1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
|
{-|
Module : VeriFuzz.Verilog.Parser
Description : Minimal Verilog parser to reconstruct the AST.
Copyright : (c) 2019, Yann Herklotz
License : GPL-3
Maintainer : ymherklotz [at] gmail [dot] com
Stability : experimental
Portability : POSIX
Minimal Verilog parser to reconstruct the AST. This parser does not support the
whole Verilog syntax, as the AST does not support it either.
-}
module VeriFuzz.Verilog.Parser
( -- * Parser
parseVerilog
, parseModDecl
-- ** Internal parsers
, parseEvent
, Parser
)
where
import Control.Lens
import Control.Monad (void)
import Data.Bifunctor (bimap)
import Data.Bits
import Data.Functor (($>))
import Data.Functor.Identity (Identity)
import Data.List (null)
import Data.List (isInfixOf, isPrefixOf)
import qualified Data.Text as T
import Text.Parsec hiding (satisfy)
import Text.Parsec.Expr
import VeriFuzz.Verilog.AST
import VeriFuzz.Verilog.BitVec
import VeriFuzz.Verilog.Internal
import VeriFuzz.Verilog.Lex
import VeriFuzz.Verilog.Preprocess
import VeriFuzz.Verilog.Token
type Parser = Parsec [Token] ()
type ParseOperator = Operator [Token] () Identity
data Decimal = Decimal Int Integer
instance Num Decimal where
(Decimal sa na) + (Decimal sb nb) = Decimal (max sa sb) (na + nb)
(Decimal sa na) - (Decimal sb nb) = Decimal (max sa sb) (na - nb)
(Decimal sa na) * (Decimal sb nb) = Decimal (max sa sb) (na * nb)
negate (Decimal s n) = Decimal s $ negate n
abs (Decimal s n) = Decimal s $ abs n
signum (Decimal s n) = Decimal s $ signum n
fromInteger = Decimal 32 . fromInteger
-- | This parser succeeds whenever the given predicate returns true when called
-- with parsed `Token`. Same as 'Text.Parsec.Char.satisfy'.
satisfy :: (Token -> Bool) -> Parser TokenName
satisfy f = tokenPrim show nextPos tokeq
where
tokeq :: Token -> Maybe TokenName
tokeq t@(Token t' _ _) = if f t then Just t' else Nothing
satisfy' :: (Token -> Maybe a) -> Parser a
satisfy' = tokenPrim show nextPos
nextPos :: SourcePos -> Token -> [Token] -> SourcePos
nextPos pos _ (Token _ _ (Position _ l c) : _) =
setSourceColumn (setSourceLine pos l) c
nextPos pos _ [] = pos
-- | Parses given `TokenName`.
tok :: TokenName -> Parser TokenName
tok t = satisfy (\(Token t' _ _) -> t' == t) <?> show t
-- | Parse without returning the `TokenName`.
tok' :: TokenName -> Parser ()
tok' p = void $ tok p
parens :: Parser a -> Parser a
parens = between (tok SymParenL) (tok SymParenR)
braces :: Parser a -> Parser a
braces = between (tok SymBraceL) (tok SymBraceR)
sBinOp :: BinaryOperator -> Expr -> Expr -> Expr
sBinOp = sOp BinOp where sOp f b a = f a b
parseExpr' :: Parser Expr
parseExpr' = buildExpressionParser parseTable parseTerm <?> "expr"
decToExpr :: Decimal -> Expr
decToExpr (Decimal s n) = Number $ bitVec s n
-- | Parse a Number depending on if it is in a hex or decimal form. Octal and
-- binary are not supported yet.
parseNum :: Parser Expr
parseNum = decToExpr <$> number
parseVar :: Parser Expr
parseVar = Id <$> identifier
systemFunc :: Parser String
systemFunc = satisfy' matchId
where
matchId (Token IdSystem s _) = Just s
matchId _ = Nothing
parseFun :: Parser Expr
parseFun = do
f <- systemFunc
expr <- parens parseExpr
return $ Appl (Identifier $ T.pack f) expr
parseTerm :: Parser Expr
parseTerm =
parens parseExpr
<|> (Concat <$> braces (commaSep parseExpr))
<|> parseFun
<|> parseNum
<|> parseVar
<?> "simple expr"
-- | Parses the ternary conditional operator. It will behave in a right
-- associative way.
parseCond :: Expr -> Parser Expr
parseCond e = do
tok' SymQuestion
expr <- parseExpr
tok' SymColon
Cond e expr <$> parseExpr
parseExpr :: Parser Expr
parseExpr = do
e <- parseExpr'
option e . try $ parseCond e
parseConstExpr :: Parser ConstExpr
parseConstExpr = fmap exprToConst parseExpr
-- | Table of binary and unary operators that encode the right precedence for
-- each.
parseTable :: [[ParseOperator Expr]]
parseTable =
[ [prefix SymBang (UnOp UnLNot), prefix SymTildy (UnOp UnNot)]
, [ prefix SymAmp (UnOp UnAnd)
, prefix SymBar (UnOp UnOr)
, prefix SymTildyAmp (UnOp UnNand)
, prefix SymTildyBar (UnOp UnNor)
, prefix SymHat (UnOp UnXor)
, prefix SymTildyHat (UnOp UnNxor)
, prefix SymHatTildy (UnOp UnNxorInv)
]
, [prefix SymPlus (UnOp UnPlus), prefix SymDash (UnOp UnMinus)]
, [binary SymAsterAster (sBinOp BinPower) AssocRight]
, [ binary SymAster (sBinOp BinTimes) AssocLeft
, binary SymSlash (sBinOp BinDiv) AssocLeft
, binary SymPercent (sBinOp BinMod) AssocLeft
]
, [ binary SymPlus (sBinOp BinPlus) AssocLeft
, binary SymDash (sBinOp BinPlus) AssocLeft
]
, [ binary SymLtLt (sBinOp BinLSL) AssocLeft
, binary SymGtGt (sBinOp BinLSR) AssocLeft
]
, [ binary SymLtLtLt (sBinOp BinASL) AssocLeft
, binary SymGtGtGt (sBinOp BinASR) AssocLeft
]
, [ binary SymLt (sBinOp BinLT) AssocNone
, binary SymGt (sBinOp BinGT) AssocNone
, binary SymLtEq (sBinOp BinLEq) AssocNone
, binary SymGtEq (sBinOp BinLEq) AssocNone
]
, [ binary SymEqEq (sBinOp BinEq) AssocNone
, binary SymBangEq (sBinOp BinNEq) AssocNone
]
, [ binary SymEqEqEq (sBinOp BinEq) AssocNone
, binary SymBangEqEq (sBinOp BinNEq) AssocNone
]
, [binary SymAmp (sBinOp BinAnd) AssocLeft]
, [ binary SymHat (sBinOp BinXor) AssocLeft
, binary SymHatTildy (sBinOp BinXNor) AssocLeft
, binary SymTildyHat (sBinOp BinXNorInv) AssocLeft
]
, [binary SymBar (sBinOp BinOr) AssocLeft]
, [binary SymAmpAmp (sBinOp BinLAnd) AssocLeft]
, [binary SymBarBar (sBinOp BinLOr) AssocLeft]
]
binary :: TokenName -> (a -> a -> a) -> Assoc -> ParseOperator a
binary name fun = Infix ((tok name <?> "binary") >> return fun)
prefix :: TokenName -> (a -> a) -> ParseOperator a
prefix name fun = Prefix ((tok name <?> "prefix") >> return fun)
commaSep :: Parser a -> Parser [a]
commaSep = flip sepBy $ tok SymComma
parseContAssign :: Parser ContAssign
parseContAssign = do
var <- tok KWAssign *> identifier
expr <- tok SymEq *> parseExpr
tok' SymSemi
return $ ContAssign var expr
numLit :: Parser String
numLit = satisfy' matchId
where
matchId (Token LitNumber s _) = Just s
matchId _ = Nothing
number :: Parser Decimal
number = number' <$> numLit
where
number' :: String -> Decimal
number' a | all (`elem` ['0' .. '9']) a = fromInteger $ read a
| head a == '\'' = fromInteger $ f a
| "'" `isInfixOf` a = Decimal (read w) (f b)
| otherwise = error $ "Invalid number format: " ++ a
where
w = takeWhile (/= '\'') a
b = dropWhile (/= '\'') a
f a'
| "'d" `isPrefixOf` a' = read $ drop 2 a'
| "'h" `isPrefixOf` a' = read $ "0x" ++ drop 2 a'
| "'b" `isPrefixOf` a' = foldl
(\n b' -> shiftL n 1 .|. (if b' == '1' then 1 else 0))
0
(drop 2 a')
| otherwise = error $ "Invalid number format: " ++ a'
-- toInteger' :: Decimal -> Integer
-- toInteger' (Decimal _ n) = n
toInt' :: Decimal -> Int
toInt' (Decimal _ n) = fromInteger n
-- | Parse a range and return the total size. As it is inclusive, 1 has to be
-- added to the difference.
parseRange :: Parser Range
parseRange = do
rangeH <- tok SymBrackL *> parseConstExpr
rangeL <- tok SymColon *> parseConstExpr
tok' SymBrackR
return $ Range rangeH rangeL
strId :: Parser String
strId = satisfy' matchId
where
matchId (Token IdSimple s _) = Just s
matchId (Token IdEscaped s _) = Just s
matchId _ = Nothing
identifier :: Parser Identifier
identifier = Identifier . T.pack <$> strId
parseNetDecl :: Maybe PortDir -> Parser ModItem
parseNetDecl pd = do
t <- option Wire type_
sign <- option False (tok KWSigned $> True)
range <- option 1 parseRange
name <- identifier
tok' SymSemi
return $ Decl pd (Port t sign range name) Nothing
where type_ = tok KWWire $> Wire <|> tok KWReg $> Reg
parsePortDir :: Parser PortDir
parsePortDir =
tok KWOutput
$> PortOut
<|> tok KWInput
$> PortIn
<|> tok KWInout
$> PortInOut
parseDecl :: Parser ModItem
parseDecl = (Just <$> parsePortDir >>= parseNetDecl) <|> parseNetDecl Nothing
parseConditional :: Parser Statement
parseConditional = do
expr <- tok' KWIf *> tok' SymParenL *> parseExpr
true <- maybeEmptyStatement
false <- option Nothing maybeEmptyStatement
return $ CondStmnt expr true false
parseLVal :: Parser LVal
parseLVal =
fmap RegConcat (braces $ commaSep parseExpr)
<|> ident
where
ident = do
i <- identifier
(try (ex i) <|> try (sz i) <|> return (RegId i))
ex i = do
e <- tok' SymBrackL *> parseExpr
tok' SymBrackR
return $ RegExpr i e
sz i = RegSize i <$> parseRange
parseDelay :: Parser Delay
parseDelay = Delay . toInt' <$> (tok' SymPound *> number)
parseAssign :: TokenName -> Parser Assign
parseAssign t = do
lval <- parseLVal
tok' t
delay <- option Nothing (fmap Just parseDelay)
expr <- parseExpr
return $ Assign lval delay expr
parseLoop :: Parser Statement
parseLoop = do
a <- tok' KWFor *> tok' SymParenL *> parseAssign SymEq
expr <- tok' SymSemi *> parseExpr
incr <- tok' SymSemi *> parseAssign SymEq
tok' SymParenR
statement <- parseStatement
return $ ForLoop a expr incr statement
eventList :: TokenName -> Parser [Event]
eventList t = do
l <- sepBy parseEvent' (tok t)
if null l then fail "Could not parse list" else return l
parseEvent :: Parser Event
parseEvent = tok' SymAtAster *> return EAll
<|> try (tok' SymAt *> tok' SymParenLAsterParenR *> return EAll)
<|> try (tok' SymAt *> tok' SymParenL *> tok' SymAster *> tok' SymParenR *> return EAll)
<|> try (tok' SymAt *> parens parseEvent')
<|> try (tok' SymAt *> parens (foldr1 EOr <$> eventList KWOr))
<|> try (tok' SymAt *> parens (foldr1 EComb <$> eventList SymComma))
parseEvent' :: Parser Event
parseEvent' =
try (tok' KWPosedge *> fmap EPosEdge identifier)
<|> try (tok' KWNegedge *> fmap ENegEdge identifier)
<|> try (fmap EId identifier)
<|> try (fmap EExpr parseExpr)
parseEventCtrl :: Parser Statement
parseEventCtrl = do
event <- parseEvent
statement <- option Nothing maybeEmptyStatement
return $ EventCtrl event statement
parseDelayCtrl :: Parser Statement
parseDelayCtrl = do
delay <- parseDelay
statement <- option Nothing maybeEmptyStatement
return $ TimeCtrl delay statement
parseBlocking :: Parser Statement
parseBlocking = BlockAssign <$> parseAssign SymEq
parseNonBlocking :: Parser Statement
parseNonBlocking = NonBlockAssign <$> parseAssign SymLtEq
parseStatement :: Parser Statement
parseStatement =
parseConditional
<|> parseLoop
<|> parseEventCtrl
<|> parseDelayCtrl
<|> try parseBlocking
<|> parseNonBlocking
maybeEmptyStatement :: Parser (Maybe Statement)
maybeEmptyStatement =
(tok' SymSemi >> return Nothing)
<|> (Just <$> parseStatement)
parseAlways :: Parser ModItem
parseAlways = tok' KWAlways *> (Always <$> parseStatement)
parseInitial :: Parser ModItem
parseInitial = tok' KWInitial *> (Initial <$> parseStatement)
parseModItem :: Parser ModItem
parseModItem = (ModCA <$> parseContAssign) <|> parseDecl
<|> parseAlways
<|> parseInitial
parseModList :: Parser [Identifier]
parseModList = list <|> return [] where list = parens $ commaSep identifier
filterDecl :: PortDir -> ModItem -> Bool
filterDecl p (Decl (Just p') _ _) = p == p'
filterDecl _ _ = False
modPorts :: PortDir -> [ModItem] -> [Port]
modPorts p mis = filter (filterDecl p) mis ^.. traverse . declPort
parseModDecl :: Parser ModDecl
parseModDecl = do
name <- tok KWModule *> identifier
_ <- fmap defaultPort <$> parseModList
tok' SymSemi
modItem <- option [] . try $ many1 parseModItem
tok' KWEndmodule
return $ ModDecl name
(modPorts PortOut modItem)
(modPorts PortIn modItem)
modItem
[]
-- | Parses a 'String' into 'Verilog' by skipping any beginning whitespace
-- and then parsing multiple Verilog source.
parseVerilogSrc :: Parser Verilog
parseVerilogSrc = Verilog <$> many parseModDecl
-- | Parse a 'String' containing verilog code. The parser currently only supports
-- the subset of Verilog that is being generated randomly.
parseVerilog
:: String -- ^ Name of parsed object.
-> String -- ^ Content to be parsed.
-> Either String Verilog -- ^ Returns 'String' with error
-- message if parse fails.
parseVerilog s =
bimap show id . parse parseVerilogSrc s . alexScanTokens . preprocess [] s
|