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);
59 void resetParserState();
60 uint64_t getMainBinarySymbolAddress(StringRef Name);
61 void loadMainBinarySymbols();
62 void loadCurrentObjectFileSymbols();
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) {
90 SmallString<80> Path(PathPrefix);
91 sys::path::append(Path, Filename);
93 auto MachOOrError = CurrentObjectHolder.GetFileAs<MachOObjectFile>(Path);
94 if (auto Error = MachOOrError.getError()) {
95 Warning(Twine("cannot open debug object \"") + Path.str() + "\": " +
96 Error.message() + "\n");
100 loadCurrentObjectFileSymbols();
101 CurrentDebugMapObject = &Result->addDebugMapObject(Path);
104 static Triple getTriple(const object::MachOObjectFile &Obj) {
105 Triple TheTriple("unknown-unknown-unknown");
106 TheTriple.setArch(Triple::ArchType(Obj.getArch()));
107 TheTriple.setObjectFormat(Triple::MachO);
111 /// This main parsing routine tries to open the main binary and if
112 /// successful iterates over the STAB entries. The real parsing is
113 /// done in handleStabSymbolTableEntry.
114 ErrorOr<std::unique_ptr<DebugMap>> MachODebugMapParser::parse() {
115 auto MainBinOrError = MainBinaryHolder.GetFileAs<MachOObjectFile>(BinaryPath);
116 if (auto Error = MainBinOrError.getError())
119 const MachOObjectFile &MainBinary = *MainBinOrError;
120 loadMainBinarySymbols();
121 Result = make_unique<DebugMap>(getTriple(MainBinary));
122 MainBinaryStrings = MainBinary.getStringTableData();
123 for (const SymbolRef &Symbol : MainBinary.symbols()) {
124 const DataRefImpl &DRI = Symbol.getRawDataRefImpl();
125 if (MainBinary.is64Bit())
126 handleStabDebugMapEntry(MainBinary.getSymbol64TableEntry(DRI));
128 handleStabDebugMapEntry(MainBinary.getSymbolTableEntry(DRI));
132 return std::move(Result);
135 /// Interpret the STAB entries to fill the DebugMap.
136 void MachODebugMapParser::handleStabSymbolTableEntry(uint32_t StringIndex,
138 uint8_t SectionIndex,
141 if (!(Type & MachO::N_STAB))
144 const char *Name = &MainBinaryStrings.data()[StringIndex];
146 // An N_OSO entry represents the start of a new object file description.
147 if (Type == MachO::N_OSO)
148 return switchToNewDebugMapObject(Name);
150 // If the last N_OSO object file wasn't found,
151 // CurrentDebugMapObject will be null. Do not update anything
152 // until we find the next valid N_OSO entry.
153 if (!CurrentDebugMapObject)
159 // This is a global variable. We need to query the main binary
160 // symbol table to find its address as it might not be in the
161 // debug map (for common symbols).
162 Value = getMainBinarySymbolAddress(Name);
165 // Functions are scopes in STABS. They have an end marker that
166 // contains the function size.
167 if (Name[0] == '\0') {
169 Value = CurrentFunctionAddress;
170 Name = CurrentFunctionName;
173 CurrentFunctionName = Name;
174 CurrentFunctionAddress = Value;
183 auto ObjectSymIt = CurrentObjectAddresses.find(Name);
184 if (ObjectSymIt == CurrentObjectAddresses.end())
185 return Warning("could not find object file symbol for symbol " +
187 if (!CurrentDebugMapObject->addSymbol(Name, ObjectSymIt->getValue(), Value,
189 return Warning(Twine("failed to insert symbol '") + Name +
190 "' in the debug map.");
193 /// Load the current object file symbols into CurrentObjectAddresses.
194 void MachODebugMapParser::loadCurrentObjectFileSymbols() {
195 CurrentObjectAddresses.clear();
197 for (auto Sym : CurrentObjectHolder.Get().symbols()) {
198 uint64_t Addr = Sym.getValue();
199 ErrorOr<StringRef> Name = Sym.getName();
202 CurrentObjectAddresses[*Name] = Addr;
206 /// Lookup a symbol address in the main binary symbol table. The
207 /// parser only needs to query common symbols, thus not every symbol's
208 /// address is available through this function.
209 uint64_t MachODebugMapParser::getMainBinarySymbolAddress(StringRef Name) {
210 auto Sym = MainBinarySymbolAddresses.find(Name);
211 if (Sym == MainBinarySymbolAddresses.end())
216 /// Load the interesting main binary symbols' addresses into
217 /// MainBinarySymbolAddresses.
218 void MachODebugMapParser::loadMainBinarySymbols() {
219 const MachOObjectFile &MainBinary = MainBinaryHolder.GetAs<MachOObjectFile>();
220 section_iterator Section = MainBinary.section_end();
221 for (const auto &Sym : MainBinary.symbols()) {
222 SymbolRef::Type Type = Sym.getType();
223 // Skip undefined and STAB entries.
224 if ((Type & SymbolRef::ST_Debug) || (Type & SymbolRef::ST_Unknown))
226 // The only symbols of interest are the global variables. These
227 // are the only ones that need to be queried because the address
228 // of common data won't be described in the debug map. All other
229 // addresses should be fetched for the debug map.
230 if (!(Sym.getFlags() & SymbolRef::SF_Global) || Sym.getSection(Section) ||
231 Section == MainBinary.section_end() || Section->isText())
233 uint64_t Addr = Sym.getValue();
234 ErrorOr<StringRef> NameOrErr = Sym.getName();
237 StringRef Name = *NameOrErr;
238 if (Name.size() == 0 || Name[0] == '\0')
240 MainBinarySymbolAddresses[Name] = Addr;
246 llvm::ErrorOr<std::unique_ptr<DebugMap>> parseDebugMap(StringRef InputFile,
247 StringRef PrependPath,
251 MachODebugMapParser Parser(InputFile, PrependPath, Verbose);
252 return Parser.parse();
254 return DebugMap::parseYAMLDebugMap(InputFile, PrependPath, Verbose);