1 //===- Signals.cpp - Signal Handling support --------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines some helpful functions for dealing with the possibility of
11 // Unix signals occurring while your program is running.
13 //===----------------------------------------------------------------------===//
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"
34 //===----------------------------------------------------------------------===//
35 //=== WARNING: Implementation here must contain only TRULY operating system
36 //=== independent code.
37 //===----------------------------------------------------------------------===//
39 static ManagedStatic<std::vector<std::pair<void (*)(void *), void *>>>
41 void sys::RunSignalHandlers() {
42 if (!CallBacksToRun.isConstructed())
44 for (auto &I : *CallBacksToRun)
46 CallBacksToRun->clear();
52 static bool findModulesAndOffsets(void **StackTrace, int Depth,
53 const char **Modules, intptr_t *Offsets,
54 const char *MainExecutableName,
55 StringSaver &StrPool);
57 /// Format a pointer value as hexadecimal. Zero pad it out so its always the
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);
65 /// Helper that launches llvm-symbolizer and symbolizes a backtrace.
66 static bool printSymbolizedStackTrace(void **StackTrace, int Depth,
67 llvm::raw_ostream &OS) {
68 // FIXME: Subtract necessary number from StackTrace entries to turn return addresses
69 // into actual instruction addresses.
70 // Use llvm-symbolizer tool to symbolize the stack traces.
71 ErrorOr<std::string> LLVMSymbolizerPathOrErr =
72 sys::findProgramByName("llvm-symbolizer");
73 if (!LLVMSymbolizerPathOrErr)
75 const std::string &LLVMSymbolizerPath = *LLVMSymbolizerPathOrErr;
76 // We don't know argv0 or the address of main() at this point, but try
77 // to guess it anyway (it's possible on some platforms).
78 std::string MainExecutableName = sys::fs::getMainExecutable(nullptr, nullptr);
79 if (MainExecutableName.empty() ||
80 MainExecutableName.find("llvm-symbolizer") != std::string::npos)
83 BumpPtrAllocator Allocator;
84 StringSaver StrPool(Allocator);
85 std::vector<const char *> Modules(Depth, nullptr);
86 std::vector<intptr_t> Offsets(Depth, 0);
87 if (!findModulesAndOffsets(StackTrace, Depth, Modules.data(), Offsets.data(),
88 MainExecutableName.c_str(), StrPool))
91 SmallString<32> InputFile, OutputFile;
92 sys::fs::createTemporaryFile("symbolizer-input", "", InputFD, InputFile);
93 sys::fs::createTemporaryFile("symbolizer-output", "", OutputFile);
94 FileRemover InputRemover(InputFile.c_str());
95 FileRemover OutputRemover(OutputFile.c_str());
98 raw_fd_ostream Input(InputFD, true);
99 for (int i = 0; i < Depth; i++) {
101 Input << Modules[i] << " " << (void*)Offsets[i] << "\n";
105 StringRef InputFileStr(InputFile);
106 StringRef OutputFileStr(OutputFile);
107 StringRef StderrFileStr;
108 const StringRef *Redirects[] = {&InputFileStr, &OutputFileStr,
110 const char *Args[] = {"llvm-symbolizer", "--functions=linkage", "--inlining",
112 // Pass --relative-address on Windows so that we don't
113 // have to add ImageBase from PE file.
114 // FIXME: Make this the default for llvm-symbolizer.
115 "--relative-address",
117 "--demangle", nullptr};
119 sys::ExecuteAndWait(LLVMSymbolizerPath, Args, nullptr, Redirects);
123 // This report format is based on the sanitizer stack trace printer. See
124 // sanitizer_stacktrace_printer.cc in compiler-rt.
125 auto OutputBuf = MemoryBuffer::getFile(OutputFile.c_str());
128 StringRef Output = OutputBuf.get()->getBuffer();
129 SmallVector<StringRef, 32> Lines;
130 Output.split(Lines, "\n");
131 auto CurLine = Lines.begin();
133 for (int i = 0; i < Depth; i++) {
135 OS << '#' << frame_no++ << ' ' << format_ptr(StackTrace[i]) << '\n';
138 // Read pairs of lines (function name and file/line info) until we
139 // encounter empty line.
141 if (CurLine == Lines.end())
143 StringRef FunctionName = *CurLine++;
144 if (FunctionName.empty())
146 OS << '#' << frame_no++ << ' ' << format_ptr(StackTrace[i]) << ' ';
147 if (!FunctionName.startswith("??"))
148 OS << FunctionName << ' ';
149 if (CurLine == Lines.end())
151 StringRef FileLineInfo = *CurLine++;
152 if (!FileLineInfo.startswith("??"))
155 OS << "(" << Modules[i] << '+' << format_hex(Offsets[i], 0) << ")";
162 // Include the platform-specific parts of this class.
164 #include "Unix/Signals.inc"
167 #include "Windows/Signals.inc"