runtime/objc-abi.h

   1 /*
   2  * Copyright (c) 2009 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
  25 #ifndef _OBJC_ABI_H
  26 #define _OBJC_ABI_H
  27
  28 /*
  29  * WARNING  DANGER  HAZARD  BEWARE  EEK
  30  *
  31  * Everything in this file is for Apple Internal use only.
  32  * These will change in arbitrary OS updates and in unpredictable ways.
  33  * When your program breaks, you get to keep both pieces.
  34  */
  35
  36 /*
  37  * objc-abi.h: Declarations for functions used by compiler codegen.
  38  */
  39
  40 #include <malloc/malloc.h>
  41 #include <TargetConditionals.h>
  42 #include <objc/objc.h>
  43 #include <objc/runtime.h>
  44 #include <objc/message.h>
  45
  46 /* Runtime startup. */
  47
  48 // Old static initializer. Used by old crt1.o and old bug workarounds.
  49 OBJC_EXPORT void _objcInit(void)
  50     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
  51
  52 /* Images */
  53
  54 // Description of an Objective-C image.
  55 // __DATA,__objc_imageinfo stores one of these.
  56 typedef struct objc_image_info {
  57     uint32_t version; // currently 0
  58     uint32_t flags;
  59
  60 #if __cplusplus >= 201103L
  61   private:
  62     enum : uint32_t {
  63         IsReplacement       = 1<<0,  // used for Fix&Continue, now ignored
  64         SupportsGC          = 1<<1,  // image supports GC
  65         RequiresGC          = 1<<2,  // image requires GC
  66         OptimizedByDyld     = 1<<3,  // image is from an optimized shared cache
  67         CorrectedSynthesize = 1<<4,  // used for an old workaround, now ignored
  68         IsSimulated         = 1<<5,  // image compiled for a simulator platform
  69         HasCategoryClassProperties  = 1<<6,  // class properties in category_t
  70
  71         SwiftVersionMaskShift = 8,
  72         SwiftVersionMask    = 0xff << SwiftVersionMaskShift  // Swift ABI version
  73
  74     };
  75    public:
  76     enum : uint32_t {
  77         SwiftVersion1   = 1,
  78         SwiftVersion1_2 = 2,
  79         SwiftVersion2   = 3,
  80         SwiftVersion3   = 4
  81     };
  82
  83   public:
  84     bool isReplacement()   const { return flags & IsReplacement; }
  85     bool supportsGC()      const { return flags & SupportsGC; }
  86     bool requiresGC()      const { return flags & RequiresGC; }
  87     bool optimizedByDyld() const { return flags & OptimizedByDyld; }
  88     bool hasCategoryClassProperties() const { return flags & HasCategoryClassProperties; }
  89     bool containsSwift()   const { return (flags & SwiftVersionMask) != 0; }
  90     uint32_t swiftVersion() const { return (flags & SwiftVersionMask) >> SwiftVersionMaskShift; }
  91 #endif
  92 } objc_image_info;
  93
  94 /*
  95 IsReplacement:
  96    Once used for Fix&Continue in old OS X object files (not final linked images)
  97    Not currently used.
  98
  99 SupportsGC:
 100    App: GC is required. Framework: GC is supported but not required.
 101
 102 RequiresGC:
 103    Framework: GC is required.
 104
 105 OptimizedByDyld:
 106    Assorted metadata precooked in the dyld shared cache.
 107    Never set for images outside the shared cache file itself.
 108
 109 CorrectedSynthesize:
 110    Once used on old iOS to mark images that did not have a particular
 111    miscompile. Not used by the runtime.
 112
 113 IsSimulated:
 114    Image was compiled for a simulator platform. Not used by the runtime.
 115
 116 HasClassProperties:
 117    New ABI: category_t.classProperties fields are present.
 118    Old ABI: Set by some compilers. Not used by the runtime.
 119 */
 120
 121
 122 /* Properties */
 123
 124 // Read or write an object property. Not all object properties use these.
 125 OBJC_EXPORT id objc_getProperty(id self, SEL _cmd, ptrdiff_t offset, BOOL atomic)
 126     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 127 OBJC_EXPORT void objc_setProperty(id self, SEL _cmd, ptrdiff_t offset, id newValue, BOOL atomic, signed char shouldCopy)
 128     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 129
 130 OBJC_EXPORT void objc_setProperty_atomic(id self, SEL _cmd, id newValue, ptrdiff_t offset)
 131     OBJC_AVAILABLE(10.8, 6.0, 9.0, 1.0);
 132 OBJC_EXPORT void objc_setProperty_nonatomic(id self, SEL _cmd, id newValue, ptrdiff_t offset)
 133     OBJC_AVAILABLE(10.8, 6.0, 9.0, 1.0);
 134 OBJC_EXPORT void objc_setProperty_atomic_copy(id self, SEL _cmd, id newValue, ptrdiff_t offset)
 135     OBJC_AVAILABLE(10.8, 6.0, 9.0, 1.0);
 136 OBJC_EXPORT void objc_setProperty_nonatomic_copy(id self, SEL _cmd, id newValue, ptrdiff_t offset)
 137     OBJC_AVAILABLE(10.8, 6.0, 9.0, 1.0);
 138
 139
 140 // Read or write a non-object property. Not all uses are C structs,
 141 // and not all C struct properties use this.
 142 OBJC_EXPORT void objc_copyStruct(void *dest, const void *src, ptrdiff_t size, BOOL atomic, BOOL hasStrong)
 143     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 144
 145 // Perform a copy of a C++ object using striped locks. Used by non-POD C++ typed atomic properties.
 146 OBJC_EXPORT void objc_copyCppObjectAtomic(void *dest, const void *src, void (*copyHelper) (void *dest, const void *source))
 147     OBJC_AVAILABLE(10.8, 6.0, 9.0, 1.0);
 148
 149 /* Classes. */
 150 #if __OBJC2__
 151 OBJC_EXPORT IMP _objc_empty_vtable
 152     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 153 #endif
 154 OBJC_EXPORT struct objc_cache _objc_empty_cache
 155     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 156
 157
 158 /* Messages */
 159
 160 #if __OBJC2__
 161 // objc_msgSendSuper2() takes the current search class, not its superclass.
 162 OBJC_EXPORT id objc_msgSendSuper2(struct objc_super *super, SEL op, ...)
 163     OBJC_AVAILABLE(10.6, 2.0, 9.0, 1.0);
 164 OBJC_EXPORT void objc_msgSendSuper2_stret(struct objc_super *super, SEL op,...)
 165     OBJC_AVAILABLE(10.6, 2.0, 9.0, 1.0)
 166     OBJC_ARM64_UNAVAILABLE;
 167
 168 // objc_msgSend_noarg() may be faster for methods with no additional arguments.
 169 OBJC_EXPORT id objc_msgSend_noarg(id self, SEL _cmd)
 170     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 171 #endif
 172
 173 #if __OBJC2__
 174 // Debug messengers. Messengers used by the compiler have a debug flavor that
 175 // may perform extra sanity checking.
 176 // Old objc_msgSendSuper() does not have a debug version; this is OBJC2 only.
 177 // *_fixup() do not have debug versions; use non-fixup only for debug mode.
 178 OBJC_EXPORT id objc_msgSend_debug(id self, SEL op, ...)
 179     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 180 OBJC_EXPORT id objc_msgSendSuper2_debug(struct objc_super *super, SEL op, ...)
 181     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 182 OBJC_EXPORT void objc_msgSend_stret_debug(id self, SEL op, ...)
 183     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0)
 184     OBJC_ARM64_UNAVAILABLE;
 185 OBJC_EXPORT void objc_msgSendSuper2_stret_debug(struct objc_super *super, SEL op,...)
 186     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0)
 187     OBJC_ARM64_UNAVAILABLE;
 188
 189 # if defined(__i386__)
 190 OBJC_EXPORT double objc_msgSend_fpret_debug(id self, SEL op, ...)
 191     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 192 # elif defined(__x86_64__)
 193 OBJC_EXPORT long double objc_msgSend_fpret_debug(id self, SEL op, ...)
 194     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 195 #  if __STDC_VERSION__ >= 199901L
 196 OBJC_EXPORT _Complex long double objc_msgSend_fp2ret_debug(id self, SEL op, ...)
 197     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 198 #  else
 199 OBJC_EXPORT void objc_msgSend_fp2ret_debug(id self, SEL op, ...)
 200     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 201 #  endif
 202 # endif
 203
 204 #endif
 205
 206 #if __OBJC2__
 207 // Lookup messengers.
 208 // These are not callable C functions. Do not call them directly.
 209 // The caller should set the method parameters, call objc_msgLookup(),
 210 // then immediately call the returned IMP.
 211 //
 212 // Generic ABI:
 213 // - Callee-saved registers are preserved.
 214 // - Receiver and selector registers may be modified. These values must
 215 //   be passed to the called IMP. Other parameter registers are preserved.
 216 // - Caller-saved non-parameter registers are not preserved. Some of
 217 //   these registers are used to pass data from objc_msgLookup() to
 218 //   the called IMP and must not be disturbed by the caller.
 219 // - Red zone is not preserved.
 220 // See each architecture's implementation for details.
 221
 222 OBJC_EXPORT void objc_msgLookup(void)
 223     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 224 OBJC_EXPORT void objc_msgLookupSuper2(void)
 225     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 226 OBJC_EXPORT void objc_msgLookup_stret(void)
 227     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0)
 228     OBJC_ARM64_UNAVAILABLE;
 229 OBJC_EXPORT void objc_msgLookupSuper2_stret(void)
 230     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0)
 231     OBJC_ARM64_UNAVAILABLE;
 232
 233 # if defined(__i386__)
 234 OBJC_EXPORT void objc_msgLookup_fpret(void)
 235     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 236 # elif defined(__x86_64__)
 237 OBJC_EXPORT void objc_msgLookup_fpret(void)
 238     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 239 OBJC_EXPORT void objc_msgLookup_fp2ret(void)
 240     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 241 # endif
 242
 243 #endif
 244
 245 #if TARGET_OS_OSX  &&  defined(__x86_64__)
 246 // objc_msgSend_fixup() is used for vtable-dispatchable call sites.
 247 OBJC_EXPORT void objc_msgSend_fixup(void)
 248     __OSX_DEPRECATED(10.5, 10.8, "fixup dispatch is no longer optimized")
 249     __IOS_UNAVAILABLE __TVOS_UNAVAILABLE __WATCHOS_UNAVAILABLE;
 250 OBJC_EXPORT void objc_msgSend_stret_fixup(void)
 251     __OSX_DEPRECATED(10.5, 10.8, "fixup dispatch is no longer optimized")
 252     __IOS_UNAVAILABLE __TVOS_UNAVAILABLE __WATCHOS_UNAVAILABLE;
 253 OBJC_EXPORT void objc_msgSendSuper2_fixup(void)
 254     __OSX_DEPRECATED(10.5, 10.8, "fixup dispatch is no longer optimized")
 255     __IOS_UNAVAILABLE __TVOS_UNAVAILABLE __WATCHOS_UNAVAILABLE;
 256 OBJC_EXPORT void objc_msgSendSuper2_stret_fixup(void)
 257     __OSX_DEPRECATED(10.5, 10.8, "fixup dispatch is no longer optimized")
 258     __IOS_UNAVAILABLE __TVOS_UNAVAILABLE __WATCHOS_UNAVAILABLE;
 259 OBJC_EXPORT void objc_msgSend_fpret_fixup(void)
 260     __OSX_DEPRECATED(10.5, 10.8, "fixup dispatch is no longer optimized")
 261     __IOS_UNAVAILABLE __TVOS_UNAVAILABLE __WATCHOS_UNAVAILABLE;
 262 OBJC_EXPORT void objc_msgSend_fp2ret_fixup(void)
 263     __OSX_DEPRECATED(10.5, 10.8, "fixup dispatch is no longer optimized")
 264     __IOS_UNAVAILABLE __TVOS_UNAVAILABLE __WATCHOS_UNAVAILABLE;
 265 #endif
 266
 267 /* C++-compatible exception handling. */
 268 #if __OBJC2__
 269
 270 // fixme these conflict with C++ compiler's internal definitions
 271 #if !defined(__cplusplus)
 272
 273 // Vtable for C++ exception typeinfo for Objective-C types.
 274 OBJC_EXPORT const void *objc_ehtype_vtable[]
 275     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 276
 277 // C++ exception typeinfo for type `id`.
 278 OBJC_EXPORT struct objc_typeinfo OBJC_EHTYPE_id
 279     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 280
 281 #endif
 282
 283 // Exception personality function for Objective-C and Objective-C++ code.
 284 struct _Unwind_Exception;
 285 struct _Unwind_Context;
 286 OBJC_EXPORT int
 287 __objc_personality_v0(int version,
 288                       int actions,
 289                       uint64_t exceptionClass,
 290                       struct _Unwind_Exception *exceptionObject,
 291                       struct _Unwind_Context *context)
 292     OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);
 293
 294 #endif
 295
 296 /* ARC */
 297
 298 OBJC_EXPORT id objc_retainBlock(id)
 299     OBJC_AVAILABLE(10.7, 5.0, 9.0, 1.0);
 300
 301
 302 /* Non-pointer isa */
 303
 304 #if __OBJC2__
 305
 306 // Extract class pointer from an isa field.
 307
 308 #if  TARGET_OS_SIMULATOR
 309     // No simulators use nonpointer isa yet.
 310
 311 #elif __LP64__
 312 #   define OBJC_HAVE_NONPOINTER_ISA 1
 313 #   define OBJC_HAVE_PACKED_NONPOINTER_ISA 1
 314
 315 // Packed-isa version. This one is used directly by Swift code.
 316 // (Class)(isa & (uintptr_t)&objc_absolute_packed_isa_class_mask) == class ptr
 317 OBJC_EXPORT const struct { char c; } objc_absolute_packed_isa_class_mask
 318     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 319
 320 #elif __ARM_ARCH_7K__ >= 2
 321 #   define OBJC_HAVE_NONPOINTER_ISA 1
 322 #   define OBJC_HAVE_INDEXED_NONPOINTER_ISA 1
 323
 324 // Indexed-isa version.
 325 // if (isa & (uintptr_t)&objc_absolute_indexed_isa_magic_mask == (uintptr_t)&objc_absolute_indexed_isa_magic_value) {
 326 //     uintptr_t index = (isa & (uintptr_t)&objc_absolute_indexed_isa_index_mask) >> (uintptr_t)&objc_absolute_indexed_isa_index_shift;
 327 //     cls = objc_indexed_classes[index];
 328 // } else
 329 //     cls = (Class)isa;
 330 // }
 331 OBJC_EXPORT const struct { char c; } objc_absolute_indexed_isa_magic_mask
 332     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 333 OBJC_EXPORT const struct { char c; } objc_absolute_indexed_isa_magic_value
 334     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 335 OBJC_EXPORT const struct { char c; } objc_absolute_indexed_isa_index_mask
 336     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 337 OBJC_EXPORT const struct { char c; } objc_absolute_indexed_isa_index_shift
 338     OBJC_AVAILABLE(10.12, 10.0, 10.0, 3.0);
 339
 340 #endif
 341
 342 // OBJC2
 343 #endif
 344
 345 // _OBJC_ABI_H
 346 #endif