c2hs-0.26.1: src/C2HS/C/Attrs.hs
-- C->Haskell Compiler: C attribute definitions and manipulation routines
--
-- Author : Manuel M. T. Chakravarty
-- Created: 12 August 99
--
-- Copyright (c) [1999..2001] Manuel M. T. Chakravarty
--
-- This file is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This file is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU General Public License for more details.
--
--- DESCRIPTION ---------------------------------------------------------------
--
-- This module provides the attributed version of the C structure tree.
--
-- * C has several name spaces of which two are represented in this module:
-- - `CObj' in `defObjsAC': The name space of objects, functions, typedef
-- names, and enum constants.
-- - `CTag' in `defTagsAC': The name space of tags of structures, unions,
-- and enumerations.
--
-- * The final state of the names spaces are preserved in the attributed
-- structure tree. This allows further fast lookups for globally defined
-- identifiers after the name anaysis is over.
--
-- * In addition to the name spaces, the attribute structure tree contains
-- a ident-definition table, which for attribute handles of identifiers
-- refers to the identifiers definition. These are only used in usage
-- occurences, except for one exception: The tag identifiers in forward
-- definitions of structures or enums get a reference to the corresponding
-- full definition - see `CTrav' for full details.
--
-- * We maintain a shadow definition table, it can be populated with aliases
-- to other objects and maps identifiers to identifiers. It is populated by
-- using the `applyPrefix' function. When looksup performed via the shadow
-- variant of a lookup function, shadow aliases are also considered, but
-- they are used only if no normal entry for the identifiers is present.
--
-- * Only ranges delimited by a block open a new range for tags (see
-- `enterNewObjRangeC' and `leaveObjRangeC').
--
--- DOCU ----------------------------------------------------------------------
--
-- language: Haskell 98
--
--- TODO ----------------------------------------------------------------------
--
module C2HS.C.Attrs (-- attributed C
--
AttrC(..), emptyAttrC, enterNewRangeC, enterNewObjRangeC,
leaveRangeC, leaveObjRangeC, addDefObjC, lookupDefObjC,
lookupDefObjCShadow, addDefTagC, lookupDefTagC,
lookupDefTagCShadow, applyPrefix, getDefOfIdentC,
setDefOfIdentC, updDefOfIdentC, freezeDefOfIdentsAttrC,
softenDefOfIdentsAttrC,
--
-- C objects
--
CObj(..), CTag(..), CDef(..))
where
import Data.Char (toUpper)
import Data.Maybe (mapMaybe)
import Language.C.Data.Node
import Language.C.Data.Ident
import Language.C.Data.Position
import Language.C.Syntax
import Language.C.Pretty
import Text.PrettyPrint.HughesPJ
import Data.Errors (interr)
import Data.Attributes (Attr(..), AttrTable, getAttr, setAttr, updAttr,
newAttrTable, freezeAttrTable, softenAttrTable)
import Data.NameSpaces (NameSpace, nameSpace, enterNewRange, leaveRange, defLocal,
defGlobal, find, nameSpaceToList)
-- attributed C structure tree
-- ---------------------------
-- | attributes relevant to the outside world gathjered from a C unit
--
data AttrC = AttrC {
defObjsAC :: CObjNS, -- defined objects
defTagsAC :: CTagNS, -- defined tags
shadowsAC :: CShadowNS, -- shadow definitions (prefix)
defsAC :: CDefTable -- ident-def associations
} deriving (Show)
-- | empty headder attribute set
--
emptyAttrC :: AttrC
emptyAttrC = AttrC {
defObjsAC = cObjNS,
defTagsAC = cTagNS,
shadowsAC = cShadowNS,
defsAC = cDefTable
}
-- the name space operations
--
-- | enter a new range
--
enterNewRangeC :: AttrC -> AttrC
enterNewRangeC ac = ac {
defObjsAC = enterNewRange . defObjsAC $ ac,
defTagsAC = enterNewRange . defTagsAC $ ac
}
-- | enter a new range, only for objects
--
enterNewObjRangeC :: AttrC -> AttrC
enterNewObjRangeC ac = ac {
defObjsAC = enterNewRange . defObjsAC $ ac
}
-- | leave the current range
--
leaveRangeC :: AttrC -> AttrC
leaveRangeC ac = ac {
defObjsAC = fst . leaveRange . defObjsAC $ ac,
defTagsAC = fst . leaveRange . defTagsAC $ ac
}
-- | leave the current range, only for objects
--
leaveObjRangeC :: AttrC -> AttrC
leaveObjRangeC ac = ac {
defObjsAC = fst . leaveRange . defObjsAC $ ac
}
-- | add another definitions to the object name space
--
-- * if a definition of the same name was already present, it is returned
--
addDefObjC :: AttrC -> Ident -> CObj -> (AttrC, Maybe CObj)
addDefObjC ac ide obj = let om = defObjsAC ac
(ac', obj') = defLocal om ide obj
in
(ac {defObjsAC = ac'}, obj')
-- | lookup an identifier in the object name space
--
lookupDefObjC :: AttrC -> Ident -> Maybe CObj
lookupDefObjC ac ide = find (defObjsAC ac) ide
-- | lookup an identifier in the object name space; if nothing found, try
-- whether there is a shadow identifier that matches
--
-- * the returned identifier is the _real_ identifier of the object
--
lookupDefObjCShadow :: AttrC -> Ident -> Maybe (CObj, Ident)
lookupDefObjCShadow ac ide =
case lookupDefObjC ac ide of
Just obj -> Just (obj, ide)
Nothing -> case find (shadowsAC ac) ide of
Nothing -> Nothing
Just ide' -> case lookupDefObjC ac ide' of
Just obj -> Just (obj, ide')
Nothing -> Nothing
-- | add another definition to the tag name space
--
-- * if a definition of the same name was already present, it is returned
--
addDefTagC :: AttrC -> Ident -> CTag -> (AttrC, Maybe CTag)
addDefTagC ac ide obj = let tm = defTagsAC ac
(ac', obj') = defLocal tm ide obj
in
(ac {defTagsAC = ac'}, obj')
-- | lookup an identifier in the tag name space
--
lookupDefTagC :: AttrC -> Ident -> Maybe CTag
lookupDefTagC ac ide = find (defTagsAC ac) ide
-- | lookup an identifier in the tag name space; if nothing found, try
-- whether there is a shadow identifier that matches
--
-- * the returned identifier is the _real_ identifier of the tag
--
lookupDefTagCShadow :: AttrC -> Ident -> Maybe (CTag, Ident)
lookupDefTagCShadow ac ide =
case lookupDefTagC ac ide of
Just tag -> Just (tag, ide)
Nothing -> case find (shadowsAC ac) ide of
Nothing -> Nothing
Just ide' -> case lookupDefTagC ac ide' of
Just tag -> Just (tag, ide')
Nothing -> Nothing
-- | enrich the shadow name space with identifiers obtained by dropping
-- the given prefix from the identifiers already in the object or tag name
-- space
--
-- * in case of a collisions, a random entry is selected
--
-- * case is not relevant in the prefix and underscores between the prefix and
-- the stem of an identifier are also dropped
--
applyPrefix :: AttrC -> String -> String -> AttrC
applyPrefix ac prefix repprefix =
let
shadows = shadowsAC ac
names = map fst (nameSpaceToList (defObjsAC ac))
++ map fst (nameSpaceToList (defTagsAC ac))
newShadows = mapMaybe (strip prefix) names
in
ac {shadowsAC = foldl define shadows newShadows}
where
strip prefx ide = case eat prefx (identToString ide) of
Nothing -> Nothing
Just "" -> Nothing
Just newName ->
Just (internalIdentAt (posOf ide) (repprefix ++ newName), ide)
--
eat [] ('_':cs) = eat [] cs
eat [] cs = Just cs
eat (p:prefx) (c:cs) | toUpper p == toUpper c = eat prefx cs
| otherwise = Nothing
eat _ _ = Nothing
--
define ns (ide, def) = fst (defGlobal ns ide def)
-- the attribute table operations on the attributes
--
-- | get the definition associated with the given identifier
--
getDefOfIdentC :: AttrC -> Ident -> CDef
getDefOfIdentC ac = getAttr (defsAC ac) . nodeInfo
setDefOfIdentC :: AttrC -> Ident -> CDef -> AttrC
setDefOfIdentC ac ide def =
let tot' = setAttr (defsAC ac) (nodeInfo ide) def
in
ac {defsAC = tot'}
updDefOfIdentC :: AttrC -> Ident -> CDef -> AttrC
updDefOfIdentC ac ide def =
let tot' = updAttr (defsAC ac) (nodeInfo ide) def
in
ac {defsAC = tot'}
freezeDefOfIdentsAttrC :: AttrC -> AttrC
freezeDefOfIdentsAttrC ac = ac {defsAC = freezeAttrTable (defsAC ac)}
softenDefOfIdentsAttrC :: AttrC -> AttrC
softenDefOfIdentsAttrC ac = ac {defsAC = softenAttrTable (defsAC ac)}
pshow :: (Pretty a) => a -> String
pshow = renderStyle (Style OneLineMode 80 1.5) . pretty
-- C objects including operations
-- ------------------------------
-- | C objects data definition
--
data CObj = TypeCO CDecl -- typedef declaration
| ObjCO CDecl -- object or function declaration
| EnumCO Ident CEnum -- enumerator
| BuiltinCO (Maybe CDecl) -- builtin object, with equivalent
-- C decl if one exists
instance Show CObj where
show (TypeCO decl) = "TypeCO { " ++ pshow decl ++ " }"
show (ObjCO decl) = "ObjCO { "++ pshow decl ++ " }"
show (EnumCO ide enum) = "EnumCO "++ show ide ++ " { " ++ pshow enum ++ " }"
show (BuiltinCO _) = "BuiltinCO"
-- two C objects are equal iff they are defined by the same structure
-- tree node (i.e., the two nodes referenced have the same attribute
-- identifier)
--
instance Eq CObj where
(TypeCO decl1 ) == (TypeCO decl2 ) = decl1 `eqByName` decl2
(ObjCO decl1 ) == (ObjCO decl2 ) = decl1 `eqByName` decl2
(EnumCO ide1 enum1) == (EnumCO ide2 enum2) = ide1 == ide2 && enum1 `eqByName` enum2
_ == _ = False
instance Pos CObj where
posOf (TypeCO def ) = posOf def
posOf (ObjCO def ) = posOf def
posOf (EnumCO ide _) = posOf ide
posOf (BuiltinCO _ ) = builtinPos
-- C tagged objects including operations
-- -------------------------------------
-- | C tagged objects data definition
--
data CTag = StructUnionCT CStructUnion -- toplevel struct-union declaration
| EnumCT CEnum -- toplevel enum declaration
instance Show CTag where
show (StructUnionCT su) = "StructUnionCT {" ++ pshow su ++ "}"
show (EnumCT e) = "EnumCT {"++ pshow e ++ "}"
-- | two C tag objects are equal iff they are defined by the same structure
-- tree node (i.e., the two nodes referenced have the same attribute
-- identifier)
--
instance Eq CTag where
(StructUnionCT struct1) == (StructUnionCT struct2) = struct1 `eqByName` struct2
(EnumCT enum1 ) == (EnumCT enum2 ) = enum1 `eqByName` enum2
_ == _ = False
instance Pos CTag where
posOf (StructUnionCT def) = posOf def
posOf (EnumCT def) = posOf def
-- C general definition
-- --------------------
-- | C general definition
--
data CDef = UndefCD -- undefined object
| DontCareCD -- don't care object
| ObjCD CObj -- C object
| TagCD CTag -- C tag
instance Show CDef where
show UndefCD = "UndefCD"
show DontCareCD = "DontCareCD"
show (ObjCD cobj) = "ObjCD { " ++ show cobj ++ "}"
show (TagCD ctag) = "TagCD { " ++ show ctag ++ "}"
-- two C definitions are equal iff they are defined by the same structure
-- tree node (i.e., the two nodes referenced have the same attribute
-- identifier), but don't care objects are equal to everything and undefined
-- objects may not be compared
--
instance Eq CDef where
(ObjCD obj1) == (ObjCD obj2) = obj1 == obj2
(TagCD tag1) == (TagCD tag2) = tag1 == tag2
DontCareCD == _ = True
_ == DontCareCD = True
UndefCD == _ =
interr "CAttrs: Attempt to compare an undefined C definition!"
_ == UndefCD =
interr "CAttrs: Attempt to compare an undefined C definition!"
_ == _ = False
instance Attr CDef where
undef = UndefCD
dontCare = DontCareCD
isUndef UndefCD = True
isUndef _ = False
isDontCare DontCareCD = True
isDontCare _ = False
instance Pos CDef where
posOf UndefCD = nopos
posOf DontCareCD = nopos
posOf (ObjCD obj) = posOf obj
posOf (TagCD tag) = posOf tag
-- object tables (internal use only)
-- ---------------------------------
-- | the object name spavce
--
type CObjNS = NameSpace CObj
-- | creating a new object name space
--
cObjNS :: CObjNS
cObjNS = nameSpace
-- the tag name space
--
type CTagNS = NameSpace CTag
-- creating a new tag name space
--
cTagNS :: CTagNS
cTagNS = nameSpace
-- | the shadow name space
--
type CShadowNS = NameSpace Ident
-- | creating a shadow name space
--
cShadowNS :: CShadowNS
cShadowNS = nameSpace
-- | the general definition table
--
type CDefTable = AttrTable CDef
-- | creating a new definition table
--
cDefTable :: CDefTable
cDefTable = newAttrTable "C General Definition Table for Idents"