ghc-9.6.3: The GHC API

Safe Haskell | Safe-Inferred
Language | Haskell2010

GHC.Utils.Panic.Plain

Description

Defines a simple exception type and utilities to throw it. The `PlainGhcException` type is a subset of the `GhcException` type. It omits the exception constructors that involve pretty-printing via `SDoc`.

There are two reasons for this:

1. To avoid import cycles / use of boot files. GHC.Utils.Outputable has many transitive dependencies. To throw exceptions from these modules, the functions here can be used without introducing import cycles.
2. To reduce the number of modules that need to be compiled to object code when loading GHC into GHCi. See #13101

Synopsis

- data PlainGhcException
  - = PlainSignal Int
  - | PlainUsageError String
  - | PlainCmdLineError String
  - | PlainPanic String
  - | PlainSorry String
  - | PlainInstallationError String
  - | PlainProgramError String
- showPlainGhcException :: PlainGhcException -> ShowS
- panic :: HasCallStack => String -> a
- sorry :: HasCallStack => String -> a
- pgmError :: HasCallStack => String -> a
- cmdLineError :: String -> a
- cmdLineErrorIO :: String -> IO a
- assertPanic :: String -> Int -> a
- assert :: HasCallStack => Bool -> a -> a
- assertM :: (HasCallStack, Monad m) => m Bool -> m ()
- massert :: (HasCallStack, Applicative m) => Bool -> m ()

# Documentation

data PlainGhcException Source #

This type is very similar to `GhcException`, but it omits the constructors that involve pretty-printing via `SDoc`. Due to the implementation of `fromException` for `GhcException`, this type can be caught as a `GhcException`.

Note that this should only be used for throwing exceptions, not for catching, as `GhcException` will not be converted to this type when catching.

Constructors

PlainSignal Int | Some other fatal signal (SIGHUP,SIGTERM)
PlainUsageError String | Prints the short usage msg after the error
PlainCmdLineError String | A problem with the command line arguments, but don't print usage.
PlainPanic String | The `impossible` happened.
PlainSorry String | The user tickled something that's known not to work yet, but we're not counting it as a bug.
PlainInstallationError String | An installation problem.
PlainProgramError String | An error in the user's code, probably.

#### Instances

Instances details

Exception PlainGhcException Source # |
Instance details Defined in GHC.Utils.Panic.Plain Methods toException :: PlainGhcException -> SomeException Source # fromException :: SomeException -> Maybe PlainGhcException Source # displayException :: PlainGhcException -> String Source #
Show PlainGhcException Source # |
Instance details Defined in GHC.Utils.Panic.Plain Methods showsPrec :: Int -> PlainGhcException -> ShowS Source # show :: PlainGhcException -> String Source # showList :: [PlainGhcException] -> ShowS Source #

showPlainGhcException :: PlainGhcException -> ShowS Source #

Append a description of the given exception to this string.

panic :: HasCallStack => String -> a Source #

Panics and asserts.

sorry :: HasCallStack => String -> a Source #

Panics and asserts.

pgmError :: HasCallStack => String -> a Source #

Panics and asserts.

cmdLineError :: String -> a Source #

cmdLineErrorIO :: String -> IO a Source #

assertPanic :: String -> Int -> a Source #

Throw a failed assertion exception for a given filename and line number.

assert :: HasCallStack => Bool -> a -> a Source #

assertM :: (HasCallStack, Monad m) => m Bool -> m () Source #

massert :: (HasCallStack, Applicative m) => Bool -> m () Source #