language-c-0.4.5: Analysis and generation of C code

Safe HaskellNone




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.


Name generation monad

class Monad m => MonadName m whereSource


genName :: m NameSource

unique name generation


Symbol table monad

class Monad m => MonadSymtab m whereSource


getDefTable :: m DefTableSource

return the definition table

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

perform an action modifying the definition table


Specialized C error-handling monad

class Monad m => MonadCError m whereSource


throwTravError :: Error e => e -> m aSource

throw an Error

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

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

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

remember that an Error occurred (without throwing it)

getErrors :: m [CError]Source

return the list of recorded errors


AST traversal monad

class (MonadName m, MonadSymtab m, MonadCError m) => MonadTrav m whereSource

Traversal monad


handleDecl :: DeclEvent -> m ()Source

handling declarations and definitions


Handling declarations

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

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

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

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).

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

handle object defintions (maybe tentative)

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

handle function definitions

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

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 ()Source

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

Symbol table scope modification

Symbol table lookup (delegate)

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

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)Source

lookup an object, function or enumerator

Symbol table modification

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

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] -> BoolSource

check wheter non-recoverable errors occurred

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

raise an error based on an Either argument

astError :: MonadCError m => NodeInfo -> String -> m aSource

raise an error caused by a malformed AST

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

Trav - default MonadTrav implementation

data Trav s a Source

simple traversal monad, providing user state and callbacks


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

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

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

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

data TravOptions Source




language :: CLanguage

Language options

data CLanguage Source

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




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

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

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

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