Switch from regex-compat to regex-tdfa

ShellCheck.cabal

@@ -43,7 +43,7 @@ library
       json,
       mtl,
       parsec,
-      regex-compat,
+      regex-tdfa,
       QuickCheck >= 2.7.4
     exposed-modules:
       ShellCheck.Analytics
@@ -51,6 +51,7 @@ library
       ShellCheck.Data
       ShellCheck.Options
       ShellCheck.Parser
+      ShellCheck.Regex
       ShellCheck.Simple
     other-modules:
       Paths_ShellCheck
@@ -64,7 +65,7 @@ executable shellcheck
       json,
       mtl,
       parsec,
-      regex-compat,
+      regex-tdfa,
       transformers,
       QuickCheck >= 2.7.4
     main-is: shellcheck.hs
@@ -79,7 +80,7 @@ test-suite test-shellcheck
       json,
       mtl,
       parsec,
-      regex-compat,
+      regex-tdfa,
       transformers,
       QuickCheck >= 2.7.4
     main-is: test/shellcheck.hs

ShellCheck/AST.hs

@@ -19,7 +19,7 @@ module ShellCheck.AST where
 
 import Control.Monad
 import Control.Monad.Identity
-import qualified Text.Regex as Re
+import qualified ShellCheck.Regex as Re
 
 data Id = Id Int deriving (Show, Eq, Ord)
 
@@ -128,11 +128,13 @@ data Token =
 data Annotation = DisableComment Integer deriving (Show, Eq)
 data ConditionType = DoubleBracket | SingleBracket deriving (Show, Eq)
 
--- I apologize for nothing!
-lolHax s = Re.subRegex (Re.mkRegex "(Id [0-9]+)") (show s) "(Id 0)"
-instance Eq Token where
-    (==) a b = lolHax a == lolHax b
+-- This is an abomination.
+tokenEquals :: Token -> Token -> Bool
+tokenEquals a b = kludge a == kludge b
+    where kludge s = Re.subRegex (Re.mkRegex "\\(Id [0-9]+\\)") (show s) "(Id 0)"
 
+instance Eq Token where
+    (==) = tokenEquals
 
 analyze :: Monad m => (Token -> m ()) -> (Token -> m ()) -> (Token -> Token) -> Token -> m Token
 analyze f g i =

ShellCheck/Analytics.hs

@@ -33,7 +33,7 @@ import ShellCheck.AST
 import ShellCheck.Options
 import ShellCheck.Data
 import ShellCheck.Parser hiding (runTests)
-import Text.Regex
+import ShellCheck.Regex
 import qualified Data.Map as Map
 import Test.QuickCheck.All (forAllProperties)
 import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
@@ -240,12 +240,6 @@ isVariableName _ = False
 
 potentially = fromMaybe (return ())
 
-matchAll re = unfoldr f
-  where
-    f str = do
-        (_, match, rest, _) <- matchRegexAll re str
-        return (match, rest)
-
 willSplit x =
   case x of
     T_DollarBraced {} -> True
@@ -280,20 +274,9 @@ getSuspiciousRegexWildcard str =
     suspicious = mkRegex "([A-Za-z1-9])\\*"
     contra = mkRegex "[^a-zA-Z1-9]\\*|[][^$+\\\\]"
 
-matches string regex = isJust $ matchRegex regex string
-
 headOrDefault _ (a:_) = a
 headOrDefault def _ = def
 
-getAllMatches :: Regex -> String -> [[String]]
-getAllMatches regex str = fromJust $ f str
-  where
-    f str = do
-        (_, _, rest, groups) <- matchRegexAll regex str
-        more <- f rest
-        return $ groups : more
-      `mappend` return []
-
 isConstant token =
     case token of
         T_NormalWord _ l   -> all isConstant l
@@ -413,14 +396,19 @@ checkEchoSed _ (T_Pipeline id _ [a, b]) =
             ["sed", "-e", v] -> checkIn v
             _ -> return ()
   where
-    sedRe = mkRegex "^s(.)(.*)\\1(.*)\\1g?$"
+    -- This should have used backreferences, but TDFA doesn't support them
+    sedRe = mkRegex "^s(.)([^\n]*)g?$"
+    isSimpleSed s = fromMaybe False $ do
+        [first,rest] <- matchRegex sedRe s
+        let delimiters = filter (== (first !! 0)) rest
+        guard $ length delimiters == 2
+        return True
+
     acmd = deadSimple a
     bcmd = deadSimple b
     checkIn s =
-        case matchRegex sedRe s of
-                Just _ -> style id 2001
-                    "See if you can use ${variable//search/replace} instead."
-                _        -> return ()
+        when (isSimpleSed s) $
+            style id 2001 "See if you can use ${variable//search/replace} instead."
 checkEchoSed _ _ = return ()
 
 prop_checkPipedAssignment1 = verify checkPipedAssignment "A=ls | grep foo"
@@ -2017,15 +2005,15 @@ data StackData =
     -- (Base expression, specific position, var name, assigned values)
     | Assignment (Token, Token, String, DataType)
     | Reference (Token, Token, String)
-  deriving (Show, Eq)
+  deriving (Show)
 
 data DataType = DataString DataSource | DataArray DataSource
-  deriving (Show, Eq)
+  deriving (Show)
 
 data DataSource = SourceFrom [Token] | SourceExternal | SourceDeclaration
-  deriving (Show, Eq)
+  deriving (Show)
 
-data VariableState = Dead Token String | Alive deriving (Show, Eq)
+data VariableState = Dead Token String | Alive deriving (Show)
 
 dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
 
@@ -2220,10 +2208,11 @@ getBracedReference s = fromMaybe s $
     getSpecial _ = fail "empty"
 
 getIndexReferences s = fromMaybe [] $ do
-    (_, index, _, _) <- matchRegexAll re s
-    return $ matchAll variableNameRegex index
+    match <- matchRegex re s
+    index <- match !!! 0
+    return $ matchAllStrings variableNameRegex index
   where
-    re = mkRegex "\\[.*\\]"
+    re = mkRegex "(\\[.*\\])"
 
 getReferencedVariables t =
     case t of
@@ -2263,7 +2252,7 @@ getReferencedVariables t =
 prop_getVariablesFromLiteral1 =
     getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
 getVariablesFromLiteral string =
-    map (!! 0) $ getAllMatches variableRegex string
+    map (!! 0) $ matchAllSubgroups variableRegex string
   where
     variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
 
@@ -3107,9 +3096,7 @@ checkMultipleAppends params t =
     mapM_ checkList $ getCommandSequences t
   where
     checkList list =
-        mapM_ checkGroup groups
-      where
-        groups = groupWith (liftM fst) $ map getTarget list
+        mapM_ checkGroup (groupWith (liftM fst) $ map getTarget list)
     checkGroup (f:_:_:_) | isJust f =
         style (snd $ fromJust f) 2129
             "Consider using { cmd1; cmd2; } >> file instead of individual redirects."

ShellCheck/Regex.hs

@@ -0,0 +1,71 @@
+{-
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE FlexibleContexts #-}
+
+-- Basically Text.Regex based on regex-tdfa instead of the buggy regex-posix.
+module ShellCheck.Regex where
+
+import Data.List
+import Data.Maybe
+import Control.Monad
+import Text.Regex.TDFA
+
+-- Precompile the regex
+mkRegex :: String -> Regex
+mkRegex str =
+    let make :: RegexMaker Regex CompOption ExecOption String => String -> Regex
+        make = makeRegex
+    in
+        make str
+
+-- Does the regex match?
+matches :: String -> Regex -> Bool
+matches = flip match
+
+-- Get all subgroups of the first match
+matchRegex :: Regex -> String -> Maybe [String]
+matchRegex re str = do
+    (_, _, _, groups) <- matchM re str :: Maybe (String,String,String,[String])
+    return groups
+
+-- Get all full matches
+matchAllStrings :: Regex -> String -> [String]
+matchAllStrings re = unfoldr f
+  where
+    f :: String -> Maybe (String, String)
+    f str = do
+        (_, match, rest, _) <- matchM re str :: Maybe (String, String, String, [String])
+        return (match, rest)
+
+-- Get all subgroups from all matches
+matchAllSubgroups :: Regex -> String -> [[String]]
+matchAllSubgroups re = unfoldr f
+  where
+    f :: String -> Maybe ([String], String)
+    f str = do
+        (_, _, rest, groups) <- matchM re str :: Maybe (String, String, String, [String])
+        return (groups, rest)
+
+-- Replace regex in input with string
+subRegex :: Regex -> String -> String -> String
+subRegex re input replacement = f input
+  where
+    f str = fromMaybe str $ do
+        (before, match, after) <- matchM re str :: Maybe (String, String, String)
+        when (null match) $ error ("Internal error: substituted empty in " ++ str)
+        return $ before ++ replacement ++ f after