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 "lld/Common/Threads.h" 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<Defined *, 4>> SymbolMapTy; 39 40 // Print out the first three columns of a line. 41 static void writeHeader(raw_ostream &OS, uint64_t Addr, uint64_t Size, 42 uint64_t Align) { 43 int W = Config->Is64 ? 16 : 8; 44 OS << format("%0*llx %0*llx %5lld ", W, Addr, W, Size, Align); 45 } 46 47 static std::string indent(int Depth) { return std::string(Depth * 8, ' '); } 48 49 // Returns a list of all symbols that we want to print out. 50 static std::vector<Defined *> getSymbols() { 51 std::vector<Defined *> V; 52 for (InputFile *File : ObjectFiles) 53 for (Symbol *B : File->getSymbols()) 54 if (auto *DR = dyn_cast<Defined>(B)) 55 if (DR->File == File && !DR->isSection() && DR->Section && 56 DR->Section->Live) 57 V.push_back(DR); 58 return V; 59 } 60 61 // Returns a map from sections to their symbols. 62 static SymbolMapTy getSectionSyms(ArrayRef<Defined *> Syms) { 63 SymbolMapTy Ret; 64 for (Defined *S : Syms) 65 Ret[S->Section].push_back(S); 66 67 // Sort symbols by address. We want to print out symbols in the 68 // order in the output file rather than the order they appeared 69 // in the input files. 70 for (auto &It : Ret) { 71 SmallVectorImpl<Defined *> &V = It.second; 72 std::sort(V.begin(), V.end(), 73 [](Defined *A, Defined *B) { return A->getVA() < B->getVA(); }); 74 } 75 return Ret; 76 } 77 78 // Construct a map from symbols to their stringified representations. 79 // Demangling symbols (which is what toString() does) is slow, so 80 // we do that in batch using parallel-for. 81 static DenseMap<Defined *, std::string> 82 getSymbolStrings(ArrayRef<Defined *> Syms) { 83 std::vector<std::string> Str(Syms.size()); 84 parallelForEachN(0, Syms.size(), [&](size_t I) { 85 raw_string_ostream OS(Str[I]); 86 writeHeader(OS, Syms[I]->getVA(), Syms[I]->getSize(), 0); 87 OS << indent(2) << toString(*Syms[I]); 88 }); 89 90 DenseMap<Defined *, std::string> Ret; 91 for (size_t I = 0, E = Syms.size(); I < E; ++I) 92 Ret[Syms[I]] = std::move(Str[I]); 93 return Ret; 94 } 95 96 void elf::writeMapFile() { 97 if (Config->MapFile.empty()) 98 return; 99 100 // Open a map file for writing. 101 std::error_code EC; 102 raw_fd_ostream OS(Config->MapFile, EC, sys::fs::F_None); 103 if (EC) { 104 error("cannot open " + Config->MapFile + ": " + EC.message()); 105 return; 106 } 107 108 // Collect symbol info that we want to print out. 109 std::vector<Defined *> Syms = getSymbols(); 110 SymbolMapTy SectionSyms = getSectionSyms(Syms); 111 DenseMap<Defined *, std::string> SymStr = getSymbolStrings(Syms); 112 113 // Print out the header line. 114 int W = Config->Is64 ? 16 : 8; 115 OS << left_justify("Address", W) << ' ' << left_justify("Size", W) 116 << " Align Out In Symbol\n"; 117 118 // Print out file contents. 119 for (OutputSection *OSec : OutputSections) { 120 writeHeader(OS, OSec->Addr, OSec->Size, OSec->Alignment); 121 OS << OSec->Name << '\n'; 122 123 // Dump symbols for each input section. 124 for (BaseCommand *Base : OSec->SectionCommands) { 125 auto *ISD = dyn_cast<InputSectionDescription>(Base); 126 if (!ISD) 127 continue; 128 for (InputSection *IS : ISD->Sections) { 129 writeHeader(OS, OSec->Addr + IS->OutSecOff, IS->getSize(), 130 IS->Alignment); 131 OS << indent(1) << toString(IS) << '\n'; 132 for (Defined *Sym : SectionSyms[IS]) 133 OS << SymStr[Sym] << '\n'; 134 } 135 } 136 } 137 } 138