Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp
Warning:line 177, column 62
Division by zero

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name JITLink.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -D PIC -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -D_RET_PROTECTOR -ret-protector -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/ExecutionEngine/JITLink/JITLink.cpp

→
1//===------------- JITLink.cpp - Core Run-time JIT linker APIs ------------===//
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#include "llvm/ExecutionEngine/JITLink/JITLink.h"
11
12#include "llvm/BinaryFormat/Magic.h"
13#include "llvm/ExecutionEngine/JITLink/ELF.h"
14#include "llvm/ExecutionEngine/JITLink/MachO.h"
15#include "llvm/Support/Format.h"
16#include "llvm/Support/ManagedStatic.h"
17#include "llvm/Support/MemoryBuffer.h"
18#include "llvm/Support/raw_ostream.h"
19
20using namespace llvm;
21using namespace llvm::object;
22
23#define DEBUG_TYPE"jitlink" "jitlink"
24
25namespace {
26
27enum JITLinkErrorCode { GenericJITLinkError = 1 };
28
29// FIXME: This class is only here to support the transition to llvm::Error. It
30// will be removed once this transition is complete. Clients should prefer to
31// deal with the Error value directly, rather than converting to error_code.
32class JITLinkerErrorCategory : public std::error_category {
33public:
34 const char *name() const noexcept override { return "runtimedyld"; }
35
36 std::string message(int Condition) const override {
37 switch (static_cast<JITLinkErrorCode>(Condition)) {
38 case GenericJITLinkError:
39 return "Generic JITLink error";
40 }
41 llvm_unreachable("Unrecognized JITLinkErrorCode")__builtin_unreachable();
42 }
43};
44
45static ManagedStatic<JITLinkerErrorCategory> JITLinkerErrorCategory;
46
47} // namespace
48
49namespace llvm {
50namespace jitlink {
51
52char JITLinkError::ID = 0;
53
54void JITLinkError::log(raw_ostream &OS) const { OS << ErrMsg; }
55
56std::error_code JITLinkError::convertToErrorCode() const {
57 return std::error_code(GenericJITLinkError, *JITLinkerErrorCategory);
58}
59
60const char *getGenericEdgeKindName(Edge::Kind K) {
61 switch (K) {
62 case Edge::Invalid:
63 return "INVALID RELOCATION";
64 case Edge::KeepAlive:
65 return "Keep-Alive";
66 default:
67 return "<Unrecognized edge kind>";
68 }
69}
70
71const char *getLinkageName(Linkage L) {
72 switch (L) {
73 case Linkage::Strong:
74 return "strong";
75 case Linkage::Weak:
76 return "weak";
77 }
78 llvm_unreachable("Unrecognized llvm.jitlink.Linkage enum")__builtin_unreachable();
79}
80
81const char *getScopeName(Scope S) {
82 switch (S) {
83 case Scope::Default:
84 return "default";
85 case Scope::Hidden:
86 return "hidden";
87 case Scope::Local:
88 return "local";
89 }
90 llvm_unreachable("Unrecognized llvm.jitlink.Scope enum")__builtin_unreachable();
91}
92
93raw_ostream &operator<<(raw_ostream &OS, const Block &B) {
94 return OS << formatv("{0:x16}", B.getAddress()) << " -- "
95 << formatv("{0:x8}", B.getAddress() + B.getSize()) << ": "
96 << "size = " << formatv("{0:x8}", B.getSize()) << ", "
97 << (B.isZeroFill() ? "zero-fill" : "content")
98 << ", align = " << B.getAlignment()
99 << ", align-ofs = " << B.getAlignmentOffset()
100 << ", section = " << B.getSection().getName();
101}
102
103raw_ostream &operator<<(raw_ostream &OS, const Symbol &Sym) {
104 OS << formatv("{0:x16}", Sym.getAddress()) << " ("
105 << (Sym.isDefined() ? "block" : "addressable") << " + "
106 << formatv("{0:x8}", Sym.getOffset())
107 << "): size: " << formatv("{0:x8}", Sym.getSize())
108 << ", linkage: " << formatv("{0:6}", getLinkageName(Sym.getLinkage()))
109 << ", scope: " << formatv("{0:8}", getScopeName(Sym.getScope())) << ", "
110 << (Sym.isLive() ? "live" : "dead") << " - "
111 << (Sym.hasName() ? Sym.getName() : "<anonymous symbol>");
112 return OS;
113}
114
115void printEdge(raw_ostream &OS, const Block &B, const Edge &E,
116 StringRef EdgeKindName) {
117 OS << "edge@" << formatv("{0:x16}", B.getAddress() + E.getOffset()) << ": "
118 << formatv("{0:x16}", B.getAddress()) << " + "
119 << formatv("{0:x}", E.getOffset()) << " -- " << EdgeKindName << " -> ";
120
121 auto &TargetSym = E.getTarget();
122 if (TargetSym.hasName())
123 OS << TargetSym.getName();
124 else {
125 auto &TargetBlock = TargetSym.getBlock();
126 auto &TargetSec = TargetBlock.getSection();
127 JITTargetAddress SecAddress = ~JITTargetAddress(0);
128 for (auto *B : TargetSec.blocks())
129 if (B->getAddress() < SecAddress)
130 SecAddress = B->getAddress();
131
132 JITTargetAddress SecDelta = TargetSym.getAddress() - SecAddress;
133 OS << formatv("{0:x16}", TargetSym.getAddress()) << " (section "
134 << TargetSec.getName();
135 if (SecDelta)
136 OS << " + " << formatv("{0:x}", SecDelta);
137 OS << " / block " << formatv("{0:x16}", TargetBlock.getAddress());
138 if (TargetSym.getOffset())
139 OS << " + " << formatv("{0:x}", TargetSym.getOffset());
140 OS << ")";
141 }
142
143 if (E.getAddend() != 0)
144 OS << " + " << E.getAddend();
145}
146
147Section::~Section() {
148 for (auto *Sym : Symbols)
149 Sym->~Symbol();
150 for (auto *B : Blocks)
151 B->~Block();
152}
153
154Block &LinkGraph::splitBlock(Block &B, size_t SplitIndex,
155 SplitBlockCache *Cache) {
156
157 assert(SplitIndex > 0 && "splitBlock can not be called with SplitIndex == 0")((void)0);
158
159 // If the split point covers all of B then just return B.
160 if (SplitIndex == B.getSize())
1
Assuming the condition is false
→
2
←
Taking false branch
→
161 return B;
162
163 assert(SplitIndex < B.getSize() && "SplitIndex out of range")((void)0);
164
165 // Create the new block covering [ 0, SplitIndex ).
166 auto &NewBlock =
167 B.isZeroFill()
3
←
'?' condition is true
→
168 ? createZeroFillBlock(B.getSection(), SplitIndex, B.getAddress(),
169 B.getAlignment(), B.getAlignmentOffset())
170 : createContentBlock(
171 B.getSection(), B.getContent().slice(0, SplitIndex),
172 B.getAddress(), B.getAlignment(), B.getAlignmentOffset());
173
174 // Modify B to cover [ SplitIndex, B.size() ).
175 B.setAddress(B.getAddress() + SplitIndex);
176 B.setContent(B.getContent().slice(SplitIndex));
177 B.setAlignmentOffset((B.getAlignmentOffset() + SplitIndex) %
7
←
Division by zero
178 B.getAlignment());
4
←
Calling 'Block::getAlignment'
→
6
←
Returning from 'Block::getAlignment'
→
179
180 // Handle edge transfer/update.
181 {
182 // Copy edges to NewBlock (recording their iterators so that we can remove
183 // them from B), and update of Edges remaining on B.
184 std::vector<Block::edge_iterator> EdgesToRemove;
185 for (auto I = B.edges().begin(); I != B.edges().end();) {
186 if (I->getOffset() < SplitIndex) {
187 NewBlock.addEdge(*I);
188 I = B.removeEdge(I);
189 } else {
190 I->setOffset(I->getOffset() - SplitIndex);
191 ++I;
192 }
193 }
194 }
195
196 // Handle symbol transfer/update.
197 {
198 // Initialize the symbols cache if necessary.
199 SplitBlockCache LocalBlockSymbolsCache;
200 if (!Cache)
201 Cache = &LocalBlockSymbolsCache;
202 if (*Cache == None) {
203 *Cache = SplitBlockCache::value_type();
204 for (auto *Sym : B.getSection().symbols())
205 if (&Sym->getBlock() == &B)
206 (*Cache)->push_back(Sym);
207
208 llvm::sort(**Cache, [](const Symbol *LHS, const Symbol *RHS) {
209 return LHS->getOffset() > RHS->getOffset();
210 });
211 }
212 auto &BlockSymbols = **Cache;
213
214 // Transfer all symbols with offset less than SplitIndex to NewBlock.
215 while (!BlockSymbols.empty() &&
216 BlockSymbols.back()->getOffset() < SplitIndex) {
217 BlockSymbols.back()->setBlock(NewBlock);
218 BlockSymbols.pop_back();
219 }
220
221 // Update offsets for all remaining symbols in B.
222 for (auto *Sym : BlockSymbols)
223 Sym->setOffset(Sym->getOffset() - SplitIndex);
224 }
225
226 return NewBlock;
227}
228
229void LinkGraph::dump(raw_ostream &OS) {
230 DenseMap<Block *, std::vector<Symbol *>> BlockSymbols;
231
232 // Map from blocks to the symbols pointing at them.
233 for (auto *Sym : defined_symbols())
234 BlockSymbols[&Sym->getBlock()].push_back(Sym);
235
236 // For each block, sort its symbols by something approximating
237 // relevance.
238 for (auto &KV : BlockSymbols)
239 llvm::sort(KV.second, [](const Symbol *LHS, const Symbol *RHS) {
240 if (LHS->getOffset() != RHS->getOffset())
241 return LHS->getOffset() < RHS->getOffset();
242 if (LHS->getLinkage() != RHS->getLinkage())
243 return LHS->getLinkage() < RHS->getLinkage();
244 if (LHS->getScope() != RHS->getScope())
245 return LHS->getScope() < RHS->getScope();
246 if (LHS->hasName()) {
247 if (!RHS->hasName())
248 return true;
249 return LHS->getName() < RHS->getName();
250 }
251 return false;
252 });
253
254 for (auto &Sec : sections()) {
255 OS << "section " << Sec.getName() << ":\n\n";
256
257 std::vector<Block *> SortedBlocks;
258 llvm::copy(Sec.blocks(), std::back_inserter(SortedBlocks));
259 llvm::sort(SortedBlocks, [](const Block *LHS, const Block *RHS) {
260 return LHS->getAddress() < RHS->getAddress();
261 });
262
263 for (auto *B : SortedBlocks) {
264 OS << " block " << formatv("{0:x16}", B->getAddress())
265 << " size = " << formatv("{0:x8}", B->getSize())
266 << ", align = " << B->getAlignment()
267 << ", alignment-offset = " << B->getAlignmentOffset();
268 if (B->isZeroFill())
269 OS << ", zero-fill";
270 OS << "\n";
271
272 auto BlockSymsI = BlockSymbols.find(B);
273 if (BlockSymsI != BlockSymbols.end()) {
274 OS << " symbols:\n";
275 auto &Syms = BlockSymsI->second;
276 for (auto *Sym : Syms)
277 OS << " " << *Sym << "\n";
278 } else
279 OS << " no symbols\n";
280
281 if (!B->edges_empty()) {
282 OS << " edges:\n";
283 std::vector<Edge> SortedEdges;
284 llvm::copy(B->edges(), std::back_inserter(SortedEdges));
285 llvm::sort(SortedEdges, [](const Edge &LHS, const Edge &RHS) {
286 return LHS.getOffset() < RHS.getOffset();
287 });
288 for (auto &E : SortedEdges) {
289 OS << " " << formatv("{0:x16}", B->getFixupAddress(E))
290 << " (block + " << formatv("{0:x8}", E.getOffset())
291 << "), addend = ";
292 if (E.getAddend() >= 0)
293 OS << formatv("+{0:x8}", E.getAddend());
294 else
295 OS << formatv("-{0:x8}", -E.getAddend());
296 OS << ", kind = " << getEdgeKindName(E.getKind()) << ", target = ";
297 if (E.getTarget().hasName())
298 OS << E.getTarget().getName();
299 else
300 OS << "addressable@"
301 << formatv("{0:x16}", E.getTarget().getAddress()) << "+"
302 << formatv("{0:x8}", E.getTarget().getOffset());
303 OS << "\n";
304 }
305 } else
306 OS << " no edges\n";
307 OS << "\n";
308 }
309 }
310
311 OS << "Absolute symbols:\n";
312 if (!llvm::empty(absolute_symbols())) {
313 for (auto *Sym : absolute_symbols())
314 OS << " " << format("0x%016" PRIx64"llx", Sym->getAddress()) << ": " << *Sym
315 << "\n";
316 } else
317 OS << " none\n";
318
319 OS << "\nExternal symbols:\n";
320 if (!llvm::empty(external_symbols())) {
321 for (auto *Sym : external_symbols())
322 OS << " " << format("0x%016" PRIx64"llx", Sym->getAddress()) << ": " << *Sym
323 << "\n";
324 } else
325 OS << " none\n";
326}
327
328raw_ostream &operator<<(raw_ostream &OS, const SymbolLookupFlags &LF) {
329 switch (LF) {
330 case SymbolLookupFlags::RequiredSymbol:
331 return OS << "RequiredSymbol";
332 case SymbolLookupFlags::WeaklyReferencedSymbol:
333 return OS << "WeaklyReferencedSymbol";
334 }
335 llvm_unreachable("Unrecognized lookup flags")__builtin_unreachable();
336}
337
338void JITLinkAsyncLookupContinuation::anchor() {}
339
340JITLinkContext::~JITLinkContext() {}
341
342bool JITLinkContext::shouldAddDefaultTargetPasses(const Triple &TT) const {
343 return true;
344}
345
346LinkGraphPassFunction JITLinkContext::getMarkLivePass(const Triple &TT) const {
347 return LinkGraphPassFunction();
348}
349
350Error JITLinkContext::modifyPassConfig(LinkGraph &G,
351 PassConfiguration &Config) {
352 return Error::success();
353}
354
355Error markAllSymbolsLive(LinkGraph &G) {
356 for (auto *Sym : G.defined_symbols())
357 Sym->setLive(true);
358 return Error::success();
359}
360
361Error makeTargetOutOfRangeError(const LinkGraph &G, const Block &B,
362 const Edge &E) {
363 std::string ErrMsg;
364 {
365 raw_string_ostream ErrStream(ErrMsg);
366 Section &Sec = B.getSection();
367 ErrStream << "In graph " << G.getName() << ", section " << Sec.getName()
368 << ": relocation target ";
369 if (E.getTarget().hasName())
370 ErrStream << "\"" << E.getTarget().getName() << "\" ";
371 ErrStream << "at address " << formatv("{0:x}", E.getTarget().getAddress());
372 ErrStream << " is out of range of " << G.getEdgeKindName(E.getKind())
373 << " fixup at " << formatv("{0:x}", B.getFixupAddress(E)) << " (";
374
375 Symbol *BestSymbolForBlock = nullptr;
376 for (auto *Sym : Sec.symbols())
377 if (&Sym->getBlock() == &B && Sym->hasName() && Sym->getOffset() == 0 &&
378 (!BestSymbolForBlock ||
379 Sym->getScope() < BestSymbolForBlock->getScope() ||
380 Sym->getLinkage() < BestSymbolForBlock->getLinkage()))
381 BestSymbolForBlock = Sym;
382
383 if (BestSymbolForBlock)
384 ErrStream << BestSymbolForBlock->getName() << ", ";
385 else
386 ErrStream << "<anonymous block> @ ";
387
388 ErrStream << formatv("{0:x}", B.getAddress()) << " + "
389 << formatv("{0:x}", E.getOffset()) << ")";
390 }
391 return make_error<JITLinkError>(std::move(ErrMsg));
392}
393
394Expected<std::unique_ptr<LinkGraph>>
395createLinkGraphFromObject(MemoryBufferRef ObjectBuffer) {
396 auto Magic = identify_magic(ObjectBuffer.getBuffer());
397 switch (Magic) {
398 case file_magic::macho_object:
399 return createLinkGraphFromMachOObject(ObjectBuffer);
400 case file_magic::elf_relocatable:
401 return createLinkGraphFromELFObject(ObjectBuffer);
402 default:
403 return make_error<JITLinkError>("Unsupported file format");
404 };
405}
406
407void link(std::unique_ptr<LinkGraph> G, std::unique_ptr<JITLinkContext> Ctx) {
408 switch (G->getTargetTriple().getObjectFormat()) {
409 case Triple::MachO:
410 return link_MachO(std::move(G), std::move(Ctx));
411 case Triple::ELF:
412 return link_ELF(std::move(G), std::move(Ctx));
413 default:
414 Ctx->notifyFailed(make_error<JITLinkError>("Unsupported object format"));
415 };
416}
417
418} // end namespace jitlink
419} // end namespace llvm
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink/JITLink.h

1//===------------ JITLink.h - JIT linker functionality ----------*- C++ -*-===//
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// Contains generic JIT-linker types.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_EXECUTIONENGINE_JITLINK_JITLINK_H
14#define LLVM_EXECUTIONENGINE_JITLINK_JITLINK_H
15
16#include "JITLinkMemoryManager.h"
17#include "llvm/ADT/DenseMap.h"
18#include "llvm/ADT/DenseSet.h"
19#include "llvm/ADT/Optional.h"
20#include "llvm/ADT/STLExtras.h"
21#include "llvm/ADT/Triple.h"
22#include "llvm/ExecutionEngine/JITSymbol.h"
23#include "llvm/Support/Allocator.h"
24#include "llvm/Support/Endian.h"
25#include "llvm/Support/Error.h"
26#include "llvm/Support/FormatVariadic.h"
27#include "llvm/Support/MathExtras.h"
28#include "llvm/Support/Memory.h"
29#include "llvm/Support/MemoryBuffer.h"
30
31#include <map>
32#include <string>
33#include <system_error>
34
35namespace llvm {
36namespace jitlink {
37
38class LinkGraph;
39class Symbol;
40class Section;
41
42/// Base class for errors originating in JIT linker, e.g. missing relocation
43/// support.
44class JITLinkError : public ErrorInfo<JITLinkError> {
45public:
46 static char ID;
47
48 JITLinkError(Twine ErrMsg) : ErrMsg(ErrMsg.str()) {}
49
50 void log(raw_ostream &OS) const override;
51 const std::string &getErrorMessage() const { return ErrMsg; }
52 std::error_code convertToErrorCode() const override;
53
54private:
55 std::string ErrMsg;
56};
57
58/// Represents fixups and constraints in the LinkGraph.
59class Edge {
60public:
61 using Kind = uint8_t;
62
63 enum GenericEdgeKind : Kind {
64 Invalid, // Invalid edge value.
65 FirstKeepAlive, // Keeps target alive. Offset/addend zero.
66 KeepAlive = FirstKeepAlive, // Tag first edge kind that preserves liveness.
67 FirstRelocation // First architecture specific relocation.
68 };
69
70 using OffsetT = uint32_t;
71 using AddendT = int64_t;
72
73 Edge(Kind K, OffsetT Offset, Symbol &Target, AddendT Addend)
74 : Target(&Target), Offset(Offset), Addend(Addend), K(K) {}
75
76 OffsetT getOffset() const { return Offset; }
77 void setOffset(OffsetT Offset) { this->Offset = Offset; }
78 Kind getKind() const { return K; }
79 void setKind(Kind K) { this->K = K; }
80 bool isRelocation() const { return K >= FirstRelocation; }
81 Kind getRelocation() const {
82 assert(isRelocation() && "Not a relocation edge")((void)0);
83 return K - FirstRelocation;
84 }
85 bool isKeepAlive() const { return K >= FirstKeepAlive; }
86 Symbol &getTarget() const { return *Target; }
87 void setTarget(Symbol &Target) { this->Target = &Target; }
88 AddendT getAddend() const { return Addend; }
89 void setAddend(AddendT Addend) { this->Addend = Addend; }
90
91private:
92 Symbol *Target = nullptr;
93 OffsetT Offset = 0;
94 AddendT Addend = 0;
95 Kind K = 0;
96};
97
98/// Returns the string name of the given generic edge kind, or "unknown"
99/// otherwise. Useful for debugging.
100const char *getGenericEdgeKindName(Edge::Kind K);
101
102/// Base class for Addressable entities (externals, absolutes, blocks).
103class Addressable {
104 friend class LinkGraph;
105
106protected:
107 Addressable(JITTargetAddress Address, bool IsDefined)
108 : Address(Address), IsDefined(IsDefined), IsAbsolute(false) {}
109
110 Addressable(JITTargetAddress Address)
111 : Address(Address), IsDefined(false), IsAbsolute(true) {
112 assert(!(IsDefined && IsAbsolute) &&((void)0)
113 "Block cannot be both defined and absolute")((void)0);
114 }
115
116public:
117 Addressable(const Addressable &) = delete;
118 Addressable &operator=(const Addressable &) = default;
119 Addressable(Addressable &&) = delete;
120 Addressable &operator=(Addressable &&) = default;
121
122 JITTargetAddress getAddress() const { return Address; }
123 void setAddress(JITTargetAddress Address) { this->Address = Address; }
124
125 /// Returns true if this is a defined addressable, in which case you
126 /// can downcast this to a Block.
127 bool isDefined() const { return static_cast<bool>(IsDefined); }
128 bool isAbsolute() const { return static_cast<bool>(IsAbsolute); }
129
130private:
131 void setAbsolute(bool IsAbsolute) {
132 assert(!IsDefined && "Cannot change the Absolute flag on a defined block")((void)0);
133 this->IsAbsolute = IsAbsolute;
134 }
135
136 JITTargetAddress Address = 0;
137 uint64_t IsDefined : 1;
138 uint64_t IsAbsolute : 1;
139
140protected:
141 // bitfields for Block, allocated here to improve packing.
142 uint64_t ContentMutable : 1;
143 uint64_t P2Align : 5;
144 uint64_t AlignmentOffset : 56;
145};
146
147using SectionOrdinal = unsigned;
148
149/// An Addressable with content and edges.
150class Block : public Addressable {
151 friend class LinkGraph;
152
153private:
154 /// Create a zero-fill defined addressable.
155 Block(Section &Parent, JITTargetAddress Size, JITTargetAddress Address,
156 uint64_t Alignment, uint64_t AlignmentOffset)
157 : Addressable(Address, true), Parent(&Parent), Size(Size) {
158 assert(isPowerOf2_64(Alignment) && "Alignment must be power of 2")((void)0);
159 assert(AlignmentOffset < Alignment &&((void)0)
160 "Alignment offset cannot exceed alignment")((void)0);
161 assert(AlignmentOffset <= MaxAlignmentOffset &&((void)0)
162 "Alignment offset exceeds maximum")((void)0);
163 ContentMutable = false;
164 P2Align = Alignment ? countTrailingZeros(Alignment) : 0;
165 this->AlignmentOffset = AlignmentOffset;
166 }
167
168 /// Create a defined addressable for the given content.
169 /// The Content is assumed to be non-writable, and will be copied when
170 /// mutations are required.
171 Block(Section &Parent, ArrayRef<char> Content, JITTargetAddress Address,
172 uint64_t Alignment, uint64_t AlignmentOffset)
173 : Addressable(Address, true), Parent(&Parent), Data(Content.data()),
174 Size(Content.size()) {
175 assert(isPowerOf2_64(Alignment) && "Alignment must be power of 2")((void)0);
176 assert(AlignmentOffset < Alignment &&((void)0)
177 "Alignment offset cannot exceed alignment")((void)0);
178 assert(AlignmentOffset <= MaxAlignmentOffset &&((void)0)
179 "Alignment offset exceeds maximum")((void)0);
180 ContentMutable = false;
181 P2Align = Alignment ? countTrailingZeros(Alignment) : 0;
182 this->AlignmentOffset = AlignmentOffset;
183 }
184
185 /// Create a defined addressable for the given content.
186 /// The content is assumed to be writable, and the caller is responsible
187 /// for ensuring that it lives for the duration of the Block's lifetime.
188 /// The standard way to achieve this is to allocate it on the Graph's
189 /// allocator.
190 Block(Section &Parent, MutableArrayRef<char> Content,
191 JITTargetAddress Address, uint64_t Alignment, uint64_t AlignmentOffset)
192 : Addressable(Address, true), Parent(&Parent), Data(Content.data()),
193 Size(Content.size()) {
194 assert(isPowerOf2_64(Alignment) && "Alignment must be power of 2")((void)0);
195 assert(AlignmentOffset < Alignment &&((void)0)
196 "Alignment offset cannot exceed alignment")((void)0);
197 assert(AlignmentOffset <= MaxAlignmentOffset &&((void)0)
198 "Alignment offset exceeds maximum")((void)0);
199 ContentMutable = true;
200 P2Align = Alignment ? countTrailingZeros(Alignment) : 0;
201 this->AlignmentOffset = AlignmentOffset;
202 }
203
204public:
205 using EdgeVector = std::vector<Edge>;
206 using edge_iterator = EdgeVector::iterator;
207 using const_edge_iterator = EdgeVector::const_iterator;
208
209 Block(const Block &) = delete;
210 Block &operator=(const Block &) = delete;
211 Block(Block &&) = delete;
212 Block &operator=(Block &&) = delete;
213
214 /// Return the parent section for this block.
215 Section &getSection() const { return *Parent; }
216
217 /// Returns true if this is a zero-fill block.
218 ///
219 /// If true, getSize is callable but getContent is not (the content is
220 /// defined to be a sequence of zero bytes of length Size).
221 bool isZeroFill() const { return !Data; }
222
223 /// Returns the size of this defined addressable.
224 size_t getSize() const { return Size; }
225
226 /// Get the content for this block. Block must not be a zero-fill block.
227 ArrayRef<char> getContent() const {
228 assert(Data && "Section does not contain content")((void)0);
229 return ArrayRef<char>(Data, Size);
230 }
231
232 /// Set the content for this block.
233 /// Caller is responsible for ensuring the underlying bytes are not
234 /// deallocated while pointed to by this block.
235 void setContent(ArrayRef<char> Content) {
236 Data = Content.data();
237 Size = Content.size();
238 ContentMutable = false;
239 }
240
241 /// Get mutable content for this block.
242 ///
243 /// If this Block's content is not already mutable this will trigger a copy
244 /// of the existing immutable content to a new, mutable buffer allocated using
245 /// LinkGraph::allocateContent.
246 MutableArrayRef<char> getMutableContent(LinkGraph &G);
247
248 /// Get mutable content for this block.
249 ///
250 /// This block's content must already be mutable. It is a programmatic error
251 /// to call this on a block with immutable content -- consider using
252 /// getMutableContent instead.
253 MutableArrayRef<char> getAlreadyMutableContent() {
254 assert(ContentMutable && "Content is not mutable")((void)0);
255 return MutableArrayRef<char>(const_cast<char *>(Data), Size);
256 }
257
258 /// Set mutable content for this block.
259 ///
260 /// The caller is responsible for ensuring that the memory pointed to by
261 /// MutableContent is not deallocated while pointed to by this block.
262 void setMutableContent(MutableArrayRef<char> MutableContent) {
263 Data = MutableContent.data();
264 Size = MutableContent.size();
265 ContentMutable = true;
266 }
267
268 /// Returns true if this block's content is mutable.
269 ///
270 /// This is primarily useful for asserting that a block is already in a
271 /// mutable state prior to modifying the content. E.g. when applying
272 /// fixups we expect the block to already be mutable as it should have been
273 /// copied to working memory.
274 bool isContentMutable() const { return ContentMutable; }
275
276 /// Get the alignment for this content.
277 uint64_t getAlignment() const { return 1ull << P2Align; }
5
←
Returning zero
→
278
279 /// Set the alignment for this content.
280 void setAlignment(uint64_t Alignment) {
281 assert(isPowerOf2_64(Alignment) && "Alignment must be a power of two")((void)0);
282 P2Align = Alignment ? countTrailingZeros(Alignment) : 0;
283 }
284
285 /// Get the alignment offset for this content.
286 uint64_t getAlignmentOffset() const { return AlignmentOffset; }
287
288 /// Set the alignment offset for this content.
289 void setAlignmentOffset(uint64_t AlignmentOffset) {
290 assert(AlignmentOffset < (1ull << P2Align) &&((void)0)
291 "Alignment offset can't exceed alignment")((void)0);
292 this->AlignmentOffset = AlignmentOffset;
293 }
294
295 /// Add an edge to this block.
296 void addEdge(Edge::Kind K, Edge::OffsetT Offset, Symbol &Target,
297 Edge::AddendT Addend) {
298 Edges.push_back(Edge(K, Offset, Target, Addend));
299 }
300
301 /// Add an edge by copying an existing one. This is typically used when
302 /// moving edges between blocks.
303 void addEdge(const Edge &E) { Edges.push_back(E); }
304
305 /// Return the list of edges attached to this content.
306 iterator_range<edge_iterator> edges() {
307 return make_range(Edges.begin(), Edges.end());
308 }
309
310 /// Returns the list of edges attached to this content.
311 iterator_range<const_edge_iterator> edges() const {
312 return make_range(Edges.begin(), Edges.end());
313 }
314
315 /// Return the size of the edges list.
316 size_t edges_size() const { return Edges.size(); }
317
318 /// Returns true if the list of edges is empty.
319 bool edges_empty() const { return Edges.empty(); }
320
321 /// Remove the edge pointed to by the given iterator.
322 /// Returns an iterator to the new next element.
323 edge_iterator removeEdge(edge_iterator I) { return Edges.erase(I); }
324
325 /// Returns the address of the fixup for the given edge, which is equal to
326 /// this block's address plus the edge's offset.
327 JITTargetAddress getFixupAddress(const Edge &E) const {
328 return getAddress() + E.getOffset();
329 }
330
331private:
332 static constexpr uint64_t MaxAlignmentOffset = (1ULL << 56) - 1;
333
334 void setSection(Section &Parent) { this->Parent = &Parent; }
335
336 Section *Parent;
337 const char *Data = nullptr;
338 size_t Size = 0;
339 std::vector<Edge> Edges;
340};
341
342/// Describes symbol linkage. This can be used to make resolve definition
343/// clashes.
344enum class Linkage : uint8_t {
345 Strong,
346 Weak,
347};
348
349/// For errors and debugging output.
350const char *getLinkageName(Linkage L);
351
352/// Defines the scope in which this symbol should be visible:
353/// Default -- Visible in the public interface of the linkage unit.
354/// Hidden -- Visible within the linkage unit, but not exported from it.
355/// Local -- Visible only within the LinkGraph.
356enum class Scope : uint8_t {
357 Default,
358 Hidden,
359 Local
360};
361
362/// For debugging output.
363const char *getScopeName(Scope S);
364
365raw_ostream &operator<<(raw_ostream &OS, const Block &B);
366
367/// Symbol representation.
368///
369/// Symbols represent locations within Addressable objects.
370/// They can be either Named or Anonymous.
371/// Anonymous symbols have neither linkage nor visibility, and must point at
372/// ContentBlocks.
373/// Named symbols may be in one of four states:
374/// - Null: Default initialized. Assignable, but otherwise unusable.
375/// - Defined: Has both linkage and visibility and points to a ContentBlock
376/// - Common: Has both linkage and visibility, points to a null Addressable.
377/// - External: Has neither linkage nor visibility, points to an external
378/// Addressable.
379///
380class Symbol {
381 friend class LinkGraph;
382
383private:
384 Symbol(Addressable &Base, JITTargetAddress Offset, StringRef Name,
385 JITTargetAddress Size, Linkage L, Scope S, bool IsLive,
386 bool IsCallable)
387 : Name(Name), Base(&Base), Offset(Offset), Size(Size) {
388 assert(Offset <= MaxOffset && "Offset out of range")((void)0);
389 setLinkage(L);
390 setScope(S);
391 setLive(IsLive);
392 setCallable(IsCallable);
393 }
394
395 static Symbol &constructCommon(void *SymStorage, Block &Base, StringRef Name,
396 JITTargetAddress Size, Scope S, bool IsLive) {
397 assert(SymStorage && "Storage cannot be null")((void)0);
398 assert(!Name.empty() && "Common symbol name cannot be empty")((void)0);
399 assert(Base.isDefined() &&((void)0)
400 "Cannot create common symbol from undefined block")((void)0);
401 assert(static_cast<Block &>(Base).getSize() == Size &&((void)0)
402 "Common symbol size should match underlying block size")((void)0);
403 auto *Sym = reinterpret_cast<Symbol *>(SymStorage);
404 new (Sym) Symbol(Base, 0, Name, Size, Linkage::Weak, S, IsLive, false);
405 return *Sym;
406 }
407
408 static Symbol &constructExternal(void *SymStorage, Addressable &Base,
409 StringRef Name, JITTargetAddress Size,
410 Linkage L) {
411 assert(SymStorage && "Storage cannot be null")((void)0);
412 assert(!Base.isDefined() &&((void)0)
413 "Cannot create external symbol from defined block")((void)0);
414 assert(!Name.empty() && "External symbol name cannot be empty")((void)0);
415 auto *Sym = reinterpret_cast<Symbol *>(SymStorage);
416 new (Sym) Symbol(Base, 0, Name, Size, L, Scope::Default, false, false);
417 return *Sym;
418 }
419
420 static Symbol &constructAbsolute(void *SymStorage, Addressable &Base,
421 StringRef Name, JITTargetAddress Size,
422 Linkage L, Scope S, bool IsLive) {
423 assert(SymStorage && "Storage cannot be null")((void)0);
424 assert(!Base.isDefined() &&((void)0)
425 "Cannot create absolute symbol from a defined block")((void)0);
426 auto *Sym = reinterpret_cast<Symbol *>(SymStorage);
427 new (Sym) Symbol(Base, 0, Name, Size, L, S, IsLive, false);
428 return *Sym;
429 }
430
431 static Symbol &constructAnonDef(void *SymStorage, Block &Base,
432 JITTargetAddress Offset,
433 JITTargetAddress Size, bool IsCallable,
434 bool IsLive) {
435 assert(SymStorage && "Storage cannot be null")((void)0);
436 assert((Offset + Size) <= Base.getSize() &&((void)0)
437 "Symbol extends past end of block")((void)0);
438 auto *Sym = reinterpret_cast<Symbol *>(SymStorage);
439 new (Sym) Symbol(Base, Offset, StringRef(), Size, Linkage::Strong,
440 Scope::Local, IsLive, IsCallable);
441 return *Sym;
442 }
443
444 static Symbol &constructNamedDef(void *SymStorage, Block &Base,
445 JITTargetAddress Offset, StringRef Name,
446 JITTargetAddress Size, Linkage L, Scope S,
447 bool IsLive, bool IsCallable) {
448 assert(SymStorage && "Storage cannot be null")((void)0);
449 assert((Offset + Size) <= Base.getSize() &&((void)0)
450 "Symbol extends past end of block")((void)0);
451 assert(!Name.empty() && "Name cannot be empty")((void)0);
452 auto *Sym = reinterpret_cast<Symbol *>(SymStorage);
453 new (Sym) Symbol(Base, Offset, Name, Size, L, S, IsLive, IsCallable);
454 return *Sym;
455 }
456
457public:
458 /// Create a null Symbol. This allows Symbols to be default initialized for
459 /// use in containers (e.g. as map values). Null symbols are only useful for
460 /// assigning to.
461 Symbol() = default;
462
463 // Symbols are not movable or copyable.
464 Symbol(const Symbol &) = delete;
465 Symbol &operator=(const Symbol &) = delete;
466 Symbol(Symbol &&) = delete;
467 Symbol &operator=(Symbol &&) = delete;
468
469 /// Returns true if this symbol has a name.
470 bool hasName() const { return !Name.empty(); }
471
472 /// Returns the name of this symbol (empty if the symbol is anonymous).
473 StringRef getName() const {
474 assert((!Name.empty() || getScope() == Scope::Local) &&((void)0)
475 "Anonymous symbol has non-local scope")((void)0);
476 return Name;
477 }
478
479 /// Rename this symbol. The client is responsible for updating scope and
480 /// linkage if this name-change requires it.
481 void setName(StringRef Name) { this->Name = Name; }
482
483 /// Returns true if this Symbol has content (potentially) defined within this
484 /// object file (i.e. is anything but an external or absolute symbol).
485 bool isDefined() const {
486 assert(Base && "Attempt to access null symbol")((void)0);
487 return Base->isDefined();
488 }
489
490 /// Returns true if this symbol is live (i.e. should be treated as a root for
491 /// dead stripping).
492 bool isLive() const {
493 assert(Base && "Attempting to access null symbol")((void)0);
494 return IsLive;
495 }
496
497 /// Set this symbol's live bit.
498 void setLive(bool IsLive) { this->IsLive = IsLive; }
499
500 /// Returns true is this symbol is callable.
501 bool isCallable() const { return IsCallable; }
502
503 /// Set this symbol's callable bit.
504 void setCallable(bool IsCallable) { this->IsCallable = IsCallable; }
505
506 /// Returns true if the underlying addressable is an unresolved external.
507 bool isExternal() const {
508 assert(Base && "Attempt to access null symbol")((void)0);
509 return !Base->isDefined() && !Base->isAbsolute();
510 }
511
512 /// Returns true if the underlying addressable is an absolute symbol.
513 bool isAbsolute() const {
514 assert(Base && "Attempt to access null symbol")((void)0);
515 return Base->isAbsolute();
516 }
517
518 /// Return the addressable that this symbol points to.
519 Addressable &getAddressable() {
520 assert(Base && "Cannot get underlying addressable for null symbol")((void)0);
521 return *Base;
522 }
523
524 /// Return the addressable that thsi symbol points to.
525 const Addressable &getAddressable() const {
526 assert(Base && "Cannot get underlying addressable for null symbol")((void)0);
527 return *Base;
528 }
529
530 /// Return the Block for this Symbol (Symbol must be defined).
531 Block &getBlock() {
532 assert(Base && "Cannot get block for null symbol")((void)0);
533 assert(Base->isDefined() && "Not a defined symbol")((void)0);
534 return static_cast<Block &>(*Base);
535 }
536
537 /// Return the Block for this Symbol (Symbol must be defined).
538 const Block &getBlock() const {
539 assert(Base && "Cannot get block for null symbol")((void)0);
540 assert(Base->isDefined() && "Not a defined symbol")((void)0);
541 return static_cast<const Block &>(*Base);
542 }
543
544 /// Returns the offset for this symbol within the underlying addressable.
545 JITTargetAddress getOffset() const { return Offset; }
546
547 /// Returns the address of this symbol.
548 JITTargetAddress getAddress() const { return Base->getAddress() + Offset; }
549
550 /// Returns the size of this symbol.
551 JITTargetAddress getSize() const { return Size; }
552
553 /// Set the size of this symbol.
554 void setSize(JITTargetAddress Size) {
555 assert(Base && "Cannot set size for null Symbol")((void)0);
556 assert((Size == 0 || Base->isDefined()) &&((void)0)
557 "Non-zero size can only be set for defined symbols")((void)0);
558 assert((Offset + Size <= static_cast<const Block &>(*Base).getSize()) &&((void)0)
559 "Symbol size cannot extend past the end of its containing block")((void)0);
560 this->Size = Size;
561 }
562
563 /// Returns true if this symbol is backed by a zero-fill block.
564 /// This method may only be called on defined symbols.
565 bool isSymbolZeroFill() const { return getBlock().isZeroFill(); }
566
567 /// Returns the content in the underlying block covered by this symbol.
568 /// This method may only be called on defined non-zero-fill symbols.
569 ArrayRef<char> getSymbolContent() const {
570 return getBlock().getContent().slice(Offset, Size);
571 }
572
573 /// Get the linkage for this Symbol.
574 Linkage getLinkage() const { return static_cast<Linkage>(L); }
575
576 /// Set the linkage for this Symbol.
577 void setLinkage(Linkage L) {
578 assert((L == Linkage::Strong || (!Base->isAbsolute() && !Name.empty())) &&((void)0)
579 "Linkage can only be applied to defined named symbols")((void)0);
580 this->L = static_cast<uint8_t>(L);
581 }
582
583 /// Get the visibility for this Symbol.
584 Scope getScope() const { return static_cast<Scope>(S); }
585
586 /// Set the visibility for this Symbol.
587 void setScope(Scope S) {
588 assert((!Name.empty() || S == Scope::Local) &&((void)0)
589 "Can not set anonymous symbol to non-local scope")((void)0);
590 assert((S == Scope::Default || Base->isDefined() || Base->isAbsolute()) &&((void)0)
591 "Invalid visibility for symbol type")((void)0);
592 this->S = static_cast<uint8_t>(S);
593 }
594
595private:
596 void makeExternal(Addressable &A) {
597 assert(!A.isDefined() && !A.isAbsolute() &&((void)0)
598 "Attempting to make external with defined or absolute block")((void)0);
599 Base = &A;
600 Offset = 0;
601 setScope(Scope::Default);
602 IsLive = 0;
603 // note: Size, Linkage and IsCallable fields left unchanged.
604 }
605
606 void makeAbsolute(Addressable &A) {
607 assert(!A.isDefined() && A.isAbsolute() &&((void)0)
608 "Attempting to make absolute with defined or external block")((void)0);
609 Base = &A;
610 Offset = 0;
611 }
612
613 void setBlock(Block &B) { Base = &B; }
614
615 void setOffset(uint64_t NewOffset) {
616 assert(NewOffset <= MaxOffset && "Offset out of range")((void)0);
617 Offset = NewOffset;
618 }
619
620 static constexpr uint64_t MaxOffset = (1ULL << 59) - 1;
621
622 // FIXME: A char* or SymbolStringPtr may pack better.
623 StringRef Name;
624 Addressable *Base = nullptr;
625 uint64_t Offset : 59;
626 uint64_t L : 1;
627 uint64_t S : 2;
628 uint64_t IsLive : 1;
629 uint64_t IsCallable : 1;
630 JITTargetAddress Size = 0;
631};
632
633raw_ostream &operator<<(raw_ostream &OS, const Symbol &A);
634
635void printEdge(raw_ostream &OS, const Block &B, const Edge &E,
636 StringRef EdgeKindName);
637
638/// Represents an object file section.
639class Section {
640 friend class LinkGraph;
641
642private:
643 Section(StringRef Name, sys::Memory::ProtectionFlags Prot,
644 SectionOrdinal SecOrdinal)
645 : Name(Name), Prot(Prot), SecOrdinal(SecOrdinal) {}
646
647 using SymbolSet = DenseSet<Symbol *>;
648 using BlockSet = DenseSet<Block *>;
649
650public:
651 using symbol_iterator = SymbolSet::iterator;
652 using const_symbol_iterator = SymbolSet::const_iterator;
653
654 using block_iterator = BlockSet::iterator;
655 using const_block_iterator = BlockSet::const_iterator;
656
657 ~Section();
658
659 // Sections are not movable or copyable.
660 Section(const Section &) = delete;
661 Section &operator=(const Section &) = delete;
662 Section(Section &&) = delete;
663 Section &operator=(Section &&) = delete;
664
665 /// Returns the name of this section.
666 StringRef getName() const { return Name; }
667
668 /// Returns the protection flags for this section.
669 sys::Memory::ProtectionFlags getProtectionFlags() const { return Prot; }
670
671 /// Set the protection flags for this section.
672 void setProtectionFlags(sys::Memory::ProtectionFlags Prot) {
673 this->Prot = Prot;
674 }
675
676 /// Returns the ordinal for this section.
677 SectionOrdinal getOrdinal() const { return SecOrdinal; }
678
679 /// Returns an iterator over the blocks defined in this section.
680 iterator_range<block_iterator> blocks() {
681 return make_range(Blocks.begin(), Blocks.end());
682 }
683
684 /// Returns an iterator over the blocks defined in this section.
685 iterator_range<const_block_iterator> blocks() const {
686 return make_range(Blocks.begin(), Blocks.end());
687 }
688
689 BlockSet::size_type blocks_size() const { return Blocks.size(); }
690
691 /// Returns an iterator over the symbols defined in this section.
692 iterator_range<symbol_iterator> symbols() {
693 return make_range(Symbols.begin(), Symbols.end());
694 }
695
696 /// Returns an iterator over the symbols defined in this section.
697 iterator_range<const_symbol_iterator> symbols() const {
698 return make_range(Symbols.begin(), Symbols.end());
699 }
700
701 /// Return the number of symbols in this section.
702 SymbolSet::size_type symbols_size() const { return Symbols.size(); }
703
704private:
705 void addSymbol(Symbol &Sym) {
706 assert(!Symbols.count(&Sym) && "Symbol is already in this section")((void)0);
707 Symbols.insert(&Sym);
708 }
709
710 void removeSymbol(Symbol &Sym) {
711 assert(Symbols.count(&Sym) && "symbol is not in this section")((void)0);
712 Symbols.erase(&Sym);
713 }
714
715 void addBlock(Block &B) {
716 assert(!Blocks.count(&B) && "Block is already in this section")((void)0);
717 Blocks.insert(&B);
718 }
719
720 void removeBlock(Block &B) {
721 assert(Blocks.count(&B) && "Block is not in this section")((void)0);
722 Blocks.erase(&B);
723 }
724
725 void transferContentTo(Section &DstSection) {
726 if (&DstSection == this)
727 return;
728 for (auto *S : Symbols)
729 DstSection.addSymbol(*S);
730 for (auto *B : Blocks)
731 DstSection.addBlock(*B);
732 Symbols.clear();
733 Blocks.clear();
734 }
735
736 StringRef Name;
737 sys::Memory::ProtectionFlags Prot;
738 SectionOrdinal SecOrdinal = 0;
739 BlockSet Blocks;
740 SymbolSet Symbols;
741};
742
743/// Represents a section address range via a pair of Block pointers
744/// to the first and last Blocks in the section.
745class SectionRange {
746public:
747 SectionRange() = default;
748 SectionRange(const Section &Sec) {
749 if (llvm::empty(Sec.blocks()))
750 return;
751 First = Last = *Sec.blocks().begin();
752 for (auto *B : Sec.blocks()) {
753 if (B->getAddress() < First->getAddress())
754 First = B;
755 if (B->getAddress() > Last->getAddress())
756 Last = B;
757 }
758 }
759 Block *getFirstBlock() const {
760 assert((!Last || First) && "First can not be null if end is non-null")((void)0);
761 return First;
762 }
763 Block *getLastBlock() const {
764 assert((First || !Last) && "Last can not be null if start is non-null")((void)0);
765 return Last;
766 }
767 bool empty() const {
768 assert((First || !Last) && "Last can not be null if start is non-null")((void)0);
769 return !First;
770 }
771 JITTargetAddress getStart() const {
772 return First ? First->getAddress() : 0;
773 }
774 JITTargetAddress getEnd() const {
775 return Last ? Last->getAddress() + Last->getSize() : 0;
776 }
777 uint64_t getSize() const { return getEnd() - getStart(); }
778
779private:
780 Block *First = nullptr;
781 Block *Last = nullptr;
782};
783
784class LinkGraph {
785private:
786 using SectionList = std::vector<std::unique_ptr<Section>>;
787 using ExternalSymbolSet = DenseSet<Symbol *>;
788 using BlockSet = DenseSet<Block *>;
789
790 template <typename... ArgTs>
791 Addressable &createAddressable(ArgTs &&... Args) {
792 Addressable *A =
793 reinterpret_cast<Addressable *>(Allocator.Allocate<Addressable>());
794 new (A) Addressable(std::forward<ArgTs>(Args)...);
795 return *A;
796 }
797
798 void destroyAddressable(Addressable &A) {
799 A.~Addressable();
800 Allocator.Deallocate(&A);
801 }
802
803 template <typename... ArgTs> Block &createBlock(ArgTs &&... Args) {
804 Block *B = reinterpret_cast<Block *>(Allocator.Allocate<Block>());
805 new (B) Block(std::forward<ArgTs>(Args)...);
806 B->getSection().addBlock(*B);
807 return *B;
808 }
809
810 void destroyBlock(Block &B) {
811 B.~Block();
812 Allocator.Deallocate(&B);
813 }
814
815 void destroySymbol(Symbol &S) {
816 S.~Symbol();
817 Allocator.Deallocate(&S);
818 }
819
820 static iterator_range<Section::block_iterator> getSectionBlocks(Section &S) {
821 return S.blocks();
822 }
823
824 static iterator_range<Section::const_block_iterator>
825 getSectionConstBlocks(Section &S) {
826 return S.blocks();
827 }
828
829 static iterator_range<Section::symbol_iterator>
830 getSectionSymbols(Section &S) {
831 return S.symbols();
832 }
833
834 static iterator_range<Section::const_symbol_iterator>
835 getSectionConstSymbols(Section &S) {
836 return S.symbols();
837 }
838
839public:
840 using external_symbol_iterator = ExternalSymbolSet::iterator;
841
842 using section_iterator = pointee_iterator<SectionList::iterator>;
843 using const_section_iterator = pointee_iterator<SectionList::const_iterator>;
844
845 template <typename OuterItrT, typename InnerItrT, typename T,
846 iterator_range<InnerItrT> getInnerRange(
847 typename OuterItrT::reference)>
848 class nested_collection_iterator
849 : public iterator_facade_base<
850 nested_collection_iterator<OuterItrT, InnerItrT, T, getInnerRange>,
851 std::forward_iterator_tag, T> {
852 public:
853 nested_collection_iterator() = default;
854
855 nested_collection_iterator(OuterItrT OuterI, OuterItrT OuterE)
856 : OuterI(OuterI), OuterE(OuterE),
857 InnerI(getInnerBegin(OuterI, OuterE)) {
858 moveToNonEmptyInnerOrEnd();
859 }
860
861 bool operator==(const nested_collection_iterator &RHS) const {
862 return (OuterI == RHS.OuterI) && (InnerI == RHS.InnerI);
863 }
864
865 T operator*() const {
866 assert(InnerI != getInnerRange(*OuterI).end() && "Dereferencing end?")((void)0);
867 return *InnerI;
868 }
869
870 nested_collection_iterator operator++() {
871 ++InnerI;
872 moveToNonEmptyInnerOrEnd();
873 return *this;
874 }
875
876 private:
877 static InnerItrT getInnerBegin(OuterItrT OuterI, OuterItrT OuterE) {
878 return OuterI != OuterE ? getInnerRange(*OuterI).begin() : InnerItrT();
879 }
880
881 void moveToNonEmptyInnerOrEnd() {
882 while (OuterI != OuterE && InnerI == getInnerRange(*OuterI).end()) {
883 ++OuterI;
884 InnerI = getInnerBegin(OuterI, OuterE);
885 }
886 }
887
888 OuterItrT OuterI, OuterE;
889 InnerItrT InnerI;
890 };
891
892 using defined_symbol_iterator =
893 nested_collection_iterator<const_section_iterator,
894 Section::symbol_iterator, Symbol *,
895 getSectionSymbols>;
896
897 using const_defined_symbol_iterator =
898 nested_collection_iterator<const_section_iterator,
899 Section::const_symbol_iterator, const Symbol *,
900 getSectionConstSymbols>;
901
902 using block_iterator = nested_collection_iterator<const_section_iterator,
903 Section::block_iterator,
904 Block *, getSectionBlocks>;
905
906 using const_block_iterator =
907 nested_collection_iterator<const_section_iterator,
908 Section::const_block_iterator, const Block *,
909 getSectionConstBlocks>;
910
911 using GetEdgeKindNameFunction = const char *(*)(Edge::Kind);
912
913 LinkGraph(std::string Name, const Triple &TT, unsigned PointerSize,
914 support::endianness Endianness,
915 GetEdgeKindNameFunction GetEdgeKindName)
916 : Name(std::move(Name)), TT(TT), PointerSize(PointerSize),
917 Endianness(Endianness), GetEdgeKindName(std::move(GetEdgeKindName)) {}
918
919 /// Returns the name of this graph (usually the name of the original
920 /// underlying MemoryBuffer).
921 const std::string &getName() const { return Name; }
922
923 /// Returns the target triple for this Graph.
924 const Triple &getTargetTriple() const { return TT; }
925
926 /// Returns the pointer size for use in this graph.
927 unsigned getPointerSize() const { return PointerSize; }
928
929 /// Returns the endianness of content in this graph.
930 support::endianness getEndianness() const { return Endianness; }
931
932 const char *getEdgeKindName(Edge::Kind K) const { return GetEdgeKindName(K); }
933
934 /// Allocate a mutable buffer of the given size using the LinkGraph's
935 /// allocator.
936 MutableArrayRef<char> allocateBuffer(size_t Size) {
937 return {Allocator.Allocate<char>(Size), Size};
938 }
939
940 /// Allocate a copy of the given string using the LinkGraph's allocator.
941 /// This can be useful when renaming symbols or adding new content to the
942 /// graph.
943 MutableArrayRef<char> allocateContent(ArrayRef<char> Source) {
944 auto *AllocatedBuffer = Allocator.Allocate<char>(Source.size());
945 llvm::copy(Source, AllocatedBuffer);
946 return MutableArrayRef<char>(AllocatedBuffer, Source.size());
947 }
948
949 /// Allocate a copy of the given string using the LinkGraph's allocator.
950 /// This can be useful when renaming symbols or adding new content to the
951 /// graph.
952 ///
953 /// Note: This Twine-based overload requires an extra string copy and an
954 /// extra heap allocation for large strings. The ArrayRef<char> overload
955 /// should be preferred where possible.
956 MutableArrayRef<char> allocateString(Twine Source) {
957 SmallString<256> TmpBuffer;
958 auto SourceStr = Source.toStringRef(TmpBuffer);
959 auto *AllocatedBuffer = Allocator.Allocate<char>(SourceStr.size());
960 llvm::copy(SourceStr, AllocatedBuffer);
961 return MutableArrayRef<char>(AllocatedBuffer, SourceStr.size());
962 }
963
964 /// Create a section with the given name, protection flags, and alignment.
965 Section &createSection(StringRef Name, sys::Memory::ProtectionFlags Prot) {
966 assert(llvm::find_if(Sections,((void)0)
967 [&](std::unique_ptr<Section> &Sec) {((void)0)
968 return Sec->getName() == Name;((void)0)
969 }) == Sections.end() &&((void)0)
970 "Duplicate section name")((void)0);
971 std::unique_ptr<Section> Sec(new Section(Name, Prot, Sections.size()));
972 Sections.push_back(std::move(Sec));
973 return *Sections.back();
974 }
975
976 /// Create a content block.
977 Block &createContentBlock(Section &Parent, ArrayRef<char> Content,
978 uint64_t Address, uint64_t Alignment,
979 uint64_t AlignmentOffset) {
980 return createBlock(Parent, Content, Address, Alignment, AlignmentOffset);
981 }
982
983 /// Create a content block with initially mutable data.
984 Block &createMutableContentBlock(Section &Parent,
985 MutableArrayRef<char> MutableContent,
986 uint64_t Address, uint64_t Alignment,
987 uint64_t AlignmentOffset) {
988 return createBlock(Parent, MutableContent, Address, Alignment,
989 AlignmentOffset);
990 }
991
992 /// Create a zero-fill block.
993 Block &createZeroFillBlock(Section &Parent, uint64_t Size, uint64_t Address,
994 uint64_t Alignment, uint64_t AlignmentOffset) {
995 return createBlock(Parent, Size, Address, Alignment, AlignmentOffset);
996 }
997
998 /// Cache type for the splitBlock function.
999 using SplitBlockCache = Optional<SmallVector<Symbol *, 8>>;
1000
1001 /// Splits block B at the given index which must be greater than zero.
1002 /// If SplitIndex == B.getSize() then this function is a no-op and returns B.
1003 /// If SplitIndex < B.getSize() then this function returns a new block
1004 /// covering the range [ 0, SplitIndex ), and B is modified to cover the range
1005 /// [ SplitIndex, B.size() ).
1006 ///
1007 /// The optional Cache parameter can be used to speed up repeated calls to
1008 /// splitBlock for a single block. If the value is None the cache will be
1009 /// treated as uninitialized and splitBlock will populate it. Otherwise it
1010 /// is assumed to contain the list of Symbols pointing at B, sorted in
1011 /// descending order of offset.
1012 ///
1013 /// Notes:
1014 ///
1015 /// 1. splitBlock must be used with care. Splitting a block may cause
1016 /// incoming edges to become invalid if the edge target subexpression
1017 /// points outside the bounds of the newly split target block (E.g. an
1018 /// edge 'S + 10 : Pointer64' where S points to a newly split block
1019 /// whose size is less than 10). No attempt is made to detect invalidation
1020 /// of incoming edges, as in general this requires context that the
1021 /// LinkGraph does not have. Clients are responsible for ensuring that
1022 /// splitBlock is not used in a way that invalidates edges.
1023 ///
1024 /// 2. The newly introduced block will have a new ordinal which will be
1025 /// higher than any other ordinals in the section. Clients are responsible
1026 /// for re-assigning block ordinals to restore a compatible order if
1027 /// needed.
1028 ///
1029 /// 3. The cache is not automatically updated if new symbols are introduced
1030 /// between calls to splitBlock. Any newly introduced symbols may be
1031 /// added to the cache manually (descending offset order must be
1032 /// preserved), or the cache can be set to None and rebuilt by
1033 /// splitBlock on the next call.
1034 Block &splitBlock(Block &B, size_t SplitIndex,
1035 SplitBlockCache *Cache = nullptr);
1036
1037 /// Add an external symbol.
1038 /// Some formats (e.g. ELF) allow Symbols to have sizes. For Symbols whose
1039 /// size is not known, you should substitute '0'.
1040 /// For external symbols Linkage determines whether the symbol must be
1041 /// present during lookup: Externals with strong linkage must be found or
1042 /// an error will be emitted. Externals with weak linkage are permitted to
1043 /// be undefined, in which case they are assigned a value of 0.
1044 Symbol &addExternalSymbol(StringRef Name, uint64_t Size, Linkage L) {
1045 assert(llvm::count_if(ExternalSymbols,((void)0)
1046 [&](const Symbol *Sym) {((void)0)
1047 return Sym->getName() == Name;((void)0)
1048 }) == 0 &&((void)0)
1049 "Duplicate external symbol")((void)0);
1050 auto &Sym =
1051 Symbol::constructExternal(Allocator.Allocate<Symbol>(),
1052 createAddressable(0, false), Name, Size, L);
1053 ExternalSymbols.insert(&Sym);
1054 return Sym;
1055 }
1056
1057 /// Add an absolute symbol.
1058 Symbol &addAbsoluteSymbol(StringRef Name, JITTargetAddress Address,
1059 uint64_t Size, Linkage L, Scope S, bool IsLive) {
1060 assert(llvm::count_if(AbsoluteSymbols,((void)0)
1061 [&](const Symbol *Sym) {((void)0)
1062 return Sym->getName() == Name;((void)0)
1063 }) == 0 &&((void)0)
1064 "Duplicate absolute symbol")((void)0);
1065 auto &Sym = Symbol::constructAbsolute(Allocator.Allocate<Symbol>(),
1066 createAddressable(Address), Name,
1067 Size, L, S, IsLive);
1068 AbsoluteSymbols.insert(&Sym);
1069 return Sym;
1070 }
1071
1072 /// Convenience method for adding a weak zero-fill symbol.
1073 Symbol &addCommonSymbol(StringRef Name, Scope S, Section &Section,
1074 JITTargetAddress Address, uint64_t Size,
1075 uint64_t Alignment, bool IsLive) {
1076 assert(llvm::count_if(defined_symbols(),((void)0)
1077 [&](const Symbol *Sym) {((void)0)
1078 return Sym->getName() == Name;((void)0)
1079 }) == 0 &&((void)0)
1080 "Duplicate defined symbol")((void)0);
1081 auto &Sym = Symbol::constructCommon(
1082 Allocator.Allocate<Symbol>(),
1083 createBlock(Section, Size, Address, Alignment, 0), Name, Size, S,
1084 IsLive);
1085 Section.addSymbol(Sym);
1086 return Sym;
1087 }
1088
1089 /// Add an anonymous symbol.
1090 Symbol &addAnonymousSymbol(Block &Content, JITTargetAddress Offset,
1091 JITTargetAddress Size, bool IsCallable,
1092 bool IsLive) {
1093 auto &Sym = Symbol::constructAnonDef(Allocator.Allocate<Symbol>(), Content,
1094 Offset, Size, IsCallable, IsLive);
1095 Content.getSection().addSymbol(Sym);
1096 return Sym;
1097 }
1098
1099 /// Add a named symbol.
1100 Symbol &addDefinedSymbol(Block &Content, JITTargetAddress Offset,
1101 StringRef Name, JITTargetAddress Size, Linkage L,
1102 Scope S, bool IsCallable, bool IsLive) {
1103 assert(llvm::count_if(defined_symbols(),((void)0)
1104 [&](const Symbol *Sym) {((void)0)
1105 return Sym->getName() == Name;((void)0)
1106 }) == 0 &&((void)0)
1107 "Duplicate defined symbol")((void)0);
1108 auto &Sym =
1109 Symbol::constructNamedDef(Allocator.Allocate<Symbol>(), Content, Offset,
1110 Name, Size, L, S, IsLive, IsCallable);
1111 Content.getSection().addSymbol(Sym);
1112 return Sym;
1113 }
1114
1115 iterator_range<section_iterator> sections() {
1116 return make_range(section_iterator(Sections.begin()),
1117 section_iterator(Sections.end()));
1118 }
1119
1120 SectionList::size_type sections_size() const { return Sections.size(); }
1121
1122 /// Returns the section with the given name if it exists, otherwise returns
1123 /// null.
1124 Section *findSectionByName(StringRef Name) {
1125 for (auto &S : sections())
1126 if (S.getName() == Name)
1127 return &S;
1128 return nullptr;
1129 }
1130
1131 iterator_range<block_iterator> blocks() {
1132 return make_range(block_iterator(Sections.begin(), Sections.end()),
1133 block_iterator(Sections.end(), Sections.end()));
1134 }
1135
1136 iterator_range<const_block_iterator> blocks() const {
1137 return make_range(const_block_iterator(Sections.begin(), Sections.end()),
1138 const_block_iterator(Sections.end(), Sections.end()));
1139 }
1140
1141 iterator_range<external_symbol_iterator> external_symbols() {
1142 return make_range(ExternalSymbols.begin(), ExternalSymbols.end());
1143 }
1144
1145 iterator_range<external_symbol_iterator> absolute_symbols() {
1146 return make_range(AbsoluteSymbols.begin(), AbsoluteSymbols.end());
1147 }
1148
1149 iterator_range<defined_symbol_iterator> defined_symbols() {
1150 return make_range(defined_symbol_iterator(Sections.begin(), Sections.end()),
1151 defined_symbol_iterator(Sections.end(), Sections.end()));
1152 }
1153
1154 iterator_range<const_defined_symbol_iterator> defined_symbols() const {
1155 return make_range(
1156 const_defined_symbol_iterator(Sections.begin(), Sections.end()),
1157 const_defined_symbol_iterator(Sections.end(), Sections.end()));
1158 }
1159
1160 /// Make the given symbol external (must not already be external).
1161 ///
1162 /// Symbol size, linkage and callability will be left unchanged. Symbol scope
1163 /// will be set to Default, and offset will be reset to 0.
1164 void makeExternal(Symbol &Sym) {
1165 assert(!Sym.isExternal() && "Symbol is already external")((void)0);
1166 if (Sym.isAbsolute()) {
1167 assert(AbsoluteSymbols.count(&Sym) &&((void)0)
1168 "Sym is not in the absolute symbols set")((void)0);
1169 assert(Sym.getOffset() == 0 && "Absolute not at offset 0")((void)0);
1170 AbsoluteSymbols.erase(&Sym);
1171 Sym.getAddressable().setAbsolute(false);
1172 } else {
1173 assert(Sym.isDefined() && "Sym is not a defined symbol")((void)0);
1174 Section &Sec = Sym.getBlock().getSection();
1175 Sec.removeSymbol(Sym);
1176 Sym.makeExternal(createAddressable(0, false));
1177 }
1178 ExternalSymbols.insert(&Sym);
1179 }
1180
1181 /// Make the given symbol an absolute with the given address (must not already
1182 /// be absolute).
1183 ///
1184 /// Symbol size, linkage, scope, and callability, and liveness will be left
1185 /// unchanged. Symbol offset will be reset to 0.
1186 void makeAbsolute(Symbol &Sym, JITTargetAddress Address) {
1187 assert(!Sym.isAbsolute() && "Symbol is already absolute")((void)0);
1188 if (Sym.isExternal()) {
1189 assert(ExternalSymbols.count(&Sym) &&((void)0)
1190 "Sym is not in the absolute symbols set")((void)0);
1191 assert(Sym.getOffset() == 0 && "External is not at offset 0")((void)0);
1192 ExternalSymbols.erase(&Sym);
1193 Sym.getAddressable().setAbsolute(true);
1194 } else {
1195 assert(Sym.isDefined() && "Sym is not a defined symbol")((void)0);
1196 Section &Sec = Sym.getBlock().getSection();
1197 Sec.removeSymbol(Sym);
1198 Sym.makeAbsolute(createAddressable(Address));
1199 }
1200 AbsoluteSymbols.insert(&Sym);
1201 }
1202
1203 /// Turn an absolute or external symbol into a defined one by attaching it to
1204 /// a block. Symbol must not already be defined.
1205 void makeDefined(Symbol &Sym, Block &Content, JITTargetAddress Offset,
1206 JITTargetAddress Size, Linkage L, Scope S, bool IsLive) {
1207 assert(!Sym.isDefined() && "Sym is already a defined symbol")((void)0);
1208 if (Sym.isAbsolute()) {
1209 assert(AbsoluteSymbols.count(&Sym) &&((void)0)
1210 "Symbol is not in the absolutes set")((void)0);
1211 AbsoluteSymbols.erase(&Sym);
1212 } else {
1213 assert(ExternalSymbols.count(&Sym) &&((void)0)
1214 "Symbol is not in the externals set")((void)0);
1215 ExternalSymbols.erase(&Sym);
1216 }
1217 Addressable &OldBase = *Sym.Base;
1218 Sym.setBlock(Content);
1219 Sym.setOffset(Offset);
1220 Sym.setSize(Size);
1221 Sym.setLinkage(L);
1222 Sym.setScope(S);
1223 Sym.setLive(IsLive);
1224 Content.getSection().addSymbol(Sym);
1225 destroyAddressable(OldBase);
1226 }
1227
1228 /// Transfer a defined symbol from one block to another.
1229 ///
1230 /// The symbol's offset within DestBlock is set to NewOffset.
1231 ///
1232 /// If ExplicitNewSize is given as None then the size of the symbol will be
1233 /// checked and auto-truncated to at most the size of the remainder (from the
1234 /// given offset) of the size of the new block.
1235 ///
1236 /// All other symbol attributes are unchanged.
1237 void transferDefinedSymbol(Symbol &Sym, Block &DestBlock,
1238 JITTargetAddress NewOffset,
1239 Optional<JITTargetAddress> ExplicitNewSize) {
1240 Sym.setBlock(DestBlock);
1241 Sym.setOffset(NewOffset);
1242 if (ExplicitNewSize)
1243 Sym.setSize(*ExplicitNewSize);
1244 else {
1245 JITTargetAddress RemainingBlockSize = DestBlock.getSize() - NewOffset;
1246 if (Sym.getSize() > RemainingBlockSize)
1247 Sym.setSize(RemainingBlockSize);
1248 }
1249 }
1250
1251 /// Transfers the given Block and all Symbols pointing to it to the given
1252 /// Section.
1253 ///
1254 /// No attempt is made to check compatibility of the source and destination
1255 /// sections. Blocks may be moved between sections with incompatible
1256 /// permissions (e.g. from data to text). The client is responsible for
1257 /// ensuring that this is safe.
1258 void transferBlock(Block &B, Section &NewSection) {
1259 auto &OldSection = B.getSection();
1260 if (&OldSection == &NewSection)
1261 return;
1262 SmallVector<Symbol *> AttachedSymbols;
1263 for (auto *S : OldSection.symbols())
1264 if (&S->getBlock() == &B)
1265 AttachedSymbols.push_back(S);
1266 for (auto *S : AttachedSymbols) {
1267 OldSection.removeSymbol(*S);
1268 NewSection.addSymbol(*S);
1269 }
1270 OldSection.removeBlock(B);
1271 NewSection.addBlock(B);
1272 }
1273
1274 /// Move all blocks and symbols from the source section to the destination
1275 /// section.
1276 ///
1277 /// If PreserveSrcSection is true (or SrcSection and DstSection are the same)
1278 /// then SrcSection is preserved, otherwise it is removed (the default).
1279 void mergeSections(Section &DstSection, Section &SrcSection,
1280 bool PreserveSrcSection = false) {
1281 if (&DstSection == &SrcSection)
1282 return;
1283 SrcSection.transferContentTo(DstSection);
1284 if (!PreserveSrcSection)
1285 removeSection(SrcSection);
1286 }
1287
1288 /// Removes an external symbol. Also removes the underlying Addressable.
1289 void removeExternalSymbol(Symbol &Sym) {
1290 assert(!Sym.isDefined() && !Sym.isAbsolute() &&((void)0)
1291 "Sym is not an external symbol")((void)0);
1292 assert(ExternalSymbols.count(&Sym) && "Symbol is not in the externals set")((void)0);
1293 ExternalSymbols.erase(&Sym);
1294 Addressable &Base = *Sym.Base;
1295 assert(llvm::find_if(ExternalSymbols,((void)0)
1296 [&](Symbol *AS) { return AS->Base == &Base; }) ==((void)0)
1297 ExternalSymbols.end() &&((void)0)
1298 "Base addressable still in use")((void)0);
1299 destroySymbol(Sym);
1300 destroyAddressable(Base);
1301 }
1302
1303 /// Remove an absolute symbol. Also removes the underlying Addressable.
1304 void removeAbsoluteSymbol(Symbol &Sym) {
1305 assert(!Sym.isDefined() && Sym.isAbsolute() &&((void)0)
1306 "Sym is not an absolute symbol")((void)0);
1307 assert(AbsoluteSymbols.count(&Sym) &&((void)0)
1308 "Symbol is not in the absolute symbols set")((void)0);
1309 AbsoluteSymbols.erase(&Sym);
1310 Addressable &Base = *Sym.Base;
1311 assert(llvm::find_if(ExternalSymbols,((void)0)
1312 [&](Symbol *AS) { return AS->Base == &Base; }) ==((void)0)
1313 ExternalSymbols.end() &&((void)0)
1314 "Base addressable still in use")((void)0);
1315 destroySymbol(Sym);
1316 destroyAddressable(Base);
1317 }
1318
1319 /// Removes defined symbols. Does not remove the underlying block.
1320 void removeDefinedSymbol(Symbol &Sym) {
1321 assert(Sym.isDefined() && "Sym is not a defined symbol")((void)0);
1322 Sym.getBlock().getSection().removeSymbol(Sym);
1323 destroySymbol(Sym);
1324 }
1325
1326 /// Remove a block. The block reference is defunct after calling this
1327 /// function and should no longer be used.
1328 void removeBlock(Block &B) {
1329 assert(llvm::none_of(B.getSection().symbols(),((void)0)
1330 [&](const Symbol *Sym) {((void)0)
1331 return &Sym->getBlock() == &B;((void)0)
1332 }) &&((void)0)
1333 "Block still has symbols attached")((void)0);
1334 B.getSection().removeBlock(B);
1335 destroyBlock(B);
1336 }
1337
1338 /// Remove a section. The section reference is defunct after calling this
1339 /// function and should no longer be used.
1340 void removeSection(Section &Sec) {
1341 auto I = llvm::find_if(Sections, [&Sec](const std::unique_ptr<Section> &S) {
1342 return S.get() == &Sec;
1343 });
1344 assert(I != Sections.end() && "Section does not appear in this graph")((void)0);
1345 Sections.erase(I);
1346 }
1347
1348 /// Dump the graph.
1349 void dump(raw_ostream &OS);
1350
1351private:
1352 // Put the BumpPtrAllocator first so that we don't free any of the underlying
1353 // memory until the Symbol/Addressable destructors have been run.
1354 BumpPtrAllocator Allocator;
1355
1356 std::string Name;
1357 Triple TT;
1358 unsigned PointerSize;
1359 support::endianness Endianness;
1360 GetEdgeKindNameFunction GetEdgeKindName = nullptr;
1361 SectionList Sections;
1362 ExternalSymbolSet ExternalSymbols;
1363 ExternalSymbolSet AbsoluteSymbols;
1364};
1365
1366inline MutableArrayRef<char> Block::getMutableContent(LinkGraph &G) {
1367 if (!ContentMutable)
1368 setMutableContent(G.allocateContent({Data, Size}));
1369 return MutableArrayRef<char>(const_cast<char *>(Data), Size);
1370}
1371
1372/// Enables easy lookup of blocks by addresses.
1373class BlockAddressMap {
1374public:
1375 using AddrToBlockMap = std::map<JITTargetAddress, Block *>;
1376 using const_iterator = AddrToBlockMap::const_iterator;
1377
1378 /// A block predicate that always adds all blocks.
1379 static bool includeAllBlocks(const Block &B) { return true; }
1380
1381 /// A block predicate that always includes blocks with non-null addresses.
1382 static bool includeNonNull(const Block &B) { return B.getAddress(); }
1383
1384 BlockAddressMap() = default;
1385
1386 /// Add a block to the map. Returns an error if the block overlaps with any
1387 /// existing block.
1388 template <typename PredFn = decltype(includeAllBlocks)>
1389 Error addBlock(Block &B, PredFn Pred = includeAllBlocks) {
1390 if (!Pred(B))
1391 return Error::success();
1392
1393 auto I = AddrToBlock.upper_bound(B.getAddress());
1394
1395 // If we're not at the end of the map, check for overlap with the next
1396 // element.
1397 if (I != AddrToBlock.end()) {
1398 if (B.getAddress() + B.getSize() > I->second->getAddress())
1399 return overlapError(B, *I->second);
1400 }
1401
1402 // If we're not at the start of the map, check for overlap with the previous
1403 // element.
1404 if (I != AddrToBlock.begin()) {
1405 auto &PrevBlock = *std::prev(I)->second;
1406 if (PrevBlock.getAddress() + PrevBlock.getSize() > B.getAddress())
1407 return overlapError(B, PrevBlock);
1408 }
1409
1410 AddrToBlock.insert(I, std::make_pair(B.getAddress(), &B));
1411 return Error::success();
1412 }
1413
1414 /// Add a block to the map without checking for overlap with existing blocks.
1415 /// The client is responsible for ensuring that the block added does not
1416 /// overlap with any existing block.
1417 void addBlockWithoutChecking(Block &B) { AddrToBlock[B.getAddress()] = &B; }
1418
1419 /// Add a range of blocks to the map. Returns an error if any block in the
1420 /// range overlaps with any other block in the range, or with any existing
1421 /// block in the map.
1422 template <typename BlockPtrRange,
1423 typename PredFn = decltype(includeAllBlocks)>
1424 Error addBlocks(BlockPtrRange &&Blocks, PredFn Pred = includeAllBlocks) {
1425 for (auto *B : Blocks)
1426 if (auto Err = addBlock(*B, Pred))
1427 return Err;
1428 return Error::success();
1429 }
1430
1431 /// Add a range of blocks to the map without checking for overlap with
1432 /// existing blocks. The client is responsible for ensuring that the block
1433 /// added does not overlap with any existing block.
1434 template <typename BlockPtrRange>
1435 void addBlocksWithoutChecking(BlockPtrRange &&Blocks) {
1436 for (auto *B : Blocks)
1437 addBlockWithoutChecking(*B);
1438 }
1439
1440 /// Iterates over (Address, Block*) pairs in ascending order of address.
1441 const_iterator begin() const { return AddrToBlock.begin(); }
1442 const_iterator end() const { return AddrToBlock.end(); }
1443
1444 /// Returns the block starting at the given address, or nullptr if no such
1445 /// block exists.
1446 Block *getBlockAt(JITTargetAddress Addr) const {
1447 auto I = AddrToBlock.find(Addr);
1448 if (I == AddrToBlock.end())
1449 return nullptr;
1450 return I->second;
1451 }
1452
1453 /// Returns the block covering the given address, or nullptr if no such block
1454 /// exists.
1455 Block *getBlockCovering(JITTargetAddress Addr) const {
1456 auto I = AddrToBlock.upper_bound(Addr);
1457 if (I == AddrToBlock.begin())
1458 return nullptr;
1459 auto *B = std::prev(I)->second;
1460 if (Addr < B->getAddress() + B->getSize())
1461 return B;
1462 return nullptr;
1463 }
1464
1465private:
1466 Error overlapError(Block &NewBlock, Block &ExistingBlock) {
1467 auto NewBlockEnd = NewBlock.getAddress() + NewBlock.getSize();
1468 auto ExistingBlockEnd =
1469 ExistingBlock.getAddress() + ExistingBlock.getSize();
1470 return make_error<JITLinkError>(
1471 "Block at " +
1472 formatv("{0:x16} -- {1:x16}", NewBlock.getAddress(), NewBlockEnd) +
1473 " overlaps " +
1474 formatv("{0:x16} -- {1:x16}", ExistingBlock.getAddress(),
1475 ExistingBlockEnd));
1476 }
1477
1478 AddrToBlockMap AddrToBlock;
1479};
1480
1481/// A map of addresses to Symbols.
1482class SymbolAddressMap {
1483public:
1484 using SymbolVector = SmallVector<Symbol *, 1>;
1485
1486 /// Add a symbol to the SymbolAddressMap.
1487 void addSymbol(Symbol &Sym) {
1488 AddrToSymbols[Sym.getAddress()].push_back(&Sym);
1489 }
1490
1491 /// Add all symbols in a given range to the SymbolAddressMap.
1492 template <typename SymbolPtrCollection>
1493 void addSymbols(SymbolPtrCollection &&Symbols) {
1494 for (auto *Sym : Symbols)
1495 addSymbol(*Sym);
1496 }
1497
1498 /// Returns the list of symbols that start at the given address, or nullptr if
1499 /// no such symbols exist.
1500 const SymbolVector *getSymbolsAt(JITTargetAddress Addr) const {
1501 auto I = AddrToSymbols.find(Addr);
1502 if (I == AddrToSymbols.end())
1503 return nullptr;
1504 return &I->second;
1505 }
1506
1507private:
1508 std::map<JITTargetAddress, SymbolVector> AddrToSymbols;
1509};
1510
1511/// A function for mutating LinkGraphs.
1512using LinkGraphPassFunction = std::function<Error(LinkGraph &)>;
1513
1514/// A list of LinkGraph passes.
1515using LinkGraphPassList = std::vector<LinkGraphPassFunction>;
1516
1517/// An LinkGraph pass configuration, consisting of a list of pre-prune,
1518/// post-prune, and post-fixup passes.
1519struct PassConfiguration {
1520
1521 /// Pre-prune passes.
1522 ///
1523 /// These passes are called on the graph after it is built, and before any
1524 /// symbols have been pruned. Graph nodes still have their original vmaddrs.
1525 ///
1526 /// Notable use cases: Marking symbols live or should-discard.
1527 LinkGraphPassList PrePrunePasses;
1528
1529 /// Post-prune passes.
1530 ///
1531 /// These passes are called on the graph after dead stripping, but before
1532 /// memory is allocated or nodes assigned their final addresses.
1533 ///
1534 /// Notable use cases: Building GOT, stub, and TLV symbols.
1535 LinkGraphPassList PostPrunePasses;
1536
1537 /// Post-allocation passes.
1538 ///
1539 /// These passes are called on the graph after memory has been allocated and
1540 /// defined nodes have been assigned their final addresses, but before the
1541 /// context has been notified of these addresses. At this point externals
1542 /// have not been resolved, and symbol content has not yet been copied into
1543 /// working memory.
1544 ///
1545 /// Notable use cases: Setting up data structures associated with addresses
1546 /// of defined symbols (e.g. a mapping of __dso_handle to JITDylib* for the
1547 /// JIT runtime) -- using a PostAllocationPass for this ensures that the
1548 /// data structures are in-place before any query for resolved symbols
1549 /// can complete.
1550 LinkGraphPassList PostAllocationPasses;
1551
1552 /// Pre-fixup passes.
1553 ///
1554 /// These passes are called on the graph after memory has been allocated,
1555 /// content copied into working memory, and all nodes (including externals)
1556 /// have been assigned their final addresses, but before any fixups have been
1557 /// applied.
1558 ///
1559 /// Notable use cases: Late link-time optimizations like GOT and stub
1560 /// elimination.
1561 LinkGraphPassList PreFixupPasses;
1562
1563 /// Post-fixup passes.
1564 ///
1565 /// These passes are called on the graph after block contents has been copied
1566 /// to working memory, and fixups applied. Blocks have been updated to point
1567 /// to their fixed up content.
1568 ///
1569 /// Notable use cases: Testing and validation.
1570 LinkGraphPassList PostFixupPasses;
1571};
1572
1573/// Flags for symbol lookup.
1574///
1575/// FIXME: These basically duplicate orc::SymbolLookupFlags -- We should merge
1576/// the two types once we have an OrcSupport library.
1577enum class SymbolLookupFlags { RequiredSymbol, WeaklyReferencedSymbol };
1578
1579raw_ostream &operator<<(raw_ostream &OS, const SymbolLookupFlags &LF);
1580
1581/// A map of symbol names to resolved addresses.
1582using AsyncLookupResult = DenseMap<StringRef, JITEvaluatedSymbol>;
1583
1584/// A function object to call with a resolved symbol map (See AsyncLookupResult)
1585/// or an error if resolution failed.
1586class JITLinkAsyncLookupContinuation {
1587public:
1588 virtual ~JITLinkAsyncLookupContinuation() {}
1589 virtual void run(Expected<AsyncLookupResult> LR) = 0;
1590
1591private:
1592 virtual void anchor();
1593};
1594
1595/// Create a lookup continuation from a function object.
1596template <typename Continuation>
1597std::unique_ptr<JITLinkAsyncLookupContinuation>
1598createLookupContinuation(Continuation Cont) {
1599
1600 class Impl final : public JITLinkAsyncLookupContinuation {
1601 public:
1602 Impl(Continuation C) : C(std::move(C)) {}
1603 void run(Expected<AsyncLookupResult> LR) override { C(std::move(LR)); }
1604
1605 private:
1606 Continuation C;
1607 };
1608
1609 return std::make_unique<Impl>(std::move(Cont));
1610}
1611
1612/// Holds context for a single jitLink invocation.
1613class JITLinkContext {
1614public:
1615 using LookupMap = DenseMap<StringRef, SymbolLookupFlags>;
1616
1617 /// Create a JITLinkContext.
1618 JITLinkContext(const JITLinkDylib *JD) : JD(JD) {}
1619
1620 /// Destroy a JITLinkContext.
1621 virtual ~JITLinkContext();
1622
1623 /// Return the JITLinkDylib that this link is targeting, if any.
1624 const JITLinkDylib *getJITLinkDylib() const { return JD; }
1625
1626 /// Return the MemoryManager to be used for this link.
1627 virtual JITLinkMemoryManager &getMemoryManager() = 0;
1628
1629 /// Notify this context that linking failed.
1630 /// Called by JITLink if linking cannot be completed.
1631 virtual void notifyFailed(Error Err) = 0;
1632
1633 /// Called by JITLink to resolve external symbols. This method is passed a
1634 /// lookup continutation which it must call with a result to continue the
1635 /// linking process.
1636 virtual void lookup(const LookupMap &Symbols,
1637 std::unique_ptr<JITLinkAsyncLookupContinuation> LC) = 0;
1638
1639 /// Called by JITLink once all defined symbols in the graph have been assigned
1640 /// their final memory locations in the target process. At this point the
1641 /// LinkGraph can be inspected to build a symbol table, however the block
1642 /// content will not generally have been copied to the target location yet.
1643 ///
1644 /// If the client detects an error in the LinkGraph state (e.g. unexpected or
1645 /// missing symbols) they may return an error here. The error will be
1646 /// propagated to notifyFailed and the linker will bail out.
1647 virtual Error notifyResolved(LinkGraph &G) = 0;
1648
1649 /// Called by JITLink to notify the context that the object has been
1650 /// finalized (i.e. emitted to memory and memory permissions set). If all of
1651 /// this objects dependencies have also been finalized then the code is ready
1652 /// to run.
1653 virtual void
1654 notifyFinalized(std::unique_ptr<JITLinkMemoryManager::Allocation> A) = 0;
1655
1656 /// Called by JITLink prior to linking to determine whether default passes for
1657 /// the target should be added. The default implementation returns true.
1658 /// If subclasses override this method to return false for any target then
1659 /// they are required to fully configure the pass pipeline for that target.
1660 virtual bool shouldAddDefaultTargetPasses(const Triple &TT) const;
1661
1662 /// Returns the mark-live pass to be used for this link. If no pass is
1663 /// returned (the default) then the target-specific linker implementation will
1664 /// choose a conservative default (usually marking all symbols live).
1665 /// This function is only called if shouldAddDefaultTargetPasses returns true,
1666 /// otherwise the JITContext is responsible for adding a mark-live pass in
1667 /// modifyPassConfig.
1668 virtual LinkGraphPassFunction getMarkLivePass(const Triple &TT) const;
1669
1670 /// Called by JITLink to modify the pass pipeline prior to linking.
1671 /// The default version performs no modification.
1672 virtual Error modifyPassConfig(LinkGraph &G, PassConfiguration &Config);
1673
1674private:
1675 const JITLinkDylib *JD = nullptr;
1676};
1677
1678/// Marks all symbols in a graph live. This can be used as a default,
1679/// conservative mark-live implementation.
1680Error markAllSymbolsLive(LinkGraph &G);
1681
1682/// Create an out of range error for the given edge in the given block.
1683Error makeTargetOutOfRangeError(const LinkGraph &G, const Block &B,
1684 const Edge &E);
1685
1686/// Create a LinkGraph from the given object buffer.
1687///
1688/// Note: The graph does not take ownership of the underlying buffer, nor copy
1689/// its contents. The caller is responsible for ensuring that the object buffer
1690/// outlives the graph.
1691Expected<std::unique_ptr<LinkGraph>>
1692createLinkGraphFromObject(MemoryBufferRef ObjectBuffer);
1693
1694/// Link the given graph.
1695void link(std::unique_ptr<LinkGraph> G, std::unique_ptr<JITLinkContext> Ctx);
1696
1697} // end namespace jitlink
1698} // end namespace llvm
1699
1700#endif // LLVM_EXECUTIONENGINE_JITLINK_JITLINK_H