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 "Symbols.h" 29 #include "SyntheticSections.h" 30 #include "lld/Common/Threads.h" 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<Symbol *, 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 static std::vector<Symbol *> getSymbols() { 52 std::vector<Symbol *> V; 53 for (InputFile *File : ObjectFiles) { 54 for (Symbol *B : File->getSymbols()) { 55 if (auto *SS = dyn_cast<SharedSymbol>(B)) 56 if (SS->CopyRelSec || SS->NeedsPltAddr) 57 V.push_back(SS); 58 if (auto *DR = dyn_cast<Defined>(B)) 59 if (DR->File == File && !DR->isSection() && DR->Section && 60 DR->Section->Live) 61 V.push_back(DR); 62 } 63 } 64 return V; 65 } 66 67 // Returns a map from sections to their symbols. 68 static SymbolMapTy getSectionSyms(ArrayRef<Symbol *> Syms) { 69 SymbolMapTy Ret; 70 for (Symbol *S : Syms) { 71 if (auto *DR = dyn_cast<Defined>(S)) { 72 Ret[DR->Section].push_back(S); 73 continue; 74 } 75 76 SharedSymbol *SS = cast<SharedSymbol>(S); 77 if (SS->CopyRelSec) 78 Ret[SS->CopyRelSec].push_back(S); 79 else 80 Ret[InX::Plt].push_back(S); 81 } 82 83 // Sort symbols by address. We want to print out symbols in the 84 // order in the output file rather than the order they appeared 85 // in the input files. 86 for (auto &It : Ret) { 87 SmallVectorImpl<Symbol *> &V = It.second; 88 std::sort(V.begin(), V.end(), 89 [](Symbol *A, Symbol *B) { return A->getVA() < B->getVA(); }); 90 } 91 return Ret; 92 } 93 94 // Construct a map from symbols to their stringified representations. 95 // Demangling symbols (which is what toString() does) is slow, so 96 // we do that in batch using parallel-for. 97 static DenseMap<Symbol *, std::string> 98 getSymbolStrings(ArrayRef<Symbol *> Syms) { 99 std::vector<std::string> Str(Syms.size()); 100 parallelForEachN(0, Syms.size(), [&](size_t I) { 101 raw_string_ostream OS(Str[I]); 102 writeHeader(OS, Syms[I]->getVA(), Syms[I]->getSize(), 0); 103 OS << indent(2) << toString(*Syms[I]); 104 }); 105 106 DenseMap<Symbol *, std::string> Ret; 107 for (size_t I = 0, E = Syms.size(); I < E; ++I) 108 Ret[Syms[I]] = std::move(Str[I]); 109 return Ret; 110 } 111 112 void elf::writeMapFile() { 113 if (Config->MapFile.empty()) 114 return; 115 116 // Open a map file for writing. 117 std::error_code EC; 118 raw_fd_ostream OS(Config->MapFile, EC, sys::fs::F_None); 119 if (EC) { 120 error("cannot open " + Config->MapFile + ": " + EC.message()); 121 return; 122 } 123 124 // Collect symbol info that we want to print out. 125 std::vector<Symbol *> Syms = getSymbols(); 126 SymbolMapTy SectionSyms = getSectionSyms(Syms); 127 DenseMap<Symbol *, std::string> SymStr = getSymbolStrings(Syms); 128 129 // Print out the header line. 130 int W = Config->Is64 ? 16 : 8; 131 OS << left_justify("Address", W) << ' ' << left_justify("Size", W) 132 << " Align Out In Symbol\n"; 133 134 // Print out file contents. 135 for (OutputSection *OSec : OutputSections) { 136 writeHeader(OS, OSec->Addr, OSec->Size, OSec->Alignment); 137 OS << OSec->Name << '\n'; 138 139 // Dump symbols for each input section. 140 for (BaseCommand *Base : OSec->SectionCommands) { 141 auto *ISD = dyn_cast<InputSectionDescription>(Base); 142 if (!ISD) 143 continue; 144 for (InputSection *IS : ISD->Sections) { 145 writeHeader(OS, OSec->Addr + IS->OutSecOff, IS->getSize(), 146 IS->Alignment); 147 OS << indent(1) << toString(IS) << '\n'; 148 for (Symbol *Sym : SectionSyms[IS]) 149 OS << SymStr[Sym] << '\n'; 150 } 151 } 152 } 153 } 154