blob: 806eb390773b9aa7ea0042b83471918536273d7c [file] [log] [blame]
//===-- Log.h ---------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_UTILITY_LOG_H
#define LLDB_UTILITY_LOG_H
#include "lldb/Utility/Flags.h"
#include "lldb/lldb-defines.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/RWMutex.h"
#include <atomic>
#include <cstdarg>
#include <cstdint>
#include <memory>
#include <mutex>
#include <string>
#include <type_traits>
namespace llvm {
class raw_ostream;
}
// Logging Options
#define LLDB_LOG_OPTION_THREADSAFE (1u << 0)
#define LLDB_LOG_OPTION_VERBOSE (1u << 1)
#define LLDB_LOG_OPTION_PREPEND_SEQUENCE (1u << 3)
#define LLDB_LOG_OPTION_PREPEND_TIMESTAMP (1u << 4)
#define LLDB_LOG_OPTION_PREPEND_PROC_AND_THREAD (1u << 5)
#define LLDB_LOG_OPTION_PREPEND_THREAD_NAME (1U << 6)
#define LLDB_LOG_OPTION_BACKTRACE (1U << 7)
#define LLDB_LOG_OPTION_APPEND (1U << 8)
#define LLDB_LOG_OPTION_PREPEND_FILE_FUNCTION (1U << 9)
// Logging Functions
namespace lldb_private {
class LogHandler {
public:
virtual ~LogHandler() = default;
virtual void Emit(llvm::StringRef message) = 0;
void EmitThreadSafe(llvm::StringRef message);
private:
std::mutex m_mutex;
};
class StreamLogHandler : public LogHandler {
public:
StreamLogHandler(int fd, bool should_close, bool unbuffered = true);
void Emit(llvm::StringRef message) override;
private:
llvm::raw_fd_ostream m_stream;
};
class CallbackLogHandler : public LogHandler {
public:
CallbackLogHandler(lldb::LogOutputCallback callback, void *baton);
void Emit(llvm::StringRef message) override;
private:
lldb::LogOutputCallback m_callback;
void *m_baton;
};
class RotatingLogHandler : public LogHandler {
public:
RotatingLogHandler(size_t size);
void Emit(llvm::StringRef message) override;
void Dump(llvm::raw_ostream &stream) const;
private:
size_t NormalizeIndex(size_t i) const;
size_t GetNumMessages() const;
size_t GetFirstMessageIndex() const;
std::unique_ptr<std::string[]> m_messages;
const size_t m_size = 0;
size_t m_next_index = 0;
size_t m_total_count = 0;
};
class Log final {
public:
/// The underlying type of all log channel enums. Declare them as:
/// enum class MyLog : MaskType {
/// Channel0 = Log::ChannelFlag<0>,
/// Channel1 = Log::ChannelFlag<1>,
/// ...,
/// LLVM_MARK_AS_BITMASK_ENUM(LastChannel),
/// };
using MaskType = uint64_t;
template <MaskType Bit>
static constexpr MaskType ChannelFlag = MaskType(1) << Bit;
// Description of a log channel category.
struct Category {
llvm::StringLiteral name;
llvm::StringLiteral description;
MaskType flag;
template <typename Cat>
constexpr Category(llvm::StringLiteral name,
llvm::StringLiteral description, Cat mask)
: name(name), description(description), flag(MaskType(mask)) {
static_assert(
std::is_same<Log::MaskType, std::underlying_type_t<Cat>>::value, "");
}
};
// This class describes a log channel. It also encapsulates the behavior
// necessary to enable a log channel in an atomic manner.
class Channel {
std::atomic<Log *> log_ptr;
friend class Log;
public:
const llvm::ArrayRef<Category> categories;
const MaskType default_flags;
template <typename Cat>
constexpr Channel(llvm::ArrayRef<Log::Category> categories,
Cat default_flags)
: log_ptr(nullptr), categories(categories),
default_flags(MaskType(default_flags)) {
static_assert(
std::is_same<Log::MaskType, std::underlying_type_t<Cat>>::value, "");
}
// This function is safe to call at any time. If the channel is disabled
// after (or concurrently with) this function returning a non-null Log
// pointer, it is still safe to attempt to write to the Log object -- the
// output will be discarded.
Log *GetLog(MaskType mask) {
Log *log = log_ptr.load(std::memory_order_relaxed);
if (log && log->GetMask().AnySet(mask))
return log;
return nullptr;
}
};
// Static accessors for logging channels
static void Register(llvm::StringRef name, Channel &channel);
static void Unregister(llvm::StringRef name);
static bool
EnableLogChannel(const std::shared_ptr<LogHandler> &log_handler_sp,
uint32_t log_options, llvm::StringRef channel,
llvm::ArrayRef<const char *> categories,
llvm::raw_ostream &error_stream);
static bool DisableLogChannel(llvm::StringRef channel,
llvm::ArrayRef<const char *> categories,
llvm::raw_ostream &error_stream);
static bool ListChannelCategories(llvm::StringRef channel,
llvm::raw_ostream &stream);
/// Returns the list of log channels.
static std::vector<llvm::StringRef> ListChannels();
/// Calls the given lambda for every category in the given channel.
/// If no channel with the given name exists, lambda is never called.
static void ForEachChannelCategory(
llvm::StringRef channel,
llvm::function_ref<void(llvm::StringRef, llvm::StringRef)> lambda);
static void DisableAllLogChannels();
static void ListAllLogChannels(llvm::raw_ostream &stream);
// Member functions
//
// These functions are safe to call at any time you have a Log* obtained from
// the Channel class. If logging is disabled between you obtaining the Log
// object and writing to it, the output will be silently discarded.
Log(Channel &channel) : m_channel(channel) {}
~Log() = default;
void PutCString(const char *cstr);
void PutString(llvm::StringRef str);
template <typename... Args>
void Format(llvm::StringRef file, llvm::StringRef function,
const char *format, Args &&... args) {
Format(file, function, llvm::formatv(format, std::forward<Args>(args)...));
}
template <typename... Args>
void FormatError(llvm::Error error, llvm::StringRef file,
llvm::StringRef function, const char *format,
Args &&... args) {
Format(file, function,
llvm::formatv(format, llvm::toString(std::move(error)),
std::forward<Args>(args)...));
}
/// Prefer using LLDB_LOGF whenever possible.
void Printf(const char *format, ...) __attribute__((format(printf, 2, 3)));
void Error(const char *fmt, ...) __attribute__((format(printf, 2, 3)));
void Verbose(const char *fmt, ...) __attribute__((format(printf, 2, 3)));
void Warning(const char *fmt, ...) __attribute__((format(printf, 2, 3)));
const Flags GetOptions() const;
const Flags GetMask() const;
bool GetVerbose() const;
void VAPrintf(const char *format, va_list args);
void VAError(const char *format, va_list args);
private:
Channel &m_channel;
// The mutex makes sure enable/disable operations are thread-safe. The
// options and mask variables are atomic to enable their reading in
// Channel::GetLogIfAny without taking the mutex to speed up the fast path.
// Their modification however, is still protected by this mutex.
llvm::sys::RWMutex m_mutex;
std::shared_ptr<LogHandler> m_handler;
std::atomic<uint32_t> m_options{0};
std::atomic<MaskType> m_mask{0};
void WriteHeader(llvm::raw_ostream &OS, llvm::StringRef file,
llvm::StringRef function);
void WriteMessage(const std::string &message);
void Format(llvm::StringRef file, llvm::StringRef function,
const llvm::formatv_object_base &payload);
std::shared_ptr<LogHandler> GetHandler() {
llvm::sys::ScopedReader lock(m_mutex);
return m_handler;
}
void Enable(const std::shared_ptr<LogHandler> &handler_sp, uint32_t options,
uint32_t flags);
void Disable(uint32_t flags);
typedef llvm::StringMap<Log> ChannelMap;
static llvm::ManagedStatic<ChannelMap> g_channel_map;
static void ForEachCategory(
const Log::ChannelMap::value_type &entry,
llvm::function_ref<void(llvm::StringRef, llvm::StringRef)> lambda);
static void ListCategories(llvm::raw_ostream &stream,
const ChannelMap::value_type &entry);
static uint32_t GetFlags(llvm::raw_ostream &stream, const ChannelMap::value_type &entry,
llvm::ArrayRef<const char *> categories);
Log(const Log &) = delete;
void operator=(const Log &) = delete;
};
// Must be specialized for a particular log type.
template <typename Cat> Log::Channel &LogChannelFor() = delete;
/// Retrieve the Log object for the channel associated with the given log enum.
///
/// Returns a valid Log object if any of the provided categories are enabled.
/// Otherwise, returns nullptr.
template <typename Cat> Log *GetLog(Cat mask) {
static_assert(std::is_same<Log::MaskType, std::underlying_type_t<Cat>>::value,
"");
return LogChannelFor<Cat>().GetLog(Log::MaskType(mask));
}
} // namespace lldb_private
/// The LLDB_LOG* macros defined below are the way to emit log messages.
///
/// Note that the macros surround the arguments in a check for the log
/// being on, so you can freely call methods in arguments without affecting
/// the non-log execution flow.
///
/// If you need to do more complex computations to prepare the log message
/// be sure to add your own if (log) check, since we don't want logging to
/// have any effect when not on.
///
/// However, the LLDB_LOG macro uses the llvm::formatv system (see the
/// ProgrammersManual page in the llvm docs for more details). This allows
/// the use of "format_providers" to auto-format datatypes, and there are
/// already formatters for some of the llvm and lldb datatypes.
///
/// So if you need to do non-trivial formatting of one of these types, be
/// sure to grep the lldb and llvm sources for "format_provider" to see if
/// there is already a formatter before doing in situ formatting, and if
/// possible add a provider if one does not already exist.
#define LLDB_LOG(log, ...) \
do { \
::lldb_private::Log *log_private = (log); \
if (log_private) \
log_private->Format(__FILE__, __func__, __VA_ARGS__); \
} while (0)
#define LLDB_LOGF(log, ...) \
do { \
::lldb_private::Log *log_private = (log); \
if (log_private) \
log_private->Printf(__VA_ARGS__); \
} while (0)
#define LLDB_LOGV(log, ...) \
do { \
::lldb_private::Log *log_private = (log); \
if (log_private && log_private->GetVerbose()) \
log_private->Format(__FILE__, __func__, __VA_ARGS__); \
} while (0)
// Write message to log, if error is set. In the log message refer to the error
// with {0}. Error is cleared regardless of whether logging is enabled.
#define LLDB_LOG_ERROR(log, error, ...) \
do { \
::lldb_private::Log *log_private = (log); \
::llvm::Error error_private = (error); \
if (log_private && error_private) { \
log_private->FormatError(::std::move(error_private), __FILE__, __func__, \
__VA_ARGS__); \
} else \
::llvm::consumeError(::std::move(error_private)); \
} while (0)
#endif // LLDB_UTILITY_LOG_H
// TODO: Remove this and fix includes everywhere.