xref: /llvm-project/llvm/lib/ObjCopy/COFF/COFFObject.cpp (revision 54dad9e269f365d0eff2f63c5ee843564eecca7e)
1 //===- COFFObject.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 "COFFObject.h"
10 #include "llvm/ADT/DenseSet.h"
11 
12 namespace llvm {
13 namespace objcopy {
14 namespace coff {
15 
16 using namespace object;
17 
18 void Object::addSymbols(ArrayRef<Symbol> NewSymbols) {
19   for (Symbol S : NewSymbols) {
20     S.UniqueId = NextSymbolUniqueId++;
21     Symbols.emplace_back(S);
22   }
23   updateSymbols();
24 }
25 
26 void Object::updateSymbols() {
27   SymbolMap = DenseMap<size_t, Symbol *>(Symbols.size());
28   for (Symbol &Sym : Symbols)
29     SymbolMap[Sym.UniqueId] = &Sym;
30 }
31 
32 const Symbol *Object::findSymbol(size_t UniqueId) const {
33   return SymbolMap.lookup(UniqueId);
34 }
35 
36 Error Object::removeSymbols(
37     function_ref<Expected<bool>(const Symbol &)> ToRemove) {
38   Error Errs = Error::success();
39   llvm::erase_if(Symbols, [ToRemove, &Errs](const Symbol &Sym) {
40     Expected<bool> ShouldRemove = ToRemove(Sym);
41     if (!ShouldRemove) {
42       Errs = joinErrors(std::move(Errs), ShouldRemove.takeError());
43       return false;
44     }
45     return *ShouldRemove;
46   });
47 
48   updateSymbols();
49   return Errs;
50 }
51 
52 Error Object::markSymbols() {
53   for (Symbol &Sym : Symbols)
54     Sym.Referenced = false;
55   for (const Section &Sec : Sections) {
56     for (const Relocation &R : Sec.Relocs) {
57       auto It = SymbolMap.find(R.Target);
58       if (It == SymbolMap.end())
59         return createStringError(object_error::invalid_symbol_index,
60                                  "relocation target %zu not found", R.Target);
61       It->second->Referenced = true;
62     }
63   }
64   return Error::success();
65 }
66 
67 void Object::addSections(ArrayRef<Section> NewSections) {
68   for (Section S : NewSections) {
69     S.UniqueId = NextSectionUniqueId++;
70     Sections.emplace_back(S);
71   }
72   updateSections();
73 }
74 
75 void Object::updateSections() {
76   SectionMap = DenseMap<ssize_t, Section *>(Sections.size());
77   size_t Index = 1;
78   for (Section &S : Sections) {
79     SectionMap[S.UniqueId] = &S;
80     S.Index = Index++;
81   }
82 }
83 
84 const Section *Object::findSection(ssize_t UniqueId) const {
85   return SectionMap.lookup(UniqueId);
86 }
87 
88 void Object::removeSections(function_ref<bool(const Section &)> ToRemove) {
89   DenseSet<ssize_t> AssociatedSections;
90   auto RemoveAssociated = [&AssociatedSections](const Section &Sec) {
91     return AssociatedSections.contains(Sec.UniqueId);
92   };
93   do {
94     DenseSet<ssize_t> RemovedSections;
95     llvm::erase_if(Sections, [ToRemove, &RemovedSections](const Section &Sec) {
96       bool Remove = ToRemove(Sec);
97       if (Remove)
98         RemovedSections.insert(Sec.UniqueId);
99       return Remove;
100     });
101     // Remove all symbols referring to the removed sections.
102     AssociatedSections.clear();
103     llvm::erase_if(
104         Symbols, [&RemovedSections, &AssociatedSections](const Symbol &Sym) {
105           // If there are sections that are associative to a removed
106           // section,
107           // remove those as well as nothing will include them (and we can't
108           // leave them dangling).
109           if (RemovedSections.contains(Sym.AssociativeComdatTargetSectionId))
110             AssociatedSections.insert(Sym.TargetSectionId);
111           return RemovedSections.contains(Sym.TargetSectionId);
112         });
113     ToRemove = RemoveAssociated;
114   } while (!AssociatedSections.empty());
115   updateSections();
116   updateSymbols();
117 }
118 
119 void Object::truncateSections(function_ref<bool(const Section &)> ToTruncate) {
120   for (Section &Sec : Sections) {
121     if (ToTruncate(Sec)) {
122       Sec.clearContents();
123       Sec.Relocs.clear();
124       Sec.Header.SizeOfRawData = 0;
125     }
126   }
127 }
128 
129 } // end namespace coff
130 } // end namespace objcopy
131 } // end namespace llvm
132