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
compareAddress(const SymEntry * A,const SymEntry * B)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
getSectionID(const ObjectFile & O,SectionRef Sec)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
getSymbolSectionID(const ObjectFile & O,SymbolRef Sym)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>>
computeSymbolSizes(const ObjectFile & O)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