sv2v/Language/SystemVerilog/AST.hs

403 lines
13 KiB
Haskell

module Language.SystemVerilog.AST
( Identifier
, Description(..)
, ModuleItem (..)
, Direction (..)
, Type (..)
, Stmt (..)
, LHS (..)
, Expr (..)
, UniOp (..)
, BinOp (..)
, Sense (..)
, BlockItemDeclaration (..)
, Parameter (..)
, Localparam (..)
, IntegerV (..)
, GenItem (..)
, AlwaysKW (..)
, AST
, PortBinding
, Case
, Range
, GenCase
, RangesOrAssignment
) where
import Data.List
import Data.Maybe
import Text.Printf
type Identifier = String
-- Note: Verilog allows modules to be declared with either a simple list of
-- ports _identifiers_, or a list of port _declarations_. If only the
-- identifiers are used, they must be declared with a type and direction
-- (potentially separately!) within the module itself.
-- Note: This AST will allow for the representation of syntactically invalid
-- things, like input regs. We might want to have a function for doing some
-- basing invariant checks. I want to avoid making a full type-checker though,
-- as we should only be given valid SystemVerilog input files.
type AST = [Description]
data Description
= Module Identifier [Identifier] [ModuleItem]
| Typedef Type Identifier
deriving Eq
instance Show Description where
showList descriptions _ = intercalate "\n" $ map show descriptions
show (Module name ports items) = unlines
[ "module " ++ name ++ portsStr ++ ";"
, indent $ unlines' $ map show items
, "endmodule" ]
where
portsStr =
if null ports
then ""
else indentedParenList ports
show (Typedef t x) = printf "typedef %s %s;" (show t) x
data Direction
= Input
| Output
| Inout
deriving Eq
instance Show Direction where
show Input = "input"
show Output = "output"
show Inout = "inout"
data Type
= Reg [Range]
| Wire [Range]
| Logic [Range]
| Alias String [Range]
deriving Eq
instance Show Type where
show (Reg r) = "reg" ++ (showRanges r)
show (Wire r) = "wire" ++ (showRanges r)
show (Logic r) = "logic" ++ (showRanges r)
show (Alias t r) = t ++ (showRanges r)
data ModuleItem
= Comment String
| MIParameter Parameter
| MILocalparam Localparam
| MIIntegerV IntegerV
| PortDecl Direction [Range] Identifier
| LocalNet Type Identifier RangesOrAssignment
| AlwaysC AlwaysKW Stmt
| Assign LHS Expr
| Instance Identifier [PortBinding] Identifier (Maybe [PortBinding]) -- `Nothing` represents `.*`
| Function (Maybe FuncRet) Identifier [(Bool, BlockItemDeclaration)] Stmt
| Genvar Identifier
| Generate [GenItem]
deriving Eq
data AlwaysKW
= Always
| AlwaysComb
| AlwaysFF
| AlwaysLatch
deriving Eq
instance Show AlwaysKW where
show Always = "always"
show AlwaysComb = "always_comb"
show AlwaysFF = "always_ff"
show AlwaysLatch = "always_latch"
-- "function inputs and outputs are inferred to be of type reg if no internal
-- data types for the ports are declared"
type PortBinding = (Identifier, Maybe Expr)
data Parameter = Parameter (Maybe Range) Identifier Expr deriving Eq
instance Show Parameter where
show (Parameter r n e) = printf "parameter %s%s = %s;" (showRange r) n (show e)
data Localparam = Localparam (Maybe Range) Identifier Expr deriving Eq
instance Show Localparam where
show (Localparam r n e) = printf "localparam %s%s = %s;" (showRange r) n (show e)
data IntegerV = IntegerV Identifier RangesOrAssignment deriving Eq
instance Show IntegerV where
show (IntegerV x v ) = printf "integer %s%s;" x (showRangesOrAssignment v)
instance Show ModuleItem where
show thing = case thing of
Comment c -> "// " ++ c
MIParameter nest -> show nest
MILocalparam nest -> show nest
MIIntegerV nest -> show nest
PortDecl d r x -> printf "%s%s %s;" (show d) (showRanges r) x
LocalNet t x v -> printf "%s %s%s;" (show t) x (showRangesOrAssignment v)
AlwaysC k b -> printf "%s %s" (show k) (show b)
Assign a b -> printf "assign %s = %s;" (show a) (show b)
Instance m params i ports
| null params -> printf "%s %s%s;" m i (showMaybePorts ports)
| otherwise -> printf "%s #%s %s%s;" m (showPorts params) i (showMaybePorts ports)
Function t x i b -> printf "function %s%s;\n%s\n%s\nendfunction" (showFuncRet t) x (indent $ unlines' $ map showFunctionItem i) (indent $ show b)
Genvar x -> printf "genvar %s;" x
Generate b -> printf "generate\n%s\nendgenerate" (indent $ unlines' $ map show b)
where
showMaybePorts :: Maybe [(Identifier, Maybe Expr)] -> String
showMaybePorts Nothing = "(.*)"
showMaybePorts (Just ports) = showPorts ports
showPorts :: [(Identifier, Maybe Expr)] -> String
showPorts ports = indentedParenList [ if i == "" then show (fromJust arg) else printf ".%s(%s)" i (if isJust arg then show $ fromJust arg else "") | (i, arg) <- ports ]
showFunctionItem :: (Bool, BlockItemDeclaration) -> String
showFunctionItem (b, item) = prefix ++ (show item)
where prefix = if b then "input " else ""
type FuncRet = Either Range ()
showFuncRet :: Maybe FuncRet -> String
showFuncRet Nothing = ""
showFuncRet (Just (Left r)) = showRange $ Just r
showFuncRet (Just (Right ())) = "integer "
type RangesOrAssignment = Either [Range] (Maybe Expr)
showRangesOrAssignment :: Either [Range] (Maybe Expr) -> String
showRangesOrAssignment (Left ranges) = showRanges ranges
showRangesOrAssignment (Right val) = showAssignment val
showAssignment :: Maybe Expr -> String
showAssignment Nothing = ""
showAssignment (Just val) = " = " ++ show val
showRanges :: [Range] -> String
showRanges [] = ""
showRanges l = " " ++ (concat $ map rangeToString l)
where rangeToString d = init $ showRange $ Just d
showRange :: Maybe Range -> String
showRange Nothing = ""
showRange (Just (h, l)) = printf "[%s:%s] " (show h) (show l)
indent :: String -> String
indent a = '\t' : f a
where
f [] = []
f (x : xs)
| x == '\n' = "\n\t" ++ f xs
| otherwise = x : f xs
unlines' :: [String] -> String
unlines' = intercalate "\n"
data Expr
= String String
| Number String
| ConstBool Bool
| Ident Identifier
| IdentRange Identifier Range
| IdentBit Identifier Expr
| Repeat Expr [Expr]
| Concat [Expr]
| Call Identifier [Expr]
| UniOp UniOp Expr
| BinOp BinOp Expr Expr
| Mux Expr Expr Expr
| Bit Expr Int
deriving Eq
data UniOp
= Not
| BWNot
| UAdd
| USub
| RedAnd
| RedNand
| RedOr
| RedNor
| RedXor
| RedXnor
deriving Eq
instance Show UniOp where
show Not = "!"
show BWNot = "~"
show UAdd = "+"
show USub = "-"
show RedAnd = "&"
show RedNand = "~&"
show RedOr = "|"
show RedNor = "~|"
show RedXor = "^"
show RedXnor = "~^"
data BinOp
= And
| Or
| BWAnd
| BWXor
| BWOr
| Mul
| Div
| Mod
| Add
| Sub
| ShiftL
| ShiftR
| Eq
| Ne
| Lt
| Le
| Gt
| Ge
| ShiftAL
| ShiftAR
deriving Eq
instance Show BinOp where
show a = case a of
And -> "&&"
Or -> "||"
BWAnd -> "&"
BWXor -> "^"
BWOr -> "|"
Mul -> "*"
Div -> "/"
Mod -> "%"
Add -> "+"
Sub -> "-"
ShiftL -> "<<"
ShiftR -> ">>"
Eq -> "=="
Ne -> "!="
Lt -> "<"
Le -> "<="
Gt -> ">"
Ge -> ">="
ShiftAL -> "<<<"
ShiftAR -> ">>>"
instance Show Expr where
show x = case x of
String a -> printf "\"%s\"" a
Number a -> a
ConstBool a -> printf "1'b%s" (if a then "1" else "0")
Ident a -> a
IdentBit a b -> printf "%s[%s]" a (show b)
IdentRange a (b, c) -> printf "%s[%s:%s]" a (show b) (show c)
Repeat a b -> printf "{%s {%s}}" (show a) (commas $ map show b)
Concat a -> printf "{%s}" (commas $ map show a)
Call a b -> printf "%s(%s)" a (commas $ map show b)
UniOp a b -> printf "(%s %s)" (show a) (show b)
BinOp a b c -> printf "(%s %s %s)" (show b) (show a) (show c)
Mux a b c -> printf "(%s ? %s : %s)" (show a) (show b) (show c)
Bit a b -> printf "(%s [%d])" (show a) b
data LHS
= LHS Identifier
| LHSBit Identifier Expr
| LHSRange Identifier Range
| LHSConcat [LHS]
deriving Eq
instance Show LHS where
show (LHS a ) = a
show (LHSBit a b ) = printf "%s[%s]" a (show b)
show (LHSRange a (b, c)) = printf "%s[%s:%s]" a (show b) (show c)
show (LHSConcat a ) = printf "{%s}" (commas $ map show a)
data Stmt
= Block (Maybe (Identifier, [BlockItemDeclaration])) [Stmt]
| Case Expr [Case] (Maybe Stmt)
| BlockingAssignment LHS Expr
| NonBlockingAssignment LHS Expr
| For (Identifier, Expr) Expr (Identifier, Expr) Stmt
| If Expr Stmt Stmt
| Timing Sense Stmt
| Null
deriving Eq
commas :: [String] -> String
commas = intercalate ", "
instance Show Stmt where
show (Block Nothing b ) = printf "begin\n%s\nend" $ indent $ unlines' $ map show b
show (Block (Just (a, i)) b ) = printf "begin : %s\n%s\nend" a $ indent $ unlines' $ (map show i ++ map show b)
show (Case a b Nothing ) = printf "case (%s)\n%s\nendcase" (show a) (indent $ unlines' $ map showCase b)
show (Case a b (Just c) ) = printf "case (%s)\n%s\n\tdefault:\n%s\nendcase" (show a) (indent $ unlines' $ map showCase b) (indent $ indent $ show c)
show (BlockingAssignment a b ) = printf "%s = %s;" (show a) (show b)
show (NonBlockingAssignment a b ) = printf "%s <= %s;" (show a) (show b)
show (For (a, b) c (d, e) f) = printf "for (%s = %s; %s; %s = %s)\n%s" a (show b) (show c) d (show e) $ indent $ show f
show (If a b Null ) = printf "if (%s)\n%s" (show a) (indent $ show b)
show (If a b c ) = printf "if (%s)\n%s\nelse\n%s" (show a) (indent $ show b) (indent $ show c)
show (Timing t s ) = printf "@(%s) %s" (show t) (show s)
show (Null ) = ";"
data BlockItemDeclaration
-- TODO: Maybe BIDReg should use [Range] for the first arg as well, but it's
-- really not clear to me what *useful* purpose this would have.
= BIDReg (Maybe Range) Identifier [Range]
| BIDParameter Parameter
| BIDLocalparam Localparam
| BIDIntegerV IntegerV
deriving Eq
instance Show BlockItemDeclaration where
show (BIDReg mr x rs) = printf "reg %s%s%s;" (showRange mr) x (showRanges rs)
show (BIDParameter nest) = show nest
show (BIDLocalparam nest) = show nest
show (BIDIntegerV nest) = show nest
type Case = ([Expr], Stmt)
showCase :: (Show x, Show y) => ([x], y) -> String
showCase (a, b) = printf "%s:\n%s" (commas $ map show a) (indent $ show b)
data Sense
= Sense LHS
| SenseOr Sense Sense
| SensePosedge LHS
| SenseNegedge LHS
| SenseStar
deriving Eq
instance Show Sense where
show (Sense a ) = show a
show (SenseOr a b) = printf "%s or %s" (show a) (show b)
show (SensePosedge a ) = printf "posedge %s" (show a)
show (SenseNegedge a ) = printf "negedge %s" (show a)
show (SenseStar ) = "*"
type Range = (Expr, Expr)
indentedParenList :: [String] -> String
indentedParenList [] = "()"
indentedParenList [x] = "(" ++ x ++ ")"
indentedParenList l =
"(\n" ++ (indent $ intercalate ",\n" l) ++ "\n)"
type GenCase = ([Expr], GenItem)
data GenItem
= GenBlock (Maybe Identifier) [GenItem]
| GenCase Expr [GenCase] (Maybe GenItem)
| GenFor (Identifier, Expr) Expr (Identifier, Expr) Identifier [GenItem]
| GenIf Expr GenItem GenItem
| GenNull
| GenModuleItem ModuleItem
deriving Eq
instance Show GenItem where
showList i _ = unlines' $ map show i
show (GenBlock Nothing i) = printf "begin\n%s\nend" (indent $ unlines' $ map show i)
show (GenBlock (Just x) i) = printf "begin : %s\n%s\nend" x (indent $ unlines' $ map show i)
show (GenCase e c Nothing ) = printf "case (%s)\n%s\nendcase" (show e) (indent $ unlines' $ map showCase c)
show (GenCase e c (Just d)) = printf "case (%s)\n%s\n\tdefault:\n%s\nendcase" (show e) (indent $ unlines' $ map showCase c) (indent $ indent $ show d)
show (GenIf e a GenNull) = printf "if (%s)\n%s" (show e) (indent $ show a)
show (GenIf e a b ) = printf "if (%s)\n%s\nelse\n%s" (show e) (indent $ show a) (indent $ show b)
show (GenFor (x1, e1) c (x2, e2) x is) = printf "for (%s = %s; %s; %s = %s) %s" x1 (show e1) (show c) x2 (show e2) (show $ GenBlock (Just x) is)
show GenNull = ";"
show (GenModuleItem item) = show item