language-c-0.3.1.1: Analysis and generation of C codeContentsIndex
Language.C.Analysis.TravMonad
Portabilityghc
Stabilityalpha
Maintainerbenedikt.huber@gmail.com
Contents
AST traversal monad
Handling declarations
Symbol table scope modification
Symbol table lookup (delegate)
Symbol table modification
Additional error handling facilities
Trav - default MonadTrav implementation
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 => MonadTrav m where
throwTravError :: Error e => e -> m a
catchTravError :: m a -> (CError -> m a) -> m a
recordError :: Error e => e -> m ()
getErrors :: m [CError]
getDefTable :: m DefTable
withDefTable :: (DefTable -> (a, DefTable)) -> m a
genName :: m Name
handleDecl :: DeclEvent -> m ()
handleTagDecl :: MonadTrav m => TagFwdDecl -> m ()
handleTagDef :: MonadTrav m => TagDef -> m ()
handleEnumeratorDef :: MonadTrav m => Enumerator -> m ()
handleTypeDef :: MonadTrav m => TypeDef -> m ()
handleObjectDef :: MonadTrav m => Ident -> ObjDef -> m ()
handleFunDef :: MonadTrav m => Ident -> FunDef -> m ()
handleVarDecl :: MonadTrav m => Decl -> m ()
handleParamDecl :: MonadTrav m => ParamDecl -> m ()
handleAsmBlock :: MonadTrav m => AsmBlock -> m ()
enterPrototypeScope :: MonadTrav m => m ()
leavePrototypeScope :: MonadTrav m => m ()
enterFunctionScope :: MonadTrav m => m ()
leaveFunctionScope :: MonadTrav m => m ()
enterBlockScope :: MonadTrav m => m ()
leaveBlockScope :: MonadTrav m => m ()
lookupTypeDef :: MonadTrav m => Ident -> m Type
lookupObject :: MonadTrav m => Ident -> m (Maybe IdentDecl)
createSUERef :: MonadTrav m => NodeInfo -> Maybe Ident -> m SUERef
hadHardErrors :: [CError] -> Bool
handleTravError :: MonadTrav m => m a -> m (Maybe a)
throwOnLeft :: (MonadTrav m, Error e) => Either e a -> m a
astError :: MonadTrav m => NodeInfo -> String -> m a
warn :: (Error e, MonadTrav 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
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]
AST traversal monad
class Monad m => MonadTrav m where
Traversal monad
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 occured (without throwing it)
getErrors :: m [CError]
return the list of recorded errors
getDefTable :: m DefTable
return the definition table
withDefTable :: (DefTable -> (a, DefTable)) -> m a
perform an action modifying the definition table
genName :: m Name
unique name generation
handleDecl :: DeclEvent -> m ()
handling declarations and definitions
show/hide Instances
Handling declarations
handleTagDecl :: MonadTrav m => TagFwdDecl -> m ()
forward declaration of a tag. Only neccessary 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 :: MonadTrav m => Enumerator -> m ()
handleTypeDef :: MonadTrav m => TypeDef -> m ()
handleObjectDef :: MonadTrav m => Ident -> ObjDef -> m ()
handle object defintions (maybe tentative)
handleFunDef :: MonadTrav m => Ident -> FunDef -> m ()
handle function definitions
handleVarDecl :: MonadTrav m => 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 :: MonadTrav m => m ()
leavePrototypeScope :: MonadTrav m => m ()
enterFunctionScope :: MonadTrav m => m ()
leaveFunctionScope :: MonadTrav m => m ()
enterBlockScope :: MonadTrav m => m ()
leaveBlockScope :: MonadTrav m => m ()
Symbol table lookup (delegate)
lookupTypeDef :: MonadTrav 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 :: MonadTrav m => Ident -> m (Maybe IdentDecl)
lookup an object, function or enumerator
Symbol table modification
createSUERef :: MonadTrav 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 occured
handleTravError :: MonadTrav m => m a -> m (Maybe a)
throwOnLeft :: (MonadTrav m, Error e) => Either e a -> m a
raise an error based on an Either argument
astError :: MonadTrav m => NodeInfo -> String -> m a
raise an error caused by a malformed AST
warn :: (Error e, MonadTrav m) => e -> m ()
Trav - default MonadTrav implementation
data Trav s a
simple traversal monad, providing user state and callbacks
show/hide Instances
Monad (Trav s)
MonadTrav (Trav s)
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
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]
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