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#include "llvm/Demangle/Demangle.h" 13 14using namespace llvm; 15using namespace lld; 16using namespace lld::macho; 17 18static_assert(sizeof(void *) != 8 || sizeof(Symbol) == 56, 19 "Try to minimize Symbol's size; we create many instances"); 20 21// The Microsoft ABI doesn't support using parent class tail padding for child 22// members, hence the _MSC_VER check. 23#if !defined(_MSC_VER) 24static_assert(sizeof(void *) != 8 || sizeof(Defined) == 88, 25 "Try to minimize Defined's size; we create many instances"); 26#endif 27 28static_assert(sizeof(SymbolUnion) == sizeof(Defined), 29 "Defined should be the largest Symbol kind"); 30 31// Returns a symbol name for an error message. 32static std::string maybeDemangleSymbol(StringRef symName) { 33 if (config->demangle) { 34 symName.consume_front("_"); 35 return demangle(symName); 36 } 37 return symName.str(); 38} 39 40std::string lld::toString(const Symbol &sym) { 41 return maybeDemangleSymbol(sym.getName()); 42} 43 44std::string lld::toMachOString(const object::Archive::Symbol &b) { 45 return maybeDemangleSymbol(b.getName()); 46} 47 48uint64_t Symbol::getStubVA() const { return in.stubs->getVA(stubsIndex); } 49uint64_t Symbol::getLazyPtrVA() const { 50 return in.lazyPointers->getVA(stubsIndex); 51} 52uint64_t Symbol::getGotVA() const { return in.got->getVA(gotIndex); } 53uint64_t Symbol::getTlvVA() const { return in.tlvPointers->getVA(gotIndex); } 54 55Defined::Defined(StringRefZ name, InputFile *file, InputSection *isec, 56 uint64_t value, uint64_t size, bool isWeakDef, bool isExternal, 57 bool isPrivateExtern, bool includeInSymtab, 58 bool isReferencedDynamically, bool noDeadStrip, 59 bool canOverrideWeakDef, bool isWeakDefCanBeHidden, 60 bool interposable) 61 : Symbol(DefinedKind, name, file), overridesWeakDef(canOverrideWeakDef), 62 privateExtern(isPrivateExtern), includeInSymtab(includeInSymtab), 63 wasIdenticalCodeFolded(false), 64 referencedDynamically(isReferencedDynamically), noDeadStrip(noDeadStrip), 65 interposable(interposable), weakDefCanBeHidden(isWeakDefCanBeHidden), 66 weakDef(isWeakDef), external(isExternal), isec(isec), value(value), 67 size(size) { 68 if (isec) { 69 isec->symbols.push_back(this); 70 // Maintain sorted order. 71 for (auto it = isec->symbols.rbegin(), rend = isec->symbols.rend(); 72 it != rend; ++it) { 73 auto next = std::next(it); 74 if (next == rend) 75 break; 76 if ((*it)->value < (*next)->value) 77 std::swap(*next, *it); 78 else 79 break; 80 } 81 } 82} 83 84bool Defined::isTlv() const { 85 return !isAbsolute() && isThreadLocalVariables(isec->getFlags()); 86} 87 88uint64_t Defined::getVA() const { 89 assert(isLive() && "this should only be called for live symbols"); 90 91 if (isAbsolute()) 92 return value; 93 94 if (!isec->isFinal) { 95 // A target arch that does not use thunks ought never ask for 96 // the address of a function that has not yet been finalized. 97 assert(target->usesThunks()); 98 99 // ConcatOutputSection::finalize() can seek the address of a 100 // function before its address is assigned. The thunking algorithm 101 // knows that unfinalized functions will be out of range, so it is 102 // expedient to return a contrived out-of-range address. 103 return TargetInfo::outOfRangeVA; 104 } 105 return isec->getVA(value); 106} 107 108ObjFile *Defined::getObjectFile() const { 109 return isec ? dyn_cast_or_null<ObjFile>(isec->getFile()) : nullptr; 110} 111 112void Defined::canonicalize() { 113 if (unwindEntry) 114 unwindEntry = unwindEntry->canonical(); 115 if (isec) 116 isec = isec->canonical(); 117} 118 119std::string Defined::getSourceLocation() { 120 if (!isec) 121 return {}; 122 return isec->getSourceLocation(value); 123} 124 125uint64_t DylibSymbol::getVA() const { 126 return isInStubs() ? getStubVA() : Symbol::getVA(); 127} 128 129void LazyArchive::fetchArchiveMember() { getFile()->fetch(sym); } 130