1 //===- SymbolSize.cpp -----------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "llvm/Object/SymbolSize.h" 11 #include "llvm/ADT/STLExtras.h" 12 #include "llvm/Object/COFF.h" 13 #include "llvm/Object/ELFObjectFile.h" 14 #include "llvm/Object/MachO.h" 15 16 using namespace llvm; 17 using namespace object; 18 19 namespace { 20 struct SymEntry { 21 symbol_iterator I; 22 uint64_t Address; 23 unsigned Number; 24 unsigned SectionID; 25 }; 26 } 27 28 static int compareAddress(const SymEntry *A, const SymEntry *B) { 29 if (A->SectionID != B->SectionID) 30 return A->SectionID - B->SectionID; 31 return A->Address - B->Address; 32 } 33 34 static unsigned getSectionID(const ObjectFile &O, SectionRef Sec) { 35 if (auto *M = dyn_cast<MachOObjectFile>(&O)) 36 return M->getSectionID(Sec); 37 return cast<COFFObjectFile>(O).getSectionID(Sec); 38 } 39 40 static unsigned getSymbolSectionID(const ObjectFile &O, SymbolRef Sym) { 41 if (auto *M = dyn_cast<MachOObjectFile>(&O)) 42 return M->getSymbolSectionID(Sym); 43 return cast<COFFObjectFile>(O).getSymbolSectionID(Sym); 44 } 45 46 std::vector<std::pair<SymbolRef, uint64_t>> 47 llvm::object::computeSymbolSizes(const ObjectFile &O) { 48 std::vector<std::pair<SymbolRef, uint64_t>> Ret; 49 50 if (const auto *E = dyn_cast<ELFObjectFileBase>(&O)) { 51 auto Syms = E->symbols(); 52 if (Syms.begin() == Syms.end()) 53 Syms = E->getDynamicSymbolIterators(); 54 for (ELFSymbolRef Sym : Syms) 55 Ret.push_back({Sym, Sym.getSize()}); 56 return Ret; 57 } 58 59 // Collect sorted symbol addresses. Include dummy addresses for the end 60 // of each section. 61 std::vector<SymEntry> Addresses; 62 unsigned SymNum = 0; 63 for (symbol_iterator I = O.symbol_begin(), E = O.symbol_end(); I != E; ++I) { 64 SymbolRef Sym = *I; 65 uint64_t Value = Sym.getValue(); 66 Addresses.push_back({I, Value, SymNum, getSymbolSectionID(O, Sym)}); 67 ++SymNum; 68 } 69 for (SectionRef Sec : O.sections()) { 70 uint64_t Address = Sec.getAddress(); 71 uint64_t Size = Sec.getSize(); 72 Addresses.push_back( 73 {O.symbol_end(), Address + Size, 0, getSectionID(O, Sec)}); 74 } 75 array_pod_sort(Addresses.begin(), Addresses.end(), compareAddress); 76 77 // Compute the size as the gap to the next symbol 78 for (unsigned I = 0, N = Addresses.size() - 1; I < N; ++I) { 79 auto &P = Addresses[I]; 80 if (P.I == O.symbol_end()) 81 continue; 82 83 // If multiple symbol have the same address, give both the same size. 84 unsigned NextI = I + 1; 85 while (NextI < N && Addresses[NextI].Address == P.Address) 86 ++NextI; 87 88 uint64_t Size = Addresses[NextI].Address - P.Address; 89 P.Address = Size; 90 } 91 92 // Assign the sorted symbols in the original order. 93 Ret.resize(SymNum); 94 for (SymEntry &P : Addresses) { 95 if (P.I == O.symbol_end()) 96 continue; 97 Ret[P.Number] = {*P.I, P.Address}; 98 } 99 return Ret; 100 } 101