1 //===- SymbolSize.cpp -----------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/Object/SymbolSize.h" 10 #include "llvm/ADT/STLExtras.h" 11 #include "llvm/Object/COFF.h" 12 #include "llvm/Object/ELFObjectFile.h" 13 #include "llvm/Object/MachO.h" 14 15 using namespace llvm; 16 using namespace object; 17 18 // Orders increasingly by (SectionID, Address). 19 int llvm::object::compareAddress(const SymEntry *A, const SymEntry *B) { 20 if (A->SectionID != B->SectionID) 21 return A->SectionID < B->SectionID ? -1 : 1; 22 if (A->Address != B->Address) 23 return A->Address < B->Address ? -1 : 1; 24 return 0; 25 } 26 27 static unsigned getSectionID(const ObjectFile &O, SectionRef Sec) { 28 if (auto *M = dyn_cast<MachOObjectFile>(&O)) 29 return M->getSectionID(Sec); 30 return cast<COFFObjectFile>(O).getSectionID(Sec); 31 } 32 33 static unsigned getSymbolSectionID(const ObjectFile &O, SymbolRef Sym) { 34 if (auto *M = dyn_cast<MachOObjectFile>(&O)) 35 return M->getSymbolSectionID(Sym); 36 return cast<COFFObjectFile>(O).getSymbolSectionID(Sym); 37 } 38 39 std::vector<std::pair<SymbolRef, uint64_t>> 40 llvm::object::computeSymbolSizes(const ObjectFile &O) { 41 std::vector<std::pair<SymbolRef, uint64_t>> Ret; 42 43 if (const auto *E = dyn_cast<ELFObjectFileBase>(&O)) { 44 auto Syms = E->symbols(); 45 if (Syms.begin() == Syms.end()) 46 Syms = E->getDynamicSymbolIterators(); 47 for (ELFSymbolRef Sym : Syms) 48 Ret.push_back({Sym, Sym.getSize()}); 49 return Ret; 50 } 51 52 // Collect sorted symbol addresses. Include dummy addresses for the end 53 // of each section. 54 std::vector<SymEntry> Addresses; 55 unsigned SymNum = 0; 56 for (symbol_iterator I = O.symbol_begin(), E = O.symbol_end(); I != E; ++I) { 57 SymbolRef Sym = *I; 58 uint64_t Value = Sym.getValue(); 59 Addresses.push_back({I, Value, SymNum, getSymbolSectionID(O, Sym)}); 60 ++SymNum; 61 } 62 for (SectionRef Sec : O.sections()) { 63 uint64_t Address = Sec.getAddress(); 64 uint64_t Size = Sec.getSize(); 65 Addresses.push_back( 66 {O.symbol_end(), Address + Size, 0, getSectionID(O, Sec)}); 67 } 68 69 if (Addresses.empty()) 70 return Ret; 71 72 array_pod_sort(Addresses.begin(), Addresses.end(), compareAddress); 73 74 // Compute the size as the gap to the next symbol 75 for (unsigned I = 0, N = Addresses.size() - 1; I < N; ++I) { 76 auto &P = Addresses[I]; 77 if (P.I == O.symbol_end()) 78 continue; 79 80 // If multiple symbol have the same address, give both the same size. 81 unsigned NextI = I + 1; 82 while (NextI < N && Addresses[NextI].Address == P.Address) 83 ++NextI; 84 85 uint64_t Size = Addresses[NextI].Address - P.Address; 86 P.Address = Size; 87 } 88 89 // Assign the sorted symbols in the original order. 90 Ret.resize(SymNum); 91 for (SymEntry &P : Addresses) { 92 if (P.I == O.symbol_end()) 93 continue; 94 Ret[P.Number] = {*P.I, P.Address}; 95 } 96 return Ret; 97 } 98