ghc-8.2.2: The GHC API

Safe Haskell | None
Language | Haskell2010

HscMain

Contents

- Making an HscEnv
- Compiling complete source files
- Running passes separately
- Safe Haskell
- Support for interactive evaluation
- Low-level exports for hooks

Description

Main API for compiling plain Haskell source code.

This module implements compilation of a Haskell source. It is not concerned with preprocessing of source files; this is handled in DriverPipeline.

There are various entry points depending on what mode we're in: "batch" mode (`--make`), "one-shot" mode (`-c`, `-S` etc.), and "interactive" mode (GHCi). There are also entry points for individual passes: parsing, typechecking/renaming, desugaring, and simplification.

All the functions here take an `HscEnv` as a parameter, but none of them return a new one: `HscEnv` is treated as an immutable value from here on in (although it has mutable components, for the caches).

We use the Hsc monad to deal with warning messages consistently: specifically, while executing within an Hsc monad, warnings are collected. When a Hsc monad returns to an IO monad, the warnings are printed, or compilation aborts if the `-Werror` flag is enabled.

(c) The GRASP/AQUA Project, Glasgow University, 1993-2000

Synopsis

- newHscEnv :: DynFlags -> IO HscEnv
- type Messager = HscEnv -> (Int, Int) -> RecompileRequired -> ModSummary -> IO ()
- batchMsg :: Messager
- data HscStatus
  - = HscNotGeneratingCode
  - | HscUpToDate
  - | HscUpdateBoot
  - | HscUpdateSig
  - | HscRecomp CgGuts ModSummary
- hscIncrementalCompile :: Bool -> Maybe TcGblEnv -> Maybe Messager -> HscEnv -> ModSummary -> SourceModified -> Maybe ModIface -> (Int, Int) -> IO (HscStatus, HomeModInfo)
- hscCompileCmmFile :: HscEnv -> FilePath -> FilePath -> IO ()
- hscGenHardCode :: HscEnv -> CgGuts -> ModSummary -> FilePath -> IO (FilePath, Maybe FilePath, [(ForeignSrcLang, FilePath)])
- hscInteractive :: HscEnv -> CgGuts -> ModSummary -> IO (Maybe FilePath, CompiledByteCode, [SptEntry])
- hscParse :: HscEnv -> ModSummary -> IO HsParsedModule
- hscTypecheckRename :: HscEnv -> ModSummary -> HsParsedModule -> IO (TcGblEnv, RenamedStuff)
- hscDesugar :: HscEnv -> ModSummary -> TcGblEnv -> IO ModGuts
- makeSimpleDetails :: HscEnv -> TcGblEnv -> IO ModDetails
- hscSimplify :: HscEnv -> ModGuts -> IO ModGuts
- hscCheckSafe :: HscEnv -> Module -> SrcSpan -> IO Bool
- hscGetSafe :: HscEnv -> Module -> SrcSpan -> IO (Bool, Set InstalledUnitId)
- hscParseIdentifier :: HscEnv -> String -> IO (Located RdrName)
- hscTcRcLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
- hscTcRnGetInfo :: HscEnv -> Name -> IO (Maybe (TyThing, Fixity, [ClsInst], [FamInst]))
- hscIsGHCiMonad :: HscEnv -> String -> IO Name
- hscGetModuleInterface :: HscEnv -> Module -> IO ModIface
- hscRnImportDecls :: HscEnv -> [LImportDecl RdrName] -> IO GlobalRdrEnv
- hscTcRnLookupRdrName :: HscEnv -> Located RdrName -> IO [Name]
- hscStmt :: HscEnv -> String -> IO (Maybe ([Id], ForeignHValue, FixityEnv))
- hscStmtWithLocation :: HscEnv -> String -> String -> Int -> IO (Maybe ([Id], ForeignHValue, FixityEnv))
- hscParsedStmt :: HscEnv -> GhciLStmt RdrName -> IO (Maybe ([Id], ForeignHValue, FixityEnv))
- hscDecls :: HscEnv -> String -> IO ([TyThing], InteractiveContext)
- hscDeclsWithLocation :: HscEnv -> String -> String -> Int -> IO ([TyThing], InteractiveContext)
- hscTcExpr :: HscEnv -> TcRnExprMode -> String -> IO Type
- data TcRnExprMode
  - = TM_Inst
  - | TM_NoInst
  - | TM_Default
- hscImport :: HscEnv -> String -> IO (ImportDecl RdrName)
- hscKcType :: HscEnv -> Bool -> String -> IO (Type, Kind)
- hscParseExpr :: String -> Hsc (LHsExpr RdrName)
- hscCompileCoreExpr :: HscEnv -> SrcSpan -> CoreExpr -> IO ForeignHValue
- hscCompileCoreExpr' :: HscEnv -> SrcSpan -> CoreExpr -> IO ForeignHValue
- hscParse' :: ModSummary -> Hsc HsParsedModule
- hscSimplify' :: ModGuts -> Hsc ModGuts
- hscDesugar' :: ModLocation -> TcGblEnv -> Hsc ModGuts
- tcRnModule' :: HscEnv -> ModSummary -> Bool -> HsParsedModule -> Hsc TcGblEnv
- getHscEnv :: Hsc HscEnv
- hscSimpleIface' :: TcGblEnv -> Maybe Fingerprint -> Hsc (ModIface, Bool, ModDetails)
- hscNormalIface' :: ModGuts -> Maybe Fingerprint -> Hsc (ModIface, Bool, ModDetails, CgGuts)
- oneShotMsg :: HscEnv -> RecompileRequired -> IO ()
- hscFileFrontEnd :: ModSummary -> Hsc TcGblEnv
- genericHscFrontend :: ModSummary -> Hsc FrontendResult
- dumpIfaceStats :: HscEnv -> IO ()
- ioMsgMaybe :: IO (Messages, Maybe a) -> Hsc a
- showModuleIndex :: (Int, Int) -> String
- hscAddSptEntries :: HscEnv -> [SptEntry] -> IO ()

# Making an HscEnv

newHscEnv :: DynFlags -> IO HscEnv #

# Compiling complete source files

type Messager = HscEnv -> (Int, Int) -> RecompileRequired -> ModSummary -> IO () #

batchMsg :: Messager #

data HscStatus #

Status of a compilation to hard-code

Constructors

HscNotGeneratingCode |
HscUpToDate |
HscUpdateBoot |
HscUpdateSig |
HscRecomp CgGuts ModSummary |

hscIncrementalCompile :: Bool -> Maybe TcGblEnv -> Maybe Messager -> HscEnv -> ModSummary -> SourceModified -> Maybe ModIface -> (Int, Int) -> IO (HscStatus, HomeModInfo) #

hscCompileCmmFile :: HscEnv -> FilePath -> FilePath -> IO () #

hscGenHardCode #

Arguments

:: HscEnv |
-> CgGuts |
-> ModSummary |
-> FilePath |
-> IO (FilePath, Maybe FilePath, [(ForeignSrcLang, FilePath)]) | `Just f` = _stub.c is f

Compile to hard-code.

hscInteractive :: HscEnv -> CgGuts -> ModSummary -> IO (Maybe FilePath, CompiledByteCode, [SptEntry]) #

# Running passes separately

hscParse :: HscEnv -> ModSummary -> IO HsParsedModule #

parse a file, returning the abstract syntax

hscTypecheckRename :: HscEnv -> ModSummary -> HsParsedModule -> IO (TcGblEnv, RenamedStuff) #

Rename and typecheck a module, additionally returning the renamed syntax

hscDesugar :: HscEnv -> ModSummary -> TcGblEnv -> IO ModGuts #

Convert a typechecked module to Core

makeSimpleDetails :: HscEnv -> TcGblEnv -> IO ModDetails #

Make a `ModDetails` from the results of typechecking. Used when typechecking only, as opposed to full compilation.

hscSimplify :: HscEnv -> ModGuts -> IO ModGuts #

# Safe Haskell

hscCheckSafe :: HscEnv -> Module -> SrcSpan -> IO Bool #

Check that a module is safe to import.

We return True to indicate the import is safe and False otherwise although in the False case an exception may be thrown first.

hscGetSafe :: HscEnv -> Module -> SrcSpan -> IO (Bool, Set InstalledUnitId) #

Return if a module is trusted and the pkgs it depends on to be trusted.

# Support for interactive evaluation

hscParseIdentifier :: HscEnv -> String -> IO (Located RdrName) #

hscTcRcLookupName :: HscEnv -> Name -> IO (Maybe TyThing) #

hscTcRnGetInfo :: HscEnv -> Name -> IO (Maybe (TyThing, Fixity, [ClsInst], [FamInst])) #

hscIsGHCiMonad :: HscEnv -> String -> IO Name #

hscGetModuleInterface :: HscEnv -> Module -> IO ModIface #

hscRnImportDecls :: HscEnv -> [LImportDecl RdrName] -> IO GlobalRdrEnv #

Rename some import declarations

hscTcRnLookupRdrName :: HscEnv -> Located RdrName -> IO [Name] #

Lookup things in the compiler's environment

hscStmt :: HscEnv -> String -> IO (Maybe ([Id], ForeignHValue, FixityEnv)) #

Compile a stmt all the way to an HValue, but don't run it

We return Nothing to indicate an empty statement (or comment only), not a parse error.

hscStmtWithLocation #

Arguments

:: HscEnv |
-> String | The statement
-> String | The source
-> Int | Starting line
-> IO (Maybe ([Id], ForeignHValue, FixityEnv)) |

Compile a stmt all the way to an HValue, but don't run it

We return Nothing to indicate an empty statement (or comment only), not a parse error.

hscParsedStmt #

Arguments

:: HscEnv |
-> GhciLStmt RdrName | The parsed statement
-> IO (Maybe ([Id], ForeignHValue, FixityEnv)) |

hscDecls #

Arguments

:: HscEnv |
-> String | The statement
-> IO ([TyThing], InteractiveContext) |

Compile a decls

hscDeclsWithLocation #

Arguments

:: HscEnv |
-> String | The statement
-> String | The source
-> Int | Starting line
-> IO ([TyThing], InteractiveContext) |

Compile a decls

hscTcExpr #

Arguments

:: HscEnv |
-> TcRnExprMode |
-> String | The expression
-> IO Type |

Typecheck an expression (but don't run it)

data TcRnExprMode #

How should we infer a type? See Note [TcRnExprMode]

Constructors

TM_Inst | Instantiate the type fully (:type)
TM_NoInst | Do not instantiate the type (:type +v)
TM_Default | Default the type eagerly (:type +d)

hscImport :: HscEnv -> String -> IO (ImportDecl RdrName) #

hscKcType #

Arguments

:: HscEnv |
-> Bool | Normalise the type
-> String | The type as a string
-> IO (Type, Kind) | Resulting type (possibly normalised) and kind

Find the kind of a type Currently this does *not* generalise the kinds of the type

hscParseExpr :: String -> Hsc (LHsExpr RdrName) #

hscCompileCoreExpr :: HscEnv -> SrcSpan -> CoreExpr -> IO ForeignHValue #

# Low-level exports for hooks

hscCompileCoreExpr' :: HscEnv -> SrcSpan -> CoreExpr -> IO ForeignHValue #

hscParse' :: ModSummary -> Hsc HsParsedModule #

hscSimplify' :: ModGuts -> Hsc ModGuts #

hscDesugar' :: ModLocation -> TcGblEnv -> Hsc ModGuts #

tcRnModule' :: HscEnv -> ModSummary -> Bool -> HsParsedModule -> Hsc TcGblEnv #

getHscEnv :: Hsc HscEnv #

hscSimpleIface' :: TcGblEnv -> Maybe Fingerprint -> Hsc (ModIface, Bool, ModDetails) #

hscNormalIface' :: ModGuts -> Maybe Fingerprint -> Hsc (ModIface, Bool, ModDetails, CgGuts) #

oneShotMsg :: HscEnv -> RecompileRequired -> IO () #

hscFileFrontEnd :: ModSummary -> Hsc TcGblEnv #

Given a `ModSummary`, parses and typechecks it, returning the `TcGblEnv` resulting from type-checking.

genericHscFrontend :: ModSummary -> Hsc FrontendResult #

dumpIfaceStats :: HscEnv -> IO () #

ioMsgMaybe :: IO (Messages, Maybe a) -> Hsc a #

Deal with errors and warnings returned by a compilation step

In order to reduce dependencies to other parts of the compiler, functions outside the "main" parts of GHC return warnings and errors as a parameter and signal success via by wrapping the result in a `Maybe` type. This function logs the returned warnings and propagates errors as exceptions (of type `SourceError`).

This function assumes the following invariants:

1. If the second result indicates success (is of the form 'Just x'), there must be no error messages in the first result.
2. If there are no error messages, but the second result indicates failure there should be warnings in the first result. That is, if the action failed, it must have been due to the warnings (i.e., `-Werror`).

showModuleIndex :: (Int, Int) -> String #

hscAddSptEntries :: HscEnv -> [SptEntry] -> IO () #

Load the given static-pointer table entries into the interpreter. See Note [Grand plan for static forms] in StaticPtrTable.