Use parsec, drop parsec flag

.travis.yml

@@ -54,9 +54,6 @@ matrix:
    - env: GHCVER=8.0.2 SCRIPT=solver-debug-flags USE_GOLD=YES
      sudo: required
      os: linux
-   - env: GHCVER=8.0.2 SCRIPT=script PARSEC=YES TAGSUFFIX="-parsec" USE_GOLD=YES
-     os: linux
-     sudo: required
    - env: GHCVER=8.0.2 SCRIPT=script DEBUG_EXPENSIVE_ASSERTIONS=YES TAGSUFFIX="-fdebug-expensive-assertions" USE_GOLD=YES
      os: linux
      sudo: required

Cabal/Cabal.cabal

@@ -32,6 +32,8 @@ extra-source-files:
   -- Generated with 'misc/gen-extra-source-files.sh'
   -- Do NOT edit this section manually; instead, run the script.
   -- BEGIN gen-extra-source-files
+  tests/ParserTests/regressions/Octree-0.5.cabal
+  tests/ParserTests/regressions/encoding-0.8.cabal
   tests/ParserTests/warnings/bom.cabal
   tests/ParserTests/warnings/bool.cabal
   tests/ParserTests/warnings/deprecatedfield.cabal
@@ -64,11 +66,6 @@ flag old-directory
   description:  Use directory < 1.2 and old-time
   default:      False
 
-flag parsec
-  description:  Use parsec parser
-  default:      False
-  manual:       True
-
 flag parsec-struct-diff
   description:  Use StructDiff in parsec tests. Affects only parsec tests.
   default:      False
@@ -267,26 +264,23 @@ library
     Language.Haskell.Extension
     Distribution.Compat.Binary
 
-  if flag(parsec)
-    cpp-options: -DCABAL_PARSEC
-    build-depends:
-      transformers,
-      parsec >= 3.1.9 && <3.2
-    build-tools:
-      alex >=3.1.4 && <3.3
-    exposed-modules:
-      Distribution.Compat.Parsec
-      Distribution.PackageDescription.Parsec
-      Distribution.PackageDescription.Parsec.FieldDescr
-      Distribution.Parsec.Class
-      Distribution.Parsec.ConfVar
-      Distribution.Parsec.Lexer
-      Distribution.Parsec.LexerMonad
-      Distribution.Parsec.Parser
-      Distribution.Parsec.Types.Common
-      Distribution.Parsec.Types.Field
-      Distribution.Parsec.Types.FieldDescr
-      Distribution.Parsec.Types.ParseResult
+  build-depends:
+    transformers,
+    parsec >= 3.1.9 && <3.2
+  exposed-modules:
+    Distribution.Compat.Parsec
+    Distribution.PackageDescription.Parsec
+    Distribution.PackageDescription.Parsec.FieldDescr
+    Distribution.PackageDescription.Parsec.Legacy
+    Distribution.Parsec.Class
+    Distribution.Parsec.ConfVar
+    Distribution.Parsec.Lexer
+    Distribution.Parsec.LexerMonad
+    Distribution.Parsec.Parser
+    Distribution.Parsec.Types.Common
+    Distribution.Parsec.Types.Field
+    Distribution.Parsec.Types.FieldDescr
+    Distribution.Parsec.Types.ParseResult
 
   other-modules:
     Distribution.Backpack.PreExistingComponent
@@ -382,9 +376,6 @@ test-suite unit-tests
   default-language: Haskell2010
 
 test-suite parser-tests
-  if !flag(parsec)
-    buildable: False
-
   type: exitcode-stdio-1.0
   hs-source-dirs: tests
   main-is: ParserTests.hs
@@ -400,15 +391,18 @@ test-suite parser-tests
   default-language: Haskell2010
 
 test-suite parser-hackage-tests
-  if !flag(parsec)
-    buildable: False
-
   type: exitcode-stdio-1.0
   main-is: ParserHackageTests.hs
 
+  -- TODO: need to get 01-index.tar on appveyor
+  if os(windows)
+    buildable: False
+
   hs-source-dirs: tests
   build-depends:
     base,
+    base-orphans == 0.6.*,
+    base-compat >=0.9.3 && <0.10,
     containers,
     tar >=0.5 && <0.6,
     bytestring,
@@ -418,7 +412,7 @@ test-suite parser-hackage-tests
 
   if flag(parsec-struct-diff)
     build-depends:
-      generics-sop ==0.2.*,
+      generics-sop >= 0.2.5 && <0.3,
       these >=0.7.1 && <0.8,
       singleton-bool >=0.1.1.0 && <0.2,
       keys

Cabal/Distribution/PackageDescription/Parsec.hs

@@ -38,6 +38,7 @@ import qualified Data.Map                                          as Map
 import qualified Distribution.Compat.SnocList                      as SnocList
 import           Distribution.PackageDescription
 import           Distribution.PackageDescription.Parsec.FieldDescr
+import           Distribution.PackageDescription.Parsec.Legacy     (patchLegacy)
 import           Distribution.Parsec.Class                         (parsec)
 import           Distribution.Parsec.ConfVar
                  (parseConditionConfVar)
@@ -103,10 +104,15 @@ readGenericPackageDescription = readAndParseFile parseGenericPackageDescription
 --
 -- TODO: add lex warnings
 parseGenericPackageDescription :: BS.ByteString -> ParseResult GenericPackageDescription
-parseGenericPackageDescription bs = case readFields' bs of
-    Right (fs, lexWarnings) -> parseGenericPackageDescription' lexWarnings fs
+parseGenericPackageDescription bs = case readFields' bs' of
+    Right (fs, lexWarnings) -> do
+        when patched $
+            parseWarning zeroPos PWTLegacyCabalFile "Legacy cabal file"
+        parseGenericPackageDescription' lexWarnings fs
     -- TODO: better marshalling of errors
-    Left perr -> parseFatalFailure (Position 0 0) (show perr)
+    Left perr -> parseFatalFailure zeroPos (show perr)
+  where
+    (patched, bs') = patchLegacy bs
 
 -- | 'Maybe' variant of 'parseGenericPackageDescription'
 parseGenericPackageDescriptionMaybe :: BS.ByteString -> Maybe GenericPackageDescription
@@ -168,7 +174,8 @@ parseGenericPackageDescription' lexWarnings fs = do
     gpd <-  goFields emptyGpd fs'
     -- Various post checks
     maybeWarnCabalVersion syntax (packageDescription gpd)
-    checkForUndefinedFlags gpd
+    -- TODO: this does nothing
+    -- checkForUndefinedFlags gpd
     -- TODO: do other validations
     return gpd
   where
@@ -326,42 +333,6 @@ parseGenericPackageDescription' lexWarnings fs = do
 
     maybeWarnCabalVersion _ _ = return ()
 
-{-
-    handleFutureVersionParseFailure :: Version -> ParseResult a -> ParseResult GenericPackageDescription
-    handleFutureVersionParseFailure _cabalVersionNeeded _parseBody =
-        error "handleFutureVersionParseFailure"
--}
-
- {-
-      undefined (unless versionOk (warning message) >> parseBody)
-        `catchParseError` \parseError -> case parseError of
-        TabsError _   -> parseFail parseError
-        _ | versionOk -> parseFail parseError
-          | otherwise -> fail message
-      where versionOk = cabalVersionNeeded <= cabalVersion
-            message   = "This package requires at least Cabal version "
-                     ++ display cabalVersionNeeded
-    -}
-
-    checkForUndefinedFlags
-        :: GenericPackageDescription
-        -> ParseResult ()
-    checkForUndefinedFlags _gpd = pure ()
-{-
-        let definedFlags = map flagName flags
-        mapM_ (checkCondTreeFlags definedFlags) (maybeToList mlib)
-        mapM_ (checkCondTreeFlags definedFlags . snd) sub_libs
-        mapM_ (checkCondTreeFlags definedFlags . snd) exes
-        mapM_ (checkCondTreeFlags definedFlags . snd) tests
-
-    checkCondTreeFlags :: [FlagName] -> CondTree ConfVar c a -> PM ()
-    checkCondTreeFlags definedFlags ct = do
-        let fv = nub $ freeVars ct
-        unless (all (`elem` definedFlags) fv) $
-            fail $ "These flags are used without having been defined: "
-                ++ intercalate ", " [ n | FlagName n <- fv \\ definedFlags ]
--}
-
 parseName :: Position -> [SectionArg Position] -> ParseResult String
 parseName pos args = case args of
     [SecArgName _pos secName] ->

Cabal/Distribution/PackageDescription/Parsec/Legacy.hs

@@ -0,0 +1,165 @@
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE OverloadedStrings #-}
+-- |
+--
+-- @since 2.2.0.0
+module Distribution.PackageDescription.Parsec.Legacy (patchLegacy) where
+
+import           Prelude ()
+import           Distribution.Compat.Prelude
+import           GHC.Fingerprint (Fingerprint (..), fingerprintData)
+import           Foreign.Ptr (castPtr)
+import           System.IO.Unsafe (unsafeDupablePerformIO)
+
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Unsafe as BS
+import qualified Data.Map as Map
+
+-- | Patch legacy @.cabal@ file contents to allow parsec parser to accept
+-- all of Hackage.
+--
+-- Bool part of the result tells whether the output is modified.
+--
+-- @since 2.2.0.0
+patchLegacy :: BS.ByteString -> (Bool, BS.ByteString)
+patchLegacy bs = case Map.lookup (BS.take 256 bs, md5 bs) patches of
+    Nothing -> (False, bs)
+    Just (post, f)
+        | post /= md5 output -> (False, bs)
+        | otherwise          -> (True, output)
+      where
+        output = f bs
+
+md5 :: BS.ByteString -> Fingerprint
+md5 bs = unsafeDupablePerformIO $ BS.unsafeUseAsCStringLen bs $ \(ptr, len) ->
+    fingerprintData (castPtr ptr) len
+
+-- | 'patches' contains first 256 bytes, pre- and post-fingerprints and a patch function.
+--
+--
+patches :: Map.Map (BS.ByteString, Fingerprint) (Fingerprint, BS.ByteString -> BS.ByteString)
+patches = Map.fromList
+    -- http://hackage.haskell.org/package/unicode-transforms-0.3.3
+    -- other-modules: .
+    -- ReadP assumed dot is empty line
+    [ mk "-- This file has been generated from package.yaml by hpack version 0.17.0.\n--\n-- see: https://github.com/sol/hpack\n\nname:                unicode-transforms\nversion:             0.3.3\nsynopsis:            Unicode normalization\ndescription:         Fast Unic"
+         (Fingerprint 15958160436627155571 10318709190730872881)
+         (Fingerprint 11008465475756725834 13815629925116264363)
+         (bsRemove "  other-modules:\n      .\n") -- TODO: remove traling \n to test structural-diff
+    -- http://hackage.haskell.org/package/DSTM-0.1.2
+    -- http://hackage.haskell.org/package/DSTM-0.1.1
+    -- http://hackage.haskell.org/package/DSTM-0.1
+    -- Other Modules: no dash
+    -- ReadP parsed as section
+    , mk "Name: DSTM\nVersion: 0.1.2\nCopyright: (c) 2010, Frank Kupke\nLicense: LGPL\nLicense-File: LICENSE\nAuthor: Frank Kupke\nMaintainer: frk@informatik.uni-kiel.de\nCabal-Version: >= 1.2.3\nStability: provisional\nSynopsis: A framework for using STM within distributed "
+         (Fingerprint 6919263071548559054 9050746360708965827)
+         (Fingerprint 17015177514298962556 11943164891661867280)
+         (bsReplace "Other modules:" "-- ")
+    , mk "Name: DSTM\nVersion: 0.1.1\nCopyright: (c) 2010, Frank Kupke\nLicense: LGPL\nLicense-File: LICENSE\nAuthor: Frank Kupke\nMaintainer: frk@informatik.uni-kiel.de\nCabal-Version: >= 1.2.3\nStability: provisional\nSynopsis: A framework for using STM within distributed "
+         (Fingerprint 17313105789069667153 9610429408495338584)
+         (Fingerprint 17250946493484671738 17629939328766863497)
+         (bsReplace "Other modules:" "-- ")
+    , mk "Name: DSTM\nVersion: 0.1\nCopyright: (c) 2010, Frank Kupke\nLicense: LGPL\nLicense-File: LICENSE\nAuthor: Frank Kupke\nMaintainer: frk@informatik.uni-kiel.de\nCabal-Version: >= 1.2.3\nStability: provisional\nSynopsis: A framework for using STM within distributed sy"
+         (Fingerprint 10502599650530614586 16424112934471063115)
+         (Fingerprint 13562014713536696107 17899511905611879358)
+         (bsReplace "Other modules:" "-- ")
+    -- http://hackage.haskell.org/package/control-monad-exception-mtl-0.10.3
+    , mk "name: control-monad-exception-mtl\nversion: 0.10.3\nCabal-Version:  >= 1.10\nbuild-type: Simple\nlicense: PublicDomain\nauthor: Pepe Iborra\nmaintainer: pepeiborra@gmail.com\nhomepage: http://pepeiborra.github.com/control-monad-exception\nsynopsis: MTL instances f"
+         (Fingerprint 18274748422558568404 4043538769550834851)
+         (Fingerprint 11395257416101232635 4303318131190196308)
+         (bsReplace " default- extensions:" "unknown-section")
+    -- http://hackage.haskell.org/package/vacuum-opengl-0.0
+    -- \DEL character
+    , mk "Name:                vacuum-opengl\nVersion:             0.0\nSynopsis:            Visualize live Haskell data structures using vacuum, graphviz and OpenGL.\nDescription:         \DELVisualize live Haskell data structures using vacuum, graphviz and OpenGL.\n     "
+         (Fingerprint 5946760521961682577 16933361639326309422)
+         (Fingerprint 14034745101467101555 14024175957788447824)
+         (bsRemove "\DEL")
+    , mk "Name:                vacuum-opengl\nVersion:             0.0.1\nSynopsis:            Visualize live Haskell data structures using vacuum, graphviz and OpenGL.\nDescription:         \DELVisualize live Haskell data structures using vacuum, graphviz and OpenGL.\n   "
+         (Fingerprint 10790950110330119503 1309560249972452700)
+         (Fingerprint 1565743557025952928 13645502325715033593)
+         (bsRemove "\DEL")
+    -- http://hackage.haskell.org/package/ixset-1.0.4
+    -- {- comments -}
+    , mk "Name:                ixset\nVersion:             1.0.4\nSynopsis:            Efficient relational queries on Haskell sets.\nDescription:\n    Create and query sets that are indexed by multiple indices.\nLicense:             BSD3\nLicense-file:        COPYING\nAut"
+         (Fingerprint 11886092342440414185 4150518943472101551)
+         (Fingerprint 5731367240051983879 17473925006273577821)
+         (bsRemoveStarting "{-")
+    -- : after section
+    -- http://hackage.haskell.org/package/ds-kanren
+    , mk "name:                ds-kanren\nversion:             0.2.0.0\nsynopsis:            A subset of the miniKanren language\ndescription:\n  ds-kanren is an implementation of the <http://minikanren.org miniKanren> language.\n  .\n  == What's in ds-kanren?\n  .\n  ['dis"
+         (Fingerprint 2804006762382336875 9677726932108735838)
+         (Fingerprint 9830506174094917897 12812107316777006473)
+         (bsReplace "Test-Suite test-unify:" "Test-Suite \"test-unify:\"" . bsReplace "Test-Suite test-list-ops:" "Test-Suite \"test-list-ops:\"")
+    , mk "name:                ds-kanren\nversion:             0.2.0.1\nsynopsis:            A subset of the miniKanren language\ndescription:\n  ds-kanren is an implementation of the <http://minikanren.org miniKanren> language.\n\nlicense:             MIT\nlicense-file:  "
+         (Fingerprint 9130259649220396193 2155671144384738932)
+         (Fingerprint 1847988234352024240 4597789823227580457)
+         (bsReplace "Test-Suite test-unify:" "Test-Suite \"test-unify:\"" . bsReplace "Test-Suite test-list-ops:" "Test-Suite \"test-list-ops:\"")
+    , mk "name:                metric\nversion:             0.1.4\nsynopsis:            Metric spaces.\nlicense:             MIT\nlicense-file:        LICENSE\nauthor:              Vikram Verma\nmaintainer:          me@vikramverma.com\ncategory:            Data\nbuild-type:"
+         (Fingerprint 6150019278861565482 3066802658031228162)
+         (Fingerprint 9124826020564520548 15629704249829132420)
+         (bsReplace "test-suite metric-tests:" "test-suite \"metric-tests:\"")
+    , mk "name:                metric\nversion:             0.2.0\nsynopsis:            Metric spaces.\nlicense:             MIT\nlicense-file:        LICENSE\nauthor:              Vikram Verma\nmaintainer:          me@vikramverma.com\ncategory:            Data\nbuild-type:"
+         (Fingerprint 4639805967994715694 7859317050376284551)
+         (Fingerprint 5566222290622325231 873197212916959151)
+         (bsReplace "test-suite metric-tests:" "test-suite \"metric-tests:\"")
+    , mk "name:          phasechange\ncategory:      Data\nversion:       0.1\nauthor:        G\195\161bor Lehel\nmaintainer:    G\195\161bor Lehel <illissius@gmail.com>\nhomepage:      http://github.com/glehel/phasechange\ncopyright:     Copyright (C) 2012 G\195\161bor Lehel\nlicense:     "
+         (Fingerprint 10546509771395401582 245508422312751943)
+         (Fingerprint 5169853482576003304 7247091607933993833)
+         (bsReplace "impl(ghc >= 7.4):" "erroneous-section" . bsReplace "impl(ghc >= 7.6):" "erroneous-section")
+    , mk "Name:                smartword\nSynopsis:            Web based flash card for Word Smart I and II vocabularies\nVersion:             0.0.0.5\nHomepage:            http://kyagrd.dyndns.org/~kyagrd/project/smartword/\nCategory:            Web,Education\nLicense: "
+         (Fingerprint 7803544783533485151 10807347873998191750)
+         (Fingerprint 1665635316718752601 16212378357991151549)
+         (bsReplace "build depends:" "--")
+    , mk "name:           shelltestrunner\n-- sync with README.md, ANNOUNCE:\nversion:        1.3\ncategory:       Testing\nsynopsis:       A tool for testing command-line programs.\ndescription:\n shelltestrunner is a cross-platform tool for testing command-line\n program"
+         (Fingerprint 4403237110790078829 15392625961066653722)
+         (Fingerprint 10218887328390239431 4644205837817510221)
+         (bsReplace "other modules:" "--")
+    ]
+  where
+    mk a b c d = ((a, b), (c, d))
+
+-- | Helper to create entries in patches
+_makePatchKey :: FilePath -> (BS.ByteString -> BS.ByteString) -> NoCallStackIO ()
+_makePatchKey fp transform = do
+    contents <- BS.readFile fp
+    let output = transform contents
+    let Fingerprint hi lo = md5 contents
+    let Fingerprint hi' lo' = md5 output
+    putStrLn
+        $ showString "    , mk "
+        . shows (BS.take 256 contents)
+        . showString "\n         (Fingerprint "
+        . shows hi
+        . showString " "
+        . shows lo
+        . showString ")\n         (Fingerprint "
+        . shows hi'
+        . showString " "
+        . shows lo'
+        . showString ")"
+        $ ""
+
+-------------------------------------------------------------------------------
+-- Patch helpers
+-------------------------------------------------------------------------------
+
+bsRemove
+    :: BS.ByteString  -- ^ needle
+    -> BS.ByteString -> BS.ByteString
+bsRemove needle haystack = case BS.breakSubstring needle haystack of
+    (h, t) -> BS.append h (BS.drop (BS.length needle) t)
+
+bsReplace
+    :: BS.ByteString -- ^ needle
+    -> BS.ByteString -- ^ replacement
+    -> BS.ByteString -> BS.ByteString
+bsReplace needle repl haystack = case BS.breakSubstring needle haystack of
+    (h, t)
+        | not (BS.null t) -> BS.append h (BS.append repl (BS.drop (BS.length needle) t))
+        | otherwise -> haystack
+
+bsRemoveStarting
+    :: BS.ByteString  -- ^ needle
+    -> BS.ByteString -> BS.ByteString
+bsRemoveStarting needle haystack = case BS.breakSubstring needle haystack of
+    (h, _) -> h

Cabal/Distribution/Parsec/Class.hs

@@ -20,6 +20,7 @@ import           Data.Functor.Identity                        (Identity)
 import qualified Distribution.Compat.Parsec                   as P
 import           Distribution.Parsec.Types.Common
                  (PWarnType (..), PWarning (..), Position (..))
+import           Distribution.Utils.Generic                   (lowercase)
 import qualified Text.Parsec                                  as Parsec
 import qualified Text.Parsec.Language                         as Parsec
 import qualified Text.Parsec.Token                            as Parsec
@@ -126,12 +127,11 @@ instance Parsec ModuleName where
         validModuleChar c = isAlphaNum c || c == '_' || c == '\''
 
 instance Parsec FlagName where
-    parsec = mkFlagName . map toLower . intercalate "-" <$> P.sepBy1 component (P.char '-')
+    parsec = mkFlagName . lowercase <$> parsec'
       where
-        -- http://hackage.haskell.org/package/cabal-debian-4.24.8/cabal-debian.cabal
-        -- has flag with all digit component: pretty-112
-        component :: P.Stream s Identity Char => P.Parsec s [PWarning] String
-        component = P.munch1 (\c -> isAlphaNum c || c `elem` "_")
+        parsec' = (:) <$> lead <*> rest
+        lead = P.satisfy (\c ->  isAlphaNum c || c == '_')
+        rest = P.munch (\c -> isAlphaNum c ||  c == '_' || c == '-')
 
 instance Parsec Dependency where
     parsec = do