clang 8.0.0

ObjCRuntime.h
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1 //===- ObjCRuntime.h - Objective-C Runtime Configuration --------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// \file
11 /// Defines types useful for describing an Objective-C runtime.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #ifndef LLVM_CLANG_BASIC_OBJCRUNTIME_H
16 #define LLVM_CLANG_BASIC_OBJCRUNTIME_H
17
18 #include "clang/Basic/LLVM.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/VersionTuple.h"
23 #include <string>
24
25 namespace clang {
26
27 /// The basic abstraction for the target Objective-C runtime.
28 class ObjCRuntime {
29 public:
30 /// The basic Objective-C runtimes that we know about.
31 enum Kind {
32 /// 'macosx' is the Apple-provided NeXT-derived runtime on Mac OS
33 /// X platforms that use the non-fragile ABI; the version is a
34 /// release of that OS.
35 MacOSX,
36
37 /// 'macosx-fragile' is the Apple-provided NeXT-derived runtime on
38 /// Mac OS X platforms that use the fragile ABI; the version is a
39 /// release of that OS.
40 FragileMacOSX,
41
42 /// 'ios' is the Apple-provided NeXT-derived runtime on iOS or the iOS
43 /// simulator; it is always non-fragile. The version is a release
44 /// version of iOS.
45 iOS,
46
47 /// 'watchos' is a variant of iOS for Apple's watchOS. The version
48 /// is a release version of watchOS.
49 WatchOS,
50
51 /// 'gcc' is the Objective-C runtime shipped with GCC, implementing a
52 /// fragile Objective-C ABI
53 GCC,
54
55 /// 'gnustep' is the modern non-fragile GNUstep runtime.
56 GNUstep,
57
58 /// 'objfw' is the Objective-C runtime included in ObjFW
59 ObjFW
60 };
61
62 private:
63 Kind TheKind = MacOSX;
64 VersionTuple Version;
65
66 public:
67 /// A bogus initialization of the runtime.
68 ObjCRuntime() = default;
69 ObjCRuntime(Kind kind, const VersionTuple &version)
70 : TheKind(kind), Version(version) {}
71
72 void set(Kind kind, VersionTuple version) {
73 TheKind = kind;
74 Version = version;
75 }
76
77 Kind getKind() const { return TheKind; }
78 const VersionTuple &getVersion() const { return Version; }
79
80 /// Does this runtime follow the set of implied behaviors for a
81 /// "non-fragile" ABI?
82 bool isNonFragile() const {
83 switch (getKind()) {
84 case FragileMacOSX: return false;
85 case GCC: return false;
86 case MacOSX: return true;
87 case GNUstep: return true;
88 case ObjFW: return true;
89 case iOS: return true;
90 case WatchOS: return true;
91 }
92 llvm_unreachable("bad kind");
93 }
94
95 /// The inverse of isNonFragile(): does this runtime follow the set of
96 /// implied behaviors for a "fragile" ABI?
97 bool isFragile() const { return !isNonFragile(); }
98
99 /// The default dispatch mechanism to use for the specified architecture
100 bool isLegacyDispatchDefaultForArch(llvm::Triple::ArchType Arch) {
101 // The GNUstep runtime uses a newer dispatch method by default from
102 // version 1.6 onwards
103 if (getKind() == GNUstep && getVersion() >= VersionTuple(1, 6)) {
104 if (Arch == llvm::Triple::arm ||
105 Arch == llvm::Triple::x86 ||
106 Arch == llvm::Triple::x86_64)
107 return false;
108 }
109 else if ((getKind() == MacOSX) && isNonFragile() &&
110 (getVersion() >= VersionTuple(10, 0)) &&
111 (getVersion() < VersionTuple(10, 6)))
112 return Arch != llvm::Triple::x86_64;
113 // Except for deployment target of 10.5 or less,
114 // Mac runtimes use legacy dispatch everywhere now.
115 return true;
116 }
117
118 /// Is this runtime basically of the GNU family of runtimes?
119 bool isGNUFamily() const {
120 switch (getKind()) {
121 case FragileMacOSX:
122 case MacOSX:
123 case iOS:
124 case WatchOS:
125 return false;
126 case GCC:
127 case GNUstep:
128 case ObjFW:
129 return true;
130 }
131 llvm_unreachable("bad kind");
132 }
133
134 /// Is this runtime basically of the NeXT family of runtimes?
135 bool isNeXTFamily() const {
136 // For now, this is just the inverse of isGNUFamily(), but that's
137 // not inherently true.
138 return !isGNUFamily();
139 }
140
141 /// Does this runtime allow ARC at all?
142 bool allowsARC() const {
143 switch (getKind()) {
144 case FragileMacOSX:
145 // No stub library for the fragile runtime.
146 return getVersion() >= VersionTuple(10, 7);
147 case MacOSX: return true;
148 case iOS: return true;
149 case WatchOS: return true;
150 case GCC: return false;
151 case GNUstep: return true;
152 case ObjFW: return true;
153 }
154 llvm_unreachable("bad kind");
155 }
156
157 /// Does this runtime natively provide the ARC entrypoints?
158 ///
159 /// ARC cannot be directly supported on a platform that does not provide
160 /// these entrypoints, although it may be supportable via a stub
161 /// library.
162 bool hasNativeARC() const {
163 switch (getKind()) {
164 case FragileMacOSX: return getVersion() >= VersionTuple(10, 7);
165 case MacOSX: return getVersion() >= VersionTuple(10, 7);
166 case iOS: return getVersion() >= VersionTuple(5);
167 case WatchOS: return true;
168
169 case GCC: return false;
170 case GNUstep: return getVersion() >= VersionTuple(1, 6);
171 case ObjFW: return true;
172 }
173 llvm_unreachable("bad kind");
174 }
175
176 /// Does this runtime provide ARC entrypoints that are likely to be faster
177 /// than an ordinary message send of the appropriate selector?
178 ///
179 /// The ARC entrypoints are guaranteed to be equivalent to just sending the
180 /// corresponding message. If the entrypoint is implemented naively as just a
181 /// message send, using it is a trade-off: it sacrifices a few cycles of
182 /// overhead to save a small amount of code. However, it's possible for
183 /// runtimes to detect and special-case classes that use "standard"
184 /// retain/release behavior; if that's dynamically a large proportion of all
185 /// retained objects, using the entrypoint will also be faster than using a
186 /// message send.
187 ///
188 /// When this method returns true, Clang will turn non-super message sends of
189 /// certain selectors into calls to the correspond entrypoint:
190 /// retain => objc_retain
191 /// release => objc_release
192 /// autorelease => objc_autorelease
193 bool shouldUseARCFunctionsForRetainRelease() const {
194 switch (getKind()) {
195 case FragileMacOSX:
196 return false;
197 case MacOSX:
198 return getVersion() >= VersionTuple(10, 10);
199 case iOS:
200 return getVersion() >= VersionTuple(8);
201 case WatchOS:
202 return true;
203 case GCC:
204 return false;
205 case GNUstep:
206 return false;
207 case ObjFW:
208 return false;
209 }
210 llvm_unreachable("bad kind");
211 }
212
213 /// Does this runtime provide entrypoints that are likely to be faster
214 /// than an ordinary message send of the "alloc" selector?
215 ///
216 /// The "alloc" entrypoint is guaranteed to be equivalent to just sending the
217 /// corresponding message. If the entrypoint is implemented naively as just a
218 /// message send, using it is a trade-off: it sacrifices a few cycles of
219 /// overhead to save a small amount of code. However, it's possible for
220 /// runtimes to detect and special-case classes that use "standard"
221 /// alloc behavior; if that's dynamically a large proportion of all
222 /// objects, using the entrypoint will also be faster than using a message
223 /// send.
224 ///
225 /// When this method returns true, Clang will turn non-super message sends of
226 /// certain selectors into calls to the corresponding entrypoint:
227 /// alloc => objc_alloc
228 /// allocWithZone:nil => objc_allocWithZone
229 bool shouldUseRuntimeFunctionsForAlloc() const {
230 switch (getKind()) {
231 case FragileMacOSX:
232 return false;
233 case MacOSX:
234 return getVersion() >= VersionTuple(10, 10);
235 case iOS:
236 return getVersion() >= VersionTuple(8);
237 case WatchOS:
238 return true;
239
240 case GCC:
241 return false;
242 case GNUstep:
243 return false;
244 case ObjFW:
245 return false;
246 }
247 llvm_unreachable("bad kind");
248 }
249
250 /// Does this runtime supports optimized setter entrypoints?
251 bool hasOptimizedSetter() const {
252 switch (getKind()) {
253 case MacOSX:
254 return getVersion() >= VersionTuple(10, 8);
255 case iOS:
256 return (getVersion() >= VersionTuple(6));
257 case WatchOS:
258 return true;
259 case GNUstep:
260 return getVersion() >= VersionTuple(1, 7);
261 default:
262 return false;
263 }
264 }
265
266 /// Does this runtime allow the use of __weak?
267 bool allowsWeak() const {
268 return hasNativeWeak();
269 }
270
271 /// Does this runtime natively provide ARC-compliant 'weak'
272 /// entrypoints?
273 bool hasNativeWeak() const {
274 // Right now, this is always equivalent to whether the runtime
275 // natively supports ARC decision.
276 return hasNativeARC();
277 }
278
279 /// Does this runtime directly support the subscripting methods?
280 ///
281 /// This is really a property of the library, not the runtime.
282 bool hasSubscripting() const {
283 switch (getKind()) {
284 case FragileMacOSX: return false;
285 case MacOSX: return getVersion() >= VersionTuple(10, 11);
286 case iOS: return getVersion() >= VersionTuple(9);
287 case WatchOS: return true;
288
289 // This is really a lie, because some implementations and versions
290 // of the runtime do not support ARC. Probably -fgnu-runtime
291 // should imply a "maximal" runtime or something?
292 case GCC: return true;
293 case GNUstep: return true;
294 case ObjFW: return true;
295 }
296 llvm_unreachable("bad kind");
297 }
298
299 /// Does this runtime allow sizeof or alignof on object types?
300 bool allowsSizeofAlignof() const {
301 return isFragile();
302 }
303
304 /// Does this runtime allow pointer arithmetic on objects?
305 ///
306 /// This covers +, -, ++, --, and (if isSubscriptPointerArithmetic()
307 /// yields true) [].
308 bool allowsPointerArithmetic() const {
309 switch (getKind()) {
310 case FragileMacOSX:
311 case GCC:
312 return true;
313 case MacOSX:
314 case iOS:
315 case WatchOS:
316 case GNUstep:
317 case ObjFW:
318 return false;
319 }
320 llvm_unreachable("bad kind");
321 }
322
323 /// Is subscripting pointer arithmetic?
324 bool isSubscriptPointerArithmetic() const {
325 return allowsPointerArithmetic();
326 }
327
328 /// Does this runtime provide an objc_terminate function?
329 ///
330 /// This is used in handlers for exceptions during the unwind process;
331 /// without it, abort() must be used in pure ObjC files.
332 bool hasTerminate() const {
333 switch (getKind()) {
334 case FragileMacOSX: return getVersion() >= VersionTuple(10, 8);
335 case MacOSX: return getVersion() >= VersionTuple(10, 8);
336 case iOS: return getVersion() >= VersionTuple(5);
337 case WatchOS: return true;
338 case GCC: return false;
339 case GNUstep: return false;
340 case ObjFW: return false;
341 }
342 llvm_unreachable("bad kind");
343 }
344
345 /// Does this runtime support weakly importing classes?
346 bool hasWeakClassImport() const {
347 switch (getKind()) {
348 case MacOSX: return true;
349 case iOS: return true;
350 case WatchOS: return true;
351 case FragileMacOSX: return false;
352 case GCC: return true;
353 case GNUstep: return true;
354 case ObjFW: return true;
355 }
356 llvm_unreachable("bad kind");
357 }
358
359 /// Does this runtime use zero-cost exceptions?
360 bool hasUnwindExceptions() const {
361 switch (getKind()) {
362 case MacOSX: return true;
363 case iOS: return true;
364 case WatchOS: return true;
365 case FragileMacOSX: return false;
366 case GCC: return true;
367 case GNUstep: return true;
368 case ObjFW: return true;
369 }
370 llvm_unreachable("bad kind");
371 }
372
373 bool hasAtomicCopyHelper() const {
374 switch (getKind()) {
375 case FragileMacOSX:
376 case MacOSX:
377 case iOS:
378 case WatchOS:
379 return true;
380 case GNUstep:
381 return getVersion() >= VersionTuple(1, 7);
382 default: return false;
383 }
384 }
385
386 /// Is objc_unsafeClaimAutoreleasedReturnValue available?
387 bool hasARCUnsafeClaimAutoreleasedReturnValue() const {
388 switch (getKind()) {
389 case MacOSX:
390 case FragileMacOSX:
391 return getVersion() >= VersionTuple(10, 11);
392 case iOS:
393 return getVersion() >= VersionTuple(9);
394 case WatchOS:
395 return getVersion() >= VersionTuple(2);
396 case GNUstep:
397 return false;
398 default:
399 return false;
400 }
401 }
402
403 /// Are the empty collection symbols available?
404 bool hasEmptyCollections() const {
405 switch (getKind()) {
406 default:
407 return false;
408 case MacOSX:
409 return getVersion() >= VersionTuple(10, 11);
410 case iOS:
411 return getVersion() >= VersionTuple(9);
412 case WatchOS:
413 return getVersion() >= VersionTuple(2);
414 }
415 }
416
417 /// Try to parse an Objective-C runtime specification from the given
418 /// string.
419 ///
420 /// \return true on error.
421 bool tryParse(StringRef input);
422
423 std::string getAsString() const;
424
425 friend bool operator==(const ObjCRuntime &left, const ObjCRuntime &right) {
426 return left.getKind() == right.getKind() &&
427 left.getVersion() == right.getVersion();
428 }
429
430 friend bool operator!=(const ObjCRuntime &left, const ObjCRuntime &right) {
431 return !(left == right);
432 }
433 };
434
435 raw_ostream &operator<<(raw_ostream &out, const ObjCRuntime &value);
436
437 } // namespace clang
438
439 #endif // LLVM_CLANG_BASIC_OBJCRUNTIME_H
clang::ObjCRuntime::shouldUseRuntimeFunctionsForAlloc
bool shouldUseRuntimeFunctionsForAlloc() const
Does this runtime provide entrypoints that are likely to be faster than an ordinary message send of t...
Definition: ObjCRuntime.h:229
clang::operator<<
const DiagnosticBuilder & operator<<(const DiagnosticBuilder &DB, const Attr *At)
Definition: Attr.h:336
clang::ObjCRuntime::allowsPointerArithmetic
bool allowsPointerArithmetic() const
Does this runtime allow pointer arithmetic on objects?
Definition: ObjCRuntime.h:308
clang::ObjCRuntime::GCC
&#39;gcc&#39; is the Objective-C runtime shipped with GCC, implementing a fragile Objective-C ABI ...
Definition: ObjCRuntime.h:53
clang::ObjCRuntime::hasWeakClassImport
bool hasWeakClassImport() const
Does this runtime support weakly importing classes?
Definition: ObjCRuntime.h:346
clang::ObjCRuntime::FragileMacOSX
&#39;macosx-fragile&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the fragil...
Definition: ObjCRuntime.h:40
clang::ObjCRuntime::hasOptimizedSetter
bool hasOptimizedSetter() const
Does this runtime supports optimized setter entrypoints?
Definition: ObjCRuntime.h:251
clang::ObjCRuntime::isNonFragile
bool isNonFragile() const
Does this runtime follow the set of implied behaviors for a "non-fragile" ABI?
Definition: ObjCRuntime.h:82
clang::ObjCRuntime::isNeXTFamily
bool isNeXTFamily() const
Is this runtime basically of the NeXT family of runtimes?
Definition: ObjCRuntime.h:135
LLVM.h
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
clang::ObjCRuntime::WatchOS
&#39;watchos&#39; is a variant of iOS for Apple&#39;s watchOS.
Definition: ObjCRuntime.h:49
clang::ObjCRuntime::isFragile
bool isFragile() const
The inverse of isNonFragile(): does this runtime follow the set of implied behaviors for a "fragile" ...
Definition: ObjCRuntime.h:97
clang::ObjCRuntime::isSubscriptPointerArithmetic
bool isSubscriptPointerArithmetic() const
Is subscripting pointer arithmetic?
Definition: ObjCRuntime.h:324
clang::ObjCRuntime::isGNUFamily
bool isGNUFamily() const
Is this runtime basically of the GNU family of runtimes?
Definition: ObjCRuntime.h:119
clang::ObjCRuntime::hasAtomicCopyHelper
bool hasAtomicCopyHelper() const
Definition: ObjCRuntime.h:373
clang::ObjCRuntime::MacOSX
&#39;macosx&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the non-fragile AB...
Definition: ObjCRuntime.h:35
clang::ObjCRuntime::getAsString
std::string getAsString() const
Definition: ObjCRuntime.cpp:24
clang::ObjCRuntime::allowsSizeofAlignof
bool allowsSizeofAlignof() const
Does this runtime allow sizeof or alignof on object types?
Definition: ObjCRuntime.h:300
clang::ObjCRuntime::tryParse
bool tryParse(StringRef input)
Try to parse an Objective-C runtime specification from the given string.
Definition: ObjCRuntime.cpp:49
clang::ObjCRuntime::hasTerminate
bool hasTerminate() const
Does this runtime provide an objc_terminate function?
Definition: ObjCRuntime.h:332
clang::ObjCRuntime::ObjCRuntime
ObjCRuntime()=default
A bogus initialization of the runtime.
clang::ObjCRuntime::ObjCRuntime
ObjCRuntime(Kind kind, const VersionTuple &version)
Definition: ObjCRuntime.h:69
clang::ObjCRuntime::GNUstep
&#39;gnustep&#39; is the modern non-fragile GNUstep runtime.
Definition: ObjCRuntime.h:56
clang::ObjCRuntime::hasEmptyCollections
bool hasEmptyCollections() const
Are the empty collection symbols available?
Definition: ObjCRuntime.h:404
clang::ObjCRuntime::hasNativeWeak
bool hasNativeWeak() const
Does this runtime natively provide ARC-compliant &#39;weak&#39; entrypoints?
Definition: ObjCRuntime.h:273
clang::ObjCRuntime::ObjFW
&#39;objfw&#39; is the Objective-C runtime included in ObjFW
Definition: ObjCRuntime.h:59
clang::ObjCRuntime::getKind
Kind getKind() const
Definition: ObjCRuntime.h:77
clang::ObjCRuntime::hasUnwindExceptions
bool hasUnwindExceptions() const
Does this runtime use zero-cost exceptions?
Definition: ObjCRuntime.h:360
clang::ObjCRuntime::isLegacyDispatchDefaultForArch
bool isLegacyDispatchDefaultForArch(llvm::Triple::ArchType Arch)
The default dispatch mechanism to use for the specified architecture.
Definition: ObjCRuntime.h:100
clang::ObjCRuntime::getVersion
const VersionTuple & getVersion() const
Definition: ObjCRuntime.h:78
clang::ObjCRuntime::allowsARC
bool allowsARC() const
Does this runtime allow ARC at all?
Definition: ObjCRuntime.h:142
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:22
clang::ObjCRuntime
The basic abstraction for the target Objective-C runtime.
Definition: ObjCRuntime.h:28
clang::ObjCRuntime::operator!=
friend bool operator!=(const ObjCRuntime &left, const ObjCRuntime &right)
Definition: ObjCRuntime.h:430
clang::ObjCRuntime::iOS
&#39;ios&#39; is the Apple-provided NeXT-derived runtime on iOS or the iOS simulator; it is always non-fragil...
Definition: ObjCRuntime.h:45
clang::ObjCRuntime::operator==
friend bool operator==(const ObjCRuntime &left, const ObjCRuntime &right)
Definition: ObjCRuntime.h:425
clang::ObjCRuntime::shouldUseARCFunctionsForRetainRelease
bool shouldUseARCFunctionsForRetainRelease() const
Does this runtime provide ARC entrypoints that are likely to be faster than an ordinary message send ...
Definition: ObjCRuntime.h:193
clang::diag::kind
unsigned kind
All of the diagnostics that can be emitted by the frontend.
Definition: DiagnosticIDs.h:61
clang::ObjCRuntime::hasARCUnsafeClaimAutoreleasedReturnValue
bool hasARCUnsafeClaimAutoreleasedReturnValue() const
Is objc_unsafeClaimAutoreleasedReturnValue available?
Definition: ObjCRuntime.h:387
clang::ObjCRuntime::hasNativeARC
bool hasNativeARC() const
Does this runtime natively provide the ARC entrypoints?
Definition: ObjCRuntime.h:162
clang::ObjCRuntime::hasSubscripting
bool hasSubscripting() const
Does this runtime directly support the subscripting methods?
Definition: ObjCRuntime.h:282
clang::ObjCRuntime::Kind
Kind
The basic Objective-C runtimes that we know about.
Definition: ObjCRuntime.h:31
clang::ObjCRuntime::allowsWeak
bool allowsWeak() const
Does this runtime allow the use of __weak?
Definition: ObjCRuntime.h:267