xref: /freebsd/contrib/llvm-project/lld/MachO/Symbols.cpp (revision fe6060f10f634930ff71b7c50291ddc610da2475)
15ffd83dbSDimitry Andric //===- Symbols.cpp --------------------------------------------------------===//
25ffd83dbSDimitry Andric //
35ffd83dbSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
45ffd83dbSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
55ffd83dbSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
65ffd83dbSDimitry Andric //
75ffd83dbSDimitry Andric //===----------------------------------------------------------------------===//
85ffd83dbSDimitry Andric 
95ffd83dbSDimitry Andric #include "Symbols.h"
105ffd83dbSDimitry Andric #include "InputFiles.h"
11e8d8bef9SDimitry Andric #include "SyntheticSections.h"
125ffd83dbSDimitry Andric 
135ffd83dbSDimitry Andric using namespace llvm;
145ffd83dbSDimitry Andric using namespace lld;
155ffd83dbSDimitry Andric using namespace lld::macho;
165ffd83dbSDimitry Andric 
17e8d8bef9SDimitry Andric // Returns a symbol for an error message.
18e8d8bef9SDimitry Andric static std::string demangle(StringRef symName) {
19e8d8bef9SDimitry Andric   if (config->demangle)
20e8d8bef9SDimitry Andric     return demangleItanium(symName);
21e8d8bef9SDimitry Andric   return std::string(symName);
22e8d8bef9SDimitry Andric }
23e8d8bef9SDimitry Andric 
24*fe6060f1SDimitry Andric std::string lld::toString(const Symbol &sym) { return demangle(sym.getName()); }
25e8d8bef9SDimitry Andric 
26e8d8bef9SDimitry Andric std::string lld::toMachOString(const object::Archive::Symbol &b) {
27e8d8bef9SDimitry Andric   return demangle(b.getName());
28e8d8bef9SDimitry Andric }
29e8d8bef9SDimitry Andric 
30*fe6060f1SDimitry Andric uint64_t Symbol::getStubVA() const { return in.stubs->getVA(stubsIndex); }
31*fe6060f1SDimitry Andric uint64_t Symbol::getGotVA() const { return in.got->getVA(gotIndex); }
32*fe6060f1SDimitry Andric uint64_t Symbol::getTlvVA() const { return in.tlvPointers->getVA(gotIndex); }
33*fe6060f1SDimitry Andric 
34*fe6060f1SDimitry Andric bool Symbol::isLive() const {
35*fe6060f1SDimitry Andric   if (isa<DylibSymbol>(this) || isa<Undefined>(this))
36*fe6060f1SDimitry Andric     return used;
37*fe6060f1SDimitry Andric 
38*fe6060f1SDimitry Andric   if (auto *d = dyn_cast<Defined>(this)) {
39*fe6060f1SDimitry Andric     // Non-absolute symbols might be alive because their section is
40*fe6060f1SDimitry Andric     // no_dead_strip or live_support. In that case, the section will know
41*fe6060f1SDimitry Andric     // that it's live but `used` might be false. Non-absolute symbols always
42*fe6060f1SDimitry Andric     // have to use the section's `live` bit as source of truth.
43*fe6060f1SDimitry Andric     if (d->isAbsolute())
44*fe6060f1SDimitry Andric       return used;
45*fe6060f1SDimitry Andric     return d->isec->canonical()->isLive(d->value);
46*fe6060f1SDimitry Andric   }
47*fe6060f1SDimitry Andric 
48*fe6060f1SDimitry Andric   assert(!isa<CommonSymbol>(this) &&
49*fe6060f1SDimitry Andric          "replaceCommonSymbols() runs before dead code stripping, and isLive() "
50*fe6060f1SDimitry Andric          "should only be called after dead code stripping");
51*fe6060f1SDimitry Andric 
52*fe6060f1SDimitry Andric   // Assume any other kind of symbol is live.
53*fe6060f1SDimitry Andric   return true;
54*fe6060f1SDimitry Andric }
55*fe6060f1SDimitry Andric 
56e8d8bef9SDimitry Andric uint64_t Defined::getVA() const {
57*fe6060f1SDimitry Andric   assert(isLive() && "this should only be called for live symbols");
58*fe6060f1SDimitry Andric 
59e8d8bef9SDimitry Andric   if (isAbsolute())
60e8d8bef9SDimitry Andric     return value;
61*fe6060f1SDimitry Andric 
62*fe6060f1SDimitry Andric   if (!isec->canonical()->isFinal) {
63*fe6060f1SDimitry Andric     // A target arch that does not use thunks ought never ask for
64*fe6060f1SDimitry Andric     // the address of a function that has not yet been finalized.
65*fe6060f1SDimitry Andric     assert(target->usesThunks());
66*fe6060f1SDimitry Andric 
67*fe6060f1SDimitry Andric     // ConcatOutputSection::finalize() can seek the address of a
68*fe6060f1SDimitry Andric     // function before its address is assigned. The thunking algorithm
69*fe6060f1SDimitry Andric     // knows that unfinalized functions will be out of range, so it is
70*fe6060f1SDimitry Andric     // expedient to return a contrived out-of-range address.
71*fe6060f1SDimitry Andric     return TargetInfo::outOfRangeVA;
72*fe6060f1SDimitry Andric   }
73*fe6060f1SDimitry Andric   return isec->canonical()->getVA(value);
74e8d8bef9SDimitry Andric }
75e8d8bef9SDimitry Andric 
76*fe6060f1SDimitry Andric uint64_t DylibSymbol::getVA() const {
77*fe6060f1SDimitry Andric   return isInStubs() ? getStubVA() : Symbol::getVA();
78e8d8bef9SDimitry Andric }
79e8d8bef9SDimitry Andric 
80*fe6060f1SDimitry Andric void LazySymbol::fetchArchiveMember() { getFile()->fetch(sym); }
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