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{-
Copyright 2012-2015 Vidar Holen
This file is part of ShellCheck.
https://www.shellcheck.net
ShellCheck is free software: you can redistribute it and/or modify
it under the terms of the GNU 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
-}
{-# LANGUAGE FlexibleContexts #-}
module ShellCheck.AnalyzerLib where
import ShellCheck.AST
import ShellCheck.ASTLib
import ShellCheck.Data
import ShellCheck.Interface
import ShellCheck.Parser
import ShellCheck.Regex
import Control.Arrow (first)
import Control.DeepSeq
import Control.Monad.Identity
import Control.Monad.RWS
import Control.Monad.State
import Control.Monad.Writer
import Data.Char
import Data.List
import qualified Data.Map as Map
import Data.Maybe
import Data.Semigroup
prop :: Bool -> IO ()
prop False = putStrLn "FAIL"
prop True = return ()
type Analysis = AnalyzerM ()
type AnalyzerM a = RWS Parameters [TokenComment] Cache a
nullCheck = const $ return ()
data Checker = Checker {
perScript :: Root -> Analysis,
perToken :: Token -> Analysis
}
runChecker :: Parameters -> Checker -> [TokenComment]
runChecker params checker = notes
where
root = rootNode params
check = perScript checker `composeAnalyzers` (\(Root x) -> void $ doAnalysis (perToken checker) x)
notes = snd $ evalRWS (check $ Root root) params Cache
instance Semigroup Checker where
(<>) x y = Checker {
perScript = perScript x `composeAnalyzers` perScript y,
perToken = perToken x `composeAnalyzers` perToken y
}
instance Monoid Checker where
mempty = Checker {
perScript = nullCheck,
perToken = nullCheck
}
mappend = (Data.Semigroup.<>)
composeAnalyzers :: (a -> Analysis) -> (a -> Analysis) -> a -> Analysis
composeAnalyzers f g x = f x >> g x
data Parameters = Parameters {
hasLastpipe :: Bool, -- Whether this script has the 'lastpipe' option set/default.
hasSetE :: Bool, -- Whether this script has 'set -e' anywhere.
variableFlow :: [StackData], -- A linear (bad) analysis of data flow
parentMap :: Map.Map Id Token, -- A map from Id to parent Token
shellType :: Shell, -- The shell type, such as Bash or Ksh
shellTypeSpecified :: Bool, -- True if shell type was forced via flags
rootNode :: Token, -- The root node of the AST
tokenPositions :: Map.Map Id (Position, Position) -- map from token id to start and end position
} deriving (Show)
-- TODO: Cache results of common AST ops here
data Cache = Cache {}
data Scope = SubshellScope String | NoneScope deriving (Show, Eq)
data StackData =
StackScope Scope
| StackScopeEnd
-- (Base expression, specific position, var name, assigned values)
| Assignment (Token, Token, String, DataType)
| Reference (Token, Token, String)
deriving (Show)
data DataType = DataString DataSource | DataArray DataSource
deriving (Show)
data DataSource =
SourceFrom [Token]
| SourceExternal
| SourceDeclaration
| SourceInteger
| SourceChecked
deriving (Show)
data VariableState = Dead Token String | Alive deriving (Show)
defaultSpec pr = spec {
asShellType = Nothing,
asCheckSourced = False,
asExecutionMode = Executed,
asTokenPositions = prTokenPositions pr
} where spec = newAnalysisSpec (fromJust $ prRoot pr)
pScript s =
let
pSpec = newParseSpec {
psFilename = "script",
psScript = s
}
in runIdentity $ parseScript (mockedSystemInterface []) pSpec
-- For testing. If parsed, returns whether there are any comments
producesComments :: Checker -> String -> Maybe Bool
producesComments c s = do
let pr = pScript s
prRoot pr
let spec = defaultSpec pr
let params = makeParameters spec
return . not . null $ runChecker params c
makeComment :: Severity -> Id -> Code -> String -> TokenComment
makeComment severity id code note =
newTokenComment {
tcId = id,
tcComment = newComment {
cSeverity = severity,
cCode = code,
cMessage = note
}
}
addComment note = note `deepseq` tell [note]
warn :: MonadWriter [TokenComment] m => Id -> Code -> String -> m ()
warn id code str = addComment $ makeComment WarningC id code str
err id code str = addComment $ makeComment ErrorC id code str
info id code str = addComment $ makeComment InfoC id code str
style id code str = addComment $ makeComment StyleC id code str
warnWithFix id code str fix = addComment $
let comment = makeComment WarningC id code str in
comment {
tcFix = Just fix
}
makeCommentWithFix :: Severity -> Id -> Code -> String -> Fix -> TokenComment
makeCommentWithFix severity id code str fix =
let comment = makeComment severity id code str
withFix = comment {
tcFix = Just fix
}
in withFix `deepseq` withFix
makeParameters spec =
let params = Parameters {
rootNode = root,
shellType = fromMaybe (determineShell root) $ asShellType spec,
hasSetE = containsSetE root,
hasLastpipe =
case shellType params of
Bash -> containsLastpipe root
Dash -> False
Sh -> False
Ksh -> True,
shellTypeSpecified = isJust $ asShellType spec,
parentMap = getParentTree root,
variableFlow = getVariableFlow params root,
tokenPositions = asTokenPositions spec
} in params
where root = asScript spec
-- Does this script mention 'set -e' anywhere?
-- Used as a hack to disable certain warnings.
containsSetE root = isNothing $ doAnalysis (guard . not . isSetE) root
where
isSetE t =
case t of
T_Script _ str _ -> str `matches` re
T_SimpleCommand {} ->
t `isUnqualifiedCommand` "set" &&
("errexit" `elem` oversimplify t ||
"e" `elem` map snd (getAllFlags t))
_ -> False
re = mkRegex "[[:space:]]-[^-]*e"
-- Does this script mention 'shopt -s lastpipe' anywhere?
-- Also used as a hack.
containsLastpipe root =
isNothing $ doAnalysis (guard . not . isShoptLastPipe) root
where
isShoptLastPipe t =
case t of
T_SimpleCommand {} ->
t `isUnqualifiedCommand` "shopt" &&
("lastpipe" `elem` oversimplify t)
_ -> False
-- |
-- >>> prop $ determineShellTest "#!/bin/sh" == Sh
-- >>> prop $ determineShellTest "#!/usr/bin/env ksh" == Ksh
-- >>> prop $ determineShellTest "" == Bash
-- >>> prop $ determineShellTest "#!/bin/sh -e" == Sh
-- >>> prop $ determineShellTest "#!/bin/ksh\n#shellcheck shell=sh\nfoo" == Sh
-- >>> prop $ determineShellTest "#shellcheck shell=sh\nfoo" == Sh
-- >>> prop $ determineShellTest "#! /bin/sh" == Sh
-- >>> prop $ determineShellTest "#! /bin/ash" == Dash
determineShellTest = determineShell . fromJust . prRoot . pScript
determineShell t = fromMaybe Bash $ do
shellString <- foldl mplus Nothing $ getCandidates t
shellForExecutable shellString
where
forAnnotation t =
case t of
(ShellOverride s) -> return s
_ -> fail ""
getCandidates :: Token -> [Maybe String]
getCandidates t@T_Script {} = [Just $ fromShebang t]
getCandidates (T_Annotation _ annotations s) =
map forAnnotation annotations ++
[Just $ fromShebang s]
fromShebang (T_Script _ s t) = executableFromShebang s
-- Given a string like "/bin/bash" or "/usr/bin/env dash",
-- return the shell basename like "bash" or "dash"
executableFromShebang :: String -> String
executableFromShebang = shellFor
where
shellFor s | "/env " `isInfixOf` s = head (drop 1 (words s)++[""])
shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
shellFor s = reverse . takeWhile (/= '/') . reverse $ s
-- Given a root node, make a map from Id to parent Token.
-- This is used to populate parentMap in Parameters
getParentTree :: Token -> Map.Map Id Token
getParentTree t =
snd . snd $ runState (doStackAnalysis pre post t) ([], Map.empty)
where
pre t = modify (first ((:) t))
post t = do
(x, map) <- get
case x of
_:rest -> case rest of [] -> put (rest, map)
(x:_) -> put (rest, Map.insert (getId t) x map)
-- Given a root node, make a map from Id to Token
getTokenMap :: Token -> Map.Map Id Token
getTokenMap t =
execState (doAnalysis f t) Map.empty
where
f t = modify (Map.insert (getId t) t)
-- Is this token in a quoting free context? (i.e. would variable expansion split)
-- True: Assignments, [[ .. ]], here docs, already in double quotes
-- False: Regular words
isStrictlyQuoteFree = isQuoteFreeNode True
-- Like above, but also allow some cases where splitting may be desired.
-- True: Like above + for loops
-- False: Like above
isQuoteFree = isQuoteFreeNode False
isQuoteFreeNode strict tree t =
(isQuoteFreeElement t == Just True) ||
head (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t) ++ [False])
where
-- Is this node self-quoting in itself?
isQuoteFreeElement t =
case t of
T_Assignment {} -> return True
T_FdRedirect {} -> return True
_ -> Nothing
-- Are any subnodes inherently self-quoting?
isQuoteFreeContext t =
case t of
TC_Nullary _ DoubleBracket _ -> return True
TC_Unary _ DoubleBracket _ _ -> return True
TC_Binary _ DoubleBracket _ _ _ -> return True
TA_Sequence {} -> return True
T_Arithmetic {} -> return True
T_Assignment {} -> return True
T_Redirecting {} -> return False
T_DoubleQuoted _ _ -> return True
T_DollarDoubleQuoted _ _ -> return True
T_CaseExpression {} -> return True
T_HereDoc {} -> return True
T_DollarBraced {} -> return True
-- When non-strict, pragmatically assume it's desirable to split here
T_ForIn {} -> return (not strict)
T_SelectIn {} -> return (not strict)
_ -> Nothing
-- Check if a token is a parameter to a certain command by name:
-- Example: isParamTo (parentMap params) "sed" t
isParamTo :: Map.Map Id Token -> String -> Token -> Bool
isParamTo tree cmd =
go
where
go x = case Map.lookup (getId x) tree of
Nothing -> False
Just parent -> check parent
check t =
case t of
T_SingleQuoted _ _ -> go t
T_DoubleQuoted _ _ -> go t
T_NormalWord _ _ -> go t
T_SimpleCommand {} -> isCommand t cmd
T_Redirecting {} -> isCommand t cmd
_ -> False
-- Get the parent command (T_Redirecting) of a Token, if any.
getClosestCommand :: Map.Map Id Token -> Token -> Maybe Token
getClosestCommand tree t =
findFirst findCommand $ getPath tree t
where
findCommand t =
case t of
T_Redirecting {} -> return True
T_Script {} -> return False
_ -> Nothing
-- Like above, if koala_man knew Haskell when starting this project.
getClosestCommandM t = do
tree <- asks parentMap
return $ getClosestCommand tree t
-- Is the token used as a command name (the first word in a T_SimpleCommand)?
usedAsCommandName tree token = go (getId token) (tail $ getPath tree token)
where
go currentId (T_NormalWord id [word]:rest)
| currentId == getId word = go id rest
go currentId (T_DoubleQuoted id [word]:rest)
| currentId == getId word = go id rest
go currentId (T_SimpleCommand _ _ (word:_):_)
| currentId == getId word = True
go _ _ = False
-- A list of the element and all its parents up to the root node.
getPath tree t = t :
case Map.lookup (getId t) tree of
Nothing -> []
Just parent -> getPath tree parent
-- Version of the above taking the map from the current context
-- Todo: give this the name "getPath"
getPathM t = do
map <- asks parentMap
return $ getPath map t
isParentOf tree parent child =
elem (getId parent) . map getId $ getPath tree child
parents params = getPath (parentMap params)
pathTo t = do
parents <- reader parentMap
return $ getPath parents t
-- Find the first match in a list where the predicate is Just True.
-- Stops if it's Just False and ignores Nothing.
findFirst :: (a -> Maybe Bool) -> [a] -> Maybe a
findFirst p l =
case l of
[] -> Nothing
(x:xs) ->
case p x of
Just True -> return x
Just False -> Nothing
Nothing -> findFirst p xs
-- Check whether a word is entirely output from a single command
tokenIsJustCommandOutput t = case t of
T_NormalWord id [T_DollarExpansion _ cmds] -> check cmds
T_NormalWord id [T_DoubleQuoted _ [T_DollarExpansion _ cmds]] -> check cmds
T_NormalWord id [T_Backticked _ cmds] -> check cmds
T_NormalWord id [T_DoubleQuoted _ [T_Backticked _ cmds]] -> check cmds
_ -> False
where
check [x] = not $ isOnlyRedirection x
check _ = False
-- TODO: Replace this with a proper Control Flow Graph
getVariableFlow params t =
let (_, stack) = runState (doStackAnalysis startScope endScope t) []
in reverse stack
where
startScope t =
let scopeType = leadType params t
in do
when (scopeType /= NoneScope) $ modify (StackScope scopeType:)
when (assignFirst t) $ setWritten t
endScope t =
let scopeType = leadType params t
in do
setRead t
unless (assignFirst t) $ setWritten t
when (scopeType /= NoneScope) $ modify (StackScopeEnd:)
assignFirst T_ForIn {} = True
assignFirst T_SelectIn {} = True
assignFirst _ = False
setRead t =
let read = getReferencedVariables (parentMap params) t
in mapM_ (\v -> modify (Reference v:)) read
setWritten t =
let written = getModifiedVariables t
in mapM_ (\v -> modify (Assignment v:)) written
leadType params t =
case t of
T_DollarExpansion _ _ -> SubshellScope "$(..) expansion"
T_Backticked _ _ -> SubshellScope "`..` expansion"
T_Backgrounded _ _ -> SubshellScope "backgrounding &"
T_Subshell _ _ -> SubshellScope "(..) group"
T_CoProcBody _ _ -> SubshellScope "coproc"
T_Redirecting {} ->
if fromMaybe False causesSubshell
then SubshellScope "pipeline"
else NoneScope
_ -> NoneScope
where
parentPipeline = do
parent <- Map.lookup (getId t) (parentMap params)
case parent of
T_Pipeline {} -> return parent
_ -> Nothing
causesSubshell = do
(T_Pipeline _ _ list) <- parentPipeline
if length list <= 1
then return False
else if not $ hasLastpipe params
then return True
else return . not $ (getId . head $ reverse list) == getId t
getModifiedVariables t =
case t of
T_SimpleCommand _ vars [] ->
concatMap (\x -> case x of
T_Assignment id _ name _ w ->
[(x, x, name, dataTypeFrom DataString w)]
_ -> []
) vars
c@T_SimpleCommand {} ->
getModifiedVariableCommand c
TA_Unary _ "++|" v@(TA_Variable _ name _) ->
[(t, v, name, DataString $ SourceFrom [v])]
TA_Unary _ "|++" v@(TA_Variable _ name _) ->
[(t, v, name, DataString $ SourceFrom [v])]
TA_Assignment _ op (TA_Variable _ name _) rhs -> maybeToList $ do
guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
return (t, t, name, DataString $ SourceFrom [rhs])
-- Count [[ -v foo ]] as an "assignment".
-- This is to prevent [ -v foo ] being unassigned or unused.
TC_Unary id _ "-v" token -> maybeToList $ do
str <- fmap (takeWhile (/= '[')) $ -- Quoted index
flip getLiteralStringExt token $ \x ->
case x of
T_Glob _ s -> return s -- Unquoted index
_ -> Nothing
guard . not . null $ str
return (t, token, str, DataString SourceChecked)
T_DollarBraced _ l -> maybeToList $ do
let string = bracedString t
let modifier = getBracedModifier string
guard $ ":=" `isPrefixOf` modifier
return (t, t, getBracedReference string, DataString $ SourceFrom [l])
t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&2 modifies foo
[(t, t, takeWhile (/= '}') var, DataString SourceInteger) | not $ isClosingFileOp op]
t@(T_CoProc _ name _) ->
[(t, t, fromMaybe "COPROC" name, DataArray SourceInteger)]
--Points to 'for' rather than variable
T_ForIn id str [] _ -> [(t, t, str, DataString SourceExternal)]
T_ForIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
T_SelectIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
_ -> []
isClosingFileOp op =
case op of
T_IoDuplicate _ (T_GREATAND _) "-" -> True
T_IoDuplicate _ (T_LESSAND _) "-" -> True
_ -> False
-- Consider 'export/declare -x' a reference, since it makes the var available
getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
case x of
"export" -> if "f" `elem` flags
then []
else concatMap getReference rest
"declare" -> if
any (`elem` flags) ["x", "p"] &&
(not $ any (`elem` flags) ["f", "F"])
then concatMap getReference rest
else []
"readonly" ->
if any (`elem` flags) ["f", "p"]
then []
else concatMap getReference rest
"trap" ->
case rest of
head:_ -> map (\x -> (head, head, x)) $ getVariablesFromLiteralToken head
_ -> []
_ -> []
where
getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)]
getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)]
getReference _ = []
flags = map snd $ getAllFlags base
getReferencedVariableCommand _ = []
-- The function returns a tuple consisting of four items describing an assignment.
-- Given e.g. declare foo=bar
-- (
-- BaseCommand :: Token, -- The command/structure assigning the variable, i.e. declare foo=bar
-- AssignmentToken :: Token, -- The specific part that assigns this variable, i.e. foo=bar
-- VariableName :: String, -- The variable name, i.e. foo
-- VariableValue :: DataType -- A description of the value being assigned, i.e. "Literal string with value foo"
-- )
getModifiedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
filter (\(_,_,s,_) -> not ("-" `isPrefixOf` s)) $
case x of
"read" ->
let params = map getLiteral rest
readArrayVars = getReadArrayVariables rest
in
catMaybes . (++ readArrayVars) . takeWhile isJust . reverse $ params
"getopts" ->
case rest of
opts:var:_ -> maybeToList $ getLiteral var
_ -> []
"let" -> concatMap letParamToLiteral rest
"export" ->
if "f" `elem` flags then [] else concatMap getModifierParamString rest
"declare" -> if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
"typeset" -> declaredVars
"local" -> concatMap getModifierParamString rest
"readonly" ->
if any (`elem` flags) ["f", "p"]
then []
else concatMap getModifierParamString rest
"set" -> maybeToList $ do
params <- getSetParams rest
return (base, base, "@", DataString $ SourceFrom params)
"printf" -> maybeToList $ getPrintfVariable rest
"mapfile" -> maybeToList $ getMapfileArray base rest
"readarray" -> maybeToList $ getMapfileArray base rest
_ -> []
where
flags = map snd $ getAllFlags base
stripEquals s = let rest = dropWhile (/= '=') s in
if rest == "" then "" else tail rest
stripEqualsFrom (T_NormalWord id1 (T_Literal id2 s:rs)) =
T_NormalWord id1 (T_Literal id2 (stripEquals s):rs)
stripEqualsFrom (T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 s]]) =
T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 (stripEquals s)]]
stripEqualsFrom t = t
declaredVars = concatMap (getModifierParam defaultType) rest
where
defaultType = if any (`elem` flags) ["a", "A"] then DataArray else DataString
getLiteralOfDataType t d = do
s <- getLiteralString t
when ("-" `isPrefixOf` s) $ fail "argument"
return (base, t, s, d)
getLiteral t = getLiteralOfDataType t (DataString SourceExternal)
getLiteralArray t = getLiteralOfDataType t (DataArray SourceExternal)
getModifierParamString = getModifierParam DataString
getModifierParam def t@(T_Assignment _ _ name _ value) =
[(base, t, name, dataTypeFrom def value)]
getModifierParam def t@T_NormalWord {} = maybeToList $ do
name <- getLiteralString t
guard $ isVariableName name
return (base, t, name, def SourceDeclaration)
getModifierParam _ _ = []
letParamToLiteral token =
if var == ""
then []
else [(base, token, var, DataString $ SourceFrom [stripEqualsFrom token])]
where var = takeWhile isVariableChar $ dropWhile (`elem` "+-") $ concat $ oversimplify token
getSetParams (t:_:rest) | getLiteralString t == Just "-o" = getSetParams rest
getSetParams (t:rest) =
let s = getLiteralString t in
case s of
Just "--" -> return rest
Just ('-':_) -> getSetParams rest
_ -> return (t:fromMaybe [] (getSetParams rest))
getSetParams [] = Nothing
getPrintfVariable list = f $ map (\x -> (x, getLiteralString x)) list
where
f ((_, Just "-v") : (t, Just var) : _) = return (base, t, var, DataString $ SourceFrom list)
f (_:rest) = f rest
f [] = fail "not found"
-- mapfile has some curious syntax allowing flags plus 0..n variable names
-- where only the first non-option one is used if any. Here we cheat and
-- just get the last one, if it's a variable name.
getMapfileArray base arguments = do
lastArg <- listToMaybe (reverse arguments)
name <- getLiteralString lastArg
guard $ isVariableName name
return (base, lastArg, name, DataArray SourceExternal)
-- get all the array variables used in read, e.g. read -a arr
getReadArrayVariables args = do
map (getLiteralArray . snd)
(filter (\(x,_) -> getLiteralString x == Just "-a") (zip (args) (tail args)))
getModifiedVariableCommand _ = []
getIndexReferences s = fromMaybe [] $ do
match <- matchRegex re s
index <- match !!! 0
return $ matchAllStrings variableNameRegex index
where
re = mkRegex "(\\[.*\\])"
-- |
-- >>> prop $ getOffsetReferences ":bar" == ["bar"]
-- >>> prop $ getOffsetReferences ":bar:baz" == ["bar", "baz"]
-- >>> prop $ getOffsetReferences "[foo]:bar" == ["bar"]
-- >>> prop $ getOffsetReferences "[foo]:bar:baz" == ["bar", "baz"]
getOffsetReferences mods = fromMaybe [] $ do
-- if mods start with [, then drop until ]
match <- matchRegex re mods
offsets <- match !!! 1
return $ matchAllStrings variableNameRegex offsets
where
re = mkRegex "^(\\[.+\\])? *:([^-=?+].*)"
getReferencedVariables parents t =
case t of
T_DollarBraced id l -> let str = bracedString t in
(t, t, getBracedReference str) :
map (\x -> (l, l, x)) (
getIndexReferences str
++ getOffsetReferences (getBracedModifier str))
TA_Variable id name _ ->
if isArithmeticAssignment t
then []
else [(t, t, name)]
T_Assignment id mode str _ word ->
[(t, t, str) | mode == Append] ++ specialReferences str t word
TC_Unary id _ "-v" token -> getIfReference t token
TC_Unary id _ "-R" token -> getIfReference t token
TC_Binary id DoubleBracket op lhs rhs ->
if isDereferencing op
then concatMap (getIfReference t) [lhs, rhs]
else []
t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&- references and closes foo
[(t, t, takeWhile (/= '}') var) | isClosingFileOp op]
x -> getReferencedVariableCommand x
where
-- Try to reduce false positives for unused vars only referenced from evaluated vars
specialReferences name base word =
if name `elem` [
"PS1", "PS2", "PS3", "PS4",
"PROMPT_COMMAND"
]
then
map (\x -> (base, base, x)) $
getVariablesFromLiteralToken word
else []
literalizer t = case t of
T_Glob _ s -> return s -- Also when parsed as globs
_ -> Nothing
getIfReference context token = maybeToList $ do
str <- getLiteralStringExt literalizer token
guard . not $ null str
when (isDigit $ head str) $ fail "is a number"
return (context, token, getBracedReference str)
isDereferencing = (`elem` ["-eq", "-ne", "-lt", "-le", "-gt", "-ge"])
isArithmeticAssignment t = case getPath parents t of
this: TA_Assignment _ "=" lhs _ :_ -> lhs == t
_ -> False
dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
--- Command specific checks
-- Compare a command to a string: t `isCommand` "sed" (also matches /usr/bin/sed)
isCommand token str = isCommandMatch token (\cmd -> cmd == str || ('/' : str) `isSuffixOf` cmd)
-- Compare a command to a literal. Like above, but checks full path.
isUnqualifiedCommand token str = isCommandMatch token (== str)
isCommandMatch token matcher = fromMaybe False $
fmap matcher (getCommandName token)
-- |
-- Does this regex look like it was intended as a glob?
--
-- >>> isConfusedGlobRegex "*foo*"
-- True
--
-- >>> isConfusedGlobRegex ".*foo.*"
-- False
--
isConfusedGlobRegex :: String -> Bool
isConfusedGlobRegex ('*':_) = True
isConfusedGlobRegex [x,'*'] | x /= '\\' = True
isConfusedGlobRegex _ = False
isVariableStartChar x = x == '_' || isAsciiLower x || isAsciiUpper x
isVariableChar x = isVariableStartChar x || isDigit x
variableNameRegex = mkRegex "[_a-zA-Z][_a-zA-Z0-9]*"
-- |
-- >>> prop $ isVariableName "_fo123"
-- >>> prop $ not $ isVariableName "4"
-- >>> prop $ not $ isVariableName "test: "
isVariableName (x:r) = isVariableStartChar x && all isVariableChar r
isVariableName _ = False
getVariablesFromLiteralToken token =
getVariablesFromLiteral (fromJust $ getLiteralStringExt (const $ return " ") token)
-- Try to get referenced variables from a literal string like "$foo"
-- Ignores tons of cases like arithmetic evaluation and array indices.
-- >>> prop $ getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
getVariablesFromLiteral string =
map (!! 0) $ matchAllSubgroups variableRegex string
where
variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
-- |
-- Get the variable name from an expansion like ${var:-foo}
--
-- >>> prop $ getBracedReference "foo" == "foo"
-- >>> prop $ getBracedReference "#foo" == "foo"
-- >>> prop $ getBracedReference "#" == "#"
-- >>> prop $ getBracedReference "##" == "#"
-- >>> prop $ getBracedReference "#!" == "!"
-- >>> prop $ getBracedReference "!#" == "#"
-- >>> prop $ getBracedReference "!foo#?" == "foo"
-- >>> prop $ getBracedReference "foo-bar" == "foo"
-- >>> prop $ getBracedReference "foo:-bar" == "foo"
-- >>> prop $ getBracedReference "foo: -1" == "foo"
-- >>> prop $ getBracedReference "!os*" == ""
-- >>> prop $ getBracedReference "!os?bar**" == ""
-- >>> prop $ getBracedReference "foo[bar]" == "foo"
getBracedReference s = fromMaybe s $
nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
where
noPrefix = dropPrefix s
dropPrefix (c:rest) = if c `elem` "!#" then rest else c:rest
dropPrefix "" = ""
takeName s = do
let name = takeWhile isVariableChar s
guard . not $ null name
return name
getSpecial (c:_) =
if c `elem` "*@#?-$!" then return [c] else fail "not special"
getSpecial _ = fail "empty"
nameExpansion ('!':rest) = do -- e.g. ${!foo*bar*}
let suffix = dropWhile isVariableChar rest
guard $ suffix /= rest -- e.g. ${!@}
first <- suffix !!! 0
guard $ first `elem` "*?"
return ""
nameExpansion _ = Nothing
-- |
-- >>> prop $ getBracedModifier "foo:bar:baz" == ":bar:baz"
-- >>> prop $ getBracedModifier "!var:-foo" == ":-foo"
-- >>> prop $ getBracedModifier "foo[bar]" == "[bar]"
getBracedModifier s = fromMaybe "" . listToMaybe $ do
let var = getBracedReference s
a <- dropModifier s
dropPrefix var a
where
dropPrefix [] t = return t
dropPrefix (a:b) (c:d) | a == c = dropPrefix b d
dropPrefix _ _ = []
dropModifier (c:rest) | c `elem` "#!" = [rest, c:rest]
dropModifier x = [x]
-- Useful generic functions.
-- Run an action in a Maybe (or do nothing).
-- Example:
--
-- @
-- potentially $ do
-- s <- getLiteralString cmd
-- guard $ s `elem` ["--recursive", "-r"]
-- return $ warn .. "Something something recursive"
-- @
potentially :: Monad m => Maybe (m ()) -> m ()
potentially = fromMaybe (return ())
-- Get element 0 or a default. Like `head` but safe.
headOrDefault _ (a:_) = a
headOrDefault def _ = def
--- Get element n of a list, or Nothing. Like `!!` but safe.
(!!!) list i =
case drop i list of
[] -> Nothing
(r:_) -> Just r
-- Run a command if the shell is in the given list
whenShell l c = do
shell <- asks shellType
when (shell `elem` l ) c
filterByAnnotation asSpec params =
filter (not . shouldIgnore)
where
token = asScript asSpec
shouldIgnore note =
any (shouldIgnoreFor (getCode note)) $
getPath parents (T_Bang $ tcId note)
shouldIgnoreFor num (T_Annotation _ anns _) =
any hasNum anns
where
hasNum (DisableComment ts) = num == ts
hasNum _ = False
shouldIgnoreFor _ T_Include {} = not $ asCheckSourced asSpec
shouldIgnoreFor _ _ = False
parents = parentMap params
getCode = cCode . tcComment
-- Is this a ${#anything}, to get string length or array count?
isCountingReference (T_DollarBraced id token) =
case concat $ oversimplify token of
'#':_ -> True
_ -> False
isCountingReference _ = False
-- FIXME: doesn't handle ${a:+$var} vs ${a:+"$var"}
isQuotedAlternativeReference t =
case t of
T_DollarBraced _ _ ->
getBracedModifier (bracedString t) `matches` re
_ -> False
where
re = mkRegex "(^|\\]):?\\+"
-- getGnuOpts "erd:u:" will parse a SimpleCommand like
-- read -re -d : -u 3 bar
-- into
-- Just [("r", -re), ("e", -re), ("d", :), ("u", 3), ("", bar)]
-- where flags with arguments map to arguments, while others map to themselves.
-- Any unrecognized flag will result in Nothing.
getGnuOpts = getOpts getAllFlags
getBsdOpts = getOpts getLeadingFlags
getOpts :: (Token -> [(Token, String)]) -> String -> Token -> Maybe [(String, Token)]
getOpts flagTokenizer string cmd = process flags
where
flags = flagTokenizer cmd
flagList (c:':':rest) = ([c], True) : flagList rest
flagList (c:rest) = ([c], False) : flagList rest
flagList [] = []
flagMap = Map.fromList $ ("", False) : flagList string
process [] = return []
process [(token, flag)] = do
takesArg <- Map.lookup flag flagMap
guard $ not takesArg
return [(flag, token)]
process ((token1, flag1):rest2@((token2, flag2):rest)) = do
takesArg <- Map.lookup flag1 flagMap
if takesArg
then do
guard $ flag2 == ""
more <- process rest
return $ (flag1, token2) : more
else do
more <- process rest2
return $ (flag1, token1) : more