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 "Threads.h" 29 30 #include "llvm/Support/raw_ostream.h" 31 32 using namespace llvm; 33 using namespace llvm::object; 34 35 using namespace lld; 36 using namespace lld::elf; 37 38 typedef DenseMap<const SectionBase *, SmallVector<DefinedRegular *, 4>> 39 SymbolMapTy; 40 41 // Print out the first three columns of a line. 42 template <class ELFT> 43 static void writeHeader(raw_ostream &OS, uint64_t Addr, uint64_t Size, 44 uint64_t Align) { 45 int W = ELFT::Is64Bits ? 16 : 8; 46 OS << format("%0*llx %0*llx %5lld ", W, Addr, W, Size, Align); 47 } 48 49 static std::string indent(int Depth) { return std::string(Depth * 8, ' '); } 50 51 // Returns a list of all symbols that we want to print out. 52 template <class ELFT> std::vector<DefinedRegular *> getSymbols() { 53 std::vector<DefinedRegular *> V; 54 for (elf::ObjectFile<ELFT> *File : Symtab<ELFT>::X->getObjectFiles()) 55 for (SymbolBody *B : File->getSymbols()) 56 if (B->File == File && !B->isSection()) 57 if (auto *Sym = dyn_cast<DefinedRegular>(B)) 58 if (Sym->Section) 59 V.push_back(Sym); 60 return V; 61 } 62 63 // Returns a map from sections to their symbols. 64 template <class ELFT> 65 SymbolMapTy getSectionSyms(ArrayRef<DefinedRegular *> Syms) { 66 SymbolMapTy Ret; 67 for (DefinedRegular *S : Syms) 68 Ret[S->Section].push_back(S); 69 70 // Sort symbols by address. We want to print out symbols in the 71 // order in the output file rather than the order they appeared 72 // in the input files. 73 for (auto &It : Ret) { 74 SmallVectorImpl<DefinedRegular *> &V = It.second; 75 std::sort(V.begin(), V.end(), [](DefinedRegular *A, DefinedRegular *B) { 76 return A->getVA() < B->getVA(); 77 }); 78 } 79 return Ret; 80 } 81 82 // Construct a map from symbols to their stringified representations. 83 // Demangling symbols (which is what toString() does) is slow, so 84 // we do that in batch using parallel-for. 85 template <class ELFT> 86 DenseMap<DefinedRegular *, std::string> 87 getSymbolStrings(ArrayRef<DefinedRegular *> Syms) { 88 std::vector<std::string> Str(Syms.size()); 89 parallelForEachN(0, Syms.size(), [&](size_t I) { 90 raw_string_ostream OS(Str[I]); 91 writeHeader<ELFT>(OS, Syms[I]->getVA(), Syms[I]->template getSize<ELFT>(), 92 0); 93 OS << indent(2) << toString(*Syms[I]); 94 }); 95 96 DenseMap<DefinedRegular *, std::string> Ret; 97 for (size_t I = 0, E = Syms.size(); I < E; ++I) 98 Ret[Syms[I]] = std::move(Str[I]); 99 return Ret; 100 } 101 102 template <class ELFT> 103 void elf::writeMapFile(llvm::ArrayRef<OutputSectionCommand *> Script) { 104 if (Config->MapFile.empty()) 105 return; 106 107 // Open a map file for writing. 108 std::error_code EC; 109 raw_fd_ostream OS(Config->MapFile, EC, sys::fs::F_None); 110 if (EC) { 111 error("cannot open " + Config->MapFile + ": " + EC.message()); 112 return; 113 } 114 115 // Collect symbol info that we want to print out. 116 std::vector<DefinedRegular *> Syms = getSymbols<ELFT>(); 117 SymbolMapTy SectionSyms = getSectionSyms<ELFT>(Syms); 118 DenseMap<DefinedRegular *, std::string> SymStr = getSymbolStrings<ELFT>(Syms); 119 120 // Print out the header line. 121 int W = ELFT::Is64Bits ? 16 : 8; 122 OS << left_justify("Address", W) << ' ' << left_justify("Size", W) 123 << " Align Out In Symbol\n"; 124 125 // Print out file contents. 126 for (OutputSectionCommand *Cmd : Script) { 127 OutputSection *OSec = Cmd->Sec; 128 writeHeader<ELFT>(OS, OSec->Addr, OSec->Size, OSec->Alignment); 129 OS << OSec->Name << '\n'; 130 131 // Dump symbols for each input section. 132 for (BaseCommand *Base : Cmd->Commands) { 133 auto *ISD = dyn_cast<InputSectionDescription>(Base); 134 if (!ISD) 135 continue; 136 for (InputSection *IS : ISD->Sections) { 137 writeHeader<ELFT>(OS, OSec->Addr + IS->OutSecOff, IS->getSize(), 138 IS->Alignment); 139 OS << indent(1) << toString(IS) << '\n'; 140 for (DefinedRegular *Sym : SectionSyms[IS]) 141 OS << SymStr[Sym] << '\n'; 142 } 143 } 144 } 145 } 146 147 template void elf::writeMapFile<ELF32LE>(ArrayRef<OutputSectionCommand *>); 148 template void elf::writeMapFile<ELF32BE>(ArrayRef<OutputSectionCommand *>); 149 template void elf::writeMapFile<ELF64LE>(ArrayRef<OutputSectionCommand *>); 150 template void elf::writeMapFile<ELF64BE>(ArrayRef<OutputSectionCommand *>); 151