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