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 #include "llvm/Object/Wasm.h" 15 #include "llvm/Object/XCOFFObjectFile.h" 16 17 using namespace llvm; 18 using namespace object; 19 20 // Orders increasingly by (SectionID, Address). 21 int llvm::object::compareAddress(const SymEntry *A, const SymEntry *B) { 22 if (A->SectionID != B->SectionID) 23 return A->SectionID < B->SectionID ? -1 : 1; 24 if (A->Address != B->Address) 25 return A->Address < B->Address ? -1 : 1; 26 return 0; 27 } 28 29 static unsigned getSectionID(const ObjectFile &O, SectionRef Sec) { 30 if (auto *M = dyn_cast<MachOObjectFile>(&O)) 31 return M->getSectionID(Sec); 32 if (isa<WasmObjectFile>(&O)) 33 return Sec.getIndex(); 34 if (isa<XCOFFObjectFile>(&O)) 35 return Sec.getIndex(); 36 return cast<COFFObjectFile>(O).getSectionID(Sec); 37 } 38 39 static unsigned getSymbolSectionID(const ObjectFile &O, SymbolRef Sym) { 40 if (auto *M = dyn_cast<MachOObjectFile>(&O)) 41 return M->getSymbolSectionID(Sym); 42 if (const auto *M = dyn_cast<WasmObjectFile>(&O)) 43 return M->getSymbolSectionId(Sym); 44 if (const auto *M = dyn_cast<XCOFFObjectFile>(&O)) 45 return M->getSymbolSectionID(Sym); 46 return cast<COFFObjectFile>(O).getSymbolSectionID(Sym); 47 } 48 49 std::vector<std::pair<SymbolRef, uint64_t>> 50 llvm::object::computeSymbolSizes(const ObjectFile &O) { 51 std::vector<std::pair<SymbolRef, uint64_t>> Ret; 52 53 if (const auto *E = dyn_cast<ELFObjectFileBase>(&O)) { 54 auto Syms = E->symbols(); 55 if (Syms.empty()) 56 Syms = E->getDynamicSymbolIterators(); 57 for (ELFSymbolRef Sym : Syms) 58 Ret.push_back({Sym, Sym.getSize()}); 59 return Ret; 60 } 61 62 // Collect sorted symbol addresses. Include dummy addresses for the end 63 // of each section. 64 std::vector<SymEntry> Addresses; 65 unsigned SymNum = 0; 66 for (symbol_iterator I = O.symbol_begin(), E = O.symbol_end(); I != E; ++I) { 67 SymbolRef Sym = *I; 68 Expected<uint64_t> ValueOrErr = Sym.getValue(); 69 if (!ValueOrErr) 70 // TODO: Actually report errors helpfully. 71 report_fatal_error(ValueOrErr.takeError()); 72 Addresses.push_back({I, *ValueOrErr, SymNum, getSymbolSectionID(O, Sym)}); 73 ++SymNum; 74 } 75 for (SectionRef Sec : O.sections()) { 76 uint64_t Address = Sec.getAddress(); 77 uint64_t Size = Sec.getSize(); 78 Addresses.push_back( 79 {O.symbol_end(), Address + Size, 0, getSectionID(O, Sec)}); 80 } 81 82 if (Addresses.empty()) 83 return Ret; 84 85 array_pod_sort(Addresses.begin(), Addresses.end(), compareAddress); 86 87 // Compute the size as the gap to the next symbol 88 for (unsigned I = 0, N = Addresses.size() - 1; I < N; ++I) { 89 auto &P = Addresses[I]; 90 if (P.I == O.symbol_end()) 91 continue; 92 93 // If multiple symbol have the same address, give both the same size. 94 unsigned NextI = I + 1; 95 while (NextI < N && Addresses[NextI].Address == P.Address) 96 ++NextI; 97 98 uint64_t Size = Addresses[NextI].Address - P.Address; 99 P.Address = Size; 100 } 101 102 // Assign the sorted symbols in the original order. 103 Ret.resize(SymNum); 104 for (SymEntry &P : Addresses) { 105 if (P.I == O.symbol_end()) 106 continue; 107 Ret[P.Number] = {*P.I, P.Address}; 108 } 109 return Ret; 110 } 111