426 lines
19 KiB
Haskell
426 lines
19 KiB
Haskell
module ShellCheck.Analytics where
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import ShellCheck.AST
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import ShellCheck.Parser
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import Control.Monad
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import Control.Monad.State
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import qualified Data.Map as Map
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import Data.Char
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import Data.List
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import Debug.Trace
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import Text.Regex
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import Data.Maybe
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checks = concat [
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map runBasicAnalysis basicChecks
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,[subshellAssignmentCheck]
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]
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runAllAnalytics = checkList checks
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checkList l t m = foldl (\x f -> f t x) m l
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runBasicAnalysis f t m = snd $ runState (doAnalysis f t) m
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basicChecks = [
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checkUuoc
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,checkForInQuoted
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,checkForInLs
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,checkMissingForQuotes
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,checkUnquotedExpansions
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,checkRedirectToSame
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,checkShorthandIf
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,checkDollarStar
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,checkUnquotedDollarAt
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,checkStderrRedirect
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,checkMissingPositionalQuotes
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,checkSingleQuotedVariables
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,checkUnquotedZN
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,checkNumberComparisons
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,checkNoaryWasBinary
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,checkBraceExpansionVars
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,checkForDecimals
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,checkDivBeforeMult
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,checkArithmeticDeref
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,checkComparisonAgainstGlob
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,checkPrintfVar
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]
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modifyMap = modify
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addNoteFor id note = modifyMap $ Map.adjust (\(Metadata pos notes) -> Metadata pos (note:notes)) id
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willSplit x =
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case x of
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T_DollarBraced _ _ -> True
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T_DollarExpansion _ _ -> True
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T_BraceExpansion _ s -> True
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T_NormalWord _ l -> any willSplit l
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T_Literal _ s -> isGlob s
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_ -> False
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isGlob str = any (`elem` str) "*?"
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makeSimple (T_NormalWord _ [f]) = f
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makeSimple (T_Redirecting _ _ f) = f
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makeSimple t = t
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simplify = doTransform makeSimple
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deadSimple (T_NormalWord _ l) = [concat (concatMap (deadSimple) l)]
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deadSimple (T_DoubleQuoted _ l) = ["\"" ++(concat (concatMap (deadSimple) l)) ++ "\""]
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deadSimple (T_SingleQuoted _ s) = [s]
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deadSimple (T_DollarBraced _ _) = ["${VAR}"]
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deadSimple (T_DollarArithmetic _ _) = ["${VAR}"]
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deadSimple (T_DollarExpansion _ _) = ["${VAR}"]
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deadSimple (T_Pipeline _ [x]) = deadSimple x
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deadSimple (T_Literal _ x) = [x]
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deadSimple (T_SimpleCommand _ vars words) = concatMap (deadSimple) words
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deadSimple (T_Redirecting _ _ foo) = deadSimple foo
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deadSimple _ = []
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verify f s = checkBasic f s == Just True
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verifyNot f s = checkBasic f s == Just False
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verifyFull f s = checkFull f s == Just True
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verifyNotFull f s = checkFull f s == Just False
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checkBasic f s = checkFull (runBasicAnalysis f) s
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checkFull f s = case parseShell "-" s of
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(ParseResult (Just (t, m)) _) -> Just . not $ (notesFromMap $ f t m) == (notesFromMap m)
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_ -> Nothing
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prop_checkUuoc = verify checkUuoc "cat foo | grep bar"
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checkUuoc (T_Pipeline _ (T_Redirecting _ _ f@(T_SimpleCommand id _ _):_:_)) =
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case deadSimple f of ["cat", _] -> addNoteFor id $ Note StyleC "Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead."
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_ -> return ()
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checkUuoc _ = return ()
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isMagicInQuotes (T_DollarBraced _ s) | '@' `elem` s = True
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isMagicInQuotes _ = False
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prop_checkForInQuoted = verify checkForInQuoted "for f in \"$(ls)\"; do echo foo; done"
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prop_checkForInQuoted2 = verifyNot checkForInQuoted "for f in \"$@\"; do echo foo; done"
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checkForInQuoted (T_ForIn _ f [T_NormalWord _ [T_DoubleQuoted id list]] _) =
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when (any (\x -> willSplit x && not (isMagicInQuotes x)) list) $
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addNoteFor id $ Note ErrorC $ "Since you double quoted this, it will not word split, and the loop will only run once"
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checkForInQuoted _ = return ()
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prop_checkForInLs = verify checkForInLs "for f in $(ls *.mp3); do mplayer \"$f\"; done"
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checkForInLs (T_ForIn _ f [T_NormalWord _ [T_DollarExpansion id [x]]] _) =
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case deadSimple x of ("ls":n) -> let args = (if n == [] then ["*"] else n) in
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addNoteFor id $ Note ErrorC $ "Don't use 'for "++f++" in $(ls " ++ (intercalate " " n) ++ ")'. Use 'for "++f++" in "++ (intercalate " " args) ++ "'"
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_ -> return ()
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checkForInLs _ = return ()
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prop_checkMissingForQuotes = verify checkMissingForQuotes "for f in *.mp3; do rm $f; done"
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prop_checkMissingForQuotes2 = verifyNot checkMissingForQuotes "for f in foo bar; do rm $f; done"
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checkMissingForQuotes (T_ForIn _ f words cmds) =
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if not $ any willSplit words then return () else do
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mapM_ (doAnalysis (markUnquoted f)) cmds
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where
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markUnquoted f (T_NormalWord _ l) = mapM_ mu l
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markUnquoted _ _ = return ()
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mu (T_DollarBraced id s) | s == f = warning id
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mu _ = return ()
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warning id = addNoteFor id $ Note WarningC $ "Variables that could contain spaces should be quoted"
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checkMissingForQuotes _ = return ()
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prop_checkMissingPositionalQuotes = verify checkMissingPositionalQuotes "rm $1"
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prop_checkMissingPositionalQuotes2 = verify checkMissingPositionalQuotes "rm ${10//foo/bar}"
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checkMissingPositionalQuotes (T_NormalWord _ list) =
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mapM_ checkPos list
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where checkPos (T_DollarBraced id s) | all isDigit (getBracedReference s) =
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addNoteFor id $ Note WarningC $ "Positional parameters should be quoted to avoid whitespace trouble"
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checkPos _ = return ()
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checkMissingPositionalQuotes _ = return ()
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prop_checkUnquotedExpansions = verify checkUnquotedExpansions "rm $(ls)"
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checkUnquotedExpansions (T_SimpleCommand _ _ cmds) = mapM_ check cmds
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where check (T_NormalWord _ [T_DollarExpansion id _]) = addNoteFor id $ Note WarningC "Quote the expansion to prevent word splitting"
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check _ = return ()
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checkUnquotedExpansions _ = return ()
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prop_checkRedirectToSame = verify checkRedirectToSame "cat foo > foo"
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prop_checkRedirectToSame2 = verify checkRedirectToSame "cat lol | sed -e 's/a/b/g' > lol"
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prop_checkRedirectToSame3 = verifyNot checkRedirectToSame "cat lol | sed -e 's/a/b/g' > foo.bar && mv foo.bar lol"
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checkRedirectToSame s@(T_Pipeline _ list) =
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mapM_ (\l -> (mapM_ (\x -> doAnalysis (checkOccurences x) l) (getAllRedirs list))) list
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where checkOccurences (T_NormalWord exceptId x) (T_NormalWord newId y) =
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when (x == y && exceptId /= newId) (do
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let note = Note InfoC $ "Make sure not to read and write the same file in the same pipeline"
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addNoteFor newId $ note
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addNoteFor exceptId $ note)
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checkOccurences _ _ = return ()
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getAllRedirs l = concatMap (\(T_Redirecting _ ls _) -> concatMap getRedirs ls) l
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getRedirs (T_FdRedirect _ _ (T_IoFile _ op file)) =
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case op of T_Greater _ -> [file]
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T_Less _ -> [file]
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T_DGREAT _ -> [file]
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_ -> []
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getRedirs _ = []
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checkRedirectToSame _ = return ()
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prop_checkShorthandIf = verify checkShorthandIf "[[ ! -z file ]] && scp file host || rm file"
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prop_checkShorthandIf2 = verifyNot checkShorthandIf "[[ ! -z file ]] && { scp file host || echo 'Eek'; }"
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checkShorthandIf (T_AndIf id _ (T_OrIf _ _ _)) =
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addNoteFor id $ Note InfoC "Note that A && B || C is not if-then-else. C may run when A is true."
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checkShorthandIf _ = return ()
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prop_checkDollarStar = verify checkDollarStar "for f in $*; do ..; done"
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checkDollarStar (T_NormalWord _ [(T_DollarBraced id "*")]) =
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addNoteFor id $ Note WarningC $ "Use \"$@\" (with quotes) to prevent whitespace problems"
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checkDollarStar _ = return ()
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prop_checkUnquotedDollarAt = verify checkUnquotedDollarAt "ls $@"
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prop_checkUnquotedDollarAt2 = verifyNot checkUnquotedDollarAt "ls \"$@\""
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checkUnquotedDollarAt (T_NormalWord _ [T_DollarBraced id "@"]) =
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addNoteFor id $ Note ErrorC $ "Add double quotes around $@, otherwise it's just like $* and breaks on spaces"
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checkUnquotedDollarAt _ = return ()
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prop_checkStderrRedirect = verify checkStderrRedirect "test 2>&1 > cow"
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prop_checkStderrRedirect2 = verifyNot checkStderrRedirect "test > cow 2>&1"
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checkStderrRedirect (T_Redirecting _ [
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T_FdRedirect id "2" (T_IoFile _ (T_GREATAND _) (T_NormalWord _ [T_Literal _ "1"])),
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T_FdRedirect _ _ (T_IoFile _ op _)
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] _) = case op of
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T_Greater _ -> error
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T_DGREAT _ -> error
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_ -> return ()
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where error = addNoteFor id $ Note ErrorC $ "The order of the 2>&1 and the redirect matters. The 2>&1 has to be last."
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checkStderrRedirect _ = return ()
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lt x = trace ("FAILURE " ++ (show x)) x
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prop_checkSingleQuotedVariables = verify checkSingleQuotedVariables "echo '$foo'"
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prop_checkSingleQuotedVariables2 = verify checkSingleQuotedVariables "echo 'lol$1.jpg'"
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prop_checkSingleQuotedVariables3 = verifyNot checkSingleQuotedVariables "sed 's/foo$/bar/'"
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checkSingleQuotedVariables (T_SingleQuoted id s) =
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case matchRegex checkSingleQuotedVariablesRe s of
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Just [var] -> addNoteFor id $ Note WarningC $ var ++ " won't be expanded in single quotes."
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_ -> return ()
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checkSingleQuotedVariables _ = return ()
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checkSingleQuotedVariablesRe = mkRegex "(\\$[0-9a-zA-Z_]+)"
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prop_checkUnquotedZN = verify checkUnquotedZN "if [ -z $foo ]; then echo cow; fi"
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prop_checkUnquotedZN2 = verify checkUnquotedZN "[ -n $cow ]"
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prop_checkUnquotedZN3 = verifyNot checkUnquotedZN "[[ -z $foo ]] && echo cow"
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checkUnquotedZN (T_Condition _ SingleBracket (TC_Unary _ SingleBracket op (T_NormalWord id [t]))) | ( op == "-z" || op == "-n" ) && willSplit t =
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addNoteFor id $ Note ErrorC "Always true because you failed to quote. Use [[ ]] instead."
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checkUnquotedZN _ = return ()
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prop_checkNumberComparisons1 = verify checkNumberComparisons "[[ $foo < 3 ]]"
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prop_checkNumberComparisons2 = verify checkNumberComparisons "[[ 0 >= $(cmd) ]]"
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prop_checkNumberComparisons3 = verifyNot checkNumberComparisons "[[ $foo ]] > 3"
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prop_checkNumberComparisons4 = verify checkNumberComparisons "[ $foo > $bar ]"
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prop_checkNumberComparisons5 = verify checkNumberComparisons "until [ $n <= $z ]; do echo foo; done"
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checkNumberComparisons (TC_Binary id typ op lhs rhs)
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| op `elem` ["<", ">", "<=", ">="] = do
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when (isNum lhs || isNum rhs) $ addNoteFor id $ Note ErrorC $ "\"" ++ op ++ "\" is for string comparisons. Use " ++ (eqv op)
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when (typ == SingleBracket) $ addNoteFor id $ Note ErrorC $ "Can't use " ++ op ++" in [ ]. Use [[ ]]."
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where
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isNum t = case deadSimple t of [v] -> all isDigit v
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_ -> False
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eqv "<" = "-lt"
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eqv ">" = "-gt"
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eqv "<=" = "-le"
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eqv ">=" = "-ge"
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eqv _ = "the numerical equivalent"
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checkNumberComparisons _ = return ()
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prop_checkNoaryWasBinary = verify checkNoaryWasBinary "[[ a==$foo ]]"
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prop_checkNoaryWasBinary2 = verify checkNoaryWasBinary "[ $foo=3 ]"
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checkNoaryWasBinary (TC_Noary _ _ t@(T_NormalWord id l)) = do
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let str = concat $ deadSimple t
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when ('=' `elem` str) $ addNoteFor id $ Note ErrorC $ "Always true because you didn't put spaces around the ="
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checkNoaryWasBinary _ = return ()
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prop_checkBraceExpansionVars = verify checkBraceExpansionVars "echo {1..$n}"
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checkBraceExpansionVars (T_BraceExpansion id s) | '$' `elem` s =
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addNoteFor id $ Note WarningC $ "You can't use variables in brace expansions."
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checkBraceExpansionVars _ = return ()
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prop_checkForDecimals = verify checkForDecimals "((3.14*c))"
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checkForDecimals (TA_Literal id s) | any (== '.') s = do
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addNoteFor id $ Note ErrorC $ "(( )) doesn't support decimals. Use bc or awk."
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checkForDecimals _ = return ()
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prop_checkDivBeforeMult = verify checkDivBeforeMult "echo $((c/n*100))"
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prop_checkDivBeforeMult2 = verifyNot checkDivBeforeMult "echo $((c*100/n))"
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checkDivBeforeMult (TA_Binary _ "*" (TA_Binary id "/" _ _) _) = do
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addNoteFor id $ Note InfoC $ "Increase precision by replacing a/b*c with a*c/b"
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checkDivBeforeMult _ = return ()
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prop_checkArithmeticDeref = verify checkArithmeticDeref "echo $((3+$foo))"
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prop_checkArithmeticDeref2 = verify checkArithmeticDeref "cow=14; (( s+= $cow ))"
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prop_checkArithmeticDeref3 = verifyNot checkArithmeticDeref "cow=1/40; (( s+= ${cow%%/*} ))"
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checkArithmeticDeref (TA_Expansion _ (T_DollarBraced id str)) | not $ any (`elem` "/.:#%") $ str =
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addNoteFor id $ Note WarningC $ "Don't use $ on variables in (( )) unless you want to dereference twice"
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checkArithmeticDeref _ = return ()
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prop_checkComparisonAgainstGlob = verify checkComparisonAgainstGlob "[[ $cow == $bar ]]"
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prop_checkComparisonAgainstGlob2 = verifyNot checkComparisonAgainstGlob "[[ $cow == \"$bar\" ]]"
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checkComparisonAgainstGlob (TC_Binary _ DoubleBracket op _ (T_NormalWord id [T_DollarBraced _ _])) | op == "=" || op == "==" =
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addNoteFor id $ Note WarningC $ "Quote the rhs of = in [[ ]] to prevent glob interpretation"
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checkComparisonAgainstGlob _ = return ()
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allModifiedVariables t = snd $ runState (doAnalysis (\x -> modify $ (++) (getModifiedVariables x)) t) []
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--- Command specific checks
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checkCommand str f (T_SimpleCommand id _ cmd) =
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case cmd of
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(w:rest) -> if w `isCommand` str then f rest else return ()
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_ -> return ()
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checkCommand _ _ _ = return ()
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getLiteralString t = g t
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where
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allInList l = let foo = map g l in if all isJust foo then return $ concat (catMaybes foo) else Nothing
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g s@(T_DoubleQuoted _ l) = allInList l
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g s@(T_NormalWord _ l) = allInList l
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g (T_SingleQuoted _ s) = return s
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g (T_Literal _ s) = return s
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g _ = Nothing
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isLiteral t = isJust $ getLiteralString t
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isCommand token str =
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case getLiteralString token of
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Just cmd -> cmd == str || ("/" ++ str) `isSuffixOf` cmd
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Nothing -> False
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prop_checkPrintfVar1 = verify checkPrintfVar "printf \"Lol: $s\""
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prop_checkPrintfVar2 = verifyNot checkPrintfVar "printf 'Lol: $s'"
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prop_checkPrintfVar3 = verify checkPrintfVar "printf -v cow $(cmd)"
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checkPrintfVar = checkCommand "printf" f where
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f (dashv:var:rest) | getLiteralString dashv == (Just "-v") = f rest
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f (format:params) = check format
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f _ = return ()
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check format =
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if not $ isLiteral format
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then addNoteFor (getId format) $ Note WarningC $ "Don't use printf \"$foo\", use printf \"%s\" \"$foo\""
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else return ()
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--- Subshell detection
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prop_subshellAssignmentCheck = verifyFull subshellAssignmentCheck "cat foo | while read bar; do a=$bar; done; echo \"$a\""
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prop_subshellAssignmentCheck2 = verifyNotFull subshellAssignmentCheck "while read bar; do a=$bar; done < file; echo \"$a\""
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prop_subshellAssignmentCheck3 = verifyFull subshellAssignmentCheck "( A=foo; ); rm $A"
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prop_subshellAssignmentCheck4 = verifyNotFull subshellAssignmentCheck "( A=foo; rm $A; )"
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prop_subshellAssignmentCheck5 = verifyFull subshellAssignmentCheck "cat foo | while read cow; do true; done; echo $cow;"
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prop_subshellAssignmentCheck6 = verifyFull subshellAssignmentCheck "( export lol=$(ls); ); echo $lol;"
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prop_subshellAssignmentCheck7 = verifyFull subshellAssignmentCheck "cmd | while read foo; do (( n++ )); done; echo \"$n lines\""
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prop_subshellAssignmentCheck8 = verifyFull subshellAssignmentCheck "n=3 & echo $((n++))"
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prop_subshellAssignmentCheck9 = verifyFull subshellAssignmentCheck "read n & n=foo$n"
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prop_subshellAssignmentCheck10 = verifyFull subshellAssignmentCheck "(( n <<= 3 )) & (( n |= 4 )) &"
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subshellAssignmentCheck t map =
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let flow = getVariableFlow t
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check = findSubshelled flow [("oops",[])] Map.empty
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in snd $ runState check map
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data Scope = SubshellScope String | NoneScope deriving (Show, Eq)
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data StackData = StackScope Scope | StackScopeEnd | Assignment (Id, String) | Reference (Id, String) deriving (Show, Eq)
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data VariableState = Dead Id String | Alive deriving (Show, Eq)
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leadType t =
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case t of
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T_DollarExpansion _ _ -> SubshellScope "$(..) expansion"
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T_Backgrounded _ _ -> SubshellScope "backgrounding &"
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T_Subshell _ _ -> SubshellScope "(..) group"
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-- This considers the whole pipeline one subshell. Consider fixing.
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T_Pipeline _ (_:_:[]) -> SubshellScope "pipeline"
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_ -> NoneScope
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getModifiedVariables t =
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case t of
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T_SimpleCommand _ vars [] ->
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concatMap (\x -> case x of
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T_Assignment id name _ -> [(id, name)]
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_ -> []
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) vars
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c@(T_SimpleCommand _ _ _) ->
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getModifiedVariableCommand c
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TA_Unary _ "++|" (TA_Variable id name) -> [(id, name)]
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TA_Unary _ "|++" (TA_Variable id name) -> [(id, name)]
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TA_Binary _ op (TA_Variable id name) _ -> if any (==op) ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
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then [(id,name)]
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else []
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--Points to 'for' rather than variable
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T_ForIn id str _ _ -> [(id, str)]
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_ -> []
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getModifiedVariableCommand (T_SimpleCommand _ _ ((T_NormalWord _ ((T_Literal _ x):_)):rest)) =
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case x of
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"read" -> concatMap getLiteral rest
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"export" -> concatMap exportParamToLiteral rest
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_ -> []
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getModifiedVariableCommand _ = []
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getLiteral (T_NormalWord _ [T_Literal id s]) = [(id,s)]
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getLiteral (T_NormalWord _ [T_DoubleQuoted _ [T_Literal id s]]) = [(id,s)]
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getLiteral x = []
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exportParamToLiteral (T_NormalWord _ ((T_Literal id s):_)) =
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[(id,prefix)]
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where prefix = takeWhile (/= '=') s
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exportParamToLiteral _ = []
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-- TODO:
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getBracedReference s = takeWhile (\x -> not $ x `elem` ":[#%/^,") $ dropWhile (== '#') s
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getReferencedVariables t =
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case t of
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T_DollarBraced id str -> map (\x -> (id, x)) $ [getBracedReference str]
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TA_Variable id str -> [(id,str)]
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x -> []
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startScope t =
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let scopeType = leadType t
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in do
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when (scopeType /= NoneScope) $ modify ((StackScope scopeType):)
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endScope t =
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let scopeType = leadType t
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written = getModifiedVariables t
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read = getReferencedVariables t
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in do
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when (scopeType /= NoneScope) $ modify ((StackScopeEnd):)
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mapM_ (\v -> modify ((Reference v):)) read
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mapM_ (\v -> modify ((Assignment v):)) written
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getVariableFlow t =
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let (_, stack) = runState (doStackAnalysis startScope endScope t) []
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in reverse stack
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findSubshelled :: [StackData] -> [(String, [(Id,String)])] -> (Map.Map String VariableState) -> State (Map.Map Id Metadata) ()
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findSubshelled [] _ _ = return ()
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findSubshelled ((Assignment x@(id, str)):rest) ((reason,scope):lol) deadVars =
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findSubshelled rest ((reason, x:scope):lol) $ Map.insert str Alive deadVars
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findSubshelled ((Reference (readId, str)):rest) scopes deadVars = do
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case Map.findWithDefault Alive str deadVars of
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Alive -> return ()
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Dead writeId reason -> do
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addNoteFor writeId $ Note InfoC $ "Modification of " ++ str ++ " is local (to subshell caused by "++ reason ++")."
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addNoteFor readId $ Note InfoC $ str ++ " was modified in a subshell. That change might be lost."
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findSubshelled rest scopes deadVars
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findSubshelled ((StackScope (SubshellScope reason)):rest) scopes deadVars =
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findSubshelled rest ((reason,[]):scopes) deadVars
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findSubshelled ((StackScopeEnd):rest) ((reason, scope):oldScopes) deadVars =
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findSubshelled rest oldScopes $ foldl (\m (id, var) -> Map.insert var (Dead id reason) m) deadVars scope
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------
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