language-c-0.6.1: Analysis and generation of C code

Copyright | (c) 2008 Benedikt Huber
License | BSD-style
Maintainer | benedikt.huber@gmail.com
Stability | alpha
Portability | ghc
Safe Haskell | None
Language | Haskell98

Language.C.Analysis.TravMonad

Contents

- Name generation monad
- Symbol table monad
- Specialized C error-handling monad
- AST traversal monad
- Handling declarations
- Symbol table scope modification
- Symbol table lookup (delegate)
- Symbol table modification
- Additional error handling facilities
- Trav - default MonadTrav implementation
- Language options
- Helpers

Description

Monad for Traversals of the C AST.

For the traversal, we maintain a symboltable and need MonadError and unique name generation facilities. Furthermore, the user may provide callbacks to handle declarations and definitions.

Synopsis

- class Monad m => MonadName m where
- class Monad m => MonadSymtab m where
- class Monad m => MonadCError m where
- class (MonadName m, MonadSymtab m, MonadCError m) => MonadTrav m where
- handleTagDecl :: (MonadCError m, MonadSymtab m) => TagFwdDecl -> m ()
- handleTagDef :: MonadTrav m => TagDef -> m ()
- handleEnumeratorDef :: (MonadCError m, MonadSymtab m) => Enumerator -> m ()
- handleTypeDef :: MonadTrav m => TypeDef -> m ()
- handleObjectDef :: MonadTrav m => Bool -> Ident -> ObjDef -> m ()
- handleFunDef :: MonadTrav m => Ident -> FunDef -> m ()
- handleVarDecl :: MonadTrav m => Bool -> Decl -> m ()
- handleParamDecl :: MonadTrav m => ParamDecl -> m ()
- handleAsmBlock :: MonadTrav m => AsmBlock -> m ()
- enterPrototypeScope :: MonadSymtab m => m ()
- leavePrototypeScope :: MonadSymtab m => m ()
- enterFunctionScope :: MonadSymtab m => m ()
- leaveFunctionScope :: MonadSymtab m => m ()
- enterBlockScope :: MonadSymtab m => m ()
- leaveBlockScope :: MonadSymtab m => m ()
- lookupTypeDef :: (MonadCError m, MonadSymtab m) => Ident -> m Type
- lookupObject :: (MonadCError m, MonadSymtab m) => Ident -> m (Maybe IdentDecl)
- createSUERef :: (MonadCError m, MonadSymtab m) => NodeInfo -> Maybe Ident -> m SUERef
- hadHardErrors :: [CError] -> Bool
- handleTravError :: MonadCError m => m a -> m (Maybe a)
- throwOnLeft :: (MonadCError m, Error e) => Either e a -> m a
- astError :: MonadCError m => NodeInfo -> String -> m a
- warn :: (Error e, MonadCError m) => e -> m ()
- data Trav s a
- runTrav :: forall s a. s -> Trav s a -> Either [CError] (a, TravState s)
- runTrav_ :: Trav () a -> Either [CError] (a, [CError])
- data TravState s
- initTravState :: s -> TravState s
- withExtDeclHandler :: Trav s a -> (DeclEvent -> Trav s ()) -> Trav s a
- modifyUserState :: (s -> s) -> Trav s ()
- userState :: TravState s -> s
- getUserState :: Trav s s
- data TravOptions = TravOptions {
  - language :: CLanguage
  }
- modifyOptions :: (TravOptions -> TravOptions) -> Trav s ()
- travErrors :: TravState s -> [CError]
- data CLanguage
  - = C89
  - | C99
  - | GNU89
  - | GNU99
- mapMaybeM :: Monad m => Maybe a -> (a -> m b) -> m (Maybe b)
- maybeM :: Monad m => Maybe a -> (a -> m ()) -> m ()
- mapSndM :: Monad m => (b -> m c) -> (a, b) -> m (a, c)
- concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b]

# Name generation monad

class Monad m => MonadName m where #

Minimal complete definition

genName

Methods

genName :: m Name #

unique name generation

Instances

MonadName (Trav s) # |
Methods genName :: Trav s Name #

# Symbol table monad

class Monad m => MonadSymtab m where #

Minimal complete definition

getDefTable, withDefTable

Methods

getDefTable :: m DefTable #

return the definition table

withDefTable :: (DefTable -> (a, DefTable)) -> m a #

perform an action modifying the definition table

Instances

MonadSymtab (Trav s) # |
Methods getDefTable :: Trav s DefTable # withDefTable :: (DefTable -> (a, DefTable)) -> Trav s a #

# Specialized C error-handling monad

class Monad m => MonadCError m where #

Minimal complete definition

throwTravError, catchTravError, recordError, getErrors

Methods

throwTravError :: Error e => e -> m a #

throw an `Error`

catchTravError :: m a -> (CError -> m a) -> m a #

catch an `Error` (we could implement dynamically-typed catch here)

recordError :: Error e => e -> m () #

remember that an `Error` occurred (without throwing it)

getErrors :: m [CError] #

return the list of recorded errors

Instances

MonadCError (Trav s) # |
Methods throwTravError :: Error e => e -> Trav s a # catchTravError :: Trav s a -> (CError -> Trav s a) -> Trav s a # recordError :: Error e => e -> Trav s () # getErrors :: Trav s [CError] #

# AST traversal monad

class (MonadName m, MonadSymtab m, MonadCError m) => MonadTrav m where #

Traversal monad

Minimal complete definition

handleDecl

Methods

handleDecl :: DeclEvent -> m () #

handling declarations and definitions

Instances

MonadTrav (Trav s) # |
Methods handleDecl :: DeclEvent -> Trav s () #

# Handling declarations

handleTagDecl :: (MonadCError m, MonadSymtab m) => TagFwdDecl -> m () #

forward declaration of a tag. Only necessary for name analysis, but otherwise no semantic consequences.

handleTagDef :: MonadTrav m => TagDef -> m () #

define the given composite type or enumeration If there is a declaration visible, overwrite it with the definition. Otherwise, enter a new definition in the current namespace. If there is already a definition present, yield an error (redeclaration).

handleEnumeratorDef :: (MonadCError m, MonadSymtab m) => Enumerator -> m () #

handleTypeDef :: MonadTrav m => TypeDef -> m () #

handleObjectDef :: MonadTrav m => Bool -> Ident -> ObjDef -> m () #

handle object defintions (maybe tentative)

handleFunDef :: MonadTrav m => Ident -> FunDef -> m () #

handle function definitions

handleVarDecl :: MonadTrav m => Bool -> Decl -> m () #

handle variable declarations (external object declarations and function prototypes) variable declarations are either function prototypes, or external declarations, and not very interesting on their own. we only put them in the symbol table and call the handle. declarations never override definitions

handleParamDecl :: MonadTrav m => ParamDecl -> m () #

handle parameter declaration. The interesting part is that parameters can be abstract (if they are part of a type). If they have a name, we enter the name (usually in function prototype or function scope), checking if there are duplicate definitions. FIXME: I think it would be more transparent to handle parameter declarations in a special way

handleAsmBlock :: MonadTrav m => AsmBlock -> m () #

# Symbol table scope modification

enterPrototypeScope :: MonadSymtab m => m () #

leavePrototypeScope :: MonadSymtab m => m () #

enterFunctionScope :: MonadSymtab m => m () #

leaveFunctionScope :: MonadSymtab m => m () #

enterBlockScope :: MonadSymtab m => m () #

leaveBlockScope :: MonadSymtab m => m () #

# Symbol table lookup (delegate)

lookupTypeDef :: (MonadCError m, MonadSymtab m) => Ident -> m Type #

lookup a type definition the 'wrong kind of object' is an internal error here, because the parser should distinguish typeDefs and other objects

lookupObject :: (MonadCError m, MonadSymtab m) => Ident -> m (Maybe IdentDecl) #

lookup an object, function or enumerator

# Symbol table modification

createSUERef :: (MonadCError m, MonadSymtab m) => NodeInfo -> Maybe Ident -> m SUERef #

create a reference to a struct/union/enum

This currently depends on the fact the structs are tagged with unique names. We could use the name generation of TravMonad as well, which might be the better choice when dealing with autogenerated code.

# Additional error handling facilities

hadHardErrors :: [CError] -> Bool #

check wheter non-recoverable errors occurred

handleTravError :: MonadCError m => m a -> m (Maybe a) #

throwOnLeft :: (MonadCError m, Error e) => Either e a -> m a #

raise an error based on an Either argument

astError :: MonadCError m => NodeInfo -> String -> m a #

raise an error caused by a malformed AST

warn :: (Error e, MonadCError m) => e -> m () #

# Trav - default MonadTrav implementation

data Trav s a #

simple traversal monad, providing user state and callbacks

Instances

Monad (Trav s) # |
Methods (>>=) :: Trav s a -> (a -> Trav s b) -> Trav s b # (>>) :: Trav s a -> Trav s b -> Trav s b # return :: a -> Trav s a # fail :: String -> Trav s a #
Functor (Trav s) # |
Methods fmap :: (a -> b) -> Trav s a -> Trav s b # (<$) :: a -> Trav s b -> Trav s a #
Applicative (Trav s) # |
Methods pure :: a -> Trav s a # (<*>) :: Trav s (a -> b) -> Trav s a -> Trav s b # (*>) :: Trav s a -> Trav s b -> Trav s b # (<*) :: Trav s a -> Trav s b -> Trav s a #
MonadTrav (Trav s) # |
Methods handleDecl :: DeclEvent -> Trav s () #
MonadCError (Trav s) # |
Methods throwTravError :: Error e => e -> Trav s a # catchTravError :: Trav s a -> (CError -> Trav s a) -> Trav s a # recordError :: Error e => e -> Trav s () # getErrors :: Trav s [CError] #
MonadSymtab (Trav s) # |
Methods getDefTable :: Trav s DefTable # withDefTable :: (DefTable -> (a, DefTable)) -> Trav s a #
MonadName (Trav s) # |
Methods genName :: Trav s Name #

runTrav :: forall s a. s -> Trav s a -> Either [CError] (a, TravState s) #

runTrav_ :: Trav () a -> Either [CError] (a, [CError]) #

data TravState s #

initTravState :: s -> TravState s #

withExtDeclHandler :: Trav s a -> (DeclEvent -> Trav s ()) -> Trav s a #

modifyUserState :: (s -> s) -> Trav s () #

userState :: TravState s -> s #

getUserState :: Trav s s #

data TravOptions #

Constructors

TravOptions |
Fields language :: CLanguage

modifyOptions :: (TravOptions -> TravOptions) -> Trav s () #

travErrors :: TravState s -> [CError] #

# Language options

data CLanguage #

The variety of the C language to accept. Note: this is not yet enforced.

Constructors

C89 |
C99 |
GNU89 |
GNU99 |

# Helpers

mapMaybeM :: Monad m => Maybe a -> (a -> m b) -> m (Maybe b) #

maybeM :: Monad m => Maybe a -> (a -> m ()) -> m () #

mapSndM :: Monad m => (b -> m c) -> (a, b) -> m (a, c) #

concatMapM :: Monad m => (a -> m [b]) -> [a] -> m [b] #