Warn about timing pipelines and compound commands in sh/dash.

ShellCheck/Analytics.hs

@@ -73,11 +73,13 @@ checksFor Sh = [
     checkBashisms
     ,checkTimeParameters
     ,checkForDecimals
+    ,checkTimedCommand
     ]
 checksFor Dash = [
     checkBashisms
     ,checkForDecimals
     ,checkLocalScope
+    ,checkTimedCommand
     ]
 checksFor Ksh = [
     checkEchoSed
@@ -1107,8 +1109,8 @@ checkStderrRedirect params redir@(T_Redirecting _ [
 
 checkStderrRedirect _ _ = return ()
 
-lt x = trace ("FAILURE " ++ show x) x
-ltt t = trace ("FAILURE " ++ show t)
+lt x = trace ("Tracing " ++ show x) x
+ltt t = trace ("Tracing " ++ show t)
 
 
 prop_checkSingleQuotedVariables  = verify checkSingleQuotedVariables "echo '$foo'"
@@ -1863,6 +1865,32 @@ checkTimeParameters _ = checkUnqualifiedCommand "time" f where
                     info (getId cmd) 2023 "The shell may override 'time' as seen in man time(1). Use 'command time ..' for that one."
     f _ _ = return ()
 
+prop_checkTimedCommand1 = verify checkTimedCommand "time -p foo | bar"
+prop_checkTimedCommand2 = verify checkTimedCommand "time ( foo; bar; )"
+prop_checkTimedCommand3 = verifyNot checkTimedCommand "time sleep 1"
+checkTimedCommand _ = checkUnqualifiedCommand "time" f where
+    f c args@(_:_) = do
+        let cmd = last args
+        when (isPiped cmd) $
+            warn (getId c) 2176 "'time' is undefined for pipelines. time single stage or sh -c instead."
+        when (isSimple cmd == Just False) $
+            warn (getId cmd) 2177 "'time' is undefined for compound commands, time sh -c instead."
+    f _ _ = return ()
+    isPiped cmd =
+        case cmd of
+            T_Pipeline _ _ (_:_:_) -> True
+            _ -> False
+    getCommand cmd =
+        case cmd of
+            T_Pipeline _ _ ((T_Redirecting _ _ a):_) -> return a
+            _ -> fail ""
+    isSimple cmd = do
+        innerCommand <- getCommand cmd
+        case innerCommand of
+            T_SimpleCommand {} -> return True
+            _ -> return False
+
+
 prop_checkTestRedirects1 = verify checkTestRedirects "test 3 > 1"
 prop_checkTestRedirects2 = verifyNot checkTestRedirects "test 3 \\> 1"
 prop_checkTestRedirects3 = verify checkTestRedirects "/usr/bin/test $var > $foo"

quicktest

@@ -4,12 +4,12 @@
 # 'cabal test' remains the source of truth.
 
 (
- var=$(echo 'liftM and $ sequence [ShellCheck.Analytics.runTests, ShellCheck.Parser.runTests, ShellCheck.Checker.runTests]' | cabal repl | tee /dev/stderr)
+ var=$(echo 'liftM and $ sequence [ShellCheck.Analytics.runTests, ShellCheck.Parser.runTests, ShellCheck.Checker.runTests]' | cabal repl 2>&1 | tee /dev/stderr)
 if [[ $var == *$'\nTrue'* ]]
 then
   exit 0
 else
-  grep -C 3 "Fail" <<< "$var"
+  grep -C 3 -e "Fail" -e "Tracing" <<< "$var"
   exit 1
 fi
 ) 2>&1