1//===- Object.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 "Object.h"
10#include "llvm/ADT/DenseSet.h"
11#include <algorithm>
12
13namespace llvm {
14namespace objcopy {
15namespace coff {
16
17using namespace object;
18
19void Object::addSymbols(ArrayRef<Symbol> NewSymbols) {
20  for (Symbol S : NewSymbols) {
21    S.UniqueId = NextSymbolUniqueId++;
22    Symbols.emplace_back(S);
23  }
24  updateSymbols();
25}
26
27void Object::updateSymbols() {
28  SymbolMap = DenseMap<size_t, Symbol *>(Symbols.size());
29  for (Symbol &Sym : Symbols)
30    SymbolMap[Sym.UniqueId] = &Sym;
31}
32
33const Symbol *Object::findSymbol(size_t UniqueId) const {
34  auto It = SymbolMap.find(UniqueId);
35  if (It == SymbolMap.end())
36    return nullptr;
37  return It->second;
38}
39
40void Object::removeSymbols(function_ref<bool(const Symbol &)> ToRemove) {
41  Symbols.erase(
42      std::remove_if(std::begin(Symbols), std::end(Symbols),
43                     [ToRemove](const Symbol &Sym) { return ToRemove(Sym); }),
44      std::end(Symbols));
45  updateSymbols();
46}
47
48Error Object::markSymbols() {
49  for (Symbol &Sym : Symbols)
50    Sym.Referenced = false;
51  for (const Section &Sec : Sections) {
52    for (const Relocation &R : Sec.Relocs) {
53      auto It = SymbolMap.find(R.Target);
54      if (It == SymbolMap.end())
55        return createStringError(object_error::invalid_symbol_index,
56                                 "relocation target %zu not found", R.Target);
57      It->second->Referenced = true;
58    }
59  }
60  return Error::success();
61}
62
63void Object::addSections(ArrayRef<Section> NewSections) {
64  for (Section S : NewSections) {
65    S.UniqueId = NextSectionUniqueId++;
66    Sections.emplace_back(S);
67  }
68  updateSections();
69}
70
71void Object::updateSections() {
72  SectionMap = DenseMap<ssize_t, Section *>(Sections.size());
73  size_t Index = 1;
74  for (Section &S : Sections) {
75    SectionMap[S.UniqueId] = &S;
76    S.Index = Index++;
77  }
78}
79
80const Section *Object::findSection(ssize_t UniqueId) const {
81  auto It = SectionMap.find(UniqueId);
82  if (It == SectionMap.end())
83    return nullptr;
84  return It->second;
85}
86
87void Object::removeSections(function_ref<bool(const Section &)> ToRemove) {
88  DenseSet<ssize_t> AssociatedSections;
89  auto RemoveAssociated = [&AssociatedSections](const Section &Sec) {
90    return AssociatedSections.count(Sec.UniqueId) == 1;
91  };
92  do {
93    DenseSet<ssize_t> RemovedSections;
94    Sections.erase(
95        std::remove_if(std::begin(Sections), std::end(Sections),
96                       [ToRemove, &RemovedSections](const Section &Sec) {
97                         bool Remove = ToRemove(Sec);
98                         if (Remove)
99                           RemovedSections.insert(Sec.UniqueId);
100                         return Remove;
101                       }),
102        std::end(Sections));
103    // Remove all symbols referring to the removed sections.
104    AssociatedSections.clear();
105    Symbols.erase(
106        std::remove_if(
107            std::begin(Symbols), std::end(Symbols),
108            [&RemovedSections, &AssociatedSections](const Symbol &Sym) {
109              // If there are sections that are associative to a removed
110              // section,
111              // remove those as well as nothing will include them (and we can't
112              // leave them dangling).
113              if (RemovedSections.count(Sym.AssociativeComdatTargetSectionId) ==
114                  1)
115                AssociatedSections.insert(Sym.TargetSectionId);
116              return RemovedSections.count(Sym.TargetSectionId) == 1;
117            }),
118        std::end(Symbols));
119    ToRemove = RemoveAssociated;
120  } while (!AssociatedSections.empty());
121  updateSections();
122  updateSymbols();
123}
124
125void Object::truncateSections(function_ref<bool(const Section &)> ToTruncate) {
126  for (Section &Sec : Sections) {
127    if (ToTruncate(Sec)) {
128      Sec.clearContents();
129      Sec.Relocs.clear();
130      Sec.Header.SizeOfRawData = 0;
131    }
132  }
133}
134
135} // end namespace coff
136} // end namespace objcopy
137} // end namespace llvm
138