1 //===-- llvm-symbolizer.cpp - Simple addr2line-like symbolizer ------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This utility works much like "addr2line". It is able of transforming
11 // tuples (module name, module offset) to code locations (function name,
12 // file, line number, column number). It is targeted for compiler-rt tools
13 // (especially AddressSanitizer and ThreadSanitizer) that can use it
14 // to symbolize stack traces in their error reports.
15 //
16 //===----------------------------------------------------------------------===//
17
18 #include "llvm/ADT/OwningPtr.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/DebugInfo/DIContext.h"
21 #include "llvm/Object/ObjectFile.h"
22 #include "llvm/Support/CommandLine.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/Support/ManagedStatic.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/PrettyStackTrace.h"
27 #include "llvm/Support/Signals.h"
28 #include "llvm/Support/raw_ostream.h"
29
30 #include <cstdio>
31 #include <cstring>
32 #include <map>
33 #include <string>
34
35 using namespace llvm;
36 using namespace object;
37 using std::string;
38
39 static cl::opt<bool>
40 UseSymbolTable("use-symbol-table", cl::init(true),
41 cl::desc("Prefer names in symbol table to names "
42 "in debug info"));
43
44 static cl::opt<bool>
45 PrintFunctions("functions", cl::init(true),
46 cl::desc("Print function names as well as line "
47 "information for a given address"));
48
49 static cl::opt<bool>
50 PrintInlining("inlining", cl::init(true),
51 cl::desc("Print all inlined frames for a given address"));
52
53 static cl::opt<bool>
54 Demangle("demangle", cl::init(true),
55 cl::desc("Demangle function names"));
56
57 static StringRef ToolInvocationPath;
58
error(error_code ec)59 static bool error(error_code ec) {
60 if (!ec) return false;
61 errs() << ToolInvocationPath << ": error reading file: "
62 << ec.message() << ".\n";
63 return true;
64 }
65
getDILineInfoSpecifierFlags()66 static uint32_t getDILineInfoSpecifierFlags() {
67 uint32_t Flags = llvm::DILineInfoSpecifier::FileLineInfo |
68 llvm::DILineInfoSpecifier::AbsoluteFilePath;
69 if (PrintFunctions)
70 Flags |= llvm::DILineInfoSpecifier::FunctionName;
71 return Flags;
72 }
73
patchFunctionNameInDILineInfo(const string & NewFunctionName,DILineInfo & LineInfo)74 static void patchFunctionNameInDILineInfo(const string &NewFunctionName,
75 DILineInfo &LineInfo) {
76 string FileName = LineInfo.getFileName();
77 LineInfo = DILineInfo(StringRef(FileName), StringRef(NewFunctionName),
78 LineInfo.getLine(), LineInfo.getColumn());
79 }
80
81 namespace {
82 class ModuleInfo {
83 OwningPtr<ObjectFile> Module;
84 OwningPtr<DIContext> DebugInfoContext;
85 public:
ModuleInfo(ObjectFile * Obj,DIContext * DICtx)86 ModuleInfo(ObjectFile *Obj, DIContext *DICtx)
87 : Module(Obj), DebugInfoContext(DICtx) {}
symbolizeCode(uint64_t ModuleOffset) const88 DILineInfo symbolizeCode(uint64_t ModuleOffset) const {
89 DILineInfo LineInfo;
90 if (DebugInfoContext) {
91 LineInfo = DebugInfoContext->getLineInfoForAddress(
92 ModuleOffset, getDILineInfoSpecifierFlags());
93 }
94 // Override function name from symbol table if necessary.
95 if (PrintFunctions && UseSymbolTable) {
96 string Function;
97 if (getFunctionNameFromSymbolTable(ModuleOffset, Function)) {
98 patchFunctionNameInDILineInfo(Function, LineInfo);
99 }
100 }
101 return LineInfo;
102 }
symbolizeInlinedCode(uint64_t ModuleOffset) const103 DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset) const {
104 DIInliningInfo InlinedContext;
105 if (DebugInfoContext) {
106 InlinedContext = DebugInfoContext->getInliningInfoForAddress(
107 ModuleOffset, getDILineInfoSpecifierFlags());
108 }
109 // Make sure there is at least one frame in context.
110 if (InlinedContext.getNumberOfFrames() == 0) {
111 InlinedContext.addFrame(DILineInfo());
112 }
113 // Override the function name in lower frame with name from symbol table.
114 if (PrintFunctions && UseSymbolTable) {
115 DIInliningInfo PatchedInlinedContext;
116 for (uint32_t i = 0, n = InlinedContext.getNumberOfFrames();
117 i != n; i++) {
118 DILineInfo LineInfo = InlinedContext.getFrame(i);
119 if (i == n - 1) {
120 string Function;
121 if (getFunctionNameFromSymbolTable(ModuleOffset, Function)) {
122 patchFunctionNameInDILineInfo(Function, LineInfo);
123 }
124 }
125 PatchedInlinedContext.addFrame(LineInfo);
126 }
127 InlinedContext = PatchedInlinedContext;
128 }
129 return InlinedContext;
130 }
131 private:
getFunctionNameFromSymbolTable(size_t Address,string & FunctionName) const132 bool getFunctionNameFromSymbolTable(size_t Address,
133 string &FunctionName) const {
134 assert(Module);
135 error_code ec;
136 for (symbol_iterator si = Module->begin_symbols(),
137 se = Module->end_symbols();
138 si != se; si.increment(ec)) {
139 if (error(ec)) return false;
140 uint64_t SymbolAddress;
141 uint64_t SymbolSize;
142 if (error(si->getAddress(SymbolAddress))) continue;
143 if (error(si->getSize(SymbolSize))) continue;
144 // FIXME: If a function has alias, there are two entries in symbol table
145 // with same address size. Make sure we choose the correct one.
146 if (SymbolAddress <= Address && Address < SymbolAddress + SymbolSize) {
147 StringRef Name;
148 if (error(si->getName(Name))) continue;
149 FunctionName = Name.str();
150 return true;
151 }
152 }
153 return false;
154 }
155 };
156
157 typedef std::map<string, ModuleInfo*> ModuleMapTy;
158 typedef ModuleMapTy::iterator ModuleMapIter;
159 typedef ModuleMapTy::const_iterator ModuleMapConstIter;
160 } // namespace
161
162 static ModuleMapTy Modules;
163
isFullNameOfDwarfSection(const StringRef & FullName,const StringRef & ShortName)164 static bool isFullNameOfDwarfSection(const StringRef &FullName,
165 const StringRef &ShortName) {
166 static const char kDwarfPrefix[] = "__DWARF,";
167 StringRef Name = FullName;
168 // Skip "__DWARF," prefix.
169 if (Name.startswith(kDwarfPrefix))
170 Name = Name.substr(strlen(kDwarfPrefix));
171 // Skip . and _ prefixes.
172 Name = Name.substr(Name.find_first_not_of("._"));
173 return (Name == ShortName);
174 }
175
176 // Returns true if the object endianness is known.
getObjectEndianness(const ObjectFile * Obj,bool & IsLittleEndian)177 static bool getObjectEndianness(const ObjectFile *Obj,
178 bool &IsLittleEndian) {
179 // FIXME: Implement this when libLLVMObject allows to do it easily.
180 IsLittleEndian = true;
181 return true;
182 }
183
getOrCreateModuleInfo(const string & ModuleName)184 static ModuleInfo *getOrCreateModuleInfo(const string &ModuleName) {
185 ModuleMapIter I = Modules.find(ModuleName);
186 if (I != Modules.end())
187 return I->second;
188
189 OwningPtr<MemoryBuffer> Buff;
190 MemoryBuffer::getFile(ModuleName, Buff);
191 ObjectFile *Obj = ObjectFile::createObjectFile(Buff.take());
192 if (Obj == 0) {
193 // Module name doesn't point to a valid object file.
194 Modules.insert(make_pair(ModuleName, (ModuleInfo*)0));
195 return 0;
196 }
197
198 DIContext *Context = 0;
199 bool IsLittleEndian;
200 if (getObjectEndianness(Obj, IsLittleEndian)) {
201 StringRef DebugInfoSection;
202 StringRef DebugAbbrevSection;
203 StringRef DebugLineSection;
204 StringRef DebugArangesSection;
205 StringRef DebugStringSection;
206 StringRef DebugRangesSection;
207 error_code ec;
208 for (section_iterator i = Obj->begin_sections(),
209 e = Obj->end_sections();
210 i != e; i.increment(ec)) {
211 if (error(ec)) break;
212 StringRef Name;
213 if (error(i->getName(Name))) continue;
214 StringRef Data;
215 if (error(i->getContents(Data))) continue;
216 if (isFullNameOfDwarfSection(Name, "debug_info"))
217 DebugInfoSection = Data;
218 else if (isFullNameOfDwarfSection(Name, "debug_abbrev"))
219 DebugAbbrevSection = Data;
220 else if (isFullNameOfDwarfSection(Name, "debug_line"))
221 DebugLineSection = Data;
222 // Don't use debug_aranges for now, as address ranges contained
223 // there may not cover all instructions in the module
224 // else if (isFullNameOfDwarfSection(Name, "debug_aranges"))
225 // DebugArangesSection = Data;
226 else if (isFullNameOfDwarfSection(Name, "debug_str"))
227 DebugStringSection = Data;
228 else if (isFullNameOfDwarfSection(Name, "debug_ranges"))
229 DebugRangesSection = Data;
230 }
231
232 Context = DIContext::getDWARFContext(
233 IsLittleEndian, DebugInfoSection, DebugAbbrevSection,
234 DebugArangesSection, DebugLineSection, DebugStringSection,
235 DebugRangesSection);
236 assert(Context);
237 }
238
239 ModuleInfo *Info = new ModuleInfo(Obj, Context);
240 Modules.insert(make_pair(ModuleName, Info));
241 return Info;
242 }
243
244 // Assume that __cxa_demangle is provided by libcxxabi.
245 extern "C" char *__cxa_demangle(const char *mangled_name, char *output_buffer,
246 size_t *length, int *status);
247
printDILineInfo(DILineInfo LineInfo)248 static void printDILineInfo(DILineInfo LineInfo) {
249 // By default, DILineInfo contains "<invalid>" for function/filename it
250 // cannot fetch. We replace it to "??" to make our output closer to addr2line.
251 static const string kDILineInfoBadString = "<invalid>";
252 static const string kSymbolizerBadString = "??";
253 if (PrintFunctions) {
254 string FunctionName = LineInfo.getFunctionName();
255 if (FunctionName == kDILineInfoBadString)
256 FunctionName = kSymbolizerBadString;
257 if (Demangle) {
258 int status = 0;
259 char *DemangledName = __cxa_demangle(
260 FunctionName.c_str(), 0, 0, &status);
261 if (status == 0) {
262 FunctionName = DemangledName;
263 free(DemangledName);
264 }
265 }
266 outs() << FunctionName << "\n";
267 }
268 string Filename = LineInfo.getFileName();
269 if (Filename == kDILineInfoBadString)
270 Filename = kSymbolizerBadString;
271 outs() << Filename <<
272 ":" << LineInfo.getLine() <<
273 ":" << LineInfo.getColumn() <<
274 "\n";
275 }
276
symbolize(string ModuleName,string ModuleOffsetStr)277 static void symbolize(string ModuleName, string ModuleOffsetStr) {
278 ModuleInfo *Info = getOrCreateModuleInfo(ModuleName);
279 uint64_t Offset = 0;
280 if (Info == 0 ||
281 StringRef(ModuleOffsetStr).getAsInteger(0, Offset)) {
282 printDILineInfo(DILineInfo());
283 } else if (PrintInlining) {
284 DIInliningInfo InlinedContext = Info->symbolizeInlinedCode(Offset);
285 uint32_t FramesNum = InlinedContext.getNumberOfFrames();
286 assert(FramesNum > 0);
287 for (uint32_t i = 0; i < FramesNum; i++) {
288 DILineInfo LineInfo = InlinedContext.getFrame(i);
289 printDILineInfo(LineInfo);
290 }
291 } else {
292 DILineInfo LineInfo = Info->symbolizeCode(Offset);
293 printDILineInfo(LineInfo);
294 }
295
296 outs() << "\n"; // Print extra empty line to mark the end of output.
297 outs().flush();
298 }
299
parseModuleNameAndOffset(string & ModuleName,string & ModuleOffsetStr)300 static bool parseModuleNameAndOffset(string &ModuleName,
301 string &ModuleOffsetStr) {
302 static const int kMaxInputStringLength = 1024;
303 static const char kDelimiters[] = " \n";
304 char InputString[kMaxInputStringLength];
305 if (!fgets(InputString, sizeof(InputString), stdin))
306 return false;
307 ModuleName = "";
308 ModuleOffsetStr = "";
309 // FIXME: Handle case when filename is given in quotes.
310 if (char *FilePath = strtok(InputString, kDelimiters)) {
311 ModuleName = FilePath;
312 if (char *OffsetStr = strtok((char*)0, kDelimiters))
313 ModuleOffsetStr = OffsetStr;
314 }
315 return true;
316 }
317
main(int argc,char ** argv)318 int main(int argc, char **argv) {
319 // Print stack trace if we signal out.
320 sys::PrintStackTraceOnErrorSignal();
321 PrettyStackTraceProgram X(argc, argv);
322 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
323
324 cl::ParseCommandLineOptions(argc, argv, "llvm symbolizer for compiler-rt\n");
325 ToolInvocationPath = argv[0];
326
327 string ModuleName;
328 string ModuleOffsetStr;
329 while (parseModuleNameAndOffset(ModuleName, ModuleOffsetStr)) {
330 symbolize(ModuleName, ModuleOffsetStr);
331 }
332 return 0;
333 }
334