1//===------ MachOPlatform.cpp - Utilities for executing MachO in Orc ------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/ExecutionEngine/Orc/MachOPlatform.h"
10
11#include "llvm/BinaryFormat/MachO.h"
12#include "llvm/ExecutionEngine/JITLink/EHFrameSupport.h"
13#include "llvm/ExecutionEngine/JITLink/MachO.h"
14#include "llvm/ExecutionEngine/JITLink/aarch64.h"
15#include "llvm/ExecutionEngine/JITLink/x86_64.h"
16#include "llvm/ExecutionEngine/Orc/AbsoluteSymbols.h"
17#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
18#include "llvm/ExecutionEngine/Orc/MachOBuilder.h"
19#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
20#include "llvm/Support/Debug.h"
21#include <optional>
22
23#define DEBUG_TYPE "orc"
24
25using namespace llvm;
26using namespace llvm::orc;
27using namespace llvm::orc::shared;
28
29namespace llvm {
30namespace orc {
31namespace shared {
32
33using SPSMachOJITDylibDepInfo = SPSTuple<bool, SPSSequence<SPSExecutorAddr>>;
34using SPSMachOJITDylibDepInfoMap =
35 SPSSequence<SPSTuple<SPSExecutorAddr, SPSMachOJITDylibDepInfo>>;
36
37class SPSMachOExecutorSymbolFlags;
38
39template <>
40class SPSSerializationTraits<SPSMachOJITDylibDepInfo,
41 MachOPlatform::MachOJITDylibDepInfo> {
42public:
43 static size_t size(const MachOPlatform::MachOJITDylibDepInfo &DDI) {
44 return SPSMachOJITDylibDepInfo::AsArgList::size(Arg: DDI.Sealed, Args: DDI.DepHeaders);
45 }
46
47 static bool serialize(SPSOutputBuffer &OB,
48 const MachOPlatform::MachOJITDylibDepInfo &DDI) {
49 return SPSMachOJITDylibDepInfo::AsArgList::serialize(OB, Arg: DDI.Sealed,
50 Args: DDI.DepHeaders);
51 }
52
53 static bool deserialize(SPSInputBuffer &IB,
54 MachOPlatform::MachOJITDylibDepInfo &DDI) {
55 return SPSMachOJITDylibDepInfo::AsArgList::deserialize(IB, Arg&: DDI.Sealed,
56 Args&: DDI.DepHeaders);
57 }
58};
59
60template <>
61class SPSSerializationTraits<SPSMachOExecutorSymbolFlags,
62 MachOPlatform::MachOExecutorSymbolFlags> {
63private:
64 using UT = std::underlying_type_t<MachOPlatform::MachOExecutorSymbolFlags>;
65
66public:
67 static size_t size(const MachOPlatform::MachOExecutorSymbolFlags &SF) {
68 return sizeof(UT);
69 }
70
71 static bool serialize(SPSOutputBuffer &OB,
72 const MachOPlatform::MachOExecutorSymbolFlags &SF) {
73 return SPSArgList<UT>::serialize(OB, Arg: static_cast<UT>(SF));
74 }
75
76 static bool deserialize(SPSInputBuffer &IB,
77 MachOPlatform::MachOExecutorSymbolFlags &SF) {
78 UT Tmp;
79 if (!SPSArgList<UT>::deserialize(IB, Arg&: Tmp))
80 return false;
81 SF = static_cast<MachOPlatform::MachOExecutorSymbolFlags>(Tmp);
82 return true;
83 }
84};
85
86} // namespace shared
87} // namespace orc
88} // namespace llvm
89
90namespace {
91
92using SPSRegisterSymbolsArgs =
93 SPSArgList<SPSExecutorAddr,
94 SPSSequence<SPSTuple<SPSExecutorAddr, SPSExecutorAddr,
95 SPSMachOExecutorSymbolFlags>>>;
96
97std::unique_ptr<jitlink::LinkGraph> createPlatformGraph(MachOPlatform &MOP,
98 std::string Name) {
99 auto &ES = MOP.getExecutionSession();
100 return std::make_unique<jitlink::LinkGraph>(
101 args: std::move(Name), args: ES.getSymbolStringPool(), args: ES.getTargetTriple(),
102 args: SubtargetFeatures(), args&: jitlink::getGenericEdgeKindName);
103}
104
105// Creates a Bootstrap-Complete LinkGraph to run deferred actions.
106class MachOPlatformCompleteBootstrapMaterializationUnit
107 : public MaterializationUnit {
108public:
109 using SymbolTableVector =
110 SmallVector<std::tuple<ExecutorAddr, ExecutorAddr,
111 MachOPlatform::MachOExecutorSymbolFlags>>;
112
113 MachOPlatformCompleteBootstrapMaterializationUnit(
114 MachOPlatform &MOP, StringRef PlatformJDName,
115 SymbolStringPtr CompleteBootstrapSymbol, SymbolTableVector SymTab,
116 shared::AllocActions DeferredAAs, ExecutorAddr MachOHeaderAddr,
117 ExecutorAddr PlatformBootstrap, ExecutorAddr PlatformShutdown,
118 ExecutorAddr RegisterJITDylib, ExecutorAddr DeregisterJITDylib,
119 ExecutorAddr RegisterObjectSymbolTable,
120 ExecutorAddr DeregisterObjectSymbolTable)
121 : MaterializationUnit(
122 {{{CompleteBootstrapSymbol, JITSymbolFlags::None}}, nullptr}),
123 MOP(MOP), PlatformJDName(PlatformJDName),
124 CompleteBootstrapSymbol(std::move(CompleteBootstrapSymbol)),
125 SymTab(std::move(SymTab)), DeferredAAs(std::move(DeferredAAs)),
126 MachOHeaderAddr(MachOHeaderAddr), PlatformBootstrap(PlatformBootstrap),
127 PlatformShutdown(PlatformShutdown), RegisterJITDylib(RegisterJITDylib),
128 DeregisterJITDylib(DeregisterJITDylib),
129 RegisterObjectSymbolTable(RegisterObjectSymbolTable),
130 DeregisterObjectSymbolTable(DeregisterObjectSymbolTable) {}
131
132 StringRef getName() const override {
133 return "MachOPlatformCompleteBootstrap";
134 }
135
136 void materialize(std::unique_ptr<MaterializationResponsibility> R) override {
137 using namespace jitlink;
138 auto G = createPlatformGraph(MOP, Name: "<OrcRTCompleteBootstrap>");
139 auto &PlaceholderSection =
140 G->createSection(Name: "__orc_rt_cplt_bs", Prot: MemProt::Read);
141 auto &PlaceholderBlock =
142 G->createZeroFillBlock(Parent&: PlaceholderSection, Size: 1, Address: ExecutorAddr(), Alignment: 1, AlignmentOffset: 0);
143 G->addDefinedSymbol(Content&: PlaceholderBlock, Offset: 0, Name: *CompleteBootstrapSymbol, Size: 1,
144 L: Linkage::Strong, S: Scope::Hidden, IsCallable: false, IsLive: true);
145
146 // Reserve space for the stolen actions, plus two extras.
147 G->allocActions().reserve(n: DeferredAAs.size() + 3);
148
149 // 1. Bootstrap the platform support code.
150 G->allocActions().push_back(
151 x: {.Finalize: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSArgList<>>(FnAddr: PlatformBootstrap)),
152 .Dealloc: cantFail(
153 ValOrErr: WrapperFunctionCall::Create<SPSArgList<>>(FnAddr: PlatformShutdown))});
154
155 // 2. Register the platform JITDylib.
156 G->allocActions().push_back(
157 x: {.Finalize: cantFail(ValOrErr: WrapperFunctionCall::Create<
158 SPSArgList<SPSString, SPSExecutorAddr>>(
159 FnAddr: RegisterJITDylib, Args: PlatformJDName, Args: MachOHeaderAddr)),
160 .Dealloc: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSArgList<SPSExecutorAddr>>(
161 FnAddr: DeregisterJITDylib, Args: MachOHeaderAddr))});
162
163 // 3. Register deferred symbols.
164 G->allocActions().push_back(
165 x: {.Finalize: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
166 FnAddr: RegisterObjectSymbolTable, Args: MachOHeaderAddr, Args: SymTab)),
167 .Dealloc: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
168 FnAddr: DeregisterObjectSymbolTable, Args: MachOHeaderAddr, Args: SymTab))});
169
170 // 4. Add the deferred actions to the graph.
171 std::move(first: DeferredAAs.begin(), last: DeferredAAs.end(),
172 result: std::back_inserter(x&: G->allocActions()));
173
174 MOP.getObjectLinkingLayer().emit(R: std::move(R), G: std::move(G));
175 }
176
177 void discard(const JITDylib &JD, const SymbolStringPtr &Sym) override {}
178
179private:
180 MachOPlatform &MOP;
181 StringRef PlatformJDName;
182 SymbolStringPtr CompleteBootstrapSymbol;
183 SymbolTableVector SymTab;
184 shared::AllocActions DeferredAAs;
185 ExecutorAddr MachOHeaderAddr;
186 ExecutorAddr PlatformBootstrap;
187 ExecutorAddr PlatformShutdown;
188 ExecutorAddr RegisterJITDylib;
189 ExecutorAddr DeregisterJITDylib;
190 ExecutorAddr RegisterObjectSymbolTable;
191 ExecutorAddr DeregisterObjectSymbolTable;
192};
193
194static StringRef ObjCRuntimeObjectSectionsData[] = {
195 MachOObjCCatListSectionName, MachOObjCCatList2SectionName,
196 MachOObjCClassListSectionName, MachOObjCClassRefsSectionName,
197 MachOObjCConstSectionName, MachOObjCDataSectionName,
198 MachOObjCProtoListSectionName, MachOObjCProtoRefsSectionName,
199 MachOObjCNLCatListSectionName, MachOObjCNLClassListSectionName,
200 MachOObjCSelRefsSectionName};
201
202static StringRef ObjCRuntimeObjectSectionsText[] = {
203 MachOObjCClassNameSectionName, MachOObjCMethNameSectionName,
204 MachOObjCMethTypeSectionName, MachOSwift5TypesSectionName,
205 MachOSwift5TypeRefSectionName, MachOSwift5FieldMetadataSectionName,
206 MachOSwift5EntrySectionName, MachOSwift5ProtoSectionName,
207 MachOSwift5ProtosSectionName};
208
209static StringRef ObjCRuntimeObjectSectionName =
210 "__llvm_jitlink_ObjCRuntimeRegistrationObject";
211
212static StringRef ObjCImageInfoSymbolName =
213 "__llvm_jitlink_macho_objc_imageinfo";
214
215struct ObjCImageInfoFlags {
216 uint16_t SwiftABIVersion;
217 uint16_t SwiftVersion;
218 bool HasCategoryClassProperties;
219 bool HasSignedObjCClassROs;
220
221 static constexpr uint32_t SIGNED_CLASS_RO = (1 << 4);
222 static constexpr uint32_t HAS_CATEGORY_CLASS_PROPERTIES = (1 << 6);
223
224 explicit ObjCImageInfoFlags(uint32_t RawFlags) {
225 HasSignedObjCClassROs = RawFlags & SIGNED_CLASS_RO;
226 HasCategoryClassProperties = RawFlags & HAS_CATEGORY_CLASS_PROPERTIES;
227 SwiftABIVersion = (RawFlags >> 8) & 0xFF;
228 SwiftVersion = (RawFlags >> 16) & 0xFFFF;
229 }
230
231 uint32_t rawFlags() const {
232 uint32_t Result = 0;
233 if (HasCategoryClassProperties)
234 Result |= HAS_CATEGORY_CLASS_PROPERTIES;
235 if (HasSignedObjCClassROs)
236 Result |= SIGNED_CLASS_RO;
237 Result |= (SwiftABIVersion << 8);
238 Result |= (SwiftVersion << 16);
239 return Result;
240 }
241};
242} // end anonymous namespace
243
244namespace llvm {
245namespace orc {
246
247std::optional<MachOPlatform::HeaderOptions::BuildVersionOpts>
248MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(const Triple &TT,
249 uint32_t MinOS,
250 uint32_t SDK) {
251
252 uint32_t Platform;
253 switch (TT.getOS()) {
254 case Triple::IOS:
255 Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_IOSSIMULATOR
256 : MachO::PLATFORM_IOS;
257 break;
258 case Triple::MacOSX:
259 Platform = MachO::PLATFORM_MACOS;
260 break;
261 case Triple::TvOS:
262 Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_TVOSSIMULATOR
263 : MachO::PLATFORM_TVOS;
264 break;
265 case Triple::WatchOS:
266 Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_WATCHOSSIMULATOR
267 : MachO::PLATFORM_WATCHOS;
268 break;
269 case Triple::XROS:
270 Platform = TT.isSimulatorEnvironment() ? MachO::PLATFORM_XROS_SIMULATOR
271 : MachO::PLATFORM_XROS;
272 break;
273 default:
274 return std::nullopt;
275 }
276
277 return MachOPlatform::HeaderOptions::BuildVersionOpts{.Platform: Platform, .MinOS: MinOS, .SDK: SDK};
278}
279
280Expected<std::unique_ptr<MachOPlatform>>
281MachOPlatform::Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
282 std::unique_ptr<DefinitionGenerator> OrcRuntime,
283 HeaderOptionsBuilder BuildHeaderOpts,
284 HeaderOptions PlatformJDOpts,
285 MachOHeaderMUBuilder BuildMachOHeaderMU,
286 std::optional<SymbolAliasMap> RuntimeAliases) {
287
288 auto &ES = ObjLinkingLayer.getExecutionSession();
289
290 // If the target is not supported then bail out immediately.
291 if (!supportedTarget(TT: ES.getTargetTriple()))
292 return make_error<StringError>(Args: "Unsupported MachOPlatform triple: " +
293 ES.getTargetTriple().str(),
294 Args: inconvertibleErrorCode());
295
296 // Create default aliases if the caller didn't supply any.
297 if (!RuntimeAliases)
298 RuntimeAliases = standardPlatformAliases(ES);
299
300 // Define the aliases.
301 if (auto Err = PlatformJD.define(MU: symbolAliases(Aliases: std::move(*RuntimeAliases))))
302 return std::move(Err);
303
304 {
305 // Add JIT dispatch reexports from bootstrap JITDylib.
306 if (auto Err = PlatformJD.define(MU: reexports(
307 SourceJD&: ES.getBootstrapJITDylib(),
308 Aliases: {{ES.intern(SymName: "___orc_rt_jit_dispatch"),
309 {ES.intern(SymName: rt::DispatchName),
310 JITSymbolFlags::Exported | JITSymbolFlags::Callable}},
311 {ES.intern(SymName: "___orc_rt_jit_dispatch_ctx"),
312 {ES.intern(SymName: rt::DispatchCtxName), JITSymbolFlags::Exported}}})))
313 return Err;
314 }
315
316 // Create the instance.
317 Error Err = Error::success();
318 auto P = std::unique_ptr<MachOPlatform>(
319 new MachOPlatform(ObjLinkingLayer, PlatformJD, std::move(OrcRuntime),
320 std::move(BuildHeaderOpts), std::move(PlatformJDOpts),
321 std::move(BuildMachOHeaderMU), Err));
322 if (Err)
323 return std::move(Err);
324 return std::move(P);
325}
326
327Expected<std::unique_ptr<MachOPlatform>> MachOPlatform::Create(
328 ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
329 const char *OrcRuntimePath, HeaderOptionsBuilder BuildHeaderOpts,
330 HeaderOptions PlatformJDOpts, MachOHeaderMUBuilder BuildMachOHeaderMU,
331 std::optional<SymbolAliasMap> RuntimeAliases) {
332
333 // Create a generator for the ORC runtime archive.
334 auto OrcRuntimeArchiveGenerator =
335 StaticLibraryDefinitionGenerator::Load(L&: ObjLinkingLayer, FileName: OrcRuntimePath);
336 if (!OrcRuntimeArchiveGenerator)
337 return OrcRuntimeArchiveGenerator.takeError();
338
339 return Create(ObjLinkingLayer, PlatformJD,
340 OrcRuntime: std::move(*OrcRuntimeArchiveGenerator),
341 BuildHeaderOpts: std::move(BuildHeaderOpts), PlatformJDOpts: std::move(PlatformJDOpts),
342 BuildMachOHeaderMU: std::move(BuildMachOHeaderMU), RuntimeAliases: std::move(RuntimeAliases));
343}
344
345Error MachOPlatform::setupJITDylib(JITDylib &JD) {
346 return setupJITDylib(JD, Opts: BuildHeaderOpts(JD));
347}
348
349Error MachOPlatform::setupJITDylib(JITDylib &JD, HeaderOptions Opts) {
350 if (auto Err = JD.define(MU: BuildMachOHeaderMU(*this, std::move(Opts))))
351 return Err;
352
353 return ES.lookup(SearchOrder: {&JD}, Symbol: MachOHeaderStartSymbol).takeError();
354}
355
356Error MachOPlatform::teardownJITDylib(JITDylib &JD) {
357 std::lock_guard<std::mutex> Lock(PlatformMutex);
358 auto I = JITDylibToHeaderAddr.find(Val: &JD);
359 if (I != JITDylibToHeaderAddr.end()) {
360 assert(HeaderAddrToJITDylib.count(I->second) &&
361 "HeaderAddrToJITDylib missing entry");
362 HeaderAddrToJITDylib.erase(Val: I->second);
363 JITDylibToHeaderAddr.erase(I);
364 }
365 JITDylibToPThreadKey.erase(Val: &JD);
366 return Error::success();
367}
368
369Error MachOPlatform::notifyAdding(ResourceTracker &RT,
370 const MaterializationUnit &MU) {
371 auto &JD = RT.getJITDylib();
372 const auto &InitSym = MU.getInitializerSymbol();
373 if (!InitSym)
374 return Error::success();
375
376 RegisteredInitSymbols[&JD].add(Name: InitSym,
377 Flags: SymbolLookupFlags::WeaklyReferencedSymbol);
378 LLVM_DEBUG({
379 dbgs() << "MachOPlatform: Registered init symbol " << *InitSym << " for MU "
380 << MU.getName() << "\n";
381 });
382 return Error::success();
383}
384
385Error MachOPlatform::notifyRemoving(ResourceTracker &RT) {
386 llvm_unreachable("Not supported yet");
387}
388
389static void addAliases(ExecutionSession &ES, SymbolAliasMap &Aliases,
390 ArrayRef<std::pair<const char *, const char *>> AL) {
391 for (auto &KV : AL) {
392 auto AliasName = ES.intern(SymName: KV.first);
393 assert(!Aliases.count(AliasName) && "Duplicate symbol name in alias map");
394 Aliases[std::move(AliasName)] = {ES.intern(SymName: KV.second),
395 JITSymbolFlags::Exported};
396 }
397}
398
399SymbolAliasMap MachOPlatform::standardPlatformAliases(ExecutionSession &ES) {
400 SymbolAliasMap Aliases;
401 addAliases(ES, Aliases, AL: requiredCXXAliases());
402 addAliases(ES, Aliases, AL: standardRuntimeUtilityAliases());
403 addAliases(ES, Aliases, AL: standardLazyCompilationAliases());
404 return Aliases;
405}
406
407ArrayRef<std::pair<const char *, const char *>>
408MachOPlatform::requiredCXXAliases() {
409 static const std::pair<const char *, const char *> RequiredCXXAliases[] = {
410 {"___cxa_atexit", "___orc_rt_macho_cxa_atexit"}};
411
412 return ArrayRef<std::pair<const char *, const char *>>(RequiredCXXAliases);
413}
414
415ArrayRef<std::pair<const char *, const char *>>
416MachOPlatform::standardRuntimeUtilityAliases() {
417 static const std::pair<const char *, const char *>
418 StandardRuntimeUtilityAliases[] = {
419 {"___orc_rt_run_program", "___orc_rt_macho_run_program"},
420 {"___orc_rt_jit_dlerror", "___orc_rt_macho_jit_dlerror"},
421 {"___orc_rt_jit_dlopen", "___orc_rt_macho_jit_dlopen"},
422 {"___orc_rt_jit_dlupdate", "___orc_rt_macho_jit_dlupdate"},
423 {"___orc_rt_jit_dlclose", "___orc_rt_macho_jit_dlclose"},
424 {"___orc_rt_jit_dlsym", "___orc_rt_macho_jit_dlsym"},
425 {"___orc_rt_log_error", "___orc_rt_log_error_to_stderr"}};
426
427 return ArrayRef<std::pair<const char *, const char *>>(
428 StandardRuntimeUtilityAliases);
429}
430
431ArrayRef<std::pair<const char *, const char *>>
432MachOPlatform::standardLazyCompilationAliases() {
433 static const std::pair<const char *, const char *>
434 StandardLazyCompilationAliases[] = {
435 {"__orc_rt_reenter", "__orc_rt_sysv_reenter"},
436 {"__orc_rt_resolve_tag", "___orc_rt_resolve_tag"}};
437
438 return ArrayRef<std::pair<const char *, const char *>>(
439 StandardLazyCompilationAliases);
440}
441
442MachOPlatform::HeaderOptions MachOPlatform::defaultHeaderOpts(JITDylib &JD) {
443 return {};
444}
445
446bool MachOPlatform::supportedTarget(const Triple &TT) {
447 switch (TT.getArch()) {
448 case Triple::aarch64:
449 case Triple::x86_64:
450 return true;
451 default:
452 return false;
453 }
454}
455
456jitlink::Edge::Kind MachOPlatform::getPointerEdgeKind(jitlink::LinkGraph &G) {
457 switch (G.getTargetTriple().getArch()) {
458 case Triple::aarch64:
459 return jitlink::aarch64::Pointer64;
460 case Triple::x86_64:
461 return jitlink::x86_64::Pointer64;
462 default:
463 llvm_unreachable("Unsupported architecture");
464 }
465}
466
467MachOPlatform::MachOExecutorSymbolFlags
468MachOPlatform::flagsForSymbol(jitlink::Symbol &Sym) {
469 MachOPlatform::MachOExecutorSymbolFlags Flags{};
470 if (Sym.getLinkage() == jitlink::Linkage::Weak)
471 Flags |= MachOExecutorSymbolFlags::Weak;
472
473 if (Sym.isCallable())
474 Flags |= MachOExecutorSymbolFlags::Callable;
475
476 return Flags;
477}
478
479MachOPlatform::MachOPlatform(
480 ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
481 std::unique_ptr<DefinitionGenerator> OrcRuntimeGenerator,
482 HeaderOptionsBuilder BuildHeaderOpts, HeaderOptions PlatformJDOpts,
483 MachOHeaderMUBuilder BuildMachOHeaderMU, Error &Err)
484 : ES(ObjLinkingLayer.getExecutionSession()), PlatformJD(PlatformJD),
485 ObjLinkingLayer(ObjLinkingLayer),
486 BuildHeaderOpts(std::move(BuildHeaderOpts)),
487 BuildMachOHeaderMU(std::move(BuildMachOHeaderMU)) {
488 ErrorAsOutParameter _(Err);
489 ObjLinkingLayer.addPlugin(P: std::make_unique<MachOPlatformPlugin>(args&: *this));
490 PlatformJD.addGenerator(DefGenerator: std::move(OrcRuntimeGenerator));
491
492 {
493 // Check for force-eh-frame
494 std::optional<bool> ForceEHFrames;
495 if ((Err = ES.getBootstrapMapValue<bool, bool>(Key: "darwin-use-ehframes-only",
496 Val&: ForceEHFrames)))
497 return;
498 this->ForceEHFrames = ForceEHFrames.value_or(u: false);
499 }
500
501 BootstrapInfo BI;
502 Bootstrap = &BI;
503
504 // Bootstrap process -- here be phase-ordering dragons.
505 //
506 // The MachOPlatform class uses allocation actions to register metadata
507 // sections with the ORC runtime, however the runtime contains metadata
508 // registration functions that have their own metadata that they need to
509 // register (e.g. the frame-info registration functions have frame-info).
510 // We can't use an ordinary lookup to find these registration functions
511 // because their address is needed during the link of the containing graph
512 // itself (to build the allocation actions that will call the registration
513 // functions). Further complicating the situation (a) the graph containing
514 // the registration functions is allowed to depend on other graphs (e.g. the
515 // graph containing the ORC runtime RTTI support) so we need to handle an
516 // unknown set of dependencies during bootstrap, and (b) these graphs may
517 // be linked concurrently if the user has installed a concurrent dispatcher.
518 //
519 // We satisfy these constraints by implementing a bootstrap phase during which
520 // allocation actions generated by MachOPlatform are appended to a list of
521 // deferred allocation actions, rather than to the graphs themselves. At the
522 // end of the bootstrap process the deferred actions are attached to a final
523 // "complete-bootstrap" graph that causes them to be run.
524 //
525 // The bootstrap steps are as follows:
526 //
527 // 1. Request the graph containing the mach header. This graph is guaranteed
528 // not to have any metadata so the fact that the registration functions
529 // are not available yet is not a problem.
530 //
531 // 2. Look up the registration functions and discard the results. This will
532 // trigger linking of the graph containing these functions, and
533 // consequently any graphs that it depends on. We do not use the lookup
534 // result to find the addresses of the functions requested (as described
535 // above the lookup will return too late for that), instead we capture the
536 // addresses in a post-allocation pass injected by the platform runtime
537 // during bootstrap only.
538 //
539 // 3. During bootstrap the MachOPlatformPlugin keeps a count of the number of
540 // graphs being linked (potentially concurrently), and we block until all
541 // of these graphs have completed linking. This is to avoid a race on the
542 // deferred-actions vector: the lookup for the runtime registration
543 // functions may return while some functions (those that are being
544 // incidentally linked in, but aren't reachable via the runtime functions)
545 // are still being linked, and we need to capture any allocation actions
546 // for this incidental code before we proceed.
547 //
548 // 4. Once all active links are complete we transfer the deferred actions to
549 // a newly added CompleteBootstrap graph and then request a symbol from
550 // the CompleteBootstrap graph to trigger materialization. This will cause
551 // all deferred actions to be run, and once this lookup returns we can
552 // proceed.
553 //
554 // 5. Finally, we associate runtime support methods in MachOPlatform with
555 // the corresponding jit-dispatch tag variables in the ORC runtime to make
556 // the support methods callable. The bootstrap is now complete.
557
558 // Step (1) Add header materialization unit and request.
559 if ((Err = PlatformJD.define(
560 MU: this->BuildMachOHeaderMU(*this, std::move(PlatformJDOpts)))))
561 return;
562 if ((Err = ES.lookup(SearchOrder: &PlatformJD, Symbol: MachOHeaderStartSymbol).takeError()))
563 return;
564
565 // Step (2) Request runtime registration functions to trigger
566 // materialization..
567 if ((Err = ES.lookup(SearchOrder: makeJITDylibSearchOrder(JDs: &PlatformJD),
568 Symbols: SymbolLookupSet(
569 {PlatformBootstrap.Name, PlatformShutdown.Name,
570 RegisterJITDylib.Name, DeregisterJITDylib.Name,
571 RegisterObjectSymbolTable.Name,
572 DeregisterObjectSymbolTable.Name,
573 RegisterObjectPlatformSections.Name,
574 DeregisterObjectPlatformSections.Name,
575 CreatePThreadKey.Name}))
576 .takeError()))
577 return;
578
579 // Step (3) Wait for any incidental linker work to complete.
580 {
581 std::unique_lock<std::mutex> Lock(PlatformMutex);
582 BI.CV.wait(lock&: Lock, p: [&]() { return BI.ActiveGraphs == 0; });
583 Bootstrap = nullptr;
584 }
585
586 // Step (4) Add complete-bootstrap materialization unit and request.
587 auto BootstrapCompleteSymbol = ES.intern(SymName: "__orc_rt_macho_complete_bootstrap");
588 if ((Err = PlatformJD.define(
589 MU: std::make_unique<MachOPlatformCompleteBootstrapMaterializationUnit>(
590 args&: *this, args: PlatformJD.getName(), args&: BootstrapCompleteSymbol,
591 args: std::move(BI.SymTab), args: std::move(BI.DeferredAAs),
592 args&: BI.MachOHeaderAddr, args&: PlatformBootstrap.Addr,
593 args&: PlatformShutdown.Addr, args&: RegisterJITDylib.Addr,
594 args&: DeregisterJITDylib.Addr, args&: RegisterObjectSymbolTable.Addr,
595 args&: DeregisterObjectSymbolTable.Addr))))
596 return;
597 if ((Err = ES.lookup(SearchOrder: makeJITDylibSearchOrder(
598 JDs: &PlatformJD, Flags: JITDylibLookupFlags::MatchAllSymbols),
599 Symbol: std::move(BootstrapCompleteSymbol))
600 .takeError()))
601 return;
602
603 // (5) Associate runtime support functions.
604 // TODO: Consider moving this above (4) to make runtime support functions
605 // available to the bootstrap completion graph. We'd just need to be
606 // sure that the runtime support functions are fully usable before any
607 // bootstrap completion actions use them (e.g. the ORC runtime
608 // macho_platform object would have to have been created and
609 // initialized).
610 if ((Err = associateRuntimeSupportFunctions()))
611 return;
612}
613
614Error MachOPlatform::associateRuntimeSupportFunctions() {
615 ExecutionSession::JITDispatchHandlerAssociationMap WFs;
616
617 using PushInitializersSPSSig =
618 SPSExpected<SPSMachOJITDylibDepInfoMap>(SPSExecutorAddr);
619 WFs[ES.intern(SymName: "___orc_rt_macho_push_initializers_tag")] =
620 ES.wrapAsyncWithSPS<PushInitializersSPSSig>(
621 Instance: this, Method: &MachOPlatform::rt_pushInitializers);
622
623 using PushSymbolsSPSSig =
624 SPSError(SPSExecutorAddr, SPSSequence<SPSTuple<SPSString, bool>>);
625 WFs[ES.intern(SymName: "___orc_rt_macho_push_symbols_tag")] =
626 ES.wrapAsyncWithSPS<PushSymbolsSPSSig>(Instance: this,
627 Method: &MachOPlatform::rt_pushSymbols);
628
629 return ES.registerJITDispatchHandlers(JD&: PlatformJD, WFs: std::move(WFs));
630}
631
632void MachOPlatform::pushInitializersLoop(
633 PushInitializersSendResultFn SendResult, JITDylibSP JD) {
634 DenseMap<JITDylib *, SymbolLookupSet> NewInitSymbols;
635 DenseMap<JITDylib *, SmallVector<JITDylib *>> JDDepMap;
636 SmallVector<JITDylib *, 16> Worklist({JD.get()});
637
638 ES.runSessionLocked(F: [&]() {
639 while (!Worklist.empty()) {
640 // FIXME: Check for defunct dylibs.
641
642 auto DepJD = Worklist.back();
643 Worklist.pop_back();
644
645 // If we've already visited this JITDylib on this iteration then continue.
646 auto [It, Inserted] = JDDepMap.try_emplace(Key: DepJD);
647 if (!Inserted)
648 continue;
649
650 // Add dep info.
651 auto &DM = It->second;
652 DepJD->withLinkOrderDo(F: [&](const JITDylibSearchOrder &O) {
653 for (auto &KV : O) {
654 if (KV.first == DepJD)
655 continue;
656 DM.push_back(Elt: KV.first);
657 Worklist.push_back(Elt: KV.first);
658 }
659 });
660
661 // Add any registered init symbols.
662 auto RISItr = RegisteredInitSymbols.find(Val: DepJD);
663 if (RISItr != RegisteredInitSymbols.end()) {
664 NewInitSymbols[DepJD] = std::move(RISItr->second);
665 RegisteredInitSymbols.erase(I: RISItr);
666 }
667 }
668 });
669
670 // If there are no further init symbols to look up then send the link order
671 // (as a list of header addresses) to the caller.
672 if (NewInitSymbols.empty()) {
673
674 // To make the list intelligible to the runtime we need to convert all
675 // JITDylib pointers to their header addresses. Only include JITDylibs
676 // that appear in the JITDylibToHeaderAddr map (i.e. those that have been
677 // through setupJITDylib) -- bare JITDylibs aren't managed by the platform.
678 DenseMap<JITDylib *, ExecutorAddr> HeaderAddrs;
679 HeaderAddrs.reserve(NumEntries: JDDepMap.size());
680 {
681 std::lock_guard<std::mutex> Lock(PlatformMutex);
682 for (auto &KV : JDDepMap) {
683 auto I = JITDylibToHeaderAddr.find(Val: KV.first);
684 if (I != JITDylibToHeaderAddr.end())
685 HeaderAddrs[KV.first] = I->second;
686 }
687 }
688
689 // Build the dep info map to return.
690 MachOJITDylibDepInfoMap DIM;
691 DIM.reserve(n: JDDepMap.size());
692 for (auto &KV : JDDepMap) {
693 auto HI = HeaderAddrs.find(Val: KV.first);
694 // Skip unmanaged JITDylibs.
695 if (HI == HeaderAddrs.end())
696 continue;
697 auto H = HI->second;
698 MachOJITDylibDepInfo DepInfo;
699 for (auto &Dep : KV.second) {
700 auto HJ = HeaderAddrs.find(Val: Dep);
701 if (HJ != HeaderAddrs.end())
702 DepInfo.DepHeaders.push_back(x: HJ->second);
703 }
704 DIM.push_back(x: std::make_pair(x&: H, y: std::move(DepInfo)));
705 }
706 SendResult(DIM);
707 return;
708 }
709
710 // Otherwise issue a lookup and re-run this phase when it completes.
711 lookupInitSymbolsAsync(
712 OnComplete: [this, SendResult = std::move(SendResult), JD](Error Err) mutable {
713 if (Err)
714 SendResult(std::move(Err));
715 else
716 pushInitializersLoop(SendResult: std::move(SendResult), JD);
717 },
718 ES, InitSyms: std::move(NewInitSymbols));
719}
720
721void MachOPlatform::rt_pushInitializers(PushInitializersSendResultFn SendResult,
722 ExecutorAddr JDHeaderAddr) {
723 JITDylibSP JD;
724 {
725 std::lock_guard<std::mutex> Lock(PlatformMutex);
726 auto I = HeaderAddrToJITDylib.find(Val: JDHeaderAddr);
727 if (I != HeaderAddrToJITDylib.end())
728 JD = I->second;
729 }
730
731 LLVM_DEBUG({
732 dbgs() << "MachOPlatform::rt_pushInitializers(" << JDHeaderAddr << ") ";
733 if (JD)
734 dbgs() << "pushing initializers for " << JD->getName() << "\n";
735 else
736 dbgs() << "No JITDylib for header address.\n";
737 });
738
739 if (!JD) {
740 SendResult(make_error<StringError>(Args: "No JITDylib with header addr " +
741 formatv(Fmt: "{0:x}", Vals&: JDHeaderAddr),
742 Args: inconvertibleErrorCode()));
743 return;
744 }
745
746 pushInitializersLoop(SendResult: std::move(SendResult), JD);
747}
748
749void MachOPlatform::rt_pushSymbols(
750 PushSymbolsInSendResultFn SendResult, ExecutorAddr Handle,
751 const std::vector<std::pair<StringRef, bool>> &SymbolNames) {
752
753 JITDylib *JD = nullptr;
754
755 {
756 std::lock_guard<std::mutex> Lock(PlatformMutex);
757 auto I = HeaderAddrToJITDylib.find(Val: Handle);
758 if (I != HeaderAddrToJITDylib.end())
759 JD = I->second;
760 }
761 LLVM_DEBUG({
762 dbgs() << "MachOPlatform::rt_pushSymbols(";
763 if (JD)
764 dbgs() << "\"" << JD->getName() << "\", [ ";
765 else
766 dbgs() << "<invalid handle " << Handle << ">, [ ";
767 for (auto &Name : SymbolNames)
768 dbgs() << "\"" << Name.first << "\" ";
769 dbgs() << "])\n";
770 });
771
772 if (!JD) {
773 SendResult(make_error<StringError>(Args: "No JITDylib associated with handle " +
774 formatv(Fmt: "{0:x}", Vals&: Handle),
775 Args: inconvertibleErrorCode()));
776 return;
777 }
778
779 SymbolLookupSet LS;
780 for (auto &[Name, Required] : SymbolNames)
781 LS.add(Name: ES.intern(SymName: Name), Flags: Required
782 ? SymbolLookupFlags::RequiredSymbol
783 : SymbolLookupFlags::WeaklyReferencedSymbol);
784
785 ES.lookup(
786 K: LookupKind::DLSym, SearchOrder: {{JD, JITDylibLookupFlags::MatchExportedSymbolsOnly}},
787 Symbols: std::move(LS), RequiredState: SymbolState::Ready,
788 NotifyComplete: [SendResult = std::move(SendResult)](Expected<SymbolMap> Result) mutable {
789 SendResult(Result.takeError());
790 },
791 RegisterDependencies: NoDependenciesToRegister);
792}
793
794Expected<uint64_t> MachOPlatform::createPThreadKey() {
795 if (!CreatePThreadKey.Addr)
796 return make_error<StringError>(
797 Args: "Attempting to create pthread key in target, but runtime support has "
798 "not been loaded yet",
799 Args: inconvertibleErrorCode());
800
801 Expected<uint64_t> Result(0);
802 if (auto Err = ES.callSPSWrapper<SPSExpected<uint64_t>(void)>(
803 WrapperFnAddr: CreatePThreadKey.Addr, WrapperCallArgs&: Result))
804 return std::move(Err);
805 return Result;
806}
807
808void MachOPlatform::MachOPlatformPlugin::modifyPassConfig(
809 MaterializationResponsibility &MR, jitlink::LinkGraph &LG,
810 jitlink::PassConfiguration &Config) {
811
812 using namespace jitlink;
813
814 bool InBootstrapPhase = false;
815
816 ExecutorAddr HeaderAddr;
817 {
818 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
819 if (LLVM_UNLIKELY(&MR.getTargetJITDylib() == &MP.PlatformJD)) {
820 if (MP.Bootstrap) {
821 InBootstrapPhase = true;
822 ++MP.Bootstrap->ActiveGraphs;
823 }
824 }
825
826 // Get the dso-base address if available.
827 auto I = MP.JITDylibToHeaderAddr.find(Val: &MR.getTargetJITDylib());
828 if (I != MP.JITDylibToHeaderAddr.end())
829 HeaderAddr = I->second;
830 }
831
832 // If we're forcing eh-frame use then discard the compact-unwind section
833 // immediately to prevent FDEs from being stripped.
834 if (MP.ForceEHFrames)
835 if (auto *CUSec = LG.findSectionByName(Name: MachOCompactUnwindSectionName))
836 LG.removeSection(Sec&: *CUSec);
837
838 // Point the libunwind dso-base absolute symbol at the header for the
839 // JITDylib. This will prevent us from synthesizing a new header for
840 // every object.
841 if (HeaderAddr)
842 LG.addAbsoluteSymbol(Name: "__jitlink$libunwind_dso_base", Address: HeaderAddr, Size: 0,
843 L: Linkage::Strong, S: Scope::Local, IsLive: true);
844
845 // If we're in the bootstrap phase then increment the active graphs.
846 if (LLVM_UNLIKELY(InBootstrapPhase))
847 Config.PostAllocationPasses.push_back(x: [this](LinkGraph &G) {
848 return bootstrapPipelineRecordRuntimeFunctions(G);
849 });
850
851 // --- Handle Initializers ---
852 if (auto InitSymbol = MR.getInitializerSymbol()) {
853
854 // If the initializer symbol is the MachOHeader start symbol then just
855 // register it and then bail out -- the header materialization unit
856 // definitely doesn't need any other passes.
857 if (InitSymbol == MP.MachOHeaderStartSymbol && !InBootstrapPhase) {
858 Config.PostAllocationPasses.push_back(x: [this, &MR](LinkGraph &G) {
859 return associateJITDylibHeaderSymbol(G, MR);
860 });
861 return;
862 }
863
864 // If the object contains an init symbol other than the header start symbol
865 // then add passes to preserve, process and register the init
866 // sections/symbols.
867 Config.PrePrunePasses.push_back(x: [this, &MR](LinkGraph &G) {
868 if (auto Err = preserveImportantSections(G, MR))
869 return Err;
870 return processObjCImageInfo(G, MR);
871 });
872 Config.PostPrunePasses.push_back(
873 x: [this](LinkGraph &G) { return createObjCRuntimeObject(G); });
874 Config.PostAllocationPasses.push_back(
875 x: [this, &MR](LinkGraph &G) { return populateObjCRuntimeObject(G, MR); });
876 }
877
878 // Insert TLV lowering at the start of the PostPrunePasses, since we want
879 // it to run before GOT/PLT lowering.
880 Config.PostPrunePasses.insert(
881 position: Config.PostPrunePasses.begin(),
882 x: [this, &JD = MR.getTargetJITDylib()](LinkGraph &G) {
883 return fixTLVSectionsAndEdges(G, JD);
884 });
885
886 // Add symbol table prepare and register passes: These will add strings for
887 // all symbols to the c-strings section, and build a symbol table registration
888 // call.
889 auto JITSymTabInfo = std::make_shared<JITSymTabVector>();
890 Config.PostPrunePasses.push_back(x: [this, JITSymTabInfo](LinkGraph &G) {
891 return prepareSymbolTableRegistration(G, JITSymTabInfo&: *JITSymTabInfo);
892 });
893 Config.PostFixupPasses.push_back(x: [this, &MR, JITSymTabInfo,
894 InBootstrapPhase](LinkGraph &G) {
895 return addSymbolTableRegistration(G, MR, JITSymTabInfo&: *JITSymTabInfo, InBootstrapPhase);
896 });
897
898 // Add a pass to register the final addresses of any special sections in the
899 // object with the runtime.
900 Config.PostAllocationPasses.push_back(x: [this, &JD = MR.getTargetJITDylib(),
901 HeaderAddr,
902 InBootstrapPhase](LinkGraph &G) {
903 return registerObjectPlatformSections(G, JD, HeaderAddr, InBootstrapPhase);
904 });
905
906 // If we're in the bootstrap phase then steal allocation actions and then
907 // decrement the active graphs.
908 if (InBootstrapPhase)
909 Config.PostFixupPasses.push_back(
910 x: [this](LinkGraph &G) { return bootstrapPipelineEnd(G); });
911}
912
913Error MachOPlatform::MachOPlatformPlugin::
914 bootstrapPipelineRecordRuntimeFunctions(jitlink::LinkGraph &G) {
915 // Record bootstrap function names.
916 std::pair<StringRef, ExecutorAddr *> RuntimeSymbols[] = {
917 {*MP.MachOHeaderStartSymbol, &MP.Bootstrap->MachOHeaderAddr},
918 {*MP.PlatformBootstrap.Name, &MP.PlatformBootstrap.Addr},
919 {*MP.PlatformShutdown.Name, &MP.PlatformShutdown.Addr},
920 {*MP.RegisterJITDylib.Name, &MP.RegisterJITDylib.Addr},
921 {*MP.DeregisterJITDylib.Name, &MP.DeregisterJITDylib.Addr},
922 {*MP.RegisterObjectSymbolTable.Name, &MP.RegisterObjectSymbolTable.Addr},
923 {*MP.DeregisterObjectSymbolTable.Name,
924 &MP.DeregisterObjectSymbolTable.Addr},
925 {*MP.RegisterObjectPlatformSections.Name,
926 &MP.RegisterObjectPlatformSections.Addr},
927 {*MP.DeregisterObjectPlatformSections.Name,
928 &MP.DeregisterObjectPlatformSections.Addr},
929 {*MP.CreatePThreadKey.Name, &MP.CreatePThreadKey.Addr},
930 {*MP.RegisterObjCRuntimeObject.Name, &MP.RegisterObjCRuntimeObject.Addr},
931 {*MP.DeregisterObjCRuntimeObject.Name,
932 &MP.DeregisterObjCRuntimeObject.Addr}};
933
934 bool RegisterMachOHeader = false;
935
936 for (auto *Sym : G.defined_symbols()) {
937 for (auto &RTSym : RuntimeSymbols) {
938 if (Sym->hasName() && *Sym->getName() == RTSym.first) {
939 if (*RTSym.second)
940 return make_error<StringError>(
941 Args: "Duplicate " + RTSym.first +
942 " detected during MachOPlatform bootstrap",
943 Args: inconvertibleErrorCode());
944
945 if (Sym->getName() == MP.MachOHeaderStartSymbol)
946 RegisterMachOHeader = true;
947
948 *RTSym.second = Sym->getAddress();
949 }
950 }
951 }
952
953 if (RegisterMachOHeader) {
954 // If this graph defines the macho header symbol then create the internal
955 // mapping between it and PlatformJD.
956 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
957 MP.JITDylibToHeaderAddr[&MP.PlatformJD] = MP.Bootstrap->MachOHeaderAddr;
958 MP.HeaderAddrToJITDylib[MP.Bootstrap->MachOHeaderAddr] = &MP.PlatformJD;
959 }
960
961 return Error::success();
962}
963
964Error MachOPlatform::MachOPlatformPlugin::bootstrapPipelineEnd(
965 jitlink::LinkGraph &G) {
966 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
967
968 --MP.Bootstrap->ActiveGraphs;
969 // Notify Bootstrap->CV while holding the mutex because the mutex is
970 // also keeping Bootstrap->CV alive.
971 if (MP.Bootstrap->ActiveGraphs == 0)
972 MP.Bootstrap->CV.notify_all();
973 return Error::success();
974}
975
976Error MachOPlatform::MachOPlatformPlugin::associateJITDylibHeaderSymbol(
977 jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
978 auto I = llvm::find_if(Range: G.defined_symbols(), P: [this](jitlink::Symbol *Sym) {
979 return Sym->getName() == MP.MachOHeaderStartSymbol;
980 });
981 assert(I != G.defined_symbols().end() && "Missing MachO header start symbol");
982
983 auto &JD = MR.getTargetJITDylib();
984 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
985 auto HeaderAddr = (*I)->getAddress();
986 MP.JITDylibToHeaderAddr[&JD] = HeaderAddr;
987 MP.HeaderAddrToJITDylib[HeaderAddr] = &JD;
988 // We can unconditionally add these actions to the Graph because this pass
989 // isn't used during bootstrap.
990 G.allocActions().push_back(
991 x: {.Finalize: cantFail(
992 ValOrErr: WrapperFunctionCall::Create<SPSArgList<SPSString, SPSExecutorAddr>>(
993 FnAddr: MP.RegisterJITDylib.Addr, Args: JD.getName(), Args: HeaderAddr)),
994 .Dealloc: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSArgList<SPSExecutorAddr>>(
995 FnAddr: MP.DeregisterJITDylib.Addr, Args: HeaderAddr))});
996 return Error::success();
997}
998
999Error MachOPlatform::MachOPlatformPlugin::preserveImportantSections(
1000 jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
1001 // __objc_imageinfo is "important": we want to preserve it and record its
1002 // address in the first graph that it appears in, then verify and discard it
1003 // in all subsequent graphs. In this pass we preserve unconditionally -- we'll
1004 // manually throw it away in the processObjCImageInfo pass.
1005 if (auto *ObjCImageInfoSec =
1006 G.findSectionByName(Name: MachOObjCImageInfoSectionName)) {
1007 if (ObjCImageInfoSec->blocks_size() != 1)
1008 return make_error<StringError>(
1009 Args: "In " + G.getName() +
1010 "__DATA,__objc_imageinfo contains multiple blocks",
1011 Args: inconvertibleErrorCode());
1012 G.addAnonymousSymbol(Content&: **ObjCImageInfoSec->blocks().begin(), Offset: 0, Size: 0, IsCallable: false,
1013 IsLive: true);
1014
1015 for (auto *B : ObjCImageInfoSec->blocks())
1016 if (!B->edges_empty())
1017 return make_error<StringError>(Args: "In " + G.getName() + ", " +
1018 MachOObjCImageInfoSectionName +
1019 " contains references to symbols",
1020 Args: inconvertibleErrorCode());
1021 }
1022
1023 // Init sections are important: We need to preserve them and so that their
1024 // addresses can be captured and reported to the ORC runtime in
1025 // registerObjectPlatformSections.
1026 if (const auto &InitSymName = MR.getInitializerSymbol()) {
1027
1028 jitlink::Symbol *InitSym = nullptr;
1029 for (auto &InitSectionName : MachOInitSectionNames) {
1030 // Skip ObjCImageInfo -- this shouldn't have any dependencies, and we may
1031 // remove it later.
1032 if (InitSectionName == MachOObjCImageInfoSectionName)
1033 continue;
1034
1035 // Skip non-init sections.
1036 auto *InitSection = G.findSectionByName(Name: InitSectionName);
1037 if (!InitSection || InitSection->empty())
1038 continue;
1039
1040 // Create the init symbol if it has not been created already and attach it
1041 // to the first block.
1042 if (!InitSym) {
1043 auto &B = **InitSection->blocks().begin();
1044 InitSym = &G.addDefinedSymbol(
1045 Content&: B, Offset: 0, Name: *InitSymName, Size: B.getSize(), L: jitlink::Linkage::Strong,
1046 S: jitlink::Scope::SideEffectsOnly, IsCallable: false, IsLive: true);
1047 }
1048
1049 // Add keep-alive edges to anonymous symbols in all other init blocks.
1050 for (auto *B : InitSection->blocks()) {
1051 if (B == &InitSym->getBlock())
1052 continue;
1053
1054 auto &S = G.addAnonymousSymbol(Content&: *B, Offset: 0, Size: B->getSize(), IsCallable: false, IsLive: true);
1055 InitSym->getBlock().addEdge(K: jitlink::Edge::KeepAlive, Offset: 0, Target&: S, Addend: 0);
1056 }
1057 }
1058 }
1059
1060 return Error::success();
1061}
1062
1063Error MachOPlatform::MachOPlatformPlugin::processObjCImageInfo(
1064 jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
1065
1066 // If there's an ObjC imagine info then either
1067 // (1) It's the first __objc_imageinfo we've seen in this JITDylib. In
1068 // this case we name and record it.
1069 // OR
1070 // (2) We already have a recorded __objc_imageinfo for this JITDylib,
1071 // in which case we just verify it.
1072 auto *ObjCImageInfo = G.findSectionByName(Name: MachOObjCImageInfoSectionName);
1073 if (!ObjCImageInfo)
1074 return Error::success();
1075
1076 auto ObjCImageInfoBlocks = ObjCImageInfo->blocks();
1077
1078 // Check that the section is not empty if present.
1079 if (ObjCImageInfoBlocks.empty())
1080 return make_error<StringError>(Args: "Empty " + MachOObjCImageInfoSectionName +
1081 " section in " + G.getName(),
1082 Args: inconvertibleErrorCode());
1083
1084 // Check that there's only one block in the section.
1085 if (std::next(x: ObjCImageInfoBlocks.begin()) != ObjCImageInfoBlocks.end())
1086 return make_error<StringError>(Args: "Multiple blocks in " +
1087 MachOObjCImageInfoSectionName +
1088 " section in " + G.getName(),
1089 Args: inconvertibleErrorCode());
1090
1091 // Check that the __objc_imageinfo section is unreferenced.
1092 // FIXME: We could optimize this check if Symbols had a ref-count.
1093 for (auto &Sec : G.sections()) {
1094 if (&Sec != ObjCImageInfo)
1095 for (auto *B : Sec.blocks())
1096 for (auto &E : B->edges())
1097 if (E.getTarget().isDefined() &&
1098 &E.getTarget().getSection() == ObjCImageInfo)
1099 return make_error<StringError>(Args: MachOObjCImageInfoSectionName +
1100 " is referenced within file " +
1101 G.getName(),
1102 Args: inconvertibleErrorCode());
1103 }
1104
1105 auto &ObjCImageInfoBlock = **ObjCImageInfoBlocks.begin();
1106 auto *ObjCImageInfoData = ObjCImageInfoBlock.getContent().data();
1107 auto Version = support::endian::read32(P: ObjCImageInfoData, E: G.getEndianness());
1108 auto Flags =
1109 support::endian::read32(P: ObjCImageInfoData + 4, E: G.getEndianness());
1110
1111 // Lock the mutex while we verify / update the ObjCImageInfos map.
1112 std::lock_guard<std::mutex> Lock(PluginMutex);
1113
1114 auto ObjCImageInfoItr = ObjCImageInfos.find(Val: &MR.getTargetJITDylib());
1115 if (ObjCImageInfoItr != ObjCImageInfos.end()) {
1116 // We've already registered an __objc_imageinfo section. Verify the
1117 // content of this new section matches, then delete it.
1118 if (ObjCImageInfoItr->second.Version != Version)
1119 return make_error<StringError>(
1120 Args: "ObjC version in " + G.getName() +
1121 " does not match first registered version",
1122 Args: inconvertibleErrorCode());
1123 if (ObjCImageInfoItr->second.Flags != Flags)
1124 if (Error E = mergeImageInfoFlags(G, MR, Info&: ObjCImageInfoItr->second, NewFlags: Flags))
1125 return E;
1126
1127 // __objc_imageinfo is valid. Delete the block.
1128 while (ObjCImageInfo->symbols_size() != 0)
1129 G.removeDefinedSymbol(Sym&: **ObjCImageInfo->symbols().begin());
1130 G.removeBlock(B&: ObjCImageInfoBlock);
1131 } else {
1132 LLVM_DEBUG({
1133 dbgs() << "MachOPlatform: Registered __objc_imageinfo for "
1134 << MR.getTargetJITDylib().getName() << " in " << G.getName()
1135 << "; flags = " << formatv("{0:x4}", Flags) << "\n";
1136 });
1137 // We haven't registered an __objc_imageinfo section yet. Register and
1138 // move on. The section should already be marked no-dead-strip.
1139 G.addDefinedSymbol(Content&: ObjCImageInfoBlock, Offset: 0, Name: ObjCImageInfoSymbolName,
1140 Size: ObjCImageInfoBlock.getSize(), L: jitlink::Linkage::Strong,
1141 S: jitlink::Scope::Hidden, IsCallable: false, IsLive: true);
1142 if (auto Err = MR.defineMaterializing(
1143 SymbolFlags: {{MR.getExecutionSession().intern(SymName: ObjCImageInfoSymbolName),
1144 JITSymbolFlags()}}))
1145 return Err;
1146 ObjCImageInfos[&MR.getTargetJITDylib()] = {.Version: Version, .Flags: Flags, .Finalized: false};
1147 }
1148
1149 return Error::success();
1150}
1151
1152Error MachOPlatform::MachOPlatformPlugin::mergeImageInfoFlags(
1153 jitlink::LinkGraph &G, MaterializationResponsibility &MR,
1154 ObjCImageInfo &Info, uint32_t NewFlags) {
1155 if (Info.Flags == NewFlags)
1156 return Error::success();
1157
1158 ObjCImageInfoFlags Old(Info.Flags);
1159 ObjCImageInfoFlags New(NewFlags);
1160
1161 // Check for incompatible flags.
1162 if (Old.SwiftABIVersion && New.SwiftABIVersion &&
1163 Old.SwiftABIVersion != New.SwiftABIVersion)
1164 return make_error<StringError>(Args: "Swift ABI version in " + G.getName() +
1165 " does not match first registered flags",
1166 Args: inconvertibleErrorCode());
1167
1168 // HasCategoryClassProperties and HasSignedObjCClassROs can be disabled before
1169 // they are registered, if necessary, but once they are in use must be
1170 // supported by subsequent objects.
1171 if (Info.Finalized && Old.HasCategoryClassProperties &&
1172 !New.HasCategoryClassProperties)
1173 return make_error<StringError>(Args: "ObjC category class property support in " +
1174 G.getName() +
1175 " does not match first registered flags",
1176 Args: inconvertibleErrorCode());
1177 if (Info.Finalized && Old.HasSignedObjCClassROs && !New.HasSignedObjCClassROs)
1178 return make_error<StringError>(Args: "ObjC class_ro_t pointer signing in " +
1179 G.getName() +
1180 " does not match first registered flags",
1181 Args: inconvertibleErrorCode());
1182
1183 // If we cannot change the flags, ignore any remaining differences. Adding
1184 // Swift or changing its version are unlikely to cause problems in practice.
1185 if (Info.Finalized)
1186 return Error::success();
1187
1188 // Use the minimum Swift version.
1189 if (Old.SwiftVersion && New.SwiftVersion)
1190 New.SwiftVersion = std::min(a: Old.SwiftVersion, b: New.SwiftVersion);
1191 else if (Old.SwiftVersion)
1192 New.SwiftVersion = Old.SwiftVersion;
1193 // Add a Swift ABI version if it was pure objc before.
1194 if (!New.SwiftABIVersion)
1195 New.SwiftABIVersion = Old.SwiftABIVersion;
1196 // Disable class properties if any object does not support it.
1197 if (Old.HasCategoryClassProperties != New.HasCategoryClassProperties)
1198 New.HasCategoryClassProperties = false;
1199 // Disable signed class ro data if any object does not support it.
1200 if (Old.HasSignedObjCClassROs != New.HasSignedObjCClassROs)
1201 New.HasSignedObjCClassROs = false;
1202
1203 LLVM_DEBUG({
1204 dbgs() << "MachOPlatform: Merging __objc_imageinfo flags for "
1205 << MR.getTargetJITDylib().getName() << " (was "
1206 << formatv("{0:x4}", Old.rawFlags()) << ")"
1207 << " with " << G.getName() << " (" << formatv("{0:x4}", NewFlags)
1208 << ")"
1209 << " -> " << formatv("{0:x4}", New.rawFlags()) << "\n";
1210 });
1211
1212 Info.Flags = New.rawFlags();
1213 return Error::success();
1214}
1215
1216Error MachOPlatform::MachOPlatformPlugin::fixTLVSectionsAndEdges(
1217 jitlink::LinkGraph &G, JITDylib &JD) {
1218 auto TLVBootStrapSymbolName = G.intern(SymbolName: "__tlv_bootstrap");
1219 // Rename external references to __tlv_bootstrap to ___orc_rt_tlv_get_addr.
1220 for (auto *Sym : G.external_symbols())
1221 if (Sym->getName() == TLVBootStrapSymbolName) {
1222 auto TLSGetADDR =
1223 MP.getExecutionSession().intern(SymName: "___orc_rt_macho_tlv_get_addr");
1224 Sym->setName(std::move(TLSGetADDR));
1225 break;
1226 }
1227
1228 // Store key in __thread_vars struct fields.
1229 if (auto *ThreadDataSec = G.findSectionByName(Name: MachOThreadVarsSectionName)) {
1230 std::optional<uint64_t> Key;
1231 {
1232 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
1233 auto I = MP.JITDylibToPThreadKey.find(Val: &JD);
1234 if (I != MP.JITDylibToPThreadKey.end())
1235 Key = I->second;
1236 }
1237
1238 if (!Key) {
1239 if (auto KeyOrErr = MP.createPThreadKey())
1240 Key = *KeyOrErr;
1241 else
1242 return KeyOrErr.takeError();
1243 }
1244
1245 uint64_t PlatformKeyBits =
1246 support::endian::byte_swap(value: *Key, endian: G.getEndianness());
1247
1248 for (auto *B : ThreadDataSec->blocks()) {
1249 if (B->getSize() != 3 * G.getPointerSize())
1250 return make_error<StringError>(Args: "__thread_vars block at " +
1251 formatv(Fmt: "{0:x}", Vals: B->getAddress()) +
1252 " has unexpected size",
1253 Args: inconvertibleErrorCode());
1254
1255 auto NewBlockContent = G.allocateBuffer(Size: B->getSize());
1256 llvm::copy(Range: B->getContent(), Out: NewBlockContent.data());
1257 memcpy(dest: NewBlockContent.data() + G.getPointerSize(), src: &PlatformKeyBits,
1258 n: G.getPointerSize());
1259 B->setContent(NewBlockContent);
1260 }
1261 }
1262
1263 // Transform any TLV edges into GOT edges.
1264 for (auto *B : G.blocks())
1265 for (auto &E : B->edges())
1266 if (E.getKind() ==
1267 jitlink::x86_64::RequestTLVPAndTransformToPCRel32TLVPLoadREXRelaxable)
1268 E.setKind(jitlink::x86_64::
1269 RequestGOTAndTransformToPCRel32GOTLoadREXRelaxable);
1270
1271 return Error::success();
1272}
1273
1274std::optional<MachOPlatform::MachOPlatformPlugin::UnwindSections>
1275MachOPlatform::MachOPlatformPlugin::findUnwindSectionInfo(
1276 jitlink::LinkGraph &G) {
1277 using namespace jitlink;
1278
1279 UnwindSections US;
1280
1281 // ScanSection records a section range and adds any executable blocks that
1282 // that section points to to the CodeBlocks vector.
1283 SmallVector<Block *> CodeBlocks;
1284 auto ScanUnwindInfoSection = [&](Section &Sec, ExecutorAddrRange &SecRange,
1285 auto AddCodeBlocks) {
1286 if (Sec.blocks().empty())
1287 return;
1288 SecRange = (*Sec.blocks().begin())->getRange();
1289 for (auto *B : Sec.blocks()) {
1290 auto R = B->getRange();
1291 SecRange.Start = std::min(a: SecRange.Start, b: R.Start);
1292 SecRange.End = std::max(a: SecRange.End, b: R.End);
1293 AddCodeBlocks(*B);
1294 }
1295 };
1296
1297 if (Section *EHFrameSec = G.findSectionByName(Name: MachOEHFrameSectionName)) {
1298 ScanUnwindInfoSection(*EHFrameSec, US.DwarfSection, [&](Block &B) {
1299 if (auto *Fn = jitlink::EHFrameCFIBlockInspector::FromEdgeScan(B)
1300 .getPCBeginEdge())
1301 if (Fn->getTarget().isDefined())
1302 CodeBlocks.push_back(Elt: &Fn->getTarget().getBlock());
1303 });
1304 }
1305
1306 if (Section *CUInfoSec = G.findSectionByName(Name: MachOUnwindInfoSectionName)) {
1307 ScanUnwindInfoSection(
1308 *CUInfoSec, US.CompactUnwindSection, [&](Block &B) {
1309 for (auto &E : B.edges()) {
1310 assert(E.getTarget().isDefined() &&
1311 "unwind-info record edge has external target");
1312 assert(E.getKind() == Edge::KeepAlive &&
1313 "unwind-info record has unexpected edge kind");
1314 CodeBlocks.push_back(Elt: &E.getTarget().getBlock());
1315 }
1316 });
1317 }
1318
1319 // If we didn't find any pointed-to code-blocks then there's no need to
1320 // register any info.
1321 if (CodeBlocks.empty())
1322 return std::nullopt;
1323
1324 // We have info to register. Sort the code blocks into address order and
1325 // build a list of contiguous address ranges covering them all.
1326 llvm::sort(C&: CodeBlocks, Comp: [](const Block *LHS, const Block *RHS) {
1327 return LHS->getAddress() < RHS->getAddress();
1328 });
1329 for (auto *B : CodeBlocks) {
1330 if (US.CodeRanges.empty() || US.CodeRanges.back().End != B->getAddress())
1331 US.CodeRanges.push_back(Elt: B->getRange());
1332 else
1333 US.CodeRanges.back().End = B->getRange().End;
1334 }
1335
1336 LLVM_DEBUG({
1337 dbgs() << "MachOPlatform identified unwind info in " << G.getName() << ":\n"
1338 << " DWARF: ";
1339 if (US.DwarfSection.Start)
1340 dbgs() << US.DwarfSection << "\n";
1341 else
1342 dbgs() << "none\n";
1343 dbgs() << " Compact-unwind: ";
1344 if (US.CompactUnwindSection.Start)
1345 dbgs() << US.CompactUnwindSection << "\n";
1346 else
1347 dbgs() << "none\n"
1348 << "for code ranges:\n";
1349 for (auto &CR : US.CodeRanges)
1350 dbgs() << " " << CR << "\n";
1351 if (US.CodeRanges.size() >= G.sections_size())
1352 dbgs() << "WARNING: High number of discontiguous code ranges! "
1353 "Padding may be interfering with coalescing.\n";
1354 });
1355
1356 return US;
1357}
1358
1359Error MachOPlatform::MachOPlatformPlugin::registerObjectPlatformSections(
1360 jitlink::LinkGraph &G, JITDylib &JD, ExecutorAddr HeaderAddr,
1361 bool InBootstrapPhase) {
1362
1363 // Get a pointer to the thread data section if there is one. It will be used
1364 // below.
1365 jitlink::Section *ThreadDataSection =
1366 G.findSectionByName(Name: MachOThreadDataSectionName);
1367
1368 // Handle thread BSS section if there is one.
1369 if (auto *ThreadBSSSection = G.findSectionByName(Name: MachOThreadBSSSectionName)) {
1370 // If there's already a thread data section in this graph then merge the
1371 // thread BSS section content into it, otherwise just treat the thread
1372 // BSS section as the thread data section.
1373 if (ThreadDataSection)
1374 G.mergeSections(DstSection&: *ThreadDataSection, SrcSection&: *ThreadBSSSection);
1375 else
1376 ThreadDataSection = ThreadBSSSection;
1377 }
1378
1379 SmallVector<std::pair<StringRef, ExecutorAddrRange>, 8> MachOPlatformSecs;
1380
1381 // Collect data sections to register.
1382 StringRef DataSections[] = {MachODataDataSectionName,
1383 MachODataCommonSectionName,
1384 MachOEHFrameSectionName};
1385 for (auto &SecName : DataSections) {
1386 if (auto *Sec = G.findSectionByName(Name: SecName)) {
1387 jitlink::SectionRange R(*Sec);
1388 if (!R.empty())
1389 MachOPlatformSecs.push_back(Elt: {SecName, R.getRange()});
1390 }
1391 }
1392
1393 // Having merged thread BSS (if present) and thread data (if present),
1394 // record the resulting section range.
1395 if (ThreadDataSection) {
1396 jitlink::SectionRange R(*ThreadDataSection);
1397 if (!R.empty())
1398 MachOPlatformSecs.push_back(Elt: {MachOThreadDataSectionName, R.getRange()});
1399 }
1400
1401 // If any platform sections were found then add an allocation action to call
1402 // the registration function.
1403 StringRef PlatformSections[] = {MachOModInitFuncSectionName,
1404 ObjCRuntimeObjectSectionName};
1405
1406 for (auto &SecName : PlatformSections) {
1407 auto *Sec = G.findSectionByName(Name: SecName);
1408 if (!Sec)
1409 continue;
1410 jitlink::SectionRange R(*Sec);
1411 if (R.empty())
1412 continue;
1413
1414 MachOPlatformSecs.push_back(Elt: {SecName, R.getRange()});
1415 }
1416
1417 std::optional<std::tuple<SmallVector<ExecutorAddrRange>, ExecutorAddrRange,
1418 ExecutorAddrRange>>
1419 UnwindInfo;
1420 if (auto UI = findUnwindSectionInfo(G))
1421 UnwindInfo = std::make_tuple(args: std::move(UI->CodeRanges), args&: UI->DwarfSection,
1422 args&: UI->CompactUnwindSection);
1423
1424 if (!MachOPlatformSecs.empty() || UnwindInfo) {
1425 // Dump the scraped inits.
1426 LLVM_DEBUG({
1427 dbgs() << "MachOPlatform: Scraped " << G.getName() << " init sections:\n";
1428 for (auto &KV : MachOPlatformSecs)
1429 dbgs() << " " << KV.first << ": " << KV.second << "\n";
1430 });
1431
1432 assert(HeaderAddr && "Null header registered for JD");
1433 using SPSRegisterObjectPlatformSectionsArgs = SPSArgList<
1434 SPSExecutorAddr,
1435 SPSOptional<SPSTuple<SPSSequence<SPSExecutorAddrRange>,
1436 SPSExecutorAddrRange, SPSExecutorAddrRange>>,
1437 SPSSequence<SPSTuple<SPSString, SPSExecutorAddrRange>>>;
1438
1439 AllocActionCallPair AllocActions = {
1440 .Finalize: cantFail(
1441 ValOrErr: WrapperFunctionCall::Create<SPSRegisterObjectPlatformSectionsArgs>(
1442 FnAddr: MP.RegisterObjectPlatformSections.Addr, Args: HeaderAddr, Args: UnwindInfo,
1443 Args: MachOPlatformSecs)),
1444 .Dealloc: cantFail(
1445 ValOrErr: WrapperFunctionCall::Create<SPSRegisterObjectPlatformSectionsArgs>(
1446 FnAddr: MP.DeregisterObjectPlatformSections.Addr, Args: HeaderAddr,
1447 Args: UnwindInfo, Args: MachOPlatformSecs))};
1448
1449 if (LLVM_LIKELY(!InBootstrapPhase))
1450 G.allocActions().push_back(x: std::move(AllocActions));
1451 else {
1452 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
1453 MP.Bootstrap->DeferredAAs.push_back(x: std::move(AllocActions));
1454 }
1455 }
1456
1457 return Error::success();
1458}
1459
1460Error MachOPlatform::MachOPlatformPlugin::createObjCRuntimeObject(
1461 jitlink::LinkGraph &G) {
1462
1463 bool NeedTextSegment = false;
1464 size_t NumRuntimeSections = 0;
1465
1466 for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsData)
1467 if (G.findSectionByName(Name: ObjCRuntimeSectionName))
1468 ++NumRuntimeSections;
1469
1470 for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsText) {
1471 if (G.findSectionByName(Name: ObjCRuntimeSectionName)) {
1472 ++NumRuntimeSections;
1473 NeedTextSegment = true;
1474 }
1475 }
1476
1477 // Early out for no runtime sections.
1478 if (NumRuntimeSections == 0)
1479 return Error::success();
1480
1481 // If there were any runtime sections then we need to add an __objc_imageinfo
1482 // section.
1483 ++NumRuntimeSections;
1484
1485 size_t MachOSize = sizeof(MachO::mach_header_64) +
1486 (NeedTextSegment + 1) * sizeof(MachO::segment_command_64) +
1487 NumRuntimeSections * sizeof(MachO::section_64);
1488
1489 auto &Sec = G.createSection(Name: ObjCRuntimeObjectSectionName,
1490 Prot: MemProt::Read | MemProt::Write);
1491 G.createMutableContentBlock(Parent&: Sec, ContentSize: MachOSize, Address: ExecutorAddr(), Alignment: 16, AlignmentOffset: 0, ZeroInitialize: true);
1492
1493 return Error::success();
1494}
1495
1496Error MachOPlatform::MachOPlatformPlugin::populateObjCRuntimeObject(
1497 jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
1498
1499 auto *ObjCRuntimeObjectSec =
1500 G.findSectionByName(Name: ObjCRuntimeObjectSectionName);
1501
1502 if (!ObjCRuntimeObjectSec)
1503 return Error::success();
1504
1505 switch (G.getTargetTriple().getArch()) {
1506 case Triple::aarch64:
1507 case Triple::x86_64:
1508 // Supported.
1509 break;
1510 default:
1511 return make_error<StringError>(Args: "Unrecognized MachO arch in triple " +
1512 G.getTargetTriple().str(),
1513 Args: inconvertibleErrorCode());
1514 }
1515
1516 auto &SecBlock = **ObjCRuntimeObjectSec->blocks().begin();
1517
1518 struct SecDesc {
1519 MachO::section_64 Sec;
1520 unique_function<void(size_t RecordOffset)> AddFixups;
1521 };
1522
1523 std::vector<SecDesc> TextSections, DataSections;
1524 auto AddSection = [&](SecDesc &SD, jitlink::Section &GraphSec) {
1525 jitlink::SectionRange SR(GraphSec);
1526 StringRef FQName = GraphSec.getName();
1527 memset(s: &SD.Sec, c: 0, n: sizeof(MachO::section_64));
1528 memcpy(dest: SD.Sec.sectname, src: FQName.drop_front(N: 7).data(), n: FQName.size() - 7);
1529 memcpy(dest: SD.Sec.segname, src: FQName.data(), n: 6);
1530 SD.Sec.addr = SR.getStart() - SecBlock.getAddress();
1531 SD.Sec.size = SR.getSize();
1532 SD.Sec.flags = MachO::S_REGULAR;
1533 };
1534
1535 // Add the __objc_imageinfo section.
1536 {
1537 DataSections.push_back(x: {});
1538 auto &SD = DataSections.back();
1539 memset(s: &SD.Sec, c: 0, n: sizeof(SD.Sec));
1540 memcpy(dest: SD.Sec.sectname, src: "__objc_imageinfo", n: 16);
1541 strcpy(dest: SD.Sec.segname, src: "__DATA");
1542 SD.Sec.size = 8;
1543 jitlink::Symbol *ObjCImageInfoSym = nullptr;
1544 SD.AddFixups = [&, ObjCImageInfoSym](size_t RecordOffset) mutable {
1545 auto PointerEdge = getPointerEdgeKind(G);
1546
1547 // Look for an existing __objc_imageinfo symbol.
1548 if (!ObjCImageInfoSym) {
1549 auto Name = G.intern(SymbolName: ObjCImageInfoSymbolName);
1550 ObjCImageInfoSym = G.findExternalSymbolByName(Name);
1551 if (!ObjCImageInfoSym)
1552 ObjCImageInfoSym = G.findAbsoluteSymbolByName(Name);
1553 if (!ObjCImageInfoSym) {
1554 ObjCImageInfoSym = G.findDefinedSymbolByName(Name);
1555 if (ObjCImageInfoSym) {
1556 std::optional<uint32_t> Flags;
1557 {
1558 std::lock_guard<std::mutex> Lock(PluginMutex);
1559 auto It = ObjCImageInfos.find(Val: &MR.getTargetJITDylib());
1560 if (It != ObjCImageInfos.end()) {
1561 It->second.Finalized = true;
1562 Flags = It->second.Flags;
1563 }
1564 }
1565
1566 if (Flags) {
1567 // We own the definition of __objc_image_info; write the final
1568 // merged flags value.
1569 auto Content = ObjCImageInfoSym->getBlock().getMutableContent(G);
1570 assert(
1571 Content.size() == 8 &&
1572 "__objc_image_info size should have been verified already");
1573 support::endian::write32(P: &Content[4], V: *Flags, E: G.getEndianness());
1574 }
1575 }
1576 }
1577 if (!ObjCImageInfoSym)
1578 ObjCImageInfoSym = &G.addExternalSymbol(Name: std::move(Name), Size: 8, IsWeaklyReferenced: false);
1579 }
1580
1581 SecBlock.addEdge(K: PointerEdge,
1582 Offset: RecordOffset + ((char *)&SD.Sec.addr - (char *)&SD.Sec),
1583 Target&: *ObjCImageInfoSym, Addend: -SecBlock.getAddress().getValue());
1584 };
1585 }
1586
1587 for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsData) {
1588 if (auto *GraphSec = G.findSectionByName(Name: ObjCRuntimeSectionName)) {
1589 DataSections.push_back(x: {});
1590 AddSection(DataSections.back(), *GraphSec);
1591 }
1592 }
1593
1594 for (auto ObjCRuntimeSectionName : ObjCRuntimeObjectSectionsText) {
1595 if (auto *GraphSec = G.findSectionByName(Name: ObjCRuntimeSectionName)) {
1596 TextSections.push_back(x: {});
1597 AddSection(TextSections.back(), *GraphSec);
1598 }
1599 }
1600
1601 assert(ObjCRuntimeObjectSec->blocks_size() == 1 &&
1602 "Unexpected number of blocks in runtime sections object");
1603
1604 // Build the header struct up-front. This also gives us a chance to check
1605 // that the triple is supported, which we'll assume below.
1606 MachO::mach_header_64 Hdr;
1607 Hdr.magic = MachO::MH_MAGIC_64;
1608 switch (G.getTargetTriple().getArch()) {
1609 case Triple::aarch64:
1610 Hdr.cputype = MachO::CPU_TYPE_ARM64;
1611 Hdr.cpusubtype = MachO::CPU_SUBTYPE_ARM64_ALL;
1612 break;
1613 case Triple::x86_64:
1614 Hdr.cputype = MachO::CPU_TYPE_X86_64;
1615 Hdr.cpusubtype = MachO::CPU_SUBTYPE_X86_64_ALL;
1616 break;
1617 default:
1618 llvm_unreachable("Unsupported architecture");
1619 }
1620
1621 Hdr.filetype = MachO::MH_DYLIB;
1622 Hdr.ncmds = 1 + !TextSections.empty();
1623 Hdr.sizeofcmds =
1624 Hdr.ncmds * sizeof(MachO::segment_command_64) +
1625 (TextSections.size() + DataSections.size()) * sizeof(MachO::section_64);
1626 Hdr.flags = 0;
1627 Hdr.reserved = 0;
1628
1629 auto SecContent = SecBlock.getAlreadyMutableContent();
1630 char *P = SecContent.data();
1631 auto WriteMachOStruct = [&](auto S) {
1632 if (G.getEndianness() != llvm::endianness::native)
1633 MachO::swapStruct(S);
1634 memcpy(P, &S, sizeof(S));
1635 P += sizeof(S);
1636 };
1637
1638 auto WriteSegment = [&](StringRef Name, std::vector<SecDesc> &Secs) {
1639 MachO::segment_command_64 SegLC;
1640 memset(s: &SegLC, c: 0, n: sizeof(SegLC));
1641 memcpy(dest: SegLC.segname, src: Name.data(), n: Name.size());
1642 SegLC.cmd = MachO::LC_SEGMENT_64;
1643 SegLC.cmdsize = sizeof(MachO::segment_command_64) +
1644 Secs.size() * sizeof(MachO::section_64);
1645 SegLC.nsects = Secs.size();
1646 WriteMachOStruct(SegLC);
1647 for (auto &SD : Secs) {
1648 if (SD.AddFixups)
1649 SD.AddFixups(P - SecContent.data());
1650 WriteMachOStruct(SD.Sec);
1651 }
1652 };
1653
1654 WriteMachOStruct(Hdr);
1655 if (!TextSections.empty())
1656 WriteSegment("__TEXT", TextSections);
1657 if (!DataSections.empty())
1658 WriteSegment("__DATA", DataSections);
1659
1660 assert(P == SecContent.end() && "Underflow writing ObjC runtime object");
1661 return Error::success();
1662}
1663
1664Error MachOPlatform::MachOPlatformPlugin::prepareSymbolTableRegistration(
1665 jitlink::LinkGraph &G, JITSymTabVector &JITSymTabInfo) {
1666
1667 auto *CStringSec = G.findSectionByName(Name: MachOCStringSectionName);
1668 if (!CStringSec)
1669 CStringSec = &G.createSection(Name: MachOCStringSectionName,
1670 Prot: MemProt::Read | MemProt::Exec);
1671
1672 // Make a map of existing strings so that we can re-use them:
1673 DenseMap<StringRef, jitlink::Symbol *> ExistingStrings;
1674 for (auto *Sym : CStringSec->symbols()) {
1675
1676 // The LinkGraph builder should have created single strings blocks, and all
1677 // plugins should have maintained this invariant.
1678 auto Content = Sym->getBlock().getContent();
1679 ExistingStrings.insert(
1680 KV: std::make_pair(x: StringRef(Content.data(), Content.size()), y&: Sym));
1681 }
1682
1683 // Add all symbol names to the string section, and record the symbols for
1684 // those names.
1685 {
1686 SmallVector<jitlink::Symbol *> SymsToProcess;
1687 llvm::append_range(C&: SymsToProcess, R: G.defined_symbols());
1688 llvm::append_range(C&: SymsToProcess, R: G.absolute_symbols());
1689
1690 for (auto *Sym : SymsToProcess) {
1691 if (!Sym->hasName())
1692 continue;
1693
1694 auto I = ExistingStrings.find(Val: *Sym->getName());
1695 if (I == ExistingStrings.end()) {
1696 auto &NameBlock = G.createMutableContentBlock(
1697 Parent&: *CStringSec, MutableContent: G.allocateCString(Source: *Sym->getName()),
1698 Address: orc::ExecutorAddr(), Alignment: 1, AlignmentOffset: 0);
1699 auto &SymbolNameSym = G.addAnonymousSymbol(
1700 Content&: NameBlock, Offset: 0, Size: NameBlock.getSize(), IsCallable: false, IsLive: true);
1701 JITSymTabInfo.push_back(Elt: {.OriginalSym: Sym, .NameSym: &SymbolNameSym});
1702 } else
1703 JITSymTabInfo.push_back(Elt: {.OriginalSym: Sym, .NameSym: I->second});
1704 }
1705 }
1706
1707 return Error::success();
1708}
1709
1710Error MachOPlatform::MachOPlatformPlugin::addSymbolTableRegistration(
1711 jitlink::LinkGraph &G, MaterializationResponsibility &MR,
1712 JITSymTabVector &JITSymTabInfo, bool InBootstrapPhase) {
1713
1714 ExecutorAddr HeaderAddr;
1715 {
1716 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
1717 auto I = MP.JITDylibToHeaderAddr.find(Val: &MR.getTargetJITDylib());
1718 assert(I != MP.JITDylibToHeaderAddr.end() && "No header registered for JD");
1719 assert(I->second && "Null header registered for JD");
1720 HeaderAddr = I->second;
1721 }
1722
1723 if (LLVM_UNLIKELY(InBootstrapPhase)) {
1724 // If we're in the bootstrap phase then just record these symbols in the
1725 // bootstrap object and then bail out -- registration will be attached to
1726 // the bootstrap graph.
1727 std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
1728 auto &SymTab = MP.Bootstrap->SymTab;
1729 for (auto &[OriginalSymbol, NameSym] : JITSymTabInfo)
1730 SymTab.push_back(Elt: {NameSym->getAddress(), OriginalSymbol->getAddress(),
1731 flagsForSymbol(Sym&: *OriginalSymbol)});
1732 return Error::success();
1733 }
1734
1735 SymbolTableVector SymTab;
1736 for (auto &[OriginalSymbol, NameSym] : JITSymTabInfo)
1737 SymTab.push_back(Elt: {NameSym->getAddress(), OriginalSymbol->getAddress(),
1738 flagsForSymbol(Sym&: *OriginalSymbol)});
1739
1740 G.allocActions().push_back(
1741 x: {.Finalize: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
1742 FnAddr: MP.RegisterObjectSymbolTable.Addr, Args: HeaderAddr, Args: SymTab)),
1743 .Dealloc: cantFail(ValOrErr: WrapperFunctionCall::Create<SPSRegisterSymbolsArgs>(
1744 FnAddr: MP.DeregisterObjectSymbolTable.Addr, Args: HeaderAddr, Args: SymTab))});
1745
1746 return Error::success();
1747}
1748
1749template <typename MachOTraits>
1750jitlink::Block &createHeaderBlock(MachOPlatform &MOP,
1751 const MachOPlatform::HeaderOptions &Opts,
1752 JITDylib &JD, jitlink::LinkGraph &G,
1753 jitlink::Section &HeaderSection) {
1754 auto HdrInfo =
1755 getMachOHeaderInfoFromTriple(TT: MOP.getExecutionSession().getTargetTriple());
1756 MachOBuilder<MachOTraits> B(HdrInfo.PageSize);
1757
1758 B.Header.filetype = MachO::MH_DYLIB;
1759 B.Header.cputype = HdrInfo.CPUType;
1760 B.Header.cpusubtype = HdrInfo.CPUSubType;
1761
1762 if (Opts.IDDylib)
1763 B.template addLoadCommand<MachO::LC_ID_DYLIB>(
1764 Opts.IDDylib->Name, Opts.IDDylib->Timestamp,
1765 Opts.IDDylib->CurrentVersion, Opts.IDDylib->CompatibilityVersion);
1766 else
1767 B.template addLoadCommand<MachO::LC_ID_DYLIB>(JD.getName(), 0, 0, 0);
1768
1769 if (Opts.UUID)
1770 B.template addLoadCommand<MachO::LC_UUID>(*Opts.UUID);
1771
1772 for (auto &BV : Opts.BuildVersions)
1773 B.template addLoadCommand<MachO::LC_BUILD_VERSION>(
1774 BV.Platform, BV.MinOS, BV.SDK, static_cast<uint32_t>(0));
1775
1776 if (Opts.TargetTriple)
1777 B.template addLoadCommand<MachO::LC_TARGET_TRIPLE>(*Opts.TargetTriple);
1778
1779 using LoadKind = MachOPlatform::HeaderOptions::LoadDylibCmd::LoadKind;
1780 for (auto &LD : Opts.LoadDylibs) {
1781 switch (LD.K) {
1782 case LoadKind::Default:
1783 B.template addLoadCommand<MachO::LC_LOAD_DYLIB>(
1784 LD.D.Name, LD.D.Timestamp, LD.D.CurrentVersion,
1785 LD.D.CompatibilityVersion);
1786 break;
1787 case LoadKind::Weak:
1788 B.template addLoadCommand<MachO::LC_LOAD_WEAK_DYLIB>(
1789 LD.D.Name, LD.D.Timestamp, LD.D.CurrentVersion,
1790 LD.D.CompatibilityVersion);
1791 break;
1792 }
1793 }
1794 for (auto &P : Opts.RPaths)
1795 B.template addLoadCommand<MachO::LC_RPATH>(P);
1796
1797 auto HeaderContent = G.allocateBuffer(Size: B.layout());
1798 B.write(HeaderContent);
1799
1800 return G.createContentBlock(Parent&: HeaderSection, Content: HeaderContent, Address: ExecutorAddr(), Alignment: 8,
1801 AlignmentOffset: 0);
1802}
1803
1804SimpleMachOHeaderMU::SimpleMachOHeaderMU(MachOPlatform &MOP,
1805 SymbolStringPtr HeaderStartSymbol,
1806 MachOPlatform::HeaderOptions Opts)
1807 : MaterializationUnit(
1808 createHeaderInterface(MOP, HeaderStartSymbol: std::move(HeaderStartSymbol))),
1809 MOP(MOP), Opts(std::move(Opts)) {}
1810
1811void SimpleMachOHeaderMU::materialize(
1812 std::unique_ptr<MaterializationResponsibility> R) {
1813 auto G = createPlatformGraph(MOP, Name: "<MachOHeaderMU>");
1814 addMachOHeader(JD&: R->getTargetJITDylib(), G&: *G, InitializerSymbol: R->getInitializerSymbol());
1815 MOP.getObjectLinkingLayer().emit(R: std::move(R), G: std::move(G));
1816}
1817
1818void SimpleMachOHeaderMU::discard(const JITDylib &JD,
1819 const SymbolStringPtr &Sym) {}
1820
1821void SimpleMachOHeaderMU::addMachOHeader(
1822 JITDylib &JD, jitlink::LinkGraph &G,
1823 const SymbolStringPtr &InitializerSymbol) {
1824 auto &HeaderSection = G.createSection(Name: "__header", Prot: MemProt::Read);
1825 auto &HeaderBlock = createHeaderBlock(JD, G, HeaderSection);
1826
1827 // Init symbol is header-start symbol.
1828 G.addDefinedSymbol(Content&: HeaderBlock, Offset: 0, Name: *InitializerSymbol, Size: HeaderBlock.getSize(),
1829 L: jitlink::Linkage::Strong, S: jitlink::Scope::Default, IsCallable: false,
1830 IsLive: true);
1831 for (auto &HS : AdditionalHeaderSymbols)
1832 G.addDefinedSymbol(Content&: HeaderBlock, Offset: HS.Offset, Name: HS.Name, Size: HeaderBlock.getSize(),
1833 L: jitlink::Linkage::Strong, S: jitlink::Scope::Default, IsCallable: false,
1834 IsLive: true);
1835}
1836
1837jitlink::Block &
1838SimpleMachOHeaderMU::createHeaderBlock(JITDylib &JD, jitlink::LinkGraph &G,
1839 jitlink::Section &HeaderSection) {
1840 switch (MOP.getExecutionSession().getTargetTriple().getArch()) {
1841 case Triple::aarch64:
1842 case Triple::x86_64:
1843 return ::createHeaderBlock<MachO64LE>(MOP, Opts, JD, G, HeaderSection);
1844 default:
1845 llvm_unreachable("Unsupported architecture");
1846 }
1847}
1848
1849MaterializationUnit::Interface SimpleMachOHeaderMU::createHeaderInterface(
1850 MachOPlatform &MOP, const SymbolStringPtr &HeaderStartSymbol) {
1851 SymbolFlagsMap HeaderSymbolFlags;
1852
1853 HeaderSymbolFlags[HeaderStartSymbol] = JITSymbolFlags::Exported;
1854 for (auto &HS : AdditionalHeaderSymbols)
1855 HeaderSymbolFlags[MOP.getExecutionSession().intern(SymName: HS.Name)] =
1856 JITSymbolFlags::Exported;
1857
1858 return MaterializationUnit::Interface(std::move(HeaderSymbolFlags),
1859 HeaderStartSymbol);
1860}
1861
1862MachOHeaderInfo getMachOHeaderInfoFromTriple(const Triple &TT) {
1863 switch (TT.getArch()) {
1864 case Triple::aarch64:
1865 return {/* PageSize = */ 16 * 1024,
1866 /* CPUType = */ MachO::CPU_TYPE_ARM64,
1867 /* CPUSubType = */ MachO::CPU_SUBTYPE_ARM64_ALL};
1868 case Triple::x86_64:
1869 return {/* PageSize = */ 4 * 1024,
1870 /* CPUType = */ MachO::CPU_TYPE_X86_64,
1871 /* CPUSubType = */ MachO::CPU_SUBTYPE_X86_64_ALL};
1872 default:
1873 llvm_unreachable("Unrecognized architecture");
1874 }
1875}
1876
1877} // End namespace orc.
1878} // End namespace llvm.
1879