46
  47   namedSelectors.init((unsigned)selrefCount);
  48
  49     // Register selectors used by libobjc
  50
  51     mutex_locker_t lock(selLock);
  52
  53     SEL_cxx_construct = sel_registerNameNoLock(".cxx_construct", NO);
  54     SEL_cxx_destruct = sel_registerNameNoLock(".cxx_destruct", NO);
  55 }
  56
  57
  58 static SEL sel_alloc(const char *name, bool copy)
  59 {
  60     selLock.assertLocked();
  61     return (SEL)(copy ? strdupIfMutable(name) : name);
  62 }
  63
  64
  65 const char *sel_getName(SEL sel)
  66 {
  67     if (!sel) return "<null selector>";
  68     return (const char *)(const void*)sel;
  69 }
  70
  71
  72 BOOL sel_isMapped(SEL sel)
  73 {
  74     if (!sel) return NO;
  75
  76     const char *name = (const char *)(void *)sel;
  77
  78     if (sel == search_builtins(name)) return YES;
  79
  80     mutex_locker_t lock(selLock);
  81     auto it = namedSelectors.get().find(name);
  82     return it != namedSelectors.get().end() && (SEL)*it == sel;
  83 }
  84
  85
  86 static SEL search_builtins(const char *name)
  87 {
  88 #if SUPPORT_PREOPT
  89   if (SEL result = (SEL)_dyld_get_objc_selector(name))
  90     return result;
  91 #endif
  92     return nil;
  93 }
  94
  95
  96 static SEL __sel_registerName(const char *name, bool shouldLock, bool copy)
  97 {
  98     SEL result = 0;
  99
 100     if (shouldLock) selLock.assertUnlocked();
 101     else selLock.assertLocked();
 102
 103     if (!name) return (SEL)0;
 104
 105     result = search_builtins(name);
 106     if (result) return result;
 107
 108     conditional_mutex_locker_t lock(selLock, shouldLock);
 109         auto it = namedSelectors.get().insert(name);
 110         if (it.second) {
 111                 // No match. Insert.
 112                 *it.first = (const char *)sel_alloc(name, copy);
 113         }
 114         return (SEL)*it.first;
 115 }
 116
 117
 118 SEL sel_registerName(const char *name) {
 119     return __sel_registerName(name, 1, 1);     // YES lock, YES copy
 120 }
 121
 122 SEL sel_registerNameNoLock(const char *name, bool copy) {
 123     return __sel_registerName(name, 0, copy);  // NO lock, maybe copy
 124 }
 125
 126
 127 // 2001/1/24
 128 // the majority of uses of this function (which used to return NULL if not found)
 129 // did not check for NULL, so, in fact, never return NULL
 130 //
 131 SEL sel_getUid(const char *name) {
 132     return __sel_registerName(name, 2, 1);  // YES lock, YES copy
 133 }
 134
 135
 136 BOOL sel_isEqual(SEL lhs, SEL rhs)
 137 {
 138     return bool(lhs == rhs);
 139 }
 140
 141
 142 #endif