LLVM 19.0.0git
JITLink.cpp
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1//===------------- JITLink.cpp - Core Run-time JIT linker APIs ------------===//
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
10
20#include "llvm/Support/Format.h"
23
24using namespace llvm;
25using namespace llvm::object;
26
27#define DEBUG_TYPE "jitlink"
28
29namespace {
30
31enum JITLinkErrorCode { GenericJITLinkError = 1 };
32
33// FIXME: This class is only here to support the transition to llvm::Error. It
34// will be removed once this transition is complete. Clients should prefer to
35// deal with the Error value directly, rather than converting to error_code.
36class JITLinkerErrorCategory : public std::error_category {
37public:
38 const char *name() const noexcept override { return "runtimedyld"; }
39
40 std::string message(int Condition) const override {
41 switch (static_cast<JITLinkErrorCode>(Condition)) {
42 case GenericJITLinkError:
43 return "Generic JITLink error";
44 }
45 llvm_unreachable("Unrecognized JITLinkErrorCode");
46 }
47};
48
49} // namespace
50
51namespace llvm {
52namespace jitlink {
53
54char JITLinkError::ID = 0;
55
56void JITLinkError::log(raw_ostream &OS) const { OS << ErrMsg; }
57
58std::error_code JITLinkError::convertToErrorCode() const {
59 static JITLinkerErrorCategory TheJITLinkerErrorCategory;
60 return std::error_code(GenericJITLinkError, TheJITLinkerErrorCategory);
61}
62
64 switch (K) {
65 case Edge::Invalid:
66 return "INVALID RELOCATION";
67 case Edge::KeepAlive:
68 return "Keep-Alive";
69 default:
70 return "<Unrecognized edge kind>";
71 }
72}
73
74const char *getLinkageName(Linkage L) {
75 switch (L) {
76 case Linkage::Strong:
77 return "strong";
78 case Linkage::Weak:
79 return "weak";
80 }
81 llvm_unreachable("Unrecognized llvm.jitlink.Linkage enum");
82}
83
84const char *getScopeName(Scope S) {
85 switch (S) {
86 case Scope::Default:
87 return "default";
88 case Scope::Hidden:
89 return "hidden";
90 case Scope::Local:
91 return "local";
92 }
93 llvm_unreachable("Unrecognized llvm.jitlink.Scope enum");
94}
95
97 if (B.getSize() == 0) // Empty blocks are not valid C-strings.
98 return false;
99
100 // Zero-fill blocks of size one are valid empty strings.
101 if (B.isZeroFill())
102 return B.getSize() == 1;
103
104 for (size_t I = 0; I != B.getSize() - 1; ++I)
105 if (B.getContent()[I] == '\0')
106 return false;
107
108 return B.getContent()[B.getSize() - 1] == '\0';
109}
110
112 return OS << B.getAddress() << " -- " << (B.getAddress() + B.getSize())
113 << ": "
114 << "size = " << formatv("{0:x8}", B.getSize()) << ", "
115 << (B.isZeroFill() ? "zero-fill" : "content")
116 << ", align = " << B.getAlignment()
117 << ", align-ofs = " << B.getAlignmentOffset()
118 << ", section = " << B.getSection().getName();
119}
120
122 OS << Sym.getAddress() << " (" << (Sym.isDefined() ? "block" : "addressable")
123 << " + " << formatv("{0:x8}", Sym.getOffset())
124 << "): size: " << formatv("{0:x8}", Sym.getSize())
125 << ", linkage: " << formatv("{0:6}", getLinkageName(Sym.getLinkage()))
126 << ", scope: " << formatv("{0:8}", getScopeName(Sym.getScope())) << ", "
127 << (Sym.isLive() ? "live" : "dead") << " - "
128 << (Sym.hasName() ? Sym.getName() : "<anonymous symbol>");
129 return OS;
130}
131
132void printEdge(raw_ostream &OS, const Block &B, const Edge &E,
133 StringRef EdgeKindName) {
134 OS << "edge@" << B.getAddress() + E.getOffset() << ": " << B.getAddress()
135 << " + " << formatv("{0:x}", E.getOffset()) << " -- " << EdgeKindName
136 << " -> ";
137
138 auto &TargetSym = E.getTarget();
139 if (TargetSym.hasName())
140 OS << TargetSym.getName();
141 else {
142 auto &TargetBlock = TargetSym.getBlock();
143 auto &TargetSec = TargetBlock.getSection();
144 orc::ExecutorAddr SecAddress(~uint64_t(0));
145 for (auto *B : TargetSec.blocks())
146 if (B->getAddress() < SecAddress)
147 SecAddress = B->getAddress();
148
149 orc::ExecutorAddrDiff SecDelta = TargetSym.getAddress() - SecAddress;
150 OS << TargetSym.getAddress() << " (section " << TargetSec.getName();
151 if (SecDelta)
152 OS << " + " << formatv("{0:x}", SecDelta);
153 OS << " / block " << TargetBlock.getAddress();
154 if (TargetSym.getOffset())
155 OS << " + " << formatv("{0:x}", TargetSym.getOffset());
156 OS << ")";
157 }
158
159 if (E.getAddend() != 0)
160 OS << " + " << E.getAddend();
161}
162
164 for (auto *Sym : Symbols)
165 Sym->~Symbol();
166 for (auto *B : Blocks)
167 B->~Block();
168}
169
170Block &LinkGraph::splitBlock(Block &B, size_t SplitIndex,
171 SplitBlockCache *Cache) {
172
173 assert(SplitIndex > 0 && "splitBlock can not be called with SplitIndex == 0");
174
175 // If the split point covers all of B then just return B.
176 if (SplitIndex == B.getSize())
177 return B;
178
179 assert(SplitIndex < B.getSize() && "SplitIndex out of range");
180
181 // Create the new block covering [ 0, SplitIndex ).
182 auto &NewBlock =
183 B.isZeroFill()
184 ? createZeroFillBlock(B.getSection(), SplitIndex, B.getAddress(),
185 B.getAlignment(), B.getAlignmentOffset())
187 B.getSection(), B.getContent().slice(0, SplitIndex),
188 B.getAddress(), B.getAlignment(), B.getAlignmentOffset());
189
190 // Modify B to cover [ SplitIndex, B.size() ).
191 B.setAddress(B.getAddress() + SplitIndex);
192 B.setContent(B.getContent().slice(SplitIndex));
193 B.setAlignmentOffset((B.getAlignmentOffset() + SplitIndex) %
194 B.getAlignment());
195
196 // Handle edge transfer/update.
197 {
198 // Copy edges to NewBlock (recording their iterators so that we can remove
199 // them from B), and update of Edges remaining on B.
200 std::vector<Block::edge_iterator> EdgesToRemove;
201 for (auto I = B.edges().begin(); I != B.edges().end();) {
202 if (I->getOffset() < SplitIndex) {
203 NewBlock.addEdge(*I);
204 I = B.removeEdge(I);
205 } else {
206 I->setOffset(I->getOffset() - SplitIndex);
207 ++I;
208 }
209 }
210 }
211
212 // Handle symbol transfer/update.
213 {
214 // Initialize the symbols cache if necessary.
215 SplitBlockCache LocalBlockSymbolsCache;
216 if (!Cache)
217 Cache = &LocalBlockSymbolsCache;
218 if (*Cache == std::nullopt) {
219 *Cache = SplitBlockCache::value_type();
220 for (auto *Sym : B.getSection().symbols())
221 if (&Sym->getBlock() == &B)
222 (*Cache)->push_back(Sym);
223
224 llvm::sort(**Cache, [](const Symbol *LHS, const Symbol *RHS) {
225 return LHS->getOffset() > RHS->getOffset();
226 });
227 }
228 auto &BlockSymbols = **Cache;
229
230 // Transfer all symbols with offset less than SplitIndex to NewBlock.
231 while (!BlockSymbols.empty() &&
232 BlockSymbols.back()->getOffset() < SplitIndex) {
233 auto *Sym = BlockSymbols.back();
234 // If the symbol extends beyond the split, update the size to be within
235 // the new block.
236 if (Sym->getOffset() + Sym->getSize() > SplitIndex)
237 Sym->setSize(SplitIndex - Sym->getOffset());
238 Sym->setBlock(NewBlock);
239 BlockSymbols.pop_back();
240 }
241
242 // Update offsets for all remaining symbols in B.
243 for (auto *Sym : BlockSymbols)
244 Sym->setOffset(Sym->getOffset() - SplitIndex);
245 }
246
247 return NewBlock;
248}
249
252
253 // Map from blocks to the symbols pointing at them.
254 for (auto *Sym : defined_symbols())
255 BlockSymbols[&Sym->getBlock()].push_back(Sym);
256
257 // For each block, sort its symbols by something approximating
258 // relevance.
259 for (auto &KV : BlockSymbols)
260 llvm::sort(KV.second, [](const Symbol *LHS, const Symbol *RHS) {
261 if (LHS->getOffset() != RHS->getOffset())
262 return LHS->getOffset() < RHS->getOffset();
263 if (LHS->getLinkage() != RHS->getLinkage())
264 return LHS->getLinkage() < RHS->getLinkage();
265 if (LHS->getScope() != RHS->getScope())
266 return LHS->getScope() < RHS->getScope();
267 if (LHS->hasName()) {
268 if (!RHS->hasName())
269 return true;
270 return LHS->getName() < RHS->getName();
271 }
272 return false;
273 });
274
275 for (auto &Sec : sections()) {
276 OS << "section " << Sec.getName() << ":\n\n";
277
278 std::vector<Block *> SortedBlocks;
279 llvm::copy(Sec.blocks(), std::back_inserter(SortedBlocks));
280 llvm::sort(SortedBlocks, [](const Block *LHS, const Block *RHS) {
281 return LHS->getAddress() < RHS->getAddress();
282 });
283
284 for (auto *B : SortedBlocks) {
285 OS << " block " << B->getAddress()
286 << " size = " << formatv("{0:x8}", B->getSize())
287 << ", align = " << B->getAlignment()
288 << ", alignment-offset = " << B->getAlignmentOffset();
289 if (B->isZeroFill())
290 OS << ", zero-fill";
291 OS << "\n";
292
293 auto BlockSymsI = BlockSymbols.find(B);
294 if (BlockSymsI != BlockSymbols.end()) {
295 OS << " symbols:\n";
296 auto &Syms = BlockSymsI->second;
297 for (auto *Sym : Syms)
298 OS << " " << *Sym << "\n";
299 } else
300 OS << " no symbols\n";
301
302 if (!B->edges_empty()) {
303 OS << " edges:\n";
304 std::vector<Edge> SortedEdges;
305 llvm::copy(B->edges(), std::back_inserter(SortedEdges));
306 llvm::sort(SortedEdges, [](const Edge &LHS, const Edge &RHS) {
307 return LHS.getOffset() < RHS.getOffset();
308 });
309 for (auto &E : SortedEdges) {
310 OS << " " << B->getFixupAddress(E) << " (block + "
311 << formatv("{0:x8}", E.getOffset()) << "), addend = ";
312 if (E.getAddend() >= 0)
313 OS << formatv("+{0:x8}", E.getAddend());
314 else
315 OS << formatv("-{0:x8}", -E.getAddend());
316 OS << ", kind = " << getEdgeKindName(E.getKind()) << ", target = ";
317 if (E.getTarget().hasName())
318 OS << E.getTarget().getName();
319 else
320 OS << "addressable@"
321 << formatv("{0:x16}", E.getTarget().getAddress()) << "+"
322 << formatv("{0:x8}", E.getTarget().getOffset());
323 OS << "\n";
324 }
325 } else
326 OS << " no edges\n";
327 OS << "\n";
328 }
329 }
330
331 OS << "Absolute symbols:\n";
332 if (!absolute_symbols().empty()) {
333 for (auto *Sym : absolute_symbols())
334 OS << " " << Sym->getAddress() << ": " << *Sym << "\n";
335 } else
336 OS << " none\n";
337
338 OS << "\nExternal symbols:\n";
339 if (!external_symbols().empty()) {
340 for (auto *Sym : external_symbols())
341 OS << " " << Sym->getAddress() << ": " << *Sym << "\n";
342 } else
343 OS << " none\n";
344}
345
347 switch (LF) {
348 case SymbolLookupFlags::RequiredSymbol:
349 return OS << "RequiredSymbol";
350 case SymbolLookupFlags::WeaklyReferencedSymbol:
351 return OS << "WeaklyReferencedSymbol";
352 }
353 llvm_unreachable("Unrecognized lookup flags");
354}
355
356void JITLinkAsyncLookupContinuation::anchor() {}
357
358JITLinkContext::~JITLinkContext() = default;
359
360bool JITLinkContext::shouldAddDefaultTargetPasses(const Triple &TT) const {
361 return true;
362}
363
364LinkGraphPassFunction JITLinkContext::getMarkLivePass(const Triple &TT) const {
365 return LinkGraphPassFunction();
366}
367
368Error JITLinkContext::modifyPassConfig(LinkGraph &G,
370 return Error::success();
371}
372
374 for (auto *Sym : G.defined_symbols())
375 Sym->setLive(true);
376 return Error::success();
377}
378
380 const Edge &E) {
381 std::string ErrMsg;
382 {
383 raw_string_ostream ErrStream(ErrMsg);
384 Section &Sec = B.getSection();
385 ErrStream << "In graph " << G.getName() << ", section " << Sec.getName()
386 << ": relocation target ";
387 if (E.getTarget().hasName()) {
388 ErrStream << "\"" << E.getTarget().getName() << "\"";
389 } else
390 ErrStream << E.getTarget().getBlock().getSection().getName() << " + "
391 << formatv("{0:x}", E.getOffset());
392 ErrStream << " at address " << formatv("{0:x}", E.getTarget().getAddress())
393 << " is out of range of " << G.getEdgeKindName(E.getKind())
394 << " fixup at " << formatv("{0:x}", B.getFixupAddress(E)) << " (";
395
396 Symbol *BestSymbolForBlock = nullptr;
397 for (auto *Sym : Sec.symbols())
398 if (&Sym->getBlock() == &B && Sym->hasName() && Sym->getOffset() == 0 &&
399 (!BestSymbolForBlock ||
400 Sym->getScope() < BestSymbolForBlock->getScope() ||
401 Sym->getLinkage() < BestSymbolForBlock->getLinkage()))
402 BestSymbolForBlock = Sym;
403
404 if (BestSymbolForBlock)
405 ErrStream << BestSymbolForBlock->getName() << ", ";
406 else
407 ErrStream << "<anonymous block> @ ";
408
409 ErrStream << formatv("{0:x}", B.getAddress()) << " + "
410 << formatv("{0:x}", E.getOffset()) << ")";
411 }
412 return make_error<JITLinkError>(std::move(ErrMsg));
413}
414
416 const Edge &E) {
417 return make_error<JITLinkError>("0x" + llvm::utohexstr(Loc.getValue()) +
418 " improper alignment for relocation " +
419 formatv("{0:d}", E.getKind()) + ": 0x" +
420 llvm::utohexstr(Value) +
421 " is not aligned to " + Twine(N) + " bytes");
422}
423
425 switch (TT.getArch()) {
426 case Triple::aarch64:
427 return aarch64::createAnonymousPointer;
428 case Triple::x86_64:
429 return x86_64::createAnonymousPointer;
430 case Triple::x86:
431 return i386::createAnonymousPointer;
434 return loongarch::createAnonymousPointer;
435 default:
436 return nullptr;
437 }
438}
439
441 switch (TT.getArch()) {
442 case Triple::aarch64:
443 return aarch64::createAnonymousPointerJumpStub;
444 case Triple::x86_64:
445 return x86_64::createAnonymousPointerJumpStub;
446 case Triple::x86:
447 return i386::createAnonymousPointerJumpStub;
450 return loongarch::createAnonymousPointerJumpStub;
451 default:
452 return nullptr;
453 }
454}
455
458 auto Magic = identify_magic(ObjectBuffer.getBuffer());
459 switch (Magic) {
461 return createLinkGraphFromMachOObject(ObjectBuffer);
463 return createLinkGraphFromELFObject(ObjectBuffer);
465 return createLinkGraphFromCOFFObject(ObjectBuffer);
466 default:
467 return make_error<JITLinkError>("Unsupported file format");
468 };
469}
470
471std::unique_ptr<LinkGraph> absoluteSymbolsLinkGraph(const Triple &TT,
472 orc::SymbolMap Symbols) {
473 unsigned PointerSize;
474 endianness Endianness =
475 TT.isLittleEndian() ? endianness::little : endianness::big;
476 switch (TT.getArch()) {
477 case Triple::aarch64:
479 case Triple::x86_64:
480 PointerSize = 8;
481 break;
485 PointerSize = 4;
486 break;
487 default:
488 llvm::report_fatal_error("unhandled target architecture");
489 }
490
491 static std::atomic<uint64_t> Counter = {0};
492 auto Index = Counter.fetch_add(1, std::memory_order_relaxed);
493 auto G = std::make_unique<LinkGraph>(
494 "<Absolute Symbols " + std::to_string(Index) + ">", TT, PointerSize,
495 Endianness, /*GetEdgeKindName=*/nullptr);
496 for (auto &[Name, Def] : Symbols) {
497 auto &Sym =
498 G->addAbsoluteSymbol(*Name, Def.getAddress(), /*Size=*/0,
499 Linkage::Strong, Scope::Default, /*IsLive=*/true);
500 Sym.setCallable(Def.getFlags().isCallable());
501 }
502
503 return G;
504}
505
506void link(std::unique_ptr<LinkGraph> G, std::unique_ptr<JITLinkContext> Ctx) {
507 switch (G->getTargetTriple().getObjectFormat()) {
508 case Triple::MachO:
509 return link_MachO(std::move(G), std::move(Ctx));
510 case Triple::ELF:
511 return link_ELF(std::move(G), std::move(Ctx));
512 case Triple::COFF:
513 return link_COFF(std::move(G), std::move(Ctx));
514 default:
515 Ctx->notifyFailed(make_error<JITLinkError>("Unsupported object format"));
516 };
517}
518
519} // end namespace jitlink
520} // end namespace llvm
bbsections Prepares for basic block sections
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
std::string Name
RelaxConfig Config
Definition: ELF_riscv.cpp:506
Symbol * Sym
Definition: ELF_riscv.cpp:479
#define I(x, y, z)
Definition: MD5.cpp:58
#define G(x, y, z)
Definition: MD5.cpp:56
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
static const char * name
Definition: SMEABIPass.cpp:49
raw_pwrite_stream & OS
This file contains some functions that are useful when dealing with strings.
Value * RHS
Value * LHS
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
static ErrorSuccess success()
Create a success value.
Definition: Error.h:334
Tagged union holding either a T or a Error.
Definition: Error.h:474
StringRef getBuffer() const
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
@ loongarch32
Definition: Triple.h:61
@ loongarch64
Definition: Triple.h:62
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
LLVM Value Representation.
Definition: Value.h:74
Represents an address in the executor process.
uint64_t getValue() const
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:660
unique_function is a type-erasing functor similar to std::function.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
file_magic identify_magic(StringRef magic)
Identify the type of a binary file based on how magical it is.
Definition: Magic.cpp:33
auto formatv(const char *Fmt, Ts &&... Vals) -> formatv_object< decltype(std::make_tuple(detail::build_format_adapter(std::forward< Ts >(Vals))...))>
void sort(IteratorTy Start, IteratorTy End)
Definition: STLExtras.h:1656
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:156
raw_ostream & operator<<(raw_ostream &OS, const APFixedPoint &FX)
Definition: APFixedPoint.h:293
OutputIt copy(R &&Range, OutputIt Out)
Definition: STLExtras.h:1833
endianness
Definition: bit.h:70
#define N
@ elf_relocatable
ELF Relocatable object file.
Definition: Magic.h:27
@ macho_object
Mach-O Object file.
Definition: Magic.h:32
@ coff_object
COFF object file.
Definition: Magic.h:47