module Verismith.Verilog.Preprocess
( uncomment
, preprocess
)
where
uncomment :: FilePath -> String -> String
uncomment file = uncomment'
where
uncomment' a = case a of
"" -> ""
'/' : '/' : rest -> " " ++ removeEOL rest
'/' : '*' : rest -> " " ++ remove rest
'(' : '*' : rest -> " " ++ remove rest
'"' : rest -> '"' : ignoreString rest
b : rest -> b : uncomment' rest
removeEOL a = case a of
"" -> ""
'\n' : rest -> '\n' : uncomment' rest
'\t' : rest -> '\t' : removeEOL rest
_ : rest -> ' ' : removeEOL rest
remove a = case a of
"" -> error $ "File ended without closing comment (*/): " ++ file
'"' : rest -> removeString rest
'\n' : rest -> '\n' : remove rest
'\t' : rest -> '\t' : remove rest
'*' : '/' : rest -> " " ++ uncomment' rest
'*' : ')' : rest -> " " ++ uncomment' rest
_ : rest -> " " ++ remove rest
removeString a = case a of
"" -> error $ "File ended without closing string: " ++ file
'"' : rest -> " " ++ remove rest
'\\' : '"' : rest -> " " ++ removeString rest
'\n' : rest -> '\n' : removeString rest
'\t' : rest -> '\t' : removeString rest
_ : rest -> ' ' : removeString rest
ignoreString a = case a of
"" -> error $ "File ended without closing string: " ++ file
'"' : rest -> '"' : uncomment' rest
'\\' : '"' : rest -> "\\\"" ++ ignoreString rest
b : rest -> b : ignoreString rest
preprocess :: [(String, String)] -> FilePath -> String -> String
preprocess env file content = unlines $ pp True [] env $ lines $ uncomment
file
content
where
pp :: Bool -> [Bool] -> [(String, String)] -> [String] -> [String]
pp _ _ _ [] = []
pp on stack env_ (a : rest) = case words a of
"`define" : name : value ->
""
: pp
on
stack
(if on
then (name, ppLine env_ $ unwords value) : env_
else env_
)
rest
"`ifdef" : name : _ ->
"" : pp (on && elem name (map fst env_)) (on : stack) env_ rest
"`ifndef" : name : _ ->
"" : pp (on && notElem name (map fst env_)) (on : stack) env_ rest
"`else" : _
| not $ null stack
-> "" : pp (head stack && not on) stack env_ rest
| otherwise
-> error $ "`else without associated `ifdef/`ifndef: " ++ file
"`endif" : _
| not $ null stack
-> "" : pp (head stack) (tail stack) env_ rest
| otherwise
-> error $ "`endif without associated `ifdef/`ifndef: " ++ file
_ -> (if on then ppLine env_ a else "") : pp on stack env_ rest
ppLine :: [(String, String)] -> String -> String
ppLine _ "" = ""
ppLine env ('`' : a) = case lookup name env of
Just value -> value ++ ppLine env rest
Nothing -> error $ "Undefined macro: `" ++ name ++ " Env: " ++ show env
where
name = takeWhile
(flip elem $ ['A' .. 'Z'] ++ ['a' .. 'z'] ++ ['0' .. '9'] ++ ['_'])
a
rest = drop (length name) a
ppLine env (a : b) = a : ppLine env b