elna/lib/Language/Elna/Glue.hs

295 lines
12 KiB
Haskell

module Language.Elna.Glue
( glue
) where
import Control.Monad.Trans.State (State, gets, modify', runState)
import Data.Bifunctor (Bifunctor(..))
import Data.Foldable (Foldable(..), traverse_)
import Data.HashMap.Strict (HashMap)
import qualified Data.HashMap.Strict as HashMap
import Data.Maybe (catMaybes)
import Data.Vector (Vector)
import qualified Data.Text.Lazy.Builder.Int as Text.Builder
import qualified Data.Text.Lazy.Builder as Text.Builder
import qualified Data.Text.Lazy as Text.Lazy
import qualified Data.Vector as Vector
import Data.Word (Word32)
import qualified Language.Elna.Frontend.AST as AST
import Language.Elna.Frontend.Types (Type(..))
import Language.Elna.Backend.Intermediate
( Label(..)
, Operand(..)
, Quadruple(..)
, Variable(..)
)
import Language.Elna.Frontend.SymbolTable (Info(..), SymbolTable)
import qualified Language.Elna.Frontend.SymbolTable as SymbolTable
import GHC.Records (HasField(..))
import Language.Elna.Frontend.AST (Identifier(..))
data Paste = Paste
{ temporaryCounter :: Word32
, labelCounter :: Word32
, localMap :: HashMap Identifier Variable
}
newtype Glue a = Glue
{ runGlue :: State Paste a }
instance Functor Glue
where
fmap f (Glue x) = Glue $ f <$> x
instance Applicative Glue
where
pure = Glue . pure
(Glue f) <*> (Glue x) = Glue $ f <*> x
instance Monad Glue
where
(Glue x) >>= f = Glue $ x >>= (runGlue . f)
glue :: SymbolTable -> AST.Program -> HashMap Identifier (Vector (Quadruple Variable))
glue globalTable
= fst
. flip runState emptyPaste
. runGlue
. program globalTable
where
emptyPaste = Paste
{ temporaryCounter = 0
, labelCounter = 0
, localMap = mempty
}
program :: SymbolTable -> AST.Program -> Glue (HashMap Identifier (Vector (Quadruple Variable)))
program globalTable (AST.Program declarations)
= HashMap.fromList . catMaybes
<$> traverse (declaration globalTable) declarations
declaration
:: SymbolTable
-> AST.Declaration
-> Glue (Maybe (AST.Identifier, Vector (Quadruple Variable)))
declaration globalTable (AST.ProcedureDeclaration procedureName _ variableDeclarations statements)
= traverse_ registerVariable variableDeclarations
>> nameQuadruplesTuple <$> traverse (statement globalTable) statements
where
registerVariable (AST.VariableDeclaration identifier _) = do
currentCounter <- fmap (fromIntegral . HashMap.size)
$ Glue $ gets $ getField @"localMap"
Glue $ modify' $ modifier identifier $ LocalVariable currentCounter
modifier identifier currentCounter generator = generator
{ localMap = HashMap.insert identifier currentCounter
$ getField @"localMap" generator
}
nameQuadruplesTuple quadrupleList = Just
( procedureName
, Vector.cons StartQuadruple
$ flip Vector.snoc StopQuadruple
$ fold quadrupleList
)
declaration _ (AST.TypeDefinition _ _) = pure Nothing
statement :: SymbolTable -> AST.Statement -> Glue (Vector (Quadruple Variable))
statement _ AST.EmptyStatement = pure mempty
statement localTable (AST.CallStatement (AST.Identifier callName) arguments) = do
visitedArguments <- traverse (expression localTable) arguments
let (parameterStatements, argumentStatements)
= bimap (Vector.fromList . fmap ParameterQuadruple) Vector.concat
$ unzip visitedArguments
in pure
$ Vector.snoc (argumentStatements <> parameterStatements)
$ CallQuadruple callName
$ fromIntegral
$ Vector.length argumentStatements
statement localTable (AST.CompoundStatement statements) =
fold <$> traverse (statement localTable) statements
statement localTable (AST.IfStatement ifCondition ifStatement elseStatement) = do
(conditionStatements, jumpConstructor) <- condition localTable ifCondition
ifLabel <- createLabel
endLabel <- createLabel
ifStatements <- statement localTable ifStatement
possibleElseStatements <- traverse (statement localTable) elseStatement
pure $ conditionStatements <> case possibleElseStatements of
Just elseStatements -> Vector.cons (jumpConstructor ifLabel) elseStatements
<> Vector.fromList [GoToQuadruple endLabel, LabelQuadruple ifLabel]
<> Vector.snoc ifStatements (LabelQuadruple endLabel)
Nothing -> Vector.fromList [jumpConstructor ifLabel, GoToQuadruple endLabel, LabelQuadruple ifLabel]
<> Vector.snoc ifStatements (LabelQuadruple endLabel)
statement localTable (AST.AssignmentStatement variableAccess' assignee) = do
(rhsOperand, rhsStatements) <- expression localTable assignee
let variableType' = variableType variableAccess' localTable
accessResult <- variableAccess localTable variableAccess' Nothing variableType' mempty
lhsStatements <- case accessResult of
{-(AST.Identifier identifier, Just accumulatedIndex, accumulatedStatements) ->
Vector.snoc accumulatedStatements
$ ArrayAssignQuadruple rhsOperand accumulatedIndex
$ LocalVariable identifier -}
(identifier, _Nothing, accumulatedStatements)
-> Vector.snoc accumulatedStatements
. AssignQuadruple rhsOperand
<$> lookupLocal identifier
pure $ rhsStatements <> lhsStatements
{- statement localTable (AST.WhileStatement whileCondition whileStatement) = do
(conditionStatements, jumpConstructor) <- condition localTable whileCondition
startLabel <- createLabel
endLabel <- createLabel
conditionLabel <- createLabel
whileStatements <- statement localTable whileStatement
pure $ Vector.fromList [LabelQuadruple conditionLabel]
<> conditionStatements
<> Vector.fromList [jumpConstructor startLabel, GoToQuadruple endLabel, LabelQuadruple startLabel]
<> whileStatements
<> Vector.fromList [GoToQuadruple conditionLabel, LabelQuadruple endLabel] -}
createTemporary :: Glue Variable
createTemporary = do
currentCounter <- Glue $ gets $ getField @"temporaryCounter"
Glue $ modify' modifier
pure $ TempVariable currentCounter
where
modifier generator = generator
{ temporaryCounter = getField @"temporaryCounter" generator + 1
}
lookupLocal :: Identifier -> Glue Variable
lookupLocal identifier =
fmap (HashMap.! identifier) $ Glue $ gets $ getField @"localMap"
createLabel :: Glue Label
createLabel = do
currentCounter <- Glue $ gets $ getField @"labelCounter"
Glue $ modify' modifier
pure $ Label
$ Text.Lazy.toStrict
$ Text.Builder.toLazyText
$ ".L" <> Text.Builder.decimal currentCounter
where
modifier generator = generator
{ labelCounter = getField @"labelCounter" generator + 1
}
condition
:: SymbolTable
-> AST.Condition
-> Glue (Vector (Quadruple Variable), Label -> Quadruple Variable)
condition localTable (AST.EqualCondition lhs rhs) = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
pure
( lhsStatements <> rhsStatements
, EqualQuadruple lhsOperand rhsOperand
)
condition localTable (AST.NonEqualCondition lhs rhs) = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
pure
( lhsStatements <> rhsStatements
, NonEqualQuadruple lhsOperand rhsOperand
)
condition localTable (AST.LessCondition lhs rhs) = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
pure (lhsStatements <> rhsStatements, LessQuadruple lhsOperand rhsOperand)
condition localTable (AST.GreaterCondition lhs rhs) = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
pure
( lhsStatements <> rhsStatements
, GreaterQuadruple lhsOperand rhsOperand
)
condition localTable (AST.LessOrEqualCondition lhs rhs) = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
pure
( lhsStatements <> rhsStatements
, LessOrEqualQuadruple lhsOperand rhsOperand
)
condition localTable (AST.GreaterOrEqualCondition lhs rhs) = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
pure
( lhsStatements <> rhsStatements
, GreaterOrEqualQuadruple lhsOperand rhsOperand
)
variableAccess
:: SymbolTable
-> AST.VariableAccess
-> Maybe (Operand Variable)
-> Type
-> Vector (Quadruple Variable)
-> Glue (AST.Identifier, Maybe (Operand Variable), Vector (Quadruple Variable))
variableAccess _ (AST.VariableAccess identifier) accumulatedIndex _ accumulatedStatements =
pure (identifier, accumulatedIndex, accumulatedStatements)
{- variableAccess localTable (AST.ArrayAccess access1 index1) Nothing (ArrayType _ baseType) _ = do
(indexPlace, statements) <- expression localTable index1
variableAccess localTable access1 (Just indexPlace) baseType statements
variableAccess localTable (AST.ArrayAccess arrayAccess' arrayIndex) (Just baseIndex) (ArrayType arraySize baseType) statements = do
(indexPlace, statements') <- expression localTable arrayIndex
resultVariable <- createTemporary
let resultOperand = VariableOperand resultVariable
indexCalculation = Vector.fromList
[ ProductQuadruple (IntOperand $ fromIntegral arraySize) baseIndex resultVariable
, AddQuadruple indexPlace resultOperand resultVariable
]
in variableAccess localTable arrayAccess' (Just resultOperand) baseType
$ statements <> indexCalculation <> statements'
variableAccess _ _ _ _ _ = error "Array access operator doesn't match the type."
-}
variableType :: AST.VariableAccess -> SymbolTable -> Type
variableType (AST.VariableAccess identifier) symbolTable
| Just (TypeInfo type') <- SymbolTable.lookup identifier symbolTable = type'
| otherwise = error "Undefined type."
{-variableType (AST.ArrayAccess arrayAccess' _) symbolTable =
variableType arrayAccess' symbolTable -}
expression :: SymbolTable -> AST.Expression -> Glue (Operand Variable, Vector (Quadruple Variable))
expression localTable = \case
(AST.LiteralExpression literal') -> pure (literal literal', mempty)
(AST.SumExpression lhs rhs) -> binaryExpression AddQuadruple lhs rhs
(AST.SubtractionExpression lhs rhs) ->
binaryExpression SubtractionQuadruple lhs rhs
(AST.NegationExpression negation) -> do
(operand, statements) <- expression localTable negation
tempVariable <- createTemporary
let negationQuadruple = NegationQuadruple operand tempVariable
pure
( VariableOperand tempVariable
, Vector.snoc statements negationQuadruple
)
(AST.ProductExpression lhs rhs) ->
binaryExpression ProductQuadruple lhs rhs
(AST.DivisionExpression lhs rhs) ->
binaryExpression DivisionQuadruple lhs rhs
(AST.VariableExpression variableExpression) -> do
let variableType' = variableType variableExpression localTable
variableAccess' <- variableAccess localTable variableExpression Nothing variableType' mempty
case variableAccess' of
(identifier, _Nothing, statements)
-> (, statements) . VariableOperand
<$> lookupLocal identifier
{-(AST.Identifier identifier, Just operand, statements) -> do
arrayAddress <- createTemporary
let arrayStatement = ArrayQuadruple (Variable identifier) operand arrayAddress
pure
( VariableOperand arrayAddress
, Vector.snoc statements arrayStatement
) -}
where
binaryExpression f lhs rhs = do
(lhsOperand, lhsStatements) <- expression localTable lhs
(rhsOperand, rhsStatements) <- expression localTable rhs
tempVariable <- createTemporary
let newQuadruple = f lhsOperand rhsOperand tempVariable
pure
( VariableOperand tempVariable
, Vector.snoc (lhsStatements <> rhsStatements) newQuadruple
)
literal :: AST.Literal -> Operand Variable
literal (AST.DecimalLiteral integer) = IntOperand integer
literal (AST.HexadecimalLiteral integer) = IntOperand integer
literal (AST.CharacterLiteral character) = IntOperand $ fromIntegral character