Merge remote-tracking branch 'randen/bug468'

5 files changed, 210 insertions, 22 deletions

diff --git a/driver-test/Main.hs b/driver-test/Main.hs
new file mode 100644
index 00000000..d3f636e9
--- /dev/null
+++ b/driver-test/Main.hs
@@ -0,0 +1,12 @@
+module Main where
+
+import Test.Hspec (describe, hspec, Spec)
+import qualified ResponseFileSpec (spec)
+
+
+main :: IO ()
+main = hspec spec
+
+spec :: Spec
+spec = do
+    describe "ResponseFile" ResponseFileSpec.spec
diff --git a/driver-test/ResponseFileSpec.hs b/driver-test/ResponseFileSpec.hs
new file mode 100644
index 00000000..997adac4
--- /dev/null
+++ b/driver-test/ResponseFileSpec.hs
@@ -0,0 +1,80 @@
+module ResponseFileSpec where
+
+import Test.Hspec (context, describe, it, shouldBe, Spec)
+import ResponseFile (escapeArgs, unescapeArgs)
+
+-- The first two elements are
+--   1) a list of 'args' to encode and
+--   2) a single string of the encoded args
+-- The 3rd element is just a description for the tests.
+testStrs :: [(([String], String), String)]
+testStrs =
+  [ ((["a simple command line"],
+      "a\\ simple\\ command\\ line\n"),
+     "the white-space, end with newline")
+
+  , ((["arg 'foo' is single quoted"],
+      "arg\\ \\'foo\\'\\ is\\ single\\ quoted\n"),
+     "the single quotes as well")
+
+  , ((["arg \"bar\" is double quoted"],
+      "arg\\ \\\"bar\\\"\\ is\\ double\\ quoted\n"),
+     "the double quotes as well" )
+
+  , ((["arg \"foo bar\" has embedded whitespace"],
+      "arg\\ \\\"foo\\ bar\\\"\\ has\\ embedded\\ whitespace\n"),
+     "the quote-embedded whitespace")
+
+  , ((["arg 'Jack said \\'hi\\'' has single quotes"],
+      "arg\\ \\'Jack\\ said\\ \\\\\\'hi\\\\\\'\\'\\ has\\ single\\ quotes\n"),
+     "the escaped single quotes")
+
+  , ((["arg 'Jack said \\\"hi\\\"' has double quotes"],
+      "arg\\ \\'Jack\\ said\\ \\\\\\\"hi\\\\\\\"\\'\\ has\\ double\\ quotes\n"),
+     "the escaped double quotes")
+
+  , ((["arg 'Jack said\\r\\n\\t \\\"hi\\\"' has other whitespace"],
+      "arg\\ \\'Jack\\ said\\\\r\\\\n\\\\t\\ \\\\\\\"hi\\\\\\\"\\'\\ has\\ \
+           \other\\ whitespace\n"),
+     "the other whitespace")
+
+  , (([ "--prologue=.\\dist\\.\\haddock-prologue3239114604.txt"
+      , "--title=HaddockNewline-0.1.0.0: This has a\n\
+        \newline yo."
+      , "-BC:\\Program Files\\Haskell Platform\\lib"],
+      "--prologue=.\\\\dist\\\\.\\\\haddock-prologue3239114604.txt\n\
+      \--title=HaddockNewline-0.1.0.0:\\ This\\ has\\ a\\\n\
+      \newline\\ yo.\n\
+      \-BC:\\\\Program\\ Files\\\\Haskell\\ Platform\\\\lib\n"),
+     "an actual haddock response file snippet with embedded newlines")
+  ]
+
+spec :: Spec
+spec = do
+  describe "escapeArgs" $ do
+      mapM_ (\((ss1,s2),des) -> do
+                  context ("given " ++ (show ss1)) $ do
+                      it ("should escape " ++ des) $ do
+                          escapeArgs ss1 `shouldBe` s2
+            ) testStrs
+  describe "unescapeArgs" $ do
+      mapM_ (\((ss1,s2),des) -> do
+                  context ("given " ++ (show s2)) $ do
+                      it ("should unescape " ++ des) $ do
+                          unescapeArgs s2 `shouldBe` ss1
+            ) testStrs
+  describe "unescapeArgs" $ do
+      context "given unescaped single quotes" $ do
+          it "should pass-through, without escaping, everything inside" $ do
+              -- backslash *always* is escaped anywhere it appears
+              (filter (not . null) $
+                unescapeArgs "this\\ is\\ 'not escape\\d \"inside\"'\\ yo\n")
+              `shouldBe`
+              ["this is not escaped \"inside\" yo"]
+      context "given unescaped double quotes" $ do
+          it "should pass-through, without escaping, everything inside" $ do
+              -- backslash *always* is escaped anywhere it appears
+              (filter (not . null) $
+                unescapeArgs "this\\ is\\ \"not escape\\d 'inside'\"\\ yo\n")
+              `shouldBe`
+              ["this is not escaped 'inside' yo"]
diff --git a/driver/Main.hs b/driver/Main.hs
index ccbb8b7d..852f44c7 100644
--- a/driver/Main.hs
+++ b/driver/Main.hs
@@ -1,29 +1,8 @@
-{-# LANGUAGE ScopedTypeVariables #-}
 module Main where
 
-import Control.Exception
 import Documentation.Haddock (haddock)
+import ResponseFile (expandResponse)
 import System.Environment (getArgs)
-import System.Exit (exitFailure)
-import System.IO
 
 main :: IO ()
 main = getArgs >>= expandResponse >>= haddock
-
-
--- | Arguments which look like '@foo' will be replaced with the
--- contents of file @foo@. The contents will be passed through 'words'
--- and blanks filtered out first.
---
--- We quit if the file is not found or reading somehow fails.
-expandResponse :: [String] -> IO [String]
-expandResponse = fmap concat . mapM expand
-  where
-    expand :: String -> IO [String]
-    expand ('@':f) = readFileExc f >>= return . filter (not . null) . lines
-    expand x = return [x]
-
-    readFileExc f =
-      readFile f `catch` \(e :: IOException) -> do
-        hPutStrLn stderr $ "Error while expanding response file: " ++ show e
-        exitFailure
diff --git a/driver/ResponseFile.hs b/driver/ResponseFile.hs
new file mode 100644
index 00000000..253c6004
--- /dev/null
+++ b/driver/ResponseFile.hs
@@ -0,0 +1,110 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module ResponseFile (
+    unescapeArgs,
+    escapeArgs,
+    expandResponse
+  ) where
+
+import Control.Exception
+import Data.Char (isSpace)
+import Data.Foldable (foldl')
+import System.Exit (exitFailure)
+import System.IO
+
+
+-- | Given a string of concatenated strings, separate each by removing
+-- a layer of /quoting/ and\/or /escaping/ of certain characters.
+--
+-- These characters are: any whitespace, single quote, double quote,
+-- and the backslash character.  The backslash character always
+-- escapes (i.e., passes through without further consideration) the
+-- character which follows.  Characters can also be escaped in blocks
+-- by quoting (i.e., surrounding the blocks with matching pairs of
+-- either single- or double-quotes which are not themselves escaped).
+--
+-- Any whitespace which appears outside of either of the quoting and
+-- escaping mechanisms, is interpreted as having been added by this
+-- special concatenation process to designate where the boundaries
+-- are between the original, un-concatenated list of strings.  These
+-- added whitespace characters are removed from the output.
+--
+-- > unescapeArgs "hello\\ \\\"world\\\"\n" == escapeArgs "hello \"world\""
+unescapeArgs :: String -> [String]
+unescapeArgs = filter (not . null) . unescape
+
+-- | Given a list of strings, concatenate them into a single string
+-- with escaping of certain characters, and the addition of a newline
+-- between each string.  The escaping is done by adding a single
+-- backslash character before any whitespace, single quote, double
+-- quote, or backslash character, so this escaping character must be
+-- removed.  Unescaped whitespace (in this case, newline) is part
+-- of this "transport" format to indicate the end of the previous
+-- string and the start of a new string.
+--
+-- While 'unescapeArgs' allows using quoting (i.e., convenient
+-- escaping of many characters) by having matching sets of single- or
+-- double-quotes,'escapeArgs' does not use the quoting mechasnism,
+-- and thus will always escape any whitespace, quotes, and
+-- backslashes.
+--
+-- > unescapeArgs "hello\\ \\\"world\\\"\\n" == escapeArgs "hello \"world\""
+escapeArgs :: [String] -> String
+escapeArgs = unlines . map escapeArg
+
+-- | Arguments which look like '@foo' will be replaced with the
+-- contents of file @foo@. A gcc-like syntax for response files arguments
+-- is expected.  This must re-constitute the argument list by doing an
+-- inverse of the escaping mechanism done by the calling-program side.
+--
+-- We quit if the file is not found or reading somehow fails.
+-- (A convenience routine for haddock or possibly other clients)
+expandResponse :: [String] -> IO [String]
+expandResponse = fmap concat . mapM expand
+  where
+    expand :: String -> IO [String]
+    expand ('@':f) = readFileExc f >>= return . unescapeArgs
+    expand x = return [x]
+
+    readFileExc f =
+      readFile f `catch` \(e :: IOException) -> do
+        hPutStrLn stderr $ "Error while expanding response file: " ++ show e
+        exitFailure
+
+data Quoting = NoneQ | SngQ | DblQ
+
+unescape :: String -> [String]
+unescape args = reverse . map reverse $ go args NoneQ False [] []
+    where
+      -- n.b., the order of these cases matters; these are cribbed from gcc
+      -- case 1: end of input
+      go []     _q    _bs   a as = a:as
+      -- case 2: back-slash escape in progress
+      go (c:cs) q     True  a as = go cs q     False (c:a) as
+      -- case 3: no back-slash escape in progress, but got a back-slash
+      go (c:cs) q     False a as
+        | '\\' == c              = go cs q     True  a     as
+      -- case 4: single-quote escaping in progress
+      go (c:cs) SngQ  False a as
+        | '\'' == c              = go cs NoneQ False a     as
+        | otherwise              = go cs SngQ  False (c:a) as
+      -- case 5: double-quote escaping in progress
+      go (c:cs) DblQ  False a as
+        | '"' == c               = go cs NoneQ False a     as
+        | otherwise              = go cs DblQ  False (c:a) as
+      -- case 6: no escaping is in progress
+      go (c:cs) NoneQ False a as
+        | isSpace c              = go cs NoneQ False []    (a:as)
+        | '\'' == c              = go cs SngQ  False a     as
+        | '"'  == c              = go cs DblQ  False a     as
+        | otherwise              = go cs NoneQ False (c:a) as
+
+escapeArg :: String -> String
+escapeArg = reverse . foldl' escape []
+
+escape :: String -> Char -> String
+escape cs c
+  |    isSpace c
+    || '\\' == c
+    || '\'' == c
+    || '"'  == c = c:'\\':cs -- n.b., our caller must reverse the result
+  | otherwise    = c:cs
diff --git a/haddock.cabal b/haddock.cabal
index 2ada188d..639b6aaf 100644
--- a/haddock.cabal
+++ b/haddock.cabal
@@ -123,6 +123,13 @@ executable haddock
   else
     build-depends:  haddock-api == 2.16.*
 
+test-suite driver-test
+  type:             exitcode-stdio-1.0
+  default-language: Haskell2010
+  main-is:          Main.hs
+  hs-source-dirs:   driver-test, driver
+  build-depends:    base, hspec
+
 test-suite html-test
   type:             exitcode-stdio-1.0
   default-language: Haskell2010