xref: /llvm-project-15.0.7/lld/MachO/Symbols.cpp (revision ee80ffbf)
1 //===- Symbols.cpp --------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "Symbols.h"
10 #include "InputFiles.h"
11 #include "SyntheticSections.h"
12 
13 using namespace llvm;
14 using namespace lld;
15 using namespace lld::macho;
16 
17 // Returns a symbol for an error message.
18 static std::string demangle(StringRef symName) {
19   if (config->demangle)
20     return demangleItanium(symName);
21   return std::string(symName);
22 }
23 
24 std::string lld::toString(const Symbol &sym) { return demangle(sym.getName()); }
25 
26 std::string lld::toMachOString(const object::Archive::Symbol &b) {
27   return demangle(b.getName());
28 }
29 
30 uint64_t Symbol::getStubVA() const { return in.stubs->getVA(stubsIndex); }
31 uint64_t Symbol::getGotVA() const { return in.got->getVA(gotIndex); }
32 uint64_t Symbol::getTlvVA() const { return in.tlvPointers->getVA(gotIndex); }
33 
34 Defined::Defined(StringRefZ name, InputFile *file, InputSection *isec,
35                  uint64_t value, uint64_t size, bool isWeakDef, bool isExternal,
36                  bool isPrivateExtern, bool isThumb,
37                  bool isReferencedDynamically, bool noDeadStrip,
38                  bool canOverrideWeakDef, bool isWeakDefCanBeHidden)
39     : Symbol(DefinedKind, name, file), isec(isec), value(value), size(size),
40       overridesWeakDef(canOverrideWeakDef), privateExtern(isPrivateExtern),
41       includeInSymtab(true), thumb(isThumb),
42       referencedDynamically(isReferencedDynamically), noDeadStrip(noDeadStrip),
43       weakDefCanBeHidden(isWeakDefCanBeHidden), weakDef(isWeakDef),
44       external(isExternal) {
45   if (isec) {
46     isec->symbols.push_back(this);
47     // Maintain sorted order.
48     for (auto it = isec->symbols.rbegin(), rend = isec->symbols.rend();
49          it != rend; ++it) {
50       auto next = std::next(it);
51       if (next == rend)
52         break;
53       if ((*it)->value < (*next)->value)
54         std::swap(*next, *it);
55       else
56         break;
57     }
58   }
59 }
60 
61 bool Defined::isTlv() const {
62   return !isAbsolute() && isThreadLocalVariables(isec->getFlags());
63 }
64 
65 uint64_t Defined::getVA() const {
66   assert(isLive() && "this should only be called for live symbols");
67 
68   if (isAbsolute())
69     return value;
70 
71   if (!isec->isFinal) {
72     // A target arch that does not use thunks ought never ask for
73     // the address of a function that has not yet been finalized.
74     assert(target->usesThunks());
75 
76     // ConcatOutputSection::finalize() can seek the address of a
77     // function before its address is assigned. The thunking algorithm
78     // knows that unfinalized functions will be out of range, so it is
79     // expedient to return a contrived out-of-range address.
80     return TargetInfo::outOfRangeVA;
81   }
82   return isec->getVA(value);
83 }
84 
85 void Defined::canonicalize() {
86   if (compactUnwind)
87     compactUnwind = compactUnwind->canonical();
88   if (isec)
89     isec = isec->canonical();
90 }
91 
92 uint64_t DylibSymbol::getVA() const {
93   return isInStubs() ? getStubVA() : Symbol::getVA();
94 }
95 
96 void LazySymbol::fetchArchiveMember() { getFile()->fetch(sym); }
97