1 //===- tools/dsymutil/MachODebugMapParser.cpp - Parse STABS debug maps ----===//
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "BinaryHolder.h"
13 #include "llvm/Object/MachO.h"
14 #include "llvm/Support/Path.h"
15 #include "llvm/Support/raw_ostream.h"
19 using namespace llvm::dsymutil;
20 using namespace llvm::object;
22 class MachODebugMapParser {
24 MachODebugMapParser(StringRef BinaryPath, StringRef PathPrefix = "",
26 : BinaryPath(BinaryPath), PathPrefix(PathPrefix),
27 MainBinaryHolder(Verbose), CurrentObjectHolder(Verbose),
28 CurrentDebugMapObject(nullptr) {}
30 /// \brief Parses and returns the DebugMap of the input binary.
31 /// \returns an error in case the provided BinaryPath doesn't exist
32 /// or isn't of a supported type.
33 ErrorOr<std::unique_ptr<DebugMap>> parse();
36 std::string BinaryPath;
37 std::string PathPrefix;
39 /// Owns the MemoryBuffer for the main binary.
40 BinaryHolder MainBinaryHolder;
41 /// Map of the binary symbol addresses.
42 StringMap<uint64_t> MainBinarySymbolAddresses;
43 StringRef MainBinaryStrings;
44 /// The constructed DebugMap.
45 std::unique_ptr<DebugMap> Result;
47 /// Owns the MemoryBuffer for the currently handled object file.
48 BinaryHolder CurrentObjectHolder;
49 /// Map of the currently processed object file symbol addresses.
50 StringMap<uint64_t> CurrentObjectAddresses;
51 /// Element of the debug map corresponfing to the current object file.
52 DebugMapObject *CurrentDebugMapObject;
54 /// Holds function info while function scope processing.
55 const char *CurrentFunctionName;
56 uint64_t CurrentFunctionAddress;
58 void switchToNewDebugMapObject(StringRef Filename, sys::TimeValue Timestamp);
59 void resetParserState();
60 uint64_t getMainBinarySymbolAddress(StringRef Name);
61 void loadMainBinarySymbols(const MachOObjectFile &MainBinary);
62 void loadCurrentObjectFileSymbols(const object::MachOObjectFile &Obj);
63 void handleStabSymbolTableEntry(uint32_t StringIndex, uint8_t Type,
64 uint8_t SectionIndex, uint16_t Flags,
67 template <typename STEType> void handleStabDebugMapEntry(const STEType &STE) {
68 handleStabSymbolTableEntry(STE.n_strx, STE.n_type, STE.n_sect, STE.n_desc,
73 static void Warning(const Twine &Msg) { errs() << "warning: " + Msg + "\n"; }
76 /// Reset the parser state coresponding to the current object
77 /// file. This is to be called after an object file is finished
79 void MachODebugMapParser::resetParserState() {
80 CurrentObjectAddresses.clear();
81 CurrentDebugMapObject = nullptr;
84 /// Create a new DebugMapObject. This function resets the state of the
85 /// parser that was referring to the last object file and sets
86 /// everything up to add symbols to the new one.
87 void MachODebugMapParser::switchToNewDebugMapObject(StringRef Filename,
88 sys::TimeValue Timestamp) {
91 SmallString<80> Path(PathPrefix);
92 sys::path::append(Path, Filename);
95 CurrentObjectHolder.GetFilesAs<MachOObjectFile>(Path, Timestamp);
96 if (auto Error = MachOOrError.getError()) {
97 Warning(Twine("cannot open debug object \"") + Path.str() + "\": " +
98 Error.message() + "\n");
103 CurrentObjectHolder.GetAs<MachOObjectFile>(Result->getTriple());
104 if (auto Err = ErrOrAchObj.getError()) {
105 return Warning(Twine("cannot open debug object \"") + Path.str() + "\": " +
106 Err.message() + "\n");
109 CurrentDebugMapObject = &Result->addDebugMapObject(Path, Timestamp);
110 loadCurrentObjectFileSymbols(*ErrOrAchObj);
113 /// This main parsing routine tries to open the main binary and if
114 /// successful iterates over the STAB entries. The real parsing is
115 /// done in handleStabSymbolTableEntry.
116 ErrorOr<std::unique_ptr<DebugMap>> MachODebugMapParser::parse() {
117 auto MainBinOrError =
118 MainBinaryHolder.GetFilesAs<MachOObjectFile>(BinaryPath);
119 if (auto Error = MainBinOrError.getError())
122 if (MainBinOrError->size() != 1)
123 return make_error_code(object::object_error::invalid_file_type);
125 const MachOObjectFile &MainBinary = *MainBinOrError->front();
126 loadMainBinarySymbols(MainBinary);
127 Result = make_unique<DebugMap>(BinaryHolder::getTriple(MainBinary));
128 MainBinaryStrings = MainBinary.getStringTableData();
129 for (const SymbolRef &Symbol : MainBinary.symbols()) {
130 const DataRefImpl &DRI = Symbol.getRawDataRefImpl();
131 if (MainBinary.is64Bit())
132 handleStabDebugMapEntry(MainBinary.getSymbol64TableEntry(DRI));
134 handleStabDebugMapEntry(MainBinary.getSymbolTableEntry(DRI));
138 return std::move(Result);
141 /// Interpret the STAB entries to fill the DebugMap.
142 void MachODebugMapParser::handleStabSymbolTableEntry(uint32_t StringIndex,
144 uint8_t SectionIndex,
147 if (!(Type & MachO::N_STAB))
150 const char *Name = &MainBinaryStrings.data()[StringIndex];
152 // An N_OSO entry represents the start of a new object file description.
153 if (Type == MachO::N_OSO) {
154 sys::TimeValue Timestamp;
155 Timestamp.fromEpochTime(Value);
156 return switchToNewDebugMapObject(Name, Timestamp);
159 // If the last N_OSO object file wasn't found,
160 // CurrentDebugMapObject will be null. Do not update anything
161 // until we find the next valid N_OSO entry.
162 if (!CurrentDebugMapObject)
168 // This is a global variable. We need to query the main binary
169 // symbol table to find its address as it might not be in the
170 // debug map (for common symbols).
171 Value = getMainBinarySymbolAddress(Name);
174 // Functions are scopes in STABS. They have an end marker that
175 // contains the function size.
176 if (Name[0] == '\0') {
178 Value = CurrentFunctionAddress;
179 Name = CurrentFunctionName;
182 CurrentFunctionName = Name;
183 CurrentFunctionAddress = Value;
192 auto ObjectSymIt = CurrentObjectAddresses.find(Name);
193 if (ObjectSymIt == CurrentObjectAddresses.end())
194 return Warning("could not find object file symbol for symbol " +
196 if (!CurrentDebugMapObject->addSymbol(Name, ObjectSymIt->getValue(), Value,
198 return Warning(Twine("failed to insert symbol '") + Name +
199 "' in the debug map.");
202 /// Load the current object file symbols into CurrentObjectAddresses.
203 void MachODebugMapParser::loadCurrentObjectFileSymbols(
204 const object::MachOObjectFile &Obj) {
205 CurrentObjectAddresses.clear();
207 for (auto Sym : Obj.symbols()) {
208 uint64_t Addr = Sym.getValue();
209 ErrorOr<StringRef> Name = Sym.getName();
212 CurrentObjectAddresses[*Name] = Addr;
216 /// Lookup a symbol address in the main binary symbol table. The
217 /// parser only needs to query common symbols, thus not every symbol's
218 /// address is available through this function.
219 uint64_t MachODebugMapParser::getMainBinarySymbolAddress(StringRef Name) {
220 auto Sym = MainBinarySymbolAddresses.find(Name);
221 if (Sym == MainBinarySymbolAddresses.end())
226 /// Load the interesting main binary symbols' addresses into
227 /// MainBinarySymbolAddresses.
228 void MachODebugMapParser::loadMainBinarySymbols(
229 const MachOObjectFile &MainBinary) {
230 section_iterator Section = MainBinary.section_end();
231 MainBinarySymbolAddresses.clear();
232 for (const auto &Sym : MainBinary.symbols()) {
233 SymbolRef::Type Type = Sym.getType();
234 // Skip undefined and STAB entries.
235 if ((Type & SymbolRef::ST_Debug) || (Type & SymbolRef::ST_Unknown))
237 // The only symbols of interest are the global variables. These
238 // are the only ones that need to be queried because the address
239 // of common data won't be described in the debug map. All other
240 // addresses should be fetched for the debug map.
241 if (!(Sym.getFlags() & SymbolRef::SF_Global) || Sym.getSection(Section) ||
242 Section == MainBinary.section_end() || Section->isText())
244 uint64_t Addr = Sym.getValue();
245 ErrorOr<StringRef> NameOrErr = Sym.getName();
248 StringRef Name = *NameOrErr;
249 if (Name.size() == 0 || Name[0] == '\0')
251 MainBinarySymbolAddresses[Name] = Addr;
257 llvm::ErrorOr<std::unique_ptr<DebugMap>> parseDebugMap(StringRef InputFile,
258 StringRef PrependPath,
262 MachODebugMapParser Parser(InputFile, PrependPath, Verbose);
263 return Parser.parse();
265 return DebugMap::parseYAMLDebugMap(InputFile, PrependPath, Verbose);