ghc-8.2.2: The GHC API

Safe HaskellNone
LanguageHaskell2010

ErrUtils

Contents

Synopsis

Basic types

data Validity #

Constructors

IsValid

Everything is fine

NotValid MsgDoc

A problem, and some indication of why

allValid :: [Validity] -> Validity #

If they aren't all valid, return the first

data Severity #

Constructors

SevOutput 
SevFatal 
SevInteractive 
SevDump

Log messagse intended for compiler developers No filelinecolumn stuff

SevInfo

Log messages intended for end users. No filelinecolumn stuff.

SevWarning 
SevError

SevWarning and SevError are used for warnings and errors o The message has a filelinecolumn heading, plus "warning:" or "error:", added by mkLocMessags o Output is intended for end users

Messages

data ErrDoc #

Categorise error msgs by their importance. This is so each section can be rendered visually distinct. See Note [Error report] for where these come from.

errDoc :: [MsgDoc] -> [MsgDoc] -> [MsgDoc] -> ErrDoc #

errDocImportant :: ErrDoc -> [MsgDoc] #

Primary error msg.

errDocContext :: ErrDoc -> [MsgDoc] #

Context e.g. "In the second argument of ...".

errDocSupplementary :: ErrDoc -> [MsgDoc] #

Supplementary information, e.g. "Relevant bindings include ...".

type MsgDoc = SDoc #

isWarnMsgFatal :: DynFlags -> WarnMsg -> Bool #

Checks if given WarnMsg is a fatal warning.

Formatting

Construction

mkLocMessage :: Severity -> SrcSpan -> MsgDoc -> MsgDoc #

Make an unannotated error message with location info.

mkLocMessageAnn #

Arguments

:: Maybe String

optional annotation

-> Severity

severity

-> SrcSpan

location

-> MsgDoc

message

-> MsgDoc 

Make a possibly annotated error message with location info.

mkErrMsg :: DynFlags -> SrcSpan -> PrintUnqualified -> MsgDoc -> ErrMsg #

A short (one-line) error message

mkPlainErrMsg :: DynFlags -> SrcSpan -> MsgDoc -> ErrMsg #

Variant that doesn't care about qualified/unqualified names

mkLongErrMsg :: DynFlags -> SrcSpan -> PrintUnqualified -> MsgDoc -> MsgDoc -> ErrMsg #

A long (multi-line) error message

mkWarnMsg :: DynFlags -> SrcSpan -> PrintUnqualified -> MsgDoc -> ErrMsg #

A short (one-line) error message

mkPlainWarnMsg :: DynFlags -> SrcSpan -> MsgDoc -> ErrMsg #

Variant that doesn't care about qualified/unqualified names

mkLongWarnMsg :: DynFlags -> SrcSpan -> PrintUnqualified -> MsgDoc -> MsgDoc -> ErrMsg #

A long (multi-line) error message

Utilities

doIfSet :: Bool -> IO () -> IO () #

Dump files

dumpIfSet :: DynFlags -> Bool -> String -> SDoc -> IO () #

dumpIfSet_dyn :: DynFlags -> DumpFlag -> String -> SDoc -> IO () #

a wrapper around dumpSDoc. First check whether the dump flag is set Do nothing if it is unset

dumpIfSet_dyn_printer :: PrintUnqualified -> DynFlags -> DumpFlag -> SDoc -> IO () #

a wrapper around dumpSDoc. First check whether the dump flag is set Do nothing if it is unset

Unlike dumpIfSet_dyn, has a printer argument but no header argument

dumpSDoc :: DynFlags -> PrintUnqualified -> DumpFlag -> String -> SDoc -> IO () #

Write out a dump. If --dump-to-file is set then this goes to a file. otherwise emit to stdout.

When hdr is empty, we print in a more compact format (no separators and blank lines)

The DumpFlag is used only to choose the filename to use if --dump-to-file is used; it is not used to decide whether to dump the output

Issuing messages during compilation

putMsg :: DynFlags -> MsgDoc -> IO () #

logOutput :: DynFlags -> PprStyle -> MsgDoc -> IO () #

Like logInfo but with SevOutput rather then SevInfo

withTiming #

Arguments

:: MonadIO m 
=> m DynFlags

A means of getting a DynFlags (often getDynFlags will work here)

-> SDoc

The name of the phase

-> (a -> ())

A function to force the result (often either const () or rnf)

-> m a

The body of the phase to be timed

-> m a 

Time a compilation phase.

When timings are enabled (e.g. with the -v2 flag), the allocations and CPU time used by the phase will be reported to stderr. Consider a typical usage: withTiming getDynFlags (text "simplify") force pass. When timings are enabled the following costs are included in the produced accounting,

  • The cost of executing pass to a result r in WHNF
  • The cost of evaluating force r to WHNF (e.g. ())

The choice of the force function depends upon the amount of forcing desired; the goal here is to ensure that the cost of evaluating the result is, to the greatest extent possible, included in the accounting provided by withTiming. Often the pass already sufficiently forces its result during construction; in this case const () is a reasonable choice. In other cases, it is necessary to evaluate the result to normal form, in which case something like Control.DeepSeq.rnf is appropriate.

To avoid adversely affecting compiler performance when timings are not requested, the result is only forced when timings are enabled.

ghcExit :: DynFlags -> Int -> IO () #