134 lines · cpp
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-exception6//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 child22// 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#endif27 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(StringRef 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 identicalCodeFoldingKind(ICFFoldKind::None),64 referencedDynamically(isReferencedDynamically), noDeadStrip(noDeadStrip),65 interposable(interposable), weakDefCanBeHidden(isWeakDefCanBeHidden),66 weakDef(isWeakDef), external(isExternal), originalIsec(isec),67 value(value), 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 else79 break;80 }81 }82}83 84bool Defined::isTlv() const {85 return !isAbsolute() && isThreadLocalVariables(originalIsec->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 for96 // the address of a function that has not yet been finalized.97 assert(target->usesThunks());98 99 // ConcatOutputSection::finalize() can seek the address of a100 // function before its address is assigned. The thunking algorithm101 // knows that unfinalized functions will be out of range, so it is102 // 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 originalIsec ? dyn_cast_or_null<ObjFile>(originalIsec->getFile())110 : nullptr;111}112 113std::string Defined::getSourceLocation() {114 if (!originalIsec)115 return {};116 return originalIsec->getSourceLocation(value);117}118 119// Get the canonical InputSection of the symbol.120InputSection *Defined::isec() const {121 return originalIsec ? originalIsec->canonical() : nullptr;122}123 124// Get the canonical unwind entry of the symbol.125ConcatInputSection *Defined::unwindEntry() const {126 return originalUnwindEntry ? originalUnwindEntry->canonical() : nullptr;127}128 129uint64_t DylibSymbol::getVA() const {130 return isInStubs() ? getStubVA() : Symbol::getVA();131}132 133void LazyArchive::fetchArchiveMember() { getFile()->fetch(sym); }134