1 //=- tools/dsymutil/DebugMap.h - Generic debug map representation -*- C++ -*-=//
2 //
3 //                             The LLVM Linker
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// \file
11 ///
12 /// This file contains the class declaration of the DebugMap
13 /// entity. A DebugMap lists all the object files linked together to
14 /// produce an executable along with the linked address of all the
15 /// atoms used in these object files.
16 /// The DebugMap is an input to the DwarfLinker class that will
17 /// extract the Dwarf debug information from the referenced object
18 /// files and link their usefull debug info together.
19 //
20 //===----------------------------------------------------------------------===//
21 
22 #ifndef LLVM_TOOLS_DSYMUTIL_DEBUGMAP_H
23 #define LLVM_TOOLS_DSYMUTIL_DEBUGMAP_H
24 
25 #include "llvm/ADT/DenseMap.h"
26 #include "llvm/ADT/Optional.h"
27 #include "llvm/ADT/StringMap.h"
28 #include "llvm/ADT/StringRef.h"
29 #include "llvm/ADT/Triple.h"
30 #include "llvm/ADT/iterator_range.h"
31 #include "llvm/Support/Chrono.h"
32 #include "llvm/Support/ErrorOr.h"
33 #include "llvm/Support/YAMLTraits.h"
34 #include <chrono>
35 #include <cstddef>
36 #include <cstdint>
37 #include <memory>
38 #include <string>
39 #include <utility>
40 #include <vector>
41 
42 namespace llvm {
43 
44 class raw_ostream;
45 
46 namespace dsymutil {
47 
48 class DebugMapObject;
49 
50 /// \brief The DebugMap object stores the list of object files to
51 /// query for debug information along with the mapping between the
52 /// symbols' addresses in the object file to their linked address in
53 /// the linked binary.
54 ///
55 /// A DebugMap producer could look like this:
56 /// DebugMap *DM = new DebugMap();
57 /// for (const auto &Obj: LinkedObjects) {
58 ///     DebugMapObject &DMO = DM->addDebugMapObject(Obj.getPath());
59 ///     for (const auto &Sym: Obj.getLinkedSymbols())
60 ///         DMO.addSymbol(Sym.getName(), Sym.getObjectFileAddress(),
61 ///                       Sym.getBinaryAddress());
62 /// }
63 ///
64 /// A DebugMap consumer can then use the map to link the debug
65 /// information. For example something along the lines of:
66 /// for (const auto &DMO: DM->objects()) {
67 ///     auto Obj = createBinary(DMO.getObjectFilename());
68 ///     for (auto &DIE: Obj.getDwarfDIEs()) {
69 ///         if (SymbolMapping *Sym = DMO.lookup(DIE.getName()))
70 ///             DIE.relocate(Sym->ObjectAddress, Sym->BinaryAddress);
71 ///         else
72 ///             DIE.discardSubtree();
73 ///     }
74 /// }
75 class DebugMap {
76   Triple BinaryTriple;
77   std::string BinaryPath;
78 
79   using ObjectContainer = std::vector<std::unique_ptr<DebugMapObject>>;
80 
81   ObjectContainer Objects;
82 
83   /// For YAML IO support.
84   ///@{
85   friend yaml::MappingTraits<std::unique_ptr<DebugMap>>;
86   friend yaml::MappingTraits<DebugMap>;
87 
88   DebugMap() = default;
89   ///@}
90 
91 public:
92   DebugMap(const Triple &BinaryTriple, StringRef BinaryPath)
93       : BinaryTriple(BinaryTriple), BinaryPath(BinaryPath) {}
94 
95   using const_iterator = ObjectContainer::const_iterator;
96 
97   iterator_range<const_iterator> objects() const {
98     return make_range(begin(), end());
99   }
100 
101   const_iterator begin() const { return Objects.begin(); }
102 
103   const_iterator end() const { return Objects.end(); }
104 
105   /// This function adds an DebugMapObject to the list owned by this
106   /// debug map.
107   DebugMapObject &
108   addDebugMapObject(StringRef ObjectFilePath,
109                     sys::TimePoint<std::chrono::seconds> Timestamp,
110                     uint8_t Type);
111 
112   const Triple &getTriple() const { return BinaryTriple; }
113 
114   StringRef getBinaryPath() const { return BinaryPath; }
115 
116   void print(raw_ostream &OS) const;
117 
118 #ifndef NDEBUG
119   void dump() const;
120 #endif
121 
122   /// Read a debug map for \a InputFile.
123   static ErrorOr<std::vector<std::unique_ptr<DebugMap>>>
124   parseYAMLDebugMap(StringRef InputFile, StringRef PrependPath, bool Verbose);
125 };
126 
127 /// \brief The DebugMapObject represents one object file described by
128 /// the DebugMap. It contains a list of mappings between addresses in
129 /// the object file and in the linked binary for all the linked atoms
130 /// in this object file.
131 class DebugMapObject {
132 public:
133   struct SymbolMapping {
134     Optional<yaml::Hex64> ObjectAddress;
135     yaml::Hex64 BinaryAddress;
136     yaml::Hex32 Size;
137 
138     SymbolMapping(Optional<uint64_t> ObjectAddr, uint64_t BinaryAddress,
139                   uint32_t Size)
140         : BinaryAddress(BinaryAddress), Size(Size) {
141       if (ObjectAddr)
142         ObjectAddress = *ObjectAddr;
143     }
144 
145     /// For YAML IO support
146     SymbolMapping() = default;
147   };
148 
149   using YAMLSymbolMapping = std::pair<std::string, SymbolMapping>;
150   using DebugMapEntry = StringMapEntry<SymbolMapping>;
151 
152   /// \brief Adds a symbol mapping to this DebugMapObject.
153   /// \returns false if the symbol was already registered. The request
154   /// is discarded in this case.
155   bool addSymbol(StringRef SymName, Optional<uint64_t> ObjectAddress,
156                  uint64_t LinkedAddress, uint32_t Size);
157 
158   /// \brief Lookup a symbol mapping.
159   /// \returns null if the symbol isn't found.
160   const DebugMapEntry *lookupSymbol(StringRef SymbolName) const;
161 
162   /// \brief Lookup an objectfile address.
163   /// \returns null if the address isn't found.
164   const DebugMapEntry *lookupObjectAddress(uint64_t Address) const;
165 
166   StringRef getObjectFilename() const { return Filename; }
167 
168   sys::TimePoint<std::chrono::seconds> getTimestamp() const {
169     return Timestamp;
170   }
171 
172   uint8_t getType() const { return Type; }
173 
174   iterator_range<StringMap<SymbolMapping>::const_iterator> symbols() const {
175     return make_range(Symbols.begin(), Symbols.end());
176   }
177 
178   void print(raw_ostream &OS) const;
179 #ifndef NDEBUG
180   void dump() const;
181 #endif
182 
183 private:
184   friend class DebugMap;
185 
186   /// DebugMapObjects can only be constructed by the owning DebugMap.
187   DebugMapObject(StringRef ObjectFilename,
188                  sys::TimePoint<std::chrono::seconds> Timestamp, uint8_t Type);
189 
190   std::string Filename;
191   sys::TimePoint<std::chrono::seconds> Timestamp;
192   StringMap<SymbolMapping> Symbols;
193   DenseMap<uint64_t, DebugMapEntry *> AddressToMapping;
194   uint8_t Type;
195 
196   /// For YAMLIO support.
197   ///@{
198   friend yaml::MappingTraits<dsymutil::DebugMapObject>;
199   friend yaml::SequenceTraits<std::vector<std::unique_ptr<DebugMapObject>>>;
200 
201   DebugMapObject() = default;
202 
203 public:
204   DebugMapObject(DebugMapObject &&) = default;
205   DebugMapObject &operator=(DebugMapObject &&) = default;
206   ///@}
207 };
208 
209 } // end namespace dsymutil
210 
211 } // end namespace llvm
212 
213 LLVM_YAML_IS_SEQUENCE_VECTOR(llvm::dsymutil::DebugMapObject::YAMLSymbolMapping)
214 
215 namespace llvm {
216 namespace yaml {
217 
218 using namespace llvm::dsymutil;
219 
220 template <>
221 struct MappingTraits<std::pair<std::string, DebugMapObject::SymbolMapping>> {
222   static void mapping(IO &io,
223                       std::pair<std::string, DebugMapObject::SymbolMapping> &s);
224   static const bool flow = true;
225 };
226 
227 template <> struct MappingTraits<dsymutil::DebugMapObject> {
228   struct YamlDMO;
229   static void mapping(IO &io, dsymutil::DebugMapObject &DMO);
230 };
231 
232 template <> struct ScalarTraits<Triple> {
233   static void output(const Triple &val, void *, raw_ostream &out);
234   static StringRef input(StringRef scalar, void *, Triple &value);
235   static bool mustQuote(StringRef) { return true; }
236 };
237 
238 template <>
239 struct SequenceTraits<std::vector<std::unique_ptr<dsymutil::DebugMapObject>>> {
240   static size_t
241   size(IO &io, std::vector<std::unique_ptr<dsymutil::DebugMapObject>> &seq);
242   static dsymutil::DebugMapObject &
243   element(IO &, std::vector<std::unique_ptr<dsymutil::DebugMapObject>> &seq,
244           size_t index);
245 };
246 
247 template <> struct MappingTraits<dsymutil::DebugMap> {
248   static void mapping(IO &io, dsymutil::DebugMap &DM);
249 };
250 
251 template <> struct MappingTraits<std::unique_ptr<dsymutil::DebugMap>> {
252   static void mapping(IO &io, std::unique_ptr<dsymutil::DebugMap> &DM);
253 };
254 
255 } // end namespace yaml
256 } // end namespace llvm
257 
258 #endif // LLVM_TOOLS_DSYMUTIL_DEBUGMAP_H
259