1 //===- MapFile.cpp --------------------------------------------------------===// 2 // 3 // The LLVM Linker 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the -Map option. It shows lists in order and 11 // hierarchically the output sections, input sections, input files and 12 // symbol: 13 // 14 // Address Size Align Out In Symbol 15 // 00201000 00000015 4 .text 16 // 00201000 0000000e 4 test.o:(.text) 17 // 0020100e 00000000 0 local 18 // 00201005 00000000 0 f(int) 19 // 20 //===----------------------------------------------------------------------===// 21 22 #include "MapFile.h" 23 #include "InputFiles.h" 24 #include "LinkerScript.h" 25 #include "OutputSections.h" 26 #include "Strings.h" 27 #include "SymbolTable.h" 28 #include "SyntheticSections.h" 29 #include "Threads.h" 30 31 #include "llvm/Support/raw_ostream.h" 32 33 using namespace llvm; 34 using namespace llvm::object; 35 36 using namespace lld; 37 using namespace lld::elf; 38 39 typedef DenseMap<const SectionBase *, SmallVector<Defined *, 4>> SymbolMapTy; 40 41 // Print out the first three columns of a line. 42 static void writeHeader(raw_ostream &OS, uint64_t Addr, uint64_t Size, 43 uint64_t Align) { 44 int W = Config->Is64 ? 16 : 8; 45 OS << format("%0*llx %0*llx %5lld ", W, Addr, W, Size, Align); 46 } 47 48 static std::string indent(int Depth) { return std::string(Depth * 8, ' '); } 49 50 // Returns a list of all symbols that we want to print out. 51 template <class ELFT> static std::vector<Defined *> getSymbols() { 52 std::vector<Defined *> V; 53 for (ObjFile<ELFT> *File : ObjFile<ELFT>::Instances) { 54 for (SymbolBody *B : File->getSymbols()) { 55 if (auto *DR = dyn_cast<DefinedRegular>(B)) { 56 if (DR->getFile() == File && !DR->isSection() && DR->Section && 57 DR->Section->Live) 58 V.push_back(DR); 59 } else if (auto *DC = dyn_cast<DefinedCommon>(B)) { 60 if (InX::Common) 61 V.push_back(DC); 62 } 63 } 64 } 65 return V; 66 } 67 68 // Returns a map from sections to their symbols. 69 static SymbolMapTy getSectionSyms(ArrayRef<Defined *> Syms) { 70 SymbolMapTy Ret; 71 for (Defined *S : Syms) { 72 if (auto *DR = dyn_cast<DefinedRegular>(S)) 73 Ret[DR->Section].push_back(S); 74 else 75 Ret[InX::Common].push_back(S); 76 } 77 78 // Sort symbols by address. We want to print out symbols in the 79 // order in the output file rather than the order they appeared 80 // in the input files. 81 for (auto &It : Ret) { 82 SmallVectorImpl<Defined *> &V = It.second; 83 std::sort(V.begin(), V.end(), 84 [](Defined *A, Defined *B) { return A->getVA() < B->getVA(); }); 85 } 86 return Ret; 87 } 88 89 // Construct a map from symbols to their stringified representations. 90 // Demangling symbols (which is what toString() does) is slow, so 91 // we do that in batch using parallel-for. 92 template <class ELFT> 93 static DenseMap<Defined *, std::string> 94 getSymbolStrings(ArrayRef<Defined *> Syms) { 95 std::vector<std::string> Str(Syms.size()); 96 parallelForEachN(0, Syms.size(), [&](size_t I) { 97 raw_string_ostream OS(Str[I]); 98 writeHeader(OS, Syms[I]->getVA(), Syms[I]->template getSize<ELFT>(), 0); 99 OS << indent(2) << toString(*Syms[I]); 100 }); 101 102 DenseMap<Defined *, std::string> Ret; 103 for (size_t I = 0, E = Syms.size(); I < E; ++I) 104 Ret[Syms[I]] = std::move(Str[I]); 105 return Ret; 106 } 107 108 template <class ELFT> void elf::writeMapFile() { 109 if (Config->MapFile.empty()) 110 return; 111 112 // Open a map file for writing. 113 std::error_code EC; 114 raw_fd_ostream OS(Config->MapFile, EC, sys::fs::F_None); 115 if (EC) { 116 error("cannot open " + Config->MapFile + ": " + EC.message()); 117 return; 118 } 119 120 // Collect symbol info that we want to print out. 121 std::vector<Defined *> Syms = getSymbols<ELFT>(); 122 SymbolMapTy SectionSyms = getSectionSyms(Syms); 123 DenseMap<Defined *, std::string> SymStr = getSymbolStrings<ELFT>(Syms); 124 125 // Print out the header line. 126 int W = ELFT::Is64Bits ? 16 : 8; 127 OS << left_justify("Address", W) << ' ' << left_justify("Size", W) 128 << " Align Out In Symbol\n"; 129 130 // Print out file contents. 131 for (OutputSection *OSec : OutputSections) { 132 writeHeader(OS, OSec->Addr, OSec->Size, OSec->Alignment); 133 OS << OSec->Name << '\n'; 134 135 // Dump symbols for each input section. 136 for (BaseCommand *Base : OSec->Commands) { 137 auto *ISD = dyn_cast<InputSectionDescription>(Base); 138 if (!ISD) 139 continue; 140 for (InputSection *IS : ISD->Sections) { 141 writeHeader(OS, OSec->Addr + IS->OutSecOff, IS->getSize(), 142 IS->Alignment); 143 OS << indent(1) << toString(IS) << '\n'; 144 for (Defined *Sym : SectionSyms[IS]) 145 OS << SymStr[Sym] << '\n'; 146 } 147 } 148 } 149 } 150 151 template void elf::writeMapFile<ELF32LE>(); 152 template void elf::writeMapFile<ELF32BE>(); 153 template void elf::writeMapFile<ELF64LE>(); 154 template void elf::writeMapFile<ELF64BE>(); 155