Parse the contents of unquoted here documents

ShellCheck/AST.hs

@@ -23,6 +23,9 @@ import qualified Text.Regex as Re
 
 data Id = Id Int deriving (Show, Eq, Ord)
 
+data Quoted = Quoted | Unquoted deriving (Show, Eq)
+data Dashed = Dashed | Undashed deriving (Show, Eq)
+
 data Token =
     TA_Base Id String Token
     | TA_Binary Id String Token Token
@@ -80,7 +83,7 @@ data Token =
     | T_GREATAND Id
     | T_Glob Id String
     | T_Greater Id
-    | T_HereDoc Id Bool Bool String String
+    | T_HereDoc Id Dashed Quoted String [Token]
     | T_HereString Id Token
     | T_If Id
     | T_IfExpression Id [([Token],[Token])] [Token]
@@ -208,6 +211,7 @@ analyze f g i t =
     delve (T_Condition id typ token) = d1 token $ T_Condition id typ
     delve (T_Extglob id str l) = dl l $ T_Extglob id str
     delve (T_DollarBraced id op) = d1 op $ T_DollarBraced id
+    delve (T_HereDoc id d q str l) = dl l $ T_HereDoc id d q str
 
     delve (TC_And id typ str t1 t2) = d2 t1 t2 $ TC_And id typ str
     delve (TC_Or id typ str t1 t2) = d2 t1 t2 $ TC_Or id typ str

ShellCheck/Analytics.hs

@@ -549,6 +549,7 @@ prop_checkUnquotedExpansions3a= verifyTree checkUnquotedExpansions "[ ! $(foo) ]
 prop_checkUnquotedExpansions4 = verifyNotTree checkUnquotedExpansions "[[ $(foo) == cow ]]"
 prop_checkUnquotedExpansions5 = verifyNotTree checkUnquotedExpansions "for f in $(cmd); do echo $f; done"
 prop_checkUnquotedExpansions6 = verifyNotTree checkUnquotedExpansions "$(cmd)"
+prop_checkUnquotedExpansions7 = verifyNotTree checkUnquotedExpansions "cat << foo\n$(ls)\nfoo"
 checkUnquotedExpansions t tree =
     check t
   where
@@ -870,6 +871,7 @@ inUnquotableContext tree t =
         T_Redirecting _ _ _ -> or $ map (isCommand t) ["local", "declare"]
         T_DoubleQuoted _ _ -> True
         T_CaseExpression _ _ _ -> True
+        T_HereDoc _ _ _ _ _ -> True
         T_ForIn _ _ _ _ -> True -- Pragmatically assume it's desirable here
         x -> case Map.lookup (getId x) tree of
                 Nothing -> False
@@ -1296,8 +1298,8 @@ checkSshHereDoc (T_Redirecting _ redirs cmd)
     mapM_ checkHereDoc redirs
   where
     hasVariables = mkRegex "[`$]"
-    checkHereDoc (T_FdRedirect _ _ (T_HereDoc id _ False token str))
-        | isJust $ matchRegex hasVariables str =
+    checkHereDoc (T_FdRedirect _ _ (T_HereDoc id _ Unquoted token tokens))
+        | not (all isConstant tokens) =
         warn id $ "Quote '" ++ token ++ "' to make here document expansions happen on the server side rather than on the client."
     checkHereDoc _ = return ()
 checkSshHereDoc _ = return ()

ShellCheck/Parser.hs

@@ -681,10 +681,15 @@ readBackTicked = called "backtick expansion" $ do
     subStart <- getPosition
     subString <- readGenericLiteral (char '`')
     char '`'
+    -- Result positions may be off due to escapes
     result <- subParse subStart readCompoundList (unEscape subString)
     return $ T_Backticked id result
   where
-    -- Position may be off due to escapes
+    unEscape [] = []
+    unEscape ('\\':x:rest) | x `elem` "\"$`\\" = x : unEscape rest
+    unEscape ('\\':'\n':rest) = unEscape rest
+    unEscape (c:rest) = c : unEscape rest
+
 subParse pos parser input = do
     lastPosition <- getPosition
     lastInput <- getInput
@@ -694,11 +699,6 @@ readBackTicked = called "backtick expansion" $ do
     setInput lastInput
     setPosition lastPosition
     return result
-    unEscape [] = []
-    unEscape ('\\':x:rest) | x `elem` "\"$`\\" = x : unEscape rest
-    unEscape ('\\':'\n':rest) = unEscape rest
-    unEscape (c:rest) = c : unEscape rest
-
 
 prop_readDoubleQuoted = isOk readDoubleQuoted "\"Hello $FOO\""
 prop_readDoubleQuoted2 = isOk readDoubleQuoted "\"$'\""
@@ -969,7 +969,7 @@ readHereDoc = called "here document" $ do
     fid <- getNextId
     pos <- getPosition
     try $ string "<<"
-    dashed <- (char '-' >> return True) <|> return False
+    dashed <- (char '-' >> return Dashed) <|> return Undashed
     tokenPosition <- getPosition
     sp <- spacing
     optional $ do
@@ -977,24 +977,43 @@ readHereDoc = called "here document" $ do
         let message = "Shells are space sensitive. Use '< <(cmd)', not '<<" ++ sp ++ "(cmd)'."
         parseProblemAt pos ErrorC message
     hid <- getNextId
-    (quoted, endToken) <- (readNormalLiteral "" >>= (\x -> return (False, stripLiteral x)) )
-                            <|> (readDoubleQuotedLiteral >>= return . (\x -> (True, stripLiteral x)))
-                            <|> (readSingleQuotedLiteral >>= return . (\x -> (True, x)))
+    (quoted, endToken) <- (readNormalLiteral "" >>= (\x -> return (Unquoted, stripLiteral x)) )
+                            <|> (readDoubleQuotedLiteral >>= return . (\x -> (Quoted, stripLiteral x)))
+                            <|> (readSingleQuotedLiteral >>= return . (\x -> (Quoted, x)))
     spacing
 
-    hereInfo <- anyChar `reluctantlyTill` (linefeed >> spacing >> (string endToken) >> (disregard whitespace <|> eof))
+    startPos <- getPosition
+    hereData <- anyChar `reluctantlyTill` (linefeed >> spacing >> (string endToken) >> (disregard whitespace <|> eof))
 
     do
         linefeed
         spaces <- spacing
-        verifyHereDoc dashed quoted spaces hereInfo
-        token <- string endToken
-        return $ T_FdRedirect fid "" $ T_HereDoc hid dashed quoted endToken hereInfo
-     `attempting` (eof >> debugHereDoc tokenPosition endToken hereInfo)
+        verifyHereDoc dashed quoted spaces hereData
+        string endToken
+        parsedData <- parseHereData quoted startPos hereData
+        return $ T_FdRedirect fid "" $ T_HereDoc hid dashed quoted endToken parsedData
+     `attempting` (eof >> debugHereDoc tokenPosition endToken hereData)
+
+  where
+    parseHereData Quoted startPos hereData = do
+        id <- getNextIdAt startPos
+        return $ [T_Literal id hereData]
+
+    parseHereData Unquoted startPos hereData = do
+        subParse startPos readHereData hereData
+
+    readHereData = many $ readNormalDollar <|> readBackTicked <|> readHereLiteral
+
+    readHereLiteral = do
+        id <- getNextId
+        chars <- anyChar `reluctantlyTill1` oneOf "`$"
+        return $ T_Literal id chars
 
     verifyHereDoc dashed quoted spacing hereInfo = do
-    when (not dashed && spacing /= "") $ parseNote ErrorC "Use <<- instead of << if you want to indent the end token."
-    when (dashed && filter (/= '\t') spacing /= "" ) $ parseNote ErrorC "When using <<-, you can only indent with tabs."
+        when (dashed == Undashed && spacing /= "") $
+            parseNote ErrorC "Use <<- instead of << if you want to indent the end token."
+        when (dashed == Dashed && filter (/= '\t') spacing /= "" ) $
+            parseNote ErrorC "When using <<-, you can only indent with tabs."
         return ()
 
     debugHereDoc pos endToken doc =