1 //===- Signals.cpp - Signal Handling support --------------------*- C++ -*-===// 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 file defines some helpful functions for dealing with the possibility of 11 // Unix signals occurring while your program is running. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/ADT/STLExtras.h" 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/Config/config.h" 18 #include "llvm/Support/ErrorOr.h" 19 #include "llvm/Support/FileSystem.h" 20 #include "llvm/Support/FileUtilities.h" 21 #include "llvm/Support/Format.h" 22 #include "llvm/Support/ManagedStatic.h" 23 #include "llvm/Support/MemoryBuffer.h" 24 #include "llvm/Support/Mutex.h" 25 #include "llvm/Support/Program.h" 26 #include "llvm/Support/Signals.h" 27 #include "llvm/Support/StringSaver.h" 28 #include "llvm/Support/raw_ostream.h" 29 #include <vector> 30 31 namespace llvm { 32 using namespace sys; 33 34 //===----------------------------------------------------------------------===// 35 //=== WARNING: Implementation here must contain only TRULY operating system 36 //=== independent code. 37 //===----------------------------------------------------------------------===// 38 39 static ManagedStatic<std::vector<std::pair<void (*)(void *), void *>>> 40 CallBacksToRun; 41 void sys::RunSignalHandlers() { 42 if (!CallBacksToRun.isConstructed()) 43 return; 44 for (auto &I : *CallBacksToRun) 45 I.first(I.second); 46 CallBacksToRun->clear(); 47 } 48 } 49 50 using namespace llvm; 51 52 static bool findModulesAndOffsets(void **StackTrace, int Depth, 53 const char **Modules, intptr_t *Offsets, 54 const char *MainExecutableName, 55 StringSaver &StrPool); 56 57 /// Format a pointer value as hexadecimal. Zero pad it out so its always the 58 /// same width. 59 static FormattedNumber format_ptr(void *PC) { 60 // Each byte is two hex digits plus 2 for the 0x prefix. 61 unsigned PtrWidth = 2 + 2 * sizeof(void *); 62 return format_hex((uint64_t)PC, PtrWidth); 63 } 64 65 static bool printSymbolizedStackTrace(StringRef Argv0, 66 void **StackTrace, int Depth, 67 llvm::raw_ostream &OS) 68 LLVM_ATTRIBUTE_USED; 69 70 /// Helper that launches llvm-symbolizer and symbolizes a backtrace. 71 static bool printSymbolizedStackTrace(StringRef Argv0, 72 void **StackTrace, int Depth, 73 llvm::raw_ostream &OS) { 74 // Don't recursively invoke the llvm-symbolizer binary. 75 if (Argv0.find("llvm-symbolizer") != std::string::npos) 76 return false; 77 78 // FIXME: Subtract necessary number from StackTrace entries to turn return addresses 79 // into actual instruction addresses. 80 // Use llvm-symbolizer tool to symbolize the stack traces. First look for it 81 // alongside our binary, then in $PATH. 82 ErrorOr<std::string> LLVMSymbolizerPathOrErr = std::error_code(); 83 if (!Argv0.empty()) { 84 StringRef Parent = llvm::sys::path::parent_path(Argv0); 85 if (!Parent.empty()) 86 LLVMSymbolizerPathOrErr = sys::findProgramByName("llvm-symbolizer", Parent); 87 } 88 if (!LLVMSymbolizerPathOrErr) 89 LLVMSymbolizerPathOrErr = sys::findProgramByName("llvm-symbolizer"); 90 if (!LLVMSymbolizerPathOrErr) 91 return false; 92 const std::string &LLVMSymbolizerPath = *LLVMSymbolizerPathOrErr; 93 94 // If we don't know argv0 or the address of main() at this point, try 95 // to guess it anyway (it's possible on some platforms). 96 std::string MainExecutableName = 97 Argv0.empty() ? sys::fs::getMainExecutable(nullptr, nullptr) 98 : (std::string)Argv0; 99 BumpPtrAllocator Allocator; 100 StringSaver StrPool(Allocator); 101 std::vector<const char *> Modules(Depth, nullptr); 102 std::vector<intptr_t> Offsets(Depth, 0); 103 if (!findModulesAndOffsets(StackTrace, Depth, Modules.data(), Offsets.data(), 104 MainExecutableName.c_str(), StrPool)) 105 return false; 106 int InputFD; 107 SmallString<32> InputFile, OutputFile; 108 sys::fs::createTemporaryFile("symbolizer-input", "", InputFD, InputFile); 109 sys::fs::createTemporaryFile("symbolizer-output", "", OutputFile); 110 FileRemover InputRemover(InputFile.c_str()); 111 FileRemover OutputRemover(OutputFile.c_str()); 112 113 { 114 raw_fd_ostream Input(InputFD, true); 115 for (int i = 0; i < Depth; i++) { 116 if (Modules[i]) 117 Input << Modules[i] << " " << (void*)Offsets[i] << "\n"; 118 } 119 } 120 121 StringRef InputFileStr(InputFile); 122 StringRef OutputFileStr(OutputFile); 123 StringRef StderrFileStr; 124 const StringRef *Redirects[] = {&InputFileStr, &OutputFileStr, 125 &StderrFileStr}; 126 const char *Args[] = {"llvm-symbolizer", "--functions=linkage", "--inlining", 127 #ifdef LLVM_ON_WIN32 128 // Pass --relative-address on Windows so that we don't 129 // have to add ImageBase from PE file. 130 // FIXME: Make this the default for llvm-symbolizer. 131 "--relative-address", 132 #endif 133 "--demangle", nullptr}; 134 int RunResult = 135 sys::ExecuteAndWait(LLVMSymbolizerPath, Args, nullptr, Redirects); 136 if (RunResult != 0) 137 return false; 138 139 // This report format is based on the sanitizer stack trace printer. See 140 // sanitizer_stacktrace_printer.cc in compiler-rt. 141 auto OutputBuf = MemoryBuffer::getFile(OutputFile.c_str()); 142 if (!OutputBuf) 143 return false; 144 StringRef Output = OutputBuf.get()->getBuffer(); 145 SmallVector<StringRef, 32> Lines; 146 Output.split(Lines, "\n"); 147 auto CurLine = Lines.begin(); 148 int frame_no = 0; 149 for (int i = 0; i < Depth; i++) { 150 if (!Modules[i]) { 151 OS << '#' << frame_no++ << ' ' << format_ptr(StackTrace[i]) << '\n'; 152 continue; 153 } 154 // Read pairs of lines (function name and file/line info) until we 155 // encounter empty line. 156 for (;;) { 157 if (CurLine == Lines.end()) 158 return false; 159 StringRef FunctionName = *CurLine++; 160 if (FunctionName.empty()) 161 break; 162 OS << '#' << frame_no++ << ' ' << format_ptr(StackTrace[i]) << ' '; 163 if (!FunctionName.startswith("??")) 164 OS << FunctionName << ' '; 165 if (CurLine == Lines.end()) 166 return false; 167 StringRef FileLineInfo = *CurLine++; 168 if (!FileLineInfo.startswith("??")) 169 OS << FileLineInfo; 170 else 171 OS << "(" << Modules[i] << '+' << format_hex(Offsets[i], 0) << ")"; 172 OS << "\n"; 173 } 174 } 175 return true; 176 } 177 178 // Include the platform-specific parts of this class. 179 #ifdef LLVM_ON_UNIX 180 #include "Unix/Signals.inc" 181 #endif 182 #ifdef LLVM_ON_WIN32 183 #include "Windows/Signals.inc" 184 #endif 185
