Drop attoparsec/text dependencies

Signed-off-by: hololeap <hololeap@users.noreply.github.com>

ShellCheck.cabal

@@ -93,6 +93,7 @@ library
       ShellCheck.Formatter.Quiet
       ShellCheck.Interface
       ShellCheck.Parser
+      ShellCheck.PortageVariables
       ShellCheck.Prelude
       ShellCheck.Regex
     other-modules:

shellcheck.1.md

@@ -87,8 +87,9 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
 
 :   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *dash* and *ksh*.
     The default is to deduce the shell from the file's `shell` directive,
-    shebang, or `.bash/.bats/.dash/.ksh` extension, in that order. *sh* refers to
-    POSIX `sh` (not the system's), and will warn of portability issues.
+    shebang, or `.bash/.bats/.dash/.ksh/.ebuild/.eclass` extension, in that
+    order. *sh* refers to POSIX `sh` (not the system's), and will warn of
+    portability issues.
 
 **-S**\ *SEVERITY*,\ **--severity=***severity*
 

shellcheck.hs

@@ -21,6 +21,7 @@ import qualified ShellCheck.Analyzer
 import           ShellCheck.Checker
 import           ShellCheck.Data
 import           ShellCheck.Interface
+import           ShellCheck.PortageVariables
 import           ShellCheck.Regex
 
 import qualified ShellCheck.Formatter.CheckStyle
@@ -396,10 +397,12 @@ ioInterface options files = do
     inputs <- mapM normalize files
     cache <- newIORef emptyCache
     configCache <- newIORef ("", Nothing)
+    portageVars <- newIORef Nothing
     return (newSystemInterface :: SystemInterface IO) {
         siReadFile = get cache inputs,
         siFindSource = findSourceFile inputs (sourcePaths options),
-        siGetConfig = getConfig configCache
+        siGetConfig = getConfig configCache,
+        siGetPortageVariables = getOrLoadPortage portageVars
     }
   where
     emptyCache :: Map.Map FilePath String
@@ -523,6 +526,21 @@ ioInterface options files = do
                 ("SCRIPTDIR":rest) -> joinPath (scriptdir:rest)
                 _ -> str
 
+    getOrLoadPortage cache = do
+        x <- readIORef cache
+        case x of
+            Just m -> do
+                return m
+            Nothing -> do
+                vars <- readPortageVariables `catch` handler
+                writeIORef cache $ Just vars
+                return vars
+      where
+        handler :: IOException -> IO (Map.Map String [String])
+        handler e = do
+            hPutStrLn stderr $ "Error finding portage repos, eclass definitions will be ignored: " ++ show e
+            return $ Map.empty
+
 inputFile file = do
     (handle, shouldCache) <-
             if file == "-"

src/ShellCheck/ASTLib.hs

@@ -36,8 +36,6 @@ import Numeric (showHex)
 
 import Test.QuickCheck
 
-arguments (T_SimpleCommand _ _ (cmd:args)) = args
-
 -- Is this a type of loop?
 isLoop t = case t of
         T_WhileExpression {} -> True
@@ -546,17 +544,16 @@ getCommandNameAndToken direct t = fromMaybe (Nothing, t) $ do
                     return t
                 _ -> fail ""
 
--- If a command substitution is a single command, get its name.
---  $(date +%s) = Just "date"
-getCommandNameFromExpansion :: Token -> Maybe String
-getCommandNameFromExpansion t =
+-- If a command substitution is a single SimpleCommand, return it.
+getSimpleCommandFromExpansion :: Token -> Maybe Token
+getSimpleCommandFromExpansion t =
     case t of
         T_DollarExpansion _ [c] -> extract c
         T_Backticked _ [c] -> extract c
         T_DollarBraceCommandExpansion _ [c] -> extract c
         _ -> Nothing
   where
-    extract (T_Pipeline _ _ [cmd]) = getCommandName cmd
+    extract (T_Pipeline _ _ [c]) = getCommand c
     extract _ = Nothing
 
 -- Get the basename of a token representing a command
@@ -564,6 +561,10 @@ getCommandBasename = fmap basename . getCommandName
 
 basename = reverse . takeWhile (/= '/') . reverse
 
+-- Get the arguments to a command
+arguments (T_SimpleCommand _ _ (cmd:args)) = args
+arguments t = maybe [] arguments (getCommand t)
+
 isAssignment t =
     case t of
         T_Redirecting _ _ w -> isAssignment w
@@ -912,5 +913,20 @@ getEnableDirectives root =
         T_Annotation _ list _ -> [s | EnableComment s <- list]
         _ -> []
 
+
+commandExpansionShouldBeSplit t = do
+    cmd <- getSimpleCommandFromExpansion t
+    name <- getCommandName cmd
+    case () of
+        -- Should probably be split
+        _ | name `elem` ["seq", "pgrep"] -> return True
+        -- Portage macros that return a single word or nothing
+        _ | name `elem` ["usev", "use_with", "use_enable"] -> return True
+        -- Portage macros that are fine as long as the arguments have no spaces
+        _ | name `elem` ["usex", "meson_use", "meson_feature"] -> do
+            return . not $ any (' ' `elem`) $ map (getLiteralStringDef " ") $ arguments cmd
+        _ -> Nothing
+
+
 return []
 runTests = $quickCheckAll

src/ShellCheck/Analytics.hs

@@ -314,7 +314,7 @@ runAndGetComments f s = do
         let pr = pScript s
         root <- prRoot pr
         let spec = defaultSpec pr
-        let params = makeParameters spec
+        let params = runIdentity $ makeParameters (mockedSystemInterface []) spec
         return $
             filterByAnnotation spec params $
                 f params root
@@ -792,6 +792,11 @@ prop_checkUnquotedExpansions8 = verifyNot checkUnquotedExpansions "set -- $(seq
 prop_checkUnquotedExpansions9 = verifyNot checkUnquotedExpansions "echo foo `# inline comment`"
 prop_checkUnquotedExpansions10 = verify checkUnquotedExpansions "#!/bin/sh\nexport var=$(val)"
 prop_checkUnquotedExpansions11 = verifyNot checkUnquotedExpansions "ps -p $(pgrep foo)"
+prop_checkUnquotedExpansions12 = verify checkUnquotedExpansions "#!/bin/sh\nexport var=$(val)"
+prop_checkUnquotedExpansions13 = verifyNot checkUnquotedExpansions "echo $(usev X)"
+prop_checkUnquotedExpansions14 = verifyNot checkUnquotedExpansions "echo $(usex X \"\" Y)"
+prop_checkUnquotedExpansions15 = verify checkUnquotedExpansions "echo $(usex X \"Y Z\" W)"
+
 checkUnquotedExpansions params =
     check
   where
@@ -801,12 +806,9 @@ checkUnquotedExpansions params =
     check _ = return ()
     tree = parentMap params
     examine t contents =
-        unless (null contents || shouldBeSplit t || isQuoteFree (shellType params) tree t || usedAsCommandName tree t) $
+        unless (null contents || commandExpansionShouldBeSplit t == Just True || isQuoteFree (shellType params) tree t || usedAsCommandName tree t) $
             warn (getId t) 2046 "Quote this to prevent word splitting."
 
-    shouldBeSplit t =
-        getCommandNameFromExpansion t `elem` [Just "seq", Just "pgrep"]
-
 
 prop_checkRedirectToSame = verify checkRedirectToSame "cat foo > foo"
 prop_checkRedirectToSame2 = verify checkRedirectToSame "cat lol | sed -e 's/a/b/g' > lol"
@@ -1037,9 +1039,6 @@ checkStderrRedirect params redir@(T_Redirecting _ [
 
 checkStderrRedirect _ _ = return ()
 
-lt x = trace ("Tracing " ++ show x) x -- STRIP
-ltt t = trace ("Tracing " ++ show t)  -- STRIP
-
 
 prop_checkSingleQuotedVariables  = verify checkSingleQuotedVariables "echo '$foo'"
 prop_checkSingleQuotedVariables2 = verify checkSingleQuotedVariables "echo 'lol$1.jpg'"
@@ -1070,6 +1069,10 @@ prop_checkSingleQuotedVariables22 = verifyNot checkSingleQuotedVariables "jq '$_
 prop_checkSingleQuotedVariables23 = verifyNot checkSingleQuotedVariables "command jq '$__loc__'"
 prop_checkSingleQuotedVariables24 = verifyNot checkSingleQuotedVariables "exec jq '$__loc__'"
 prop_checkSingleQuotedVariables25 = verifyNot checkSingleQuotedVariables "exec -c -a foo jq '$__loc__'"
+prop_checkSingleQuotedVariablesCros1 = verifyNot checkSingleQuotedVariables "python_gen_any_dep 'dev-python/pyyaml[${PYTHON_USEDEP}]'"
+prop_checkSingleQuotedVariablesCros2 = verifyNot checkSingleQuotedVariables "python_gen_cond_dep 'dev-python/unittest2[${PYTHON_USEDEP}]' python2_7 pypy"
+prop_checkSingleQuotedVariablesCros3 = verifyNot checkSingleQuotedVariables "version_format_string '${PN}_source_$1_$2-$3_$4'"
+
 
 
 checkSingleQuotedVariables params t@(T_SingleQuoted id s) =
@@ -1109,6 +1112,9 @@ checkSingleQuotedVariables params t@(T_SingleQuoted id s) =
                 ,"git filter-branch"
                 ,"mumps -run %XCMD"
                 ,"mumps -run LOOP%XCMD"
+                ,"python_gen_any_dep"
+                ,"python_gen_cond_dep"
+                ,"version_format_string"
                 ]
             || "awk" `isSuffixOf` commandName
             || "perl" `isPrefixOf` commandName
@@ -2392,7 +2398,7 @@ checkUnusedAssignments params t = execWriter (mapM_ warnFor unused)
                 name ++ " appears unused. Verify use (or export if used externally)."
 
     stripSuffix = takeWhile isVariableChar
-    defaultMap = Map.fromList $ zip internalVariables $ repeat ()
+    defaultMap = Map.fromList $ zip (internalVariables ++ additionalKnownVariables params) $ repeat ()
 
 prop_checkUnassignedReferences1 = verifyTree checkUnassignedReferences "echo $foo"
 prop_checkUnassignedReferences2 = verifyNotTree checkUnassignedReferences "foo=hello; echo $foo"
@@ -2451,7 +2457,7 @@ checkUnassignedReferences = checkUnassignedReferences' False
 checkUnassignedReferences' includeGlobals params t = warnings
   where
     (readMap, writeMap) = execState (mapM tally $ variableFlow params) (Map.empty, Map.empty)
-    defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) internalVariables
+    defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) (internalVariables ++ additionalKnownVariables params)
 
     tally (Assignment (_, _, name, _))  =
         modify (\(read, written) -> (read, Map.insert name () written))
@@ -3509,6 +3515,7 @@ prop_checkSplittingInArrays5 = verifyNot checkSplittingInArrays "a=( $! $$ $# )"
 prop_checkSplittingInArrays6 = verifyNot checkSplittingInArrays "a=( ${#arr[@]} )"
 prop_checkSplittingInArrays7 = verifyNot checkSplittingInArrays "a=( foo{1,2} )"
 prop_checkSplittingInArrays8 = verifyNot checkSplittingInArrays "a=( * )"
+prop_checkSplittingInArrays9 = verifyNot checkSplittingInArrays "a=( $(use_enable foo) )"
 checkSplittingInArrays params t =
     case t of
         T_Array _ elements -> mapM_ check elements
@@ -3518,6 +3525,7 @@ checkSplittingInArrays params t =
         T_NormalWord _ parts -> mapM_ checkPart parts
         _ -> return ()
     checkPart part = case part of
+        _ | commandExpansionShouldBeSplit part == Just True -> return ()
         T_DollarExpansion id _ -> forCommand id
         T_DollarBraceCommandExpansion id _ -> forCommand id
         T_Backticked id _ -> forCommand id

src/ShellCheck/Analyzer.hs

@@ -31,14 +31,14 @@ import qualified ShellCheck.Checks.ShellSupport
 
 
 -- TODO: Clean up the cruft this is layered on
-analyzeScript :: AnalysisSpec -> AnalysisResult
-analyzeScript spec = newAnalysisResult {
+analyzeScript :: Monad m => SystemInterface m -> AnalysisSpec -> m AnalysisResult
+analyzeScript sys spec = do
+    params <- makeParameters sys spec
+    return $ newAnalysisResult {
             arComments =
                 filterByAnnotation spec params . nub $
                     runChecker params (checkers spec params)
         }
-  where
-    params = makeParameters spec
 
 checkers spec params = mconcat $ map ($ params) [
     ShellCheck.Analytics.checker spec,

src/ShellCheck/AnalyzerLib.hs

@@ -88,6 +88,8 @@ data Parameters = Parameters {
     hasSetE            :: Bool,
     -- Whether this script has 'set -o pipefail' anywhere.
     hasPipefail        :: Bool,
+    -- Whether this script is an Ebuild file.
+    isPortage          :: Bool,
     -- A linear (bad) analysis of data flow
     variableFlow       :: [StackData],
     -- A map from Id to Token
@@ -103,9 +105,12 @@ data Parameters = Parameters {
     -- map from token id to start and end position
     tokenPositions     :: Map.Map Id (Position, Position),
     -- Result from Control Flow Graph analysis (including data flow analysis)
-    cfgAnalysis :: CF.CFGAnalysis
+    cfgAnalysis :: CF.CFGAnalysis,
+    -- A set of additional variables known to be set (TODO: make this more general?)
+    additionalKnownVariables :: [String]
     } deriving (Show)
 
+
 -- TODO: Cache results of common AST ops here
 data Cache = Cache {}
 
@@ -152,7 +157,7 @@ producesComments c s = do
         let pr = pScript s
         prRoot pr
         let spec = defaultSpec pr
-        let params = makeParameters spec
+        let params = runIdentity $ makeParameters (mockedSystemInterface []) spec
         return . not . null $ filterByAnnotation spec params $ runChecker params c
 
 makeComment :: Severity -> Id -> Code -> String -> TokenComment
@@ -196,11 +201,25 @@ makeCommentWithFix severity id code str fix =
         }
     in force withFix
 
-makeParameters spec = params
+makeParameters :: Monad m => SystemInterface m -> AnalysisSpec -> m Parameters
+makeParameters sys spec = do
+    extraVars <-
+        if asIsPortage spec
+        then do
+            vars <- siGetPortageVariables sys
+            let classes = getInheritedEclasses root
+            return $ concatMap (\c -> Map.findWithDefault [] c vars) classes
+        else
+            return []
+
+    return $ makeParams extraVars
+  where
+    shell = fromMaybe (determineShell (asFallbackShell spec) root) $ asShellType spec
+    makeParams extraVars = params
       where
         params = Parameters {
             rootNode = root,
-        shellType = fromMaybe (determineShell (asFallbackShell spec) root) $ asShellType spec,
+            shellType = shell,
             hasSetE = containsSetE root,
             hasLastpipe =
                 case shellType params of
@@ -221,15 +240,18 @@ makeParameters spec = params
                     Sh   -> True
                     Ksh  -> isOptionSet "pipefail" root,
             shellTypeSpecified = isJust (asShellType spec) || isJust (asFallbackShell spec),
+            isPortage = asIsPortage spec,
             idMap = getTokenMap root,
             parentMap = getParentTree root,
             variableFlow = getVariableFlow params root,
             tokenPositions = asTokenPositions spec,
-        cfgAnalysis = CF.analyzeControlFlow cfParams root
+            cfgAnalysis = CF.analyzeControlFlow cfParams root,
+            additionalKnownVariables = extraVars
         }
         cfParams = CF.CFGParameters {
             CF.cfLastpipe = hasLastpipe params,
-        CF.cfPipefail = hasPipefail params
+            CF.cfPipefail = hasPipefail params,
+            CF.cfAdditionalInitialVariables = additionalKnownVariables params
         }
     root = asScript spec
 
@@ -582,6 +604,17 @@ getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Litera
                 head:_ -> map (\x -> (base, head, x)) $ getVariablesFromLiteralToken head
                 _ -> []
         "alias" -> [(base, token, name) | token <- rest, name <- getVariablesFromLiteralToken token]
+
+        -- tc-export makes a list of toolchain variables available, similar to export.
+        -- Usage tc-export CC CXX
+        "tc-export" -> concatMap getReference rest
+
+        -- tc-export_build_env exports the listed variables plus a bunch of BUILD_XX variables.
+        -- Usage tc-export_build_env BUILD_CC
+        "tc-export_build_env" ->
+            concatMap getReference rest
+                ++ [ (base, base, v) | v <- portageBuildEnvVariables ]
+
         _ -> []
   where
     forDeclare =
@@ -653,6 +686,16 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
         "DEFINE_integer" -> maybeToList $ getFlagVariable rest
         "DEFINE_string" -> maybeToList $ getFlagVariable rest
 
+        "tc-export" -> concatMap getModifierParamString rest
+
+        -- tc-export_build_env exports the listed variables plus a bunch of BUILD_XX variables.
+        -- Usage tc-export_build_env BUILD_CC
+        "tc-export_build_env" ->
+            concatMap getModifierParamString rest
+                ++ [ (base, base, var, DataString $ SourceExternal) |
+                        var <- ["BUILD_" ++ x, x ++ "_FOR_BUILD" ],
+                        x <- portageBuildEnvVariables ]
+
         _ -> []
   where
     flags = map snd $ getAllFlags base
@@ -918,6 +961,13 @@ modifiesVariable params token name =
             Assignment (_, _, n, source) -> isTrueAssignmentSource source && n == name
             _ -> False
 
+-- Ebuild files inherit eclasses using 'inherit myclass1 myclass2'
+getInheritedEclasses :: Token -> [String]
+getInheritedEclasses root = execWriter $ doAnalysis findInheritedEclasses root
+  where
+    findInheritedEclasses cmd
+        | cmd `isCommand` "inherit" = tell $ catMaybes $ getLiteralString <$> (arguments cmd)
+    findInheritedEclasses _ = return ()
 
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/CFG.hs

@@ -167,7 +167,9 @@ data CFGParameters = CFGParameters {
     -- Whether the last element in a pipeline runs in the current shell
     cfLastpipe :: Bool,
     -- Whether all elements in a pipeline count towards the exit status
-    cfPipefail :: Bool
+    cfPipefail :: Bool,
+    -- Additional variables to consider defined
+    cfAdditionalInitialVariables :: [String]
 }
 
 data CFGResult = CFGResult {

src/ShellCheck/CFGAnalysis.hs

@@ -197,12 +197,13 @@ unreachableState = modified newInternalState {
 }
 
 -- The default state we assume we get from the environment
-createEnvironmentState :: InternalState
-createEnvironmentState = do
+createEnvironmentState :: CFGParameters -> InternalState
+createEnvironmentState params = do
     foldl' (flip ($)) newInternalState $ concat [
         addVars Data.internalVariables unknownVariableState,
         addVars Data.variablesWithoutSpaces spacelessVariableState,
-        addVars Data.specialIntegerVariables integerVariableState
+        addVars Data.specialIntegerVariables integerVariableState,
+        addVars (cfAdditionalInitialVariables params) unknownVariableState
         ]
   where
     addVars names val = map (\name -> insertGlobal name val) names
@@ -1344,7 +1345,7 @@ analyzeControlFlow params t =
         runST $ f cfg entry exit
   where
     f cfg entry exit = do
-        let env = createEnvironmentState
+        let env = createEnvironmentState params
         ctx <- newCtx $ cfGraph cfg
         -- Do a dataflow analysis starting on the root node
         exitState <- runRoot ctx env entry exit

src/ShellCheck/Checker.hs

@@ -25,6 +25,7 @@ import ShellCheck.ASTLib
 import ShellCheck.Interface
 import ShellCheck.Parser
 
+import Data.Char
 import Data.Either
 import Data.Functor
 import Data.List
@@ -54,6 +55,8 @@ shellFromFilename filename = listToMaybe candidates
     shellExtensions = [(".ksh", Ksh)
                       ,(".bash", Bash)
                       ,(".bats", Bash)
+                      ,(".ebuild", Bash)
+                      ,(".eclass", Bash)
                       ,(".dash", Dash)]
                       -- The `.sh` is too generic to determine the shell:
                       -- We fallback to Bash in this case and emit SC2148 if there is no shebang
@@ -84,18 +87,24 @@ checkScript sys spec = do
                     asShellType = csShellTypeOverride spec,
                     asFallbackShell = shellFromFilename $ csFilename spec,
                     asCheckSourced = csCheckSourced spec,
+                    asIsPortage = isPortage $ csFilename spec,
                     asExecutionMode = Executed,
                     asTokenPositions = tokenPositions,
                     asOptionalChecks = getEnableDirectives root ++ csOptionalChecks spec
                 } where as = newAnalysisSpec root
-        let analysisMessages =
-                maybe []
-                    (arComments . analyzeScript . analysisSpec)
-                        $ prRoot result
+        let getAnalysisMessages =
+                case prRoot result of
+                    Just root -> arComments <$> (analyzeScript sys $ analysisSpec root)
+                    Nothing -> return []
         let translator = tokenToPosition tokenPositions
+        analysisMessages <- getAnalysisMessages
         return . nub . sortMessages . filter shouldInclude $
             (parseMessages ++ map translator analysisMessages)
 
+    isPortage filename =
+        let f = map toLower filename in
+            ".ebuild" `isSuffixOf` f || ".eclass" `isSuffixOf` f
+
     shouldInclude pc =
             severity <= csMinSeverity spec &&
             case csIncludedWarnings spec of

src/ShellCheck/Data.hs

@@ -62,8 +62,92 @@ internalVariables = [
     , "FLAGS_ARGC", "FLAGS_ARGV", "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_HELP",
     "FLAGS_PARENT", "FLAGS_RESERVED", "FLAGS_TRUE", "FLAGS_VERSION",
     "flags_error", "flags_return"
+  ] ++ portageManualInternalVariables
+
+
+portageManualInternalVariables = [
+    -- toolchain settings
+    "CFLAGS", "CXXFLAGS", "CPPFLAGS", "LDFLAGS", "FFLAGS", "FCFLAGS",
+    "CBUILD", "CHOST", "MAKEOPTS",
+    -- TODO: Delete these if we can handle `tc-export CC` implicit export.
+    "CC", "CPP", "CXX",
+
+    -- portage internals
+    "EBUILD_PHASE", "EBUILD_SH_ARGS", "EMERGE_FROM", "FILESDIR",
+    "MERGE_TYPE", "PM_EBUILD_HOOK_DIR", "PORTAGE_ACTUAL_DISTDIR",
+    "PORTAGE_ARCHLIST", "PORTAGE_BASHRC", "PORTAGE_BINPKG_FILE",
+    "PORTAGE_BINPKG_TAR_OPTS", "PORTAGE_BINPKG_TMPFILE", "PORTAGE_BIN_PATH",
+    "PORTAGE_BUILDDIR", "PORTAGE_BUILD_GROUP", "PORTAGE_BUILD_USER",
+    "PORTAGE_BUNZIP2_COMMAND", "PORTAGE_BZIP2_COMMAND", "PORTAGE_COLORMAP",
+    "PORTAGE_CONFIGROOT", "PORTAGE_DEBUG", "PORTAGE_DEPCACHEDIR",
+    "PORTAGE_EBUILD_EXIT_FILE", "PORTAGE_ECLASS_LOCATIONS", "PORTAGE_GID",
+    "PORTAGE_GRPNAME", "PORTAGE_INST_GID", "PORTAGE_INST_UID",
+    "PORTAGE_INTERNAL_CALLER", "PORTAGE_IPC_DAEMON", "PORTAGE_IUSE",
+    "PORTAGE_LOG_FILE", "PORTAGE_MUTABLE_FILTERED_VARS",
+    "PORTAGE_OVERRIDE_EPREFIX", "PORTAGE_PYM_PATH", "PORTAGE_PYTHON",
+    "PORTAGE_PYTHONPATH", "PORTAGE_READONLY_METADATA", "PORTAGE_READONLY_VARS",
+    "PORTAGE_REPO_NAME", "PORTAGE_REPOSITORIES", "PORTAGE_RESTRICT",
+    "PORTAGE_SAVED_READONLY_VARS", "PORTAGE_SIGPIPE_STATUS", "PORTAGE_TMPDIR",
+    "PORTAGE_UPDATE_ENV", "PORTAGE_USERNAME", "PORTAGE_VERBOSE",
+    "PORTAGE_WORKDIR_MODE", "PORTAGE_XATTR_EXCLUDE", "REPLACING_VERSIONS",
+    "REPLACED_BY_VERSION", "__PORTAGE_HELPER", "__PORTAGE_TEST_HARDLINK_LOCKS",
+
+    -- generic ebuilds
+    "A", "ARCH", "BDEPEND", "BOARD_USE", "BROOT", "CATEGORY", "D",
+    "DEFINED_PHASES", "DEPEND", "DESCRIPTION", "DISTDIR", "DOCS", "EAPI",
+    "ECLASS", "ED", "EPREFIX", "EROOT", "ESYSROOT", "EXTRA_ECONF",
+    "EXTRA_EINSTALL", "EXTRA_MAKE", "FEATURES", "FILESDIR", "HOME", "HOMEPAGE",
+    "HTML_DOCS", "INHERITED", "IUSE", "KEYWORDS", "LICENSE", "P", "PATCHES",
+    "PDEPEND", "PF", "PKG_INSTALL_MASK", "PKGUSE", "PN", "PR", "PROPERTIES",
+    "PROVIDES_EXCLUDE", "PV", "PVR", "QA_AM_MAINTAINER_MODE",
+    "QA_CONFIGURE_OPTIONS", "QA_DESKTOP_FILE", "QA_DT_NEEDED", "QA_EXECSTACK",
+    "QA_FLAGS_IGNORED", "QA_MULTILIB_PATHS", "QA_PREBUILT", "QA_PRESTRIPPED",
+    "QA_SONAME", "QA_SONAME_NO_SYMLINK", "QA_TEXTRELS", "QA_WX_LOAD", "RDEPEND",
+    "REPOSITORY", "REQUIRED_USE", "REQUIRES_EXCLUDE", "RESTRICT", "ROOT", "S",
+    "SLOT", "SRC_TEST", "SRC_URI", "STRIP_MASK", "SUBSLOT", "SYSROOT", "T",
+    "WORKDIR",
+
+    -- autotest.eclass declared incorrectly
+    "AUTOTEST_CLIENT_TESTS", "AUTOTEST_CLIENT_SITE_TESTS",
+    "AUTOTEST_SERVER_TESTS", "AUTOTEST_SERVER_SITE_TESTS", "AUTOTEST_CONFIG",
+    "AUTOTEST_DEPS", "AUTOTEST_PROFILERS", "AUTOTEST_CONFIG_LIST",
+    "AUTOTEST_DEPS_LIST", "AUTOTEST_PROFILERS_LIST",
+
+    -- cros-board.eclass declared incorrectly
+    "CROS_BOARDS",
+
+    -- Undeclared cros-kernel2 vars
+    "AFDO_PROFILE_VERSION",
+
+    -- haskell-cabal.eclass declared incorrectly
+    "CABAL_FEATURES",
+
+    -- Undeclared haskell-cabal.eclass vars
+    "CABAL_CORE_LIB_GHC_PV",
+
+    -- Undeclared readme.gentoo.eclass vars
+    "DOC_CONTENTS",
+
+    -- Backwards compatibility perl-module.eclass vars
+    "MODULE_AUTHOR", "MODULE_VERSION",
+
+    -- Undeclared perl-module.eclass vars
+    "mydoc",
+
+    -- python-utils-r1.eclass declared incorrectly
+    "RESTRICT_PYTHON_ABIS", "PYTHON_MODNAME",
+
+    -- ABI variables
+    "ABI", "DEFAULT_ABI",
+
+    -- AFDO variables
+    "AFDO_LOCATION",
+
+    -- Linguas
+    "LINGUAS"
   ]
 
+
 specialIntegerVariables = [
     "$", "?", "!", "#"
   ]
@@ -90,7 +174,9 @@ unbracedVariables = specialVariables ++ [
 arrayVariables = [
     "BASH_ALIASES", "BASH_ARGC", "BASH_ARGV", "BASH_CMDS", "BASH_LINENO",
     "BASH_REMATCH", "BASH_SOURCE", "BASH_VERSINFO", "COMP_WORDS", "COPROC",
-    "DIRSTACK", "FUNCNAME", "GROUPS", "MAPFILE", "PIPESTATUS", "COMPREPLY"
+    "DIRSTACK", "FUNCNAME", "GROUPS", "MAPFILE", "PIPESTATUS", "COMPREPLY",
+    -- For Portage
+    "PATCHES"
   ]
 
 commonCommands = [
@@ -150,6 +236,11 @@ unaryTestOps = [
     "-o", "-v", "-R"
   ]
 
+-- Variables inspected by Portage tc-export_build_env
+portageBuildEnvVariables = [
+    "CFLAGS", "CXXFLAGS", "CPPFLAGS", "LDFLAGS"
+  ]
+
 shellForExecutable :: String -> Maybe Shell
 shellForExecutable name =
     case name of

src/ShellCheck/Debug.hs

@@ -117,7 +117,8 @@ dummySystemInterface = mockedSystemInterface [
 cfgParams :: CFGParameters
 cfgParams = CFGParameters {
     cfLastpipe = False,
-    cfPipefail = False
+    cfPipefail = False,
+    cfAdditionalInitialVariables = []
 }
 
 -- An example script to play with

src/ShellCheck/Interface.hs

@@ -25,7 +25,7 @@ module ShellCheck.Interface
     , CheckResult(crFilename, crComments)
     , ParseSpec(psFilename, psScript, psCheckSourced, psIgnoreRC, psShellTypeOverride)
     , ParseResult(prComments, prTokenPositions, prRoot)
-    , AnalysisSpec(asScript, asShellType, asFallbackShell, asExecutionMode, asCheckSourced, asTokenPositions, asOptionalChecks)
+    , AnalysisSpec(..)
     , AnalysisResult(arComments)
     , FormatterOptions(foColorOption, foWikiLinkCount)
     , Shell(Ksh, Sh, Bash, Dash)
@@ -87,7 +87,9 @@ data SystemInterface m = SystemInterface {
     --   find the sourced file
     siFindSource :: String -> Maybe Bool -> [String] -> String -> m FilePath,
     -- | Get the configuration file (name, contents) for a filename
-    siGetConfig :: String -> m (Maybe (FilePath, String))
+    siGetConfig :: String -> m (Maybe (FilePath, String)),
+    -- | Look up Portage Eclass variables
+    siGetPortageVariables :: m (Map.Map String [String])
 }
 
 -- ShellCheck input and output
@@ -141,7 +143,8 @@ newSystemInterface =
     SystemInterface {
         siReadFile = \_ _ -> return $ Left "Not implemented",
         siFindSource = \_ _ _ name -> return name,
-        siGetConfig = \_ -> return Nothing
+        siGetConfig = \_ -> return Nothing,
+        siGetPortageVariables = return Map.empty
     }
 
 -- Parser input and output
@@ -173,6 +176,7 @@ data AnalysisSpec = AnalysisSpec {
     asFallbackShell :: Maybe Shell,
     asExecutionMode :: ExecutionMode,
     asCheckSourced :: Bool,
+    asIsPortage :: Bool,
     asOptionalChecks :: [String],
     asTokenPositions :: Map.Map Id (Position, Position)
 }
@@ -183,6 +187,7 @@ newAnalysisSpec token = AnalysisSpec {
     asFallbackShell = Nothing,
     asExecutionMode = Executed,
     asCheckSourced = False,
+    asIsPortage = False,
     asOptionalChecks = [],
     asTokenPositions = Map.empty
 }

src/ShellCheck/PortageVariables.hs

@@ -0,0 +1,138 @@
+{-# LANGUAGE ApplicativeDo #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TupleSections #-}
+
+module ShellCheck.PortageVariables (
+    readPortageVariables
+  ) where
+
+import ShellCheck.Regex
+
+import Control.Exception
+import Control.Monad
+import Data.Maybe
+import System.Directory (listDirectory)
+import System.Exit (ExitCode(..))
+import System.FilePath
+import System.IO
+import System.Process
+
+import qualified Data.ByteString as B
+import qualified Data.Map as M
+
+type RepoName = String
+type RepoPath = String
+type EclassName = String
+type EclassVar = String
+
+-- | This is used for looking up what eclass variables are inherited,
+--   keyed by the name of the eclass.
+type EclassMap = M.Map EclassName [EclassVar]
+
+data Repository = Repository
+    { repositoryName :: RepoName
+    , repositoryLocation :: RepoPath
+    , repositoryEclasses :: [Eclass]
+    } deriving (Show, Eq, Ord)
+
+data Eclass = Eclass
+    { eclassName :: EclassName
+    , eclassVars :: [EclassVar]
+    } deriving (Show, Eq, Ord)
+
+readPortageVariables :: IO (M.Map String [String])
+readPortageVariables = portageVariables <$> scanRepos
+
+-- | Map from eclass names to a list of eclass variables
+portageVariables :: [Repository] -> EclassMap
+portageVariables = foldMap $ foldMap go . repositoryEclasses
+  where
+    go e = M.singleton (eclassName e) (eclassVars e)
+
+-- | Run @portageq@ to gather a list of repo names and paths, then scan each
+--   one for eclasses and ultimately eclass metadata.
+scanRepos :: IO [Repository]
+scanRepos = do
+    let cmd = "portageq"
+    let args = ["repos_config", "/"]
+    out <- runOrDie cmd args
+    forM (reposParser $ lines out) $ \(n,p) -> Repository n p <$> getEclasses p
+
+-- | Get the name of the repo and its path from blocks outputted by
+--   @portageq@. If the path doesn't exist, this will return @Nothing@.
+reposParser :: [String] -> [(RepoName, RepoPath)]
+reposParser = f ""
+  where
+    segmentRegex = mkRegex "^\\[(.*)\\].*"
+    locationRegex = mkRegex "^[[:space:]]*location[[:space:]]*=[[:space:]]*(.*)[[:space:]]*$"
+    f name [] = []
+    f name (line:rest) =
+        case (matchRegex segmentRegex line, matchRegex locationRegex line) of
+            (Just [next], _) -> f next rest
+            (_, Just [location]) -> (name, location) : f name rest
+            _ -> f name rest
+
+-- | Scan the repo path for @*.eclass@ files in @eclass/@, then run
+--   'eclassParser' on each of them to produce @[Eclass]@.
+--
+--   If the @eclass/@ directory doesn't exist, the scan is skipped for that
+--   repo.
+getEclasses :: RepoPath -> IO [Eclass]
+getEclasses repoLoc = do
+    let eclassDir = repoLoc </> "eclass"
+
+    files <- handle catcher $ listDirectory eclassDir
+    let names = filter (\(_, e) -> e == ".eclass") $ map splitExtension files
+
+    forM (names :: [(String, String)]) $ \(name, ext) -> do
+        contents <- withFile (eclassDir </> name <.> ext) ReadMode readFully
+        return $ Eclass name $ eclassParser (lines contents)
+
+  where
+    catcher :: IOException -> IO [String]
+    catcher e = do
+        hPutStrLn stderr $ "Unable to find .eclass files: " ++ show e
+        return []
+
+-- | Scan a @.eclass@ file for any @@@ECLASS_VARIABLE:@ comments, generating
+--   a list of eclass variables.
+eclassParser :: [String] -> [String]
+eclassParser lines = mapMaybe match lines
+  where
+    varRegex = mkRegex "^[[:space:]]*#[[:space:]]*@ECLASS_VARIABLE:[[:space:]]*([^[:space:]]*)[[:space:]]*$"
+    match str = head <$> matchRegex varRegex str
+
+-- | Run the command and return the full stdout string (stdin is ignored).
+--
+--   If the command exits with a non-zero exit code, this will throw an
+--   error including the captured contents of stdout and stderr.
+runOrDie :: FilePath -> [String] -> IO String
+runOrDie cmd args = bracket acquire release $ \(_,o,e,p) -> do
+    ot <- readFully (fromJust o)
+    et <- readFully (fromJust e)
+    ec <- waitForProcess p
+    case ec of
+        ExitSuccess -> pure ot
+        ExitFailure i -> fail $ unlines $ map unwords
+            $   [ [ show cmd ]
+                    ++ map show args
+                    ++ [ "failed with exit code", show i]
+                , [ "stdout:" ], [ ot ]
+                , [ "stderr:" ], [ et ]
+                ]
+  where
+    acquire = createProcess (proc cmd args)
+        { std_in = NoStream
+        , std_out = CreatePipe
+        , std_err = CreatePipe
+        }
+    release (i,o,e,p) = do
+        _ <- waitForProcess p
+        forM_ [i,o,e] $ mapM_ hClose
+
+readFully :: Handle -> IO String
+readFully handle = do
+    hSetBinaryMode handle True
+    str <- hGetContents handle
+    length str `seq` return str