GHC.Utils.Logger

Logger

The Logger is an configurable entity that is used by the compiler to output messages on the console (stdout, stderr) and in dump files.

The behaviour of default Logger returned by initLogger can be modified with hooks. The compiler itself uses hooks in multithreaded code (--make) and it is also probably used by ghc-api users (IDEs, etc.).

In addition to hooks, the Logger suppors LogFlags: basically a subset of the command-line flags that control the logger behaviour at a higher level than hooks.

1. Hooks are used to define how to generate a infowarningerror/dump messages
2. LogFlags are used to decide when and how to generate messages

Documentation

data Logger

class HasLogger m where

Methods

getLogger :: m Logger

Instances

HasLogger LlvmM

Defined in GHC.CmmToLlvm.Base

Methods

getLogger :: LlvmM Logger

HasLogger CoreM

Defined in GHC.Core.Opt.Monad

Methods

getLogger :: CoreM Logger

HasLogger SimplM

Defined in GHC.Core.Opt.Simplify.Monad

Methods

getLogger :: SimplM Logger

HasLogger Hsc

Defined in GHC.Driver.Env.Types

Methods

getLogger :: Hsc Logger

HasLogger Ghc

Defined in GHC.Driver.Monad

Methods

getLogger :: Ghc Logger

ContainsLogger env => HasLogger (IOEnv env)

Defined in GHC.Data.IOEnv

Methods

getLogger :: IOEnv env Logger

MonadIO m => HasLogger (GhcT m)

Defined in GHC.Driver.Monad

Methods

getLogger :: GhcT m Logger

class ContainsLogger t where

Methods

extractLogger :: t -> Logger

Instances

ContainsLogger (Env gbl lcl)

Defined in GHC.Tc.Types

Methods

extractLogger :: Env gbl lcl -> Logger

Logger setup

initLogger :: IO Logger

type LogAction = LogFlags -> MessageClass -> SrcSpan -> SDoc -> IO ()

type DumpAction = LogFlags -> PprStyle -> DumpFlag -> String -> DumpFormat -> SDoc -> IO ()

type TraceAction a = LogFlags -> String -> SDoc -> a -> a

data DumpFormat

Format of a dump

Dump formats are loosely defined: dumps may contain various additional headers and annotations and they may be partial. DumpFormat is mainly a hint (e.g. for syntax highlighters).

Constructors

FormatHaskell

Haskell

FormatCore

Core

FormatSTG

STG

FormatByteCode

ByteCode

FormatCMM

Cmm

FormatASM

Assembly code

FormatC

C code/header

FormatLLVM

LLVM bytecode

FormatText

Unstructured dump

Instances

Show DumpFormat

Defined in GHC.Utils.Logger

Methods

showsPrec :: Int -> DumpFormat -> ShowS

show :: DumpFormat -> String

showList :: [DumpFormat] -> ShowS

Eq DumpFormat

Defined in GHC.Utils.Logger

Methods

(==) :: DumpFormat -> DumpFormat -> Bool

(/=) :: DumpFormat -> DumpFormat -> Bool

Hooks

popLogHook :: Logger -> Logger

Pop a log hook

pushLogHook :: (LogAction -> LogAction) -> Logger -> Logger

Push a log hook

popDumpHook :: Logger -> Logger

Pop a dump hook

pushDumpHook :: (DumpAction -> DumpAction) -> Logger -> Logger

Push a dump hook

popTraceHook :: Logger -> Logger

Pop a trace hook

pushTraceHook :: (forall a. TraceAction a -> TraceAction a) -> Logger -> Logger

Push a trace hook

makeThreadSafe :: Logger -> IO Logger

Make the logger thread-safe

Flags

data LogFlags

Logger flags

Constructors

LogFlags

Fields

• log_default_user_context :: SDocContext
• log_default_dump_context :: SDocContext
• log_dump_flags :: !(EnumSet DumpFlag)

  Dump flags

• log_show_caret :: !Bool

  Show caret in diagnostics

• log_show_warn_groups :: !Bool

  Show warning flag groups

• log_enable_timestamps :: !Bool

  Enable timestamps

• log_dump_to_file :: !Bool

  Enable dump to file

• log_dump_dir :: !(Maybe FilePath)

  Dump directory

• log_dump_prefix :: !FilePath

  Normal dump path ("basename.")

• log_dump_prefix_override :: !(Maybe FilePath)

  Overriden dump path

• log_enable_debug :: !Bool

  Enable debug output

• log_verbosity :: !Int

  Verbosity level

defaultLogFlags :: LogFlags

Default LogFlags

log_dopt :: DumpFlag -> LogFlags -> Bool

Test if a DumpFlag is enabled

log_set_dopt :: DumpFlag -> LogFlags -> LogFlags

Enable a DumpFlag

setLogFlags :: Logger -> LogFlags -> Logger

Set LogFlags

updateLogFlags :: Logger -> (LogFlags -> LogFlags) -> Logger

Update LogFlags

logFlags :: Logger -> LogFlags

Logger flags

logHasDumpFlag :: Logger -> DumpFlag -> Bool

Test if a DumpFlag is set

logVerbAtLeast :: Logger -> Int -> Bool

Test if verbosity is >= to the given value

Logging

jsonLogAction :: LogAction

putLogMsg :: Logger -> LogAction

Log something

defaultLogAction :: LogAction

defaultLogActionHPrintDoc :: LogFlags -> Bool -> Handle -> SDoc -> IO ()

Like defaultLogActionHPutStrDoc but appends an extra newline.

defaultLogActionHPutStrDoc :: LogFlags -> Bool -> Handle -> SDoc -> IO ()

The boolean arguments let's the pretty printer know if it can optimize indent by writing ascii ' ' characters without going through decoding.

logMsg :: Logger -> MessageClass -> SrcSpan -> SDoc -> IO ()

Log something

logDumpMsg :: Logger -> String -> SDoc -> IO ()

Log a dump message (not a dump file)

Dumping

defaultDumpAction :: DumpCache -> LogAction -> DumpAction

Default action for dumpAction hook

putDumpFile :: Logger -> DumpAction

Dump something

putDumpFileMaybe :: Logger -> DumpFlag -> String -> DumpFormat -> SDoc -> IO ()

Dump if the given DumpFlag is set

putDumpFileMaybe' :: Logger -> PrintUnqualified -> DumpFlag -> String -> DumpFormat -> SDoc -> IO ()

Dump if the given DumpFlag is set

Unlike putDumpFileMaybe, has a PrintUnqualified argument

withDumpFileHandle :: DumpCache -> LogFlags -> DumpFlag -> (Maybe Handle -> IO ()) -> IO ()

Run an action with the handle of a DumpFlag if we are outputting to a file, otherwise Nothing.

touchDumpFile :: Logger -> DumpFlag -> IO ()

Ensure that a dump file is created even if it stays empty

logDumpFile :: Logger -> PprStyle -> DumpFlag -> String -> DumpFormat -> SDoc -> IO ()

Dump something

Tracing

defaultTraceAction :: TraceAction a

Default action for traceAction hook

putTraceMsg :: Logger -> TraceAction a

Trace something

loggerTraceFlushUpdate :: Logger -> (IO () -> IO ()) -> Logger

Set the trace flushing function

The currently set trace flushing function is passed to the updating function

loggerTraceFlush :: Logger -> IO ()

Calls the trace flushing function

logTraceMsg :: Logger -> String -> SDoc -> a -> a

Log a trace message