129 lines · cpp
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-exception6//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 17using namespace llvm;18using namespace object;19 20// Orders increasingly by (SectionID, Address).21int 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 29static 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 39static 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 49std::vector<std::pair<SymbolRef, uint64_t>>50llvm::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 if (const auto *E = dyn_cast<XCOFFObjectFile>(&O)) {63 for (XCOFFSymbolRef Sym : E->symbols())64 Ret.push_back({Sym, Sym.getSize()});65 return Ret;66 }67 68 if (const auto *E = dyn_cast<WasmObjectFile>(&O)) {69 for (SymbolRef Sym : E->symbols()) {70 Ret.push_back({Sym, E->getSymbolSize(Sym)});71 }72 return Ret;73 }74 75 // Collect sorted symbol addresses. Include dummy addresses for the end76 // of each section.77 std::vector<SymEntry> Addresses;78 unsigned SymNum = 0;79 for (symbol_iterator I = O.symbol_begin(), E = O.symbol_end(); I != E; ++I) {80 SymbolRef Sym = *I;81 Expected<uint64_t> ValueOrErr = Sym.getValue();82 if (!ValueOrErr)83 // TODO: Actually report errors helpfully.84 report_fatal_error(ValueOrErr.takeError());85 Addresses.push_back({I, *ValueOrErr, SymNum, getSymbolSectionID(O, Sym)});86 ++SymNum;87 }88 for (SectionRef Sec : O.sections()) {89 uint64_t Address = Sec.getAddress();90 uint64_t Size = Sec.getSize();91 Addresses.push_back(92 {O.symbol_end(), Address + Size, 0, getSectionID(O, Sec)});93 }94 95 if (Addresses.empty())96 return Ret;97 98 array_pod_sort(Addresses.begin(), Addresses.end(), compareAddress);99 100 // Compute the size as the gap to the next symbol. If multiple symbols have101 // the same address, give both the same size. Because Addresses is sorted,102 // use two pointers to keep track of the current symbol vs. the next symbol103 // that doesn't have the same address for size computation.104 for (unsigned I = 0, NextI = 0, N = Addresses.size() - 1; I < N; ++I) {105 auto &P = Addresses[I];106 if (P.I == O.symbol_end())107 continue;108 109 // If the next pointer is behind, update it to the next symbol.110 if (NextI <= I) {111 NextI = I + 1;112 while (NextI < N && Addresses[NextI].Address == P.Address)113 ++NextI;114 }115 116 uint64_t Size = Addresses[NextI].Address - P.Address;117 P.Address = Size;118 }119 120 // Assign the sorted symbols in the original order.121 Ret.resize(SymNum);122 for (SymEntry &P : Addresses) {123 if (P.I == O.symbol_end())124 continue;125 Ret[P.Number] = {*P.I, P.Address};126 }127 return Ret;128}129