/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2012-present Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* limitations under the License.
*/
-#ifndef FOLLY_EXPERIMENTAL_SYMBOLIZER_SYMBOLIZER_H_
-#define FOLLY_EXPERIMENTAL_SYMBOLIZER_SYMBOLIZER_H_
+#pragma once
#include <array>
#include <cstdint>
#include <folly/FBString.h>
#include <folly/Range.h>
#include <folly/String.h>
-#include <folly/io/IOBuf.h>
+#include <folly/experimental/symbolizer/Dwarf.h>
#include <folly/experimental/symbolizer/Elf.h>
#include <folly/experimental/symbolizer/ElfCache.h>
-#include <folly/experimental/symbolizer/Dwarf.h>
#include <folly/experimental/symbolizer/StackTrace.h>
+#include <folly/io/IOBuf.h>
namespace folly {
namespace symbolizer {
* Frame information: symbol name and location.
*/
struct SymbolizedFrame {
- SymbolizedFrame() { }
+ SymbolizedFrame() {}
- void set(const std::shared_ptr<ElfFile>& file, uintptr_t address);
- void clear() { *this = SymbolizedFrame(); }
+ void set(
+ const std::shared_ptr<ElfFile>& file,
+ uintptr_t address,
+ Dwarf::LocationInfoMode mode);
+
+ void clear() {
+ *this = SymbolizedFrame();
+ }
bool found = false;
const char* name = nullptr;
fbstring demangledName() const {
return name ? demangle(name) : fbstring();
}
+
private:
std::shared_ptr<ElfFile> file_;
};
template <size_t N>
struct FrameArray {
- FrameArray() { }
+ FrameArray() {}
size_t frameCount = 0;
uintptr_t addresses[N];
return false;
}
}
-} // namespace detail
+} // namespace detail
// Always inline these functions; they don't do much, and unittests rely
// on them never showing up in a stack trace.
class Symbolizer {
public:
- explicit Symbolizer(ElfCacheBase* cache = nullptr);
+ static constexpr Dwarf::LocationInfoMode kDefaultLocationInfoMode =
+ Dwarf::LocationInfoMode::FAST;
+
+ explicit Symbolizer(Dwarf::LocationInfoMode mode = kDefaultLocationInfoMode)
+ : Symbolizer(nullptr, mode) {}
+
+ explicit Symbolizer(
+ ElfCacheBase* cache,
+ Dwarf::LocationInfoMode mode = kDefaultLocationInfoMode);
/**
* Symbolize given addresses.
*/
- void symbolize(const uintptr_t* addresses,
- SymbolizedFrame* frames,
- size_t frameCount);
+ void symbolize(
+ const uintptr_t* addresses,
+ SymbolizedFrame* frames,
+ size_t frameCount);
template <size_t N>
void symbolize(FrameArray<N>& fa) {
}
private:
- ElfCacheBase* const cache_ = nullptr;
+ ElfCacheBase* const cache_;
+ const Dwarf::LocationInfoMode mode_;
};
/**
- * Format one address in the way it's usually printer by SymbolizePrinter.
+ * Format one address in the way it's usually printed by SymbolizePrinter.
* Async-signal-safe.
*/
class AddressFormatter {
/**
* Print multiple addresses on separate lines.
*/
- void println(const uintptr_t* addresses,
- const SymbolizedFrame* frames,
- size_t frameCount);
+ void println(
+ const uintptr_t* addresses,
+ const SymbolizedFrame* frames,
+ size_t frameCount);
/**
* Print a string, no endling newline.
*/
- void print(StringPiece sp) { doPrint(sp); }
+ void print(StringPiece sp) {
+ doPrint(sp);
+ }
/**
* Print multiple addresses on separate lines, skipping the first
* skip addresses.
*/
template <size_t N>
- void println(const FrameArray<N>& fa, size_t skip=0) {
+ void println(const FrameArray<N>& fa, size_t skip = 0) {
if (skip < fa.frameCount) {
println(fa.addresses + skip, fa.frames + skip, fa.frameCount - skip);
}
}
- virtual ~SymbolizePrinter() { }
+ virtual ~SymbolizePrinter() {}
enum Options {
// Skip file and line information
// Colorize output only if output is printed to a TTY (ANSI escape code)
COLOR_IF_TTY = 1 << 3,
+
+ // Skip frame address information
+ NO_FRAME_ADDRESS = 1 << 4,
};
// NOTE: enum values used as indexes in kColorMap.
protected:
explicit SymbolizePrinter(int options, bool isTty = false)
- : options_(options),
- isTty_(isTty) {
- }
+ : options_(options), isTty_(isTty) {}
const int options_;
const bool isTty_;
*/
class OStreamSymbolizePrinter : public SymbolizePrinter {
public:
- explicit OStreamSymbolizePrinter(std::ostream& out, int options=0);
+ explicit OStreamSymbolizePrinter(std::ostream& out, int options = 0);
+
private:
void doPrint(StringPiece sp) override;
std::ostream& out_;
*/
class FDSymbolizePrinter : public SymbolizePrinter {
public:
- explicit FDSymbolizePrinter(int fd, int options=0,
- size_t bufferSize=0);
- ~FDSymbolizePrinter();
+ explicit FDSymbolizePrinter(int fd, int options = 0, size_t bufferSize = 0);
+ ~FDSymbolizePrinter() override;
void flush();
+
private:
void doPrint(StringPiece sp) override;
*/
class FILESymbolizePrinter : public SymbolizePrinter {
public:
- explicit FILESymbolizePrinter(FILE* file, int options=0);
+ explicit FILESymbolizePrinter(FILE* file, int options = 0);
+
private:
void doPrint(StringPiece sp) override;
FILE* const file_ = nullptr;
*/
class StringSymbolizePrinter : public SymbolizePrinter {
public:
- explicit StringSymbolizePrinter(int options=0) : SymbolizePrinter(options) { }
+ explicit StringSymbolizePrinter(int options = 0)
+ : SymbolizePrinter(options) {}
- std::string str() const { return buf_.toStdString(); }
- const fbstring& fbstr() const { return buf_; }
- fbstring moveFbString() { return std::move(buf_); }
+ std::string str() const {
+ return buf_.toStdString();
+ }
+ const fbstring& fbstr() const {
+ return buf_;
+ }
+ fbstring moveFbString() {
+ return std::move(buf_);
+ }
private:
void doPrint(StringPiece sp) override;
fbstring buf_;
};
-} // namespace symbolizer
-} // namespace folly
+/**
+ * Use this class to print a stack trace from a signal handler, or other place
+ * where you shouldn't allocate memory on the heap, and fsync()ing your file
+ * descriptor is more important than performance.
+ *
+ * Make sure to create one of these on startup, not in the signal handler, as
+ * the constructo allocates on the heap, whereas the other methods don't. Best
+ * practice is to just leak this object, rather than worry about destruction
+ * order.
+ *
+ * These methods aren't thread safe, so if you could have signals on multiple
+ * threads at the same time, you need to do your own locking to ensure you don't
+ * call these methods from multiple threads. They are signal safe, however.
+ */
+class StackTracePrinter {
+ public:
+ static constexpr size_t kDefaultMinSignalSafeElfCacheSize = 500;
+
+ explicit StackTracePrinter(
+ size_t minSignalSafeElfCacheSize = kDefaultMinSignalSafeElfCacheSize,
+ int fd = STDERR_FILENO);
+
+ /**
+ * Only allocates on the stack and is signal-safe but not thread-safe. Don't
+ * call printStackTrace() on the same StackTracePrinter object from multiple
+ * threads at the same time.
+ */
+ FOLLY_NOINLINE void printStackTrace(bool symbolize);
+
+ void print(StringPiece sp) {
+ printer_.print(sp);
+ }
+
+ // Flush printer_, also fsync, in case we're about to crash again...
+ void flush();
+
+ private:
+ static constexpr size_t kMaxStackTraceDepth = 100;
+
+ int fd_;
+ SignalSafeElfCache elfCache_;
+ FDSymbolizePrinter printer_;
+ std::unique_ptr<FrameArray<kMaxStackTraceDepth>> addresses_;
+};
-#endif /* FOLLY_EXPERIMENTAL_SYMBOLIZER_SYMBOLIZER_H_ */
+} // namespace symbolizer
+} // namespace folly
projects / folly.git / blobdiff