State.hs 88 KB
Newer Older
Austin Seipp's avatar
Austin Seipp committed
1 2
-- (c) The University of Glasgow, 2006

Edward Z. Yang's avatar
Edward Z. Yang committed
3
{-# LANGUAGE CPP, ScopedTypeVariables, BangPatterns, FlexibleContexts #-}
4

5
-- | Package manipulation
6
module GHC.Unit.State (
7
        module GHC.Unit.Info,
8 9

        -- * Reading the package config, and processing cmdline args
10
        PackageState(..),
11 12
        PackageDatabase (..),
        UnitInfoMap,
13
        emptyPackageState,
14
        initPackages,
15 16
        readPackageDatabases,
        readPackageDatabase,
17
        getPackageConfRefs,
18 19
        resolvePackageDatabase,
        listUnitInfoMap,
20 21

        -- * Querying the package config
22 23
        lookupUnit,
        lookupUnit',
Sylvain Henry's avatar
Sylvain Henry committed
24 25 26 27 28
        unsafeLookupUnit,
        lookupUnitId,
        lookupUnitId',
        unsafeLookupUnitId,

Edward Z. Yang's avatar
Edward Z. Yang committed
29
        lookupPackageName,
30
        improveUnit,
31
        searchPackageId,
32
        displayUnitId,
33
        listVisibleModuleNames,
34 35
        lookupModuleInAllPackages,
        lookupModuleWithSuggestions,
36
        lookupPluginModuleWithSuggestions,
37
        LookupResult(..),
38 39
        ModuleSuggestion(..),
        ModuleOrigin(..),
40 41
        UnusablePackageReason(..),
        pprReason,
42 43 44 45 46 47 48 49 50

        -- * Inspecting the set of packages in scope
        getPackageIncludePath,
        getPackageLibraryPath,
        getPackageLinkOpts,
        getPackageExtraCcOpts,
        getPackageFrameworkPath,
        getPackageFrameworks,
        getPreloadPackagesAnd,
51

Moritz Angermann's avatar
Moritz Angermann committed
52
        collectArchives,
53
        collectIncludeDirs, collectLibraryPaths, collectLinkOpts,
54
        packageHsLibs, getLibs,
55

56
        -- * Utils
57 58 59
        mkIndefUnitId,
        updateIndefUnitId,
        unwireUnit,
60
        pprFlag,
61 62
        pprPackages,
        pprPackagesSimple,
63
        pprModuleMap,
Sylvain Henry's avatar
Sylvain Henry committed
64 65
        homeUnitIsIndefinite,
        homeUnitIsDefinite,
66
    )
67 68 69
where

#include "HsVersions.h"
70

71
import GHC.Prelude
72

73
import GHC.Unit.Database
74
import GHC.Unit.Info
75 76 77
import GHC.Unit.Types
import GHC.Unit.Module
import GHC.Unit.Subst
Sylvain Henry's avatar
Sylvain Henry committed
78
import GHC.Driver.Session
Sylvain Henry's avatar
Sylvain Henry committed
79
import GHC.Driver.Ways
Sylvain Henry's avatar
Sylvain Henry committed
80 81 82
import GHC.Types.Unique.FM
import GHC.Types.Unique.DFM
import GHC.Types.Unique.Set
83 84 85 86
import GHC.Utils.Misc
import GHC.Utils.Panic
import GHC.Utils.Outputable as Outputable
import GHC.Data.Maybe
87

88
import System.Environment ( getEnv )
89 90
import GHC.Data.FastString
import GHC.Utils.Error  ( debugTraceMsg, MsgDoc, dumpIfSet_dyn,
Sylvain Henry's avatar
Sylvain Henry committed
91
                          withTiming, DumpFormat (..) )
92
import GHC.Utils.Exception
93

Simon Marlow's avatar
Simon Marlow committed
94
import System.Directory
95
import System.FilePath as FilePath
Simon Marlow's avatar
Simon Marlow committed
96
import Control.Monad
97
import Data.Graph (stronglyConnComp, SCC(..))
98
import Data.Char ( toUpper )
99
import Data.List as List
100
import Data.Map (Map)
101
import Data.Set (Set)
Edward Z. Yang's avatar
Edward Z. Yang committed
102
import Data.Monoid (First(..))
103
import qualified Data.Semigroup as Semigroup
104
import qualified Data.Map as Map
105
import qualified Data.Map.Strict as MapStrict
106
import qualified Data.Set as Set
Simon Marlow's avatar
Simon Marlow committed
107

108 109 110
-- ---------------------------------------------------------------------------
-- The Package state

111
-- | Package state is all stored in 'DynFlags', including the details of
112 113 114
-- all packages, which packages are exposed, and which modules they
-- provide.
--
115
-- The package state is computed by 'initPackages', and kept in DynFlags.
116
-- It is influenced by various package flags:
117
--
118 119 120
--   * @-package <pkg>@ and @-package-id <pkg>@ cause @<pkg>@ to become exposed.
--     If @-hide-all-packages@ was not specified, these commands also cause
--      all other packages with the same name to become hidden.
121
--
122
--   * @-hide-package <pkg>@ causes @<pkg>@ to become hidden.
123
--
124 125 126 127
--   * (there are a few more flags, check below for their semantics)
--
-- The package state has the following properties.
--
128
--   * Let @exposedPackages@ be the set of packages thus exposed.
129
--     Let @depExposedPackages@ be the transitive closure from @exposedPackages@ of
130 131
--     their dependencies.
--
Gabor Greif's avatar
Gabor Greif committed
132
--   * When searching for a module from a preload import declaration,
133
--     only the exposed modules in @exposedPackages@ are valid.
134 135
--
--   * When searching for a module from an implicit import, all modules
136
--     from @depExposedPackages@ are valid.
137
--
138
--   * When linking in a compilation manager mode, we link in packages the
139 140
--     program depends on (the compiler knows this list by the
--     time it gets to the link step).  Also, we link in all packages
141
--     which were mentioned with preload @-package@ flags on the command-line,
Ian Lynagh's avatar
Ian Lynagh committed
142
--     or are a transitive dependency of same, or are \"base\"\/\"rts\".
143
--     The reason for this is that we might need packages which don't
144 145 146 147 148
--     contain any Haskell modules, and therefore won't be discovered
--     by the normal mechanism of dependency tracking.

-- Notes on DLLs
-- ~~~~~~~~~~~~~
149 150 151 152
-- When compiling module A, which imports module B, we need to
-- know whether B will be in the same DLL as A.
--      If it's in the same DLL, we refer to B_f_closure
--      If it isn't, we refer to _imp__B_f_closure
153 154 155
-- When compiling A, we record in B's Module value whether it's
-- in a different DLL, by setting the DLL flag.

156
-- | Given a module name, there may be multiple ways it came into scope,
157 158 159
-- possibly simultaneously.  This data type tracks all the possible ways
-- it could have come into scope.  Warning: don't use the record functions,
-- they're partial!
160
data ModuleOrigin =
161 162 163 164
    -- | Module is hidden, and thus never will be available for import.
    -- (But maybe the user didn't realize), so we'll still keep track
    -- of these modules.)
    ModHidden
165 166
    -- | Module is unavailable because the package is unusable.
  | ModUnusable UnusablePackageReason
167 168 169 170 171 172 173 174 175
    -- | Module is public, and could have come from some places.
  | ModOrigin {
        -- | @Just False@ means that this module is in
        -- someone's @exported-modules@ list, but that package is hidden;
        -- @Just True@ means that it is available; @Nothing@ means neither
        -- applies.
        fromOrigPackage :: Maybe Bool
        -- | Is the module available from a reexport of an exposed package?
        -- There could be multiple.
176
      , fromExposedReexport :: [UnitInfo]
177
        -- | Is the module available from a reexport of a hidden package?
178
      , fromHiddenReexport :: [UnitInfo]
179 180 181 182 183 184
        -- | Did the module export come from a package flag? (ToDo: track
        -- more information.
      , fromPackageFlag :: Bool
      }

instance Outputable ModuleOrigin where
185
    ppr ModHidden = text "hidden module"
186
    ppr (ModUnusable _) = text "unusable module"
187 188 189 190 191 192 193 194
    ppr (ModOrigin e res rhs f) = sep (punctuate comma (
        (case e of
            Nothing -> []
            Just False -> [text "hidden package"]
            Just True -> [text "exposed package"]) ++
        (if null res
            then []
            else [text "reexport by" <+>
195
                    sep (map (ppr . mkUnit) res)]) ++
196 197 198
        (if null rhs
            then []
            else [text "hidden reexport by" <+>
199
                    sep (map (ppr . mkUnit) res)]) ++
200 201 202
        (if f then [text "package flag"] else [])
        ))

203 204 205 206
-- | Smart constructor for a module which is in @exposed-modules@.  Takes
-- as an argument whether or not the defining package is exposed.
fromExposedModules :: Bool -> ModuleOrigin
fromExposedModules e = ModOrigin (Just e) [] [] False
207

208
-- | Smart constructor for a module which is in @reexported-modules@.  Takes
209
-- as an argument whether or not the reexporting package is exposed, and
210 211
-- also its 'UnitInfo'.
fromReexportedModules :: Bool -> UnitInfo -> ModuleOrigin
212 213
fromReexportedModules True pkg = ModOrigin Nothing [pkg] [] False
fromReexportedModules False pkg = ModOrigin Nothing [] [pkg] False
214 215 216 217 218

-- | Smart constructor for a module which was bound by a package flag.
fromFlag :: ModuleOrigin
fromFlag = ModOrigin Nothing [] [] True

219 220 221 222 223 224 225 226 227 228
instance Semigroup ModuleOrigin where
    ModOrigin e res rhs f <> ModOrigin e' res' rhs' f' =
        ModOrigin (g e e') (res ++ res') (rhs ++ rhs') (f || f')
      where g (Just b) (Just b')
                | b == b'   = Just b
                | otherwise = panic "ModOrigin: package both exposed/hidden"
            g Nothing x = x
            g x Nothing = x
    _x <> _y = panic "ModOrigin: hidden module redefined"

229 230
instance Monoid ModuleOrigin where
    mempty = ModOrigin Nothing [] [] False
231
    mappend = (Semigroup.<>)
232 233 234

-- | Is the name from the import actually visible? (i.e. does it cause
-- ambiguity, or is it only relevant when we're making suggestions?)
235 236
originVisible :: ModuleOrigin -> Bool
originVisible ModHidden = False
237
originVisible (ModUnusable _) = False
238 239 240 241 242 243 244
originVisible (ModOrigin b res _ f) = b == Just True || not (null res) || f

-- | Are there actually no providers for this module?  This will never occur
-- except when we're filtering based on package imports.
originEmpty :: ModuleOrigin -> Bool
originEmpty (ModOrigin Nothing [] [] False) = True
originEmpty _ = False
245

246 247 248 249 250 251 252 253 254 255 256 257 258
-- | Map from 'UnitId' to 'UnitInfo', plus
-- the transitive closure of preload units.
data UnitInfoMap = UnitInfoMap
   { unUnitInfoMap :: UniqDFM UnitInfo
      -- ^ Map from 'UnitId' to 'UnitInfo'

   , preloadClosure :: UniqSet UnitId
     -- ^ The set of transitively reachable units according
     -- to the explicitly provided command line arguments.
     -- A fully instantiated VirtUnit may only be replaced by a RealUnit from
     -- this set.
     -- See Note [VirtUnit to RealUnit improvement]
   }
Edward Z. Yang's avatar
Edward Z. Yang committed
259

260 261
-- | 'UniqFM' map from 'Unit' to a 'UnitVisibility'.
type VisibilityMap = Map Unit UnitVisibility
Edward Z. Yang's avatar
Edward Z. Yang committed
262 263

-- | 'UnitVisibility' records the various aspects of visibility of a particular
264
-- 'Unit'.
Edward Z. Yang's avatar
Edward Z. Yang committed
265 266 267 268 269 270 271
data UnitVisibility = UnitVisibility
    { uv_expose_all :: Bool
      --  ^ Should all modules in exposed-modules should be dumped into scope?
    , uv_renamings :: [(ModuleName, ModuleName)]
      -- ^ Any custom renamings that should bring extra 'ModuleName's into
      -- scope.
    , uv_package_name :: First FastString
272
      -- ^ The package name associated with the 'Unit'.  This is used
Edward Z. Yang's avatar
Edward Z. Yang committed
273 274
      -- to implement legacy behavior where @-package foo-0.1@ implicitly
      -- hides any packages named @foo@
275
    , uv_requirements :: Map ModuleName (Set InstantiatedModule)
Edward Z. Yang's avatar
Edward Z. Yang committed
276 277 278 279 280 281 282
      -- ^ The signatures which are contributed to the requirements context
      -- from this unit ID.
    , uv_explicit :: Bool
      -- ^ Whether or not this unit was explicitly brought into scope,
      -- as opposed to implicitly via the 'exposed' fields in the
      -- package database (when @-hide-all-packages@ is not passed.)
    }
283

Edward Z. Yang's avatar
Edward Z. Yang committed
284 285 286 287 288 289 290 291
instance Outputable UnitVisibility where
    ppr (UnitVisibility {
        uv_expose_all = b,
        uv_renamings = rns,
        uv_package_name = First mb_pn,
        uv_requirements = reqs,
        uv_explicit = explicit
    }) = ppr (b, rns, mb_pn, reqs, explicit)
292 293 294 295 296 297 298 299 300 301 302

instance Semigroup UnitVisibility where
    uv1 <> uv2
        = UnitVisibility
          { uv_expose_all = uv_expose_all uv1 || uv_expose_all uv2
          , uv_renamings = uv_renamings uv1 ++ uv_renamings uv2
          , uv_package_name = mappend (uv_package_name uv1) (uv_package_name uv2)
          , uv_requirements = Map.unionWith Set.union (uv_requirements uv1) (uv_requirements uv2)
          , uv_explicit = uv_explicit uv1 || uv_explicit uv2
          }

Edward Z. Yang's avatar
Edward Z. Yang committed
303 304 305 306 307 308 309 310
instance Monoid UnitVisibility where
    mempty = UnitVisibility
             { uv_expose_all = False
             , uv_renamings = []
             , uv_package_name = First Nothing
             , uv_requirements = Map.empty
             , uv_explicit = False
             }
311
    mappend = (Semigroup.<>)
312

313
type WiredUnitId = DefUnitId
314
type PreloadUnitId = UnitId
315

316 317 318 319 320 321
-- | Map from 'ModuleName' to a set of of module providers (i.e. a 'Module' and
-- its 'ModuleOrigin').
--
-- NB: the set is in fact a 'Map Module ModuleOrigin', probably to keep only one
-- origin for a given 'Module'
type ModuleNameProvidersMap =
322
    Map ModuleName (Map Module ModuleOrigin)
323

324
data PackageState = PackageState {
325
  -- | A mapping of 'Unit' to 'UnitInfo'.  This list is adjusted
326
  -- so that only valid packages are here.  'UnitInfo' reflects
327 328 329
  -- what was stored *on disk*, except for the 'trusted' flag, which
  -- is adjusted at runtime.  (In particular, some packages in this map
  -- may have the 'exposed' flag be 'False'.)
330
  unitInfoMap :: UnitInfoMap,
331

332
  -- | A mapping of 'PackageName' to 'IndefUnitId'.  This is used when
Edward Z. Yang's avatar
Edward Z. Yang committed
333
  -- users refer to packages in Backpack includes.
334
  packageNameMap            :: Map PackageName IndefUnitId,
Edward Z. Yang's avatar
Edward Z. Yang committed
335 336 337

  -- | A mapping from wired in names to the original names from the
  -- package database.
338
  unwireMap :: Map WiredUnitId WiredUnitId,
Edward Z. Yang's avatar
Edward Z. Yang committed
339

340 341 342
  -- | The packages we're going to link in eagerly.  This list
  -- should be in reverse dependency order; that is, a package
  -- is always mentioned before the packages it depends on.
343
  preloadPackages      :: [PreloadUnitId],
344

345 346
  -- | Packages which we explicitly depend on (from a command line flag).
  -- We'll use this to generate version macros.
347
  explicitPackages      :: [Unit],
348

349 350 351
  -- | This is a full map from 'ModuleName' to all modules which may possibly
  -- be providing it.  These providers may be hidden (but we'll still want
  -- to report them in error messages), or it may be an ambiguous import.
352
  moduleNameProvidersMap    :: !ModuleNameProvidersMap,
353

354 355
  -- | A map, like 'moduleNameProvidersMap', but controlling plugin visibility.
  pluginModuleNameProvidersMap    :: !ModuleNameProvidersMap,
Edward Z. Yang's avatar
Edward Z. Yang committed
356 357 358 359 360 361 362 363

  -- | A map saying, for each requirement, what interfaces must be merged
  -- together when we use them.  For example, if our dependencies
  -- are @p[A=<A>]@ and @q[A=<A>,B=r[C=<A>]:B]@, then the interfaces
  -- to merge for A are @p[A=<A>]:A@, @q[A=<A>,B=r[C=<A>]:B]:A@
  -- and @r[C=<A>]:C@.
  --
  -- There's an entry in this map for each hole in our home library.
364 365 366 367 368 369 370
  requirementContext :: Map ModuleName [InstantiatedModule],

  -- | Indicate if we can instantiate units on-the-fly.
  --
  -- This should only be true when we are type-checking an indefinite unit.
  -- See Note [About units] in GHC.Unit.
  allowVirtualUnits :: !Bool
371 372
  }

373 374
emptyPackageState :: PackageState
emptyPackageState = PackageState {
375
    unitInfoMap = emptyUnitInfoMap,
Edward Z. Yang's avatar
Edward Z. Yang committed
376 377
    packageNameMap = Map.empty,
    unwireMap = Map.empty,
378
    preloadPackages = [],
379
    explicitPackages = [],
380 381
    moduleNameProvidersMap = Map.empty,
    pluginModuleNameProvidersMap = Map.empty,
382 383
    requirementContext = Map.empty,
    allowVirtualUnits = False
384 385
    }

386
-- | Package database
387
data PackageDatabase unit = PackageDatabase
388
   { packageDatabasePath  :: FilePath
389
   , packageDatabaseUnits :: [GenUnitInfo unit]
390 391
   }

392
type InstalledPackageIndex = Map UnitId UnitInfo
393

394
-- | Empty package configuration map
395 396
emptyUnitInfoMap :: UnitInfoMap
emptyUnitInfoMap = UnitInfoMap emptyUDFM emptyUniqSet
397

Sylvain Henry's avatar
Sylvain Henry committed
398
-- | Find the unit we know about with the given unit, if any
399 400
lookupUnit :: PackageState -> Unit -> Maybe UnitInfo
lookupUnit pkgs = lookupUnit' (allowVirtualUnits pkgs) (unitInfoMap pkgs)
Edward Z. Yang's avatar
Edward Z. Yang committed
401 402 403

-- | A more specialized interface, which takes a boolean specifying
-- whether or not to look for on-the-fly renamed interfaces, and
404
-- just a 'UnitInfoMap' rather than a 'PackageState' (so it can
Edward Z. Yang's avatar
Edward Z. Yang committed
405
-- be used while we're initializing 'DynFlags'
406 407 408 409 410 411 412
lookupUnit' :: Bool -> UnitInfoMap -> Unit -> Maybe UnitInfo
lookupUnit' False (UnitInfoMap pkg_map _) uid  = lookupUDFM pkg_map uid
lookupUnit' True m@(UnitInfoMap pkg_map _) uid = case uid of
   HoleUnit   -> error "Hole unit"
   RealUnit _ -> lookupUDFM pkg_map uid
   VirtUnit i -> fmap (renamePackage m (instUnitInsts i))
                      (lookupUDFM pkg_map (instUnitInstanceOf i))
Edward Z. Yang's avatar
Edward Z. Yang committed
413

Sylvain Henry's avatar
Sylvain Henry committed
414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435
-- | Find the unit we know about with the given unit id, if any
lookupUnitId :: PackageState -> UnitId -> Maybe UnitInfo
lookupUnitId state uid = lookupUnitId' (unitInfoMap state) uid

-- | Find the unit we know about with the given unit id, if any
lookupUnitId' :: UnitInfoMap -> UnitId -> Maybe UnitInfo
lookupUnitId' (UnitInfoMap db _) uid = lookupUDFM db uid


-- | Looks up the given unit in the package state, panicing if it is not found
unsafeLookupUnit :: HasDebugCallStack => PackageState -> Unit -> UnitInfo
unsafeLookupUnit state u = case lookupUnit state u of
   Just info -> info
   Nothing   -> pprPanic "unsafeLookupUnit" (ppr u)

-- | Looks up the given unit id in the package state, panicing if it is not found
unsafeLookupUnitId :: HasDebugCallStack => PackageState -> UnitId -> UnitInfo
unsafeLookupUnitId state uid = case lookupUnitId state uid of
   Just info -> info
   Nothing   -> pprPanic "unsafeLookupUnitId" (ppr uid)


Edward Z. Yang's avatar
Edward Z. Yang committed
436 437
-- | Find the package we know about with the given package name (e.g. @foo@), if any
-- (NB: there might be a locally defined unit name which overrides this)
438
lookupPackageName :: PackageState -> PackageName -> Maybe IndefUnitId
Sylvain Henry's avatar
Sylvain Henry committed
439
lookupPackageName pkgstate n = Map.lookup n (packageNameMap pkgstate)
440 441

-- | Search for packages with a given package ID (e.g. \"foo-0.1\")
Sylvain Henry's avatar
Sylvain Henry committed
442 443
searchPackageId :: PackageState -> PackageId -> [UnitInfo]
searchPackageId pkgstate pid = filter ((pid ==) . unitPackageId)
Sylvain Henry's avatar
Sylvain Henry committed
444
                               (listUnitInfoMap pkgstate)
445

446
-- | Extends the package configuration map with a list of package configs.
447 448 449 450
extendUnitInfoMap
   :: UnitInfoMap -> [UnitInfo] -> UnitInfoMap
extendUnitInfoMap (UnitInfoMap pkg_map closure) new_pkgs
  = UnitInfoMap (foldl' add pkg_map new_pkgs) closure
451 452
    -- We also add the expanded version of the mkUnit, so that
    -- 'improveUnit' can find it.
453
  where add pkg_map p = addToUDFM (addToUDFM pkg_map (expandedUnitInfoId p) p)
454
                                  (unitId p) p
455

456
-- | Get a list of entries from the package database.  NB: be careful with
457 458 459
-- this function, although all packages in this map are "visible", this
-- does not imply that the exposed-modules of the package are available
-- (they may have been thinned or renamed).
Sylvain Henry's avatar
Sylvain Henry committed
460 461
listUnitInfoMap :: PackageState -> [UnitInfo]
listUnitInfoMap pkgstate = eltsUDFM pkg_map
Edward Z. Yang's avatar
Edward Z. Yang committed
462
  where
Sylvain Henry's avatar
Sylvain Henry committed
463
    UnitInfoMap pkg_map _ = unitInfoMap pkgstate
464

465
-- ----------------------------------------------------------------------------
466
-- Loading the package db files and building up the package state
467

468 469
-- | Read the package database files, and sets up various internal tables of
-- package information, according to the package-related flags on the
470
-- command-line (@-package@, @-hide-package@ etc.)
471 472 473
--
-- Returns a list of packages to link in if we're doing dynamic linking.
-- This list contains the packages that the user explicitly mentioned with
474
-- @-package@ flags.
475 476 477
--
-- 'initPackages' can be called again subsequently after updating the
-- 'packageFlags' field of the 'DynFlags', and it will update the
478
-- 'pkgState' in 'DynFlags' and return a list of packages to
479
-- link in.
480
initPackages :: DynFlags -> IO (DynFlags, [PreloadUnitId])
481
initPackages dflags = withTiming dflags
482 483
                                  (text "initializing package database")
                                  forcePkgDb $ do
484
  read_pkg_dbs <-
485
    case pkgDatabase dflags of
486 487 488 489 490 491 492 493 494 495
        Nothing  -> readPackageDatabases dflags
        Just dbs -> return dbs

  let
      distrust_all db = db { packageDatabaseUnits = distrustAllUnits (packageDatabaseUnits db) }

      pkg_dbs
         | gopt Opt_DistrustAllPackages dflags = map distrust_all read_pkg_dbs
         | otherwise                           = read_pkg_dbs

496
  (pkg_state, preload, insts)
497 498
        <- mkPackageState dflags pkg_dbs []
  return (dflags{ pkgDatabase = Just read_pkg_dbs,
499
                  pkgState = pkg_state,
Sylvain Henry's avatar
Sylvain Henry committed
500
                  homeUnitInstantiations = insts },
501
          preload)
502
  where
503
    forcePkgDb (dflags, _) = unitInfoMap (pkgState dflags) `seq` ()
504 505

-- -----------------------------------------------------------------------------
506 507
-- Reading the package database(s)

508
readPackageDatabases :: DynFlags -> IO [PackageDatabase UnitId]
509
readPackageDatabases dflags = do
510
  conf_refs <- getPackageConfRefs dflags
511 512
  confs     <- liftM catMaybes $ mapM (resolvePackageDatabase dflags) conf_refs
  mapM (readPackageDatabase dflags) confs
513

514

515
getPackageConfRefs :: DynFlags -> IO [PkgDbRef]
516
getPackageConfRefs dflags = do
517
  let system_conf_refs = [UserPkgDb, GlobalPkgDb]
518

519
  e_pkg_path <- tryIO (getEnv $ map toUpper (programName dflags) ++ "_PACKAGE_PATH")
520 521 522
  let base_conf_refs = case e_pkg_path of
        Left _ -> system_conf_refs
        Right path
523
         | not (null path) && isSearchPathSeparator (last path)
524
         -> map PkgDbPath (splitSearchPath (init path)) ++ system_conf_refs
525
         | otherwise
526
         -> map PkgDbPath (splitSearchPath path)
527

528 529 530 531 532 533 534 535 536 537 538 539 540 541 542
  -- Apply the package DB-related flags from the command line to get the
  -- final list of package DBs.
  --
  -- Notes on ordering:
  --  * The list of flags is reversed (later ones first)
  --  * We work with the package DB list in "left shadows right" order
  --  * and finally reverse it at the end, to get "right shadows left"
  --
  return $ reverse (foldr doFlag base_conf_refs (packageDBFlags dflags))
 where
  doFlag (PackageDB p) dbs = p : dbs
  doFlag NoUserPackageDB dbs = filter isNotUser dbs
  doFlag NoGlobalPackageDB dbs = filter isNotGlobal dbs
  doFlag ClearPackageDBs _ = []

543
  isNotUser UserPkgDb = False
544 545
  isNotUser _ = True

546
  isNotGlobal GlobalPkgDb = False
547
  isNotGlobal _ = True
548

549 550 551
-- | Return the path of a package database from a 'PkgDbRef'. Return 'Nothing'
-- when the user database filepath is expected but the latter doesn't exist.
--
552
-- NB: This logic is reimplemented in Cabal, so if you change it,
553
-- make sure you update Cabal. (Or, better yet, dump it in the
554
-- compiler info so Cabal can use the info.)
555 556 557
resolvePackageDatabase :: DynFlags -> PkgDbRef -> IO (Maybe FilePath)
resolvePackageDatabase dflags GlobalPkgDb = return $ Just (globalPackageDatabasePath dflags)
resolvePackageDatabase dflags UserPkgDb = runMaybeT $ do
558
  dir <- versionedAppDir dflags
Edsko de Vries's avatar
Edsko de Vries committed
559
  let pkgconf = dir </> "package.conf.d"
560 561
  exist <- tryMaybeT $ doesDirectoryExist pkgconf
  if exist then return pkgconf else mzero
562
resolvePackageDatabase _ (PkgDbPath name) = return $ Just name
563

564
readPackageDatabase :: DynFlags -> FilePath -> IO (PackageDatabase UnitId)
565
readPackageDatabase dflags conf_file = do
566 567
  isdir <- doesDirectoryExist conf_file

568
  proto_pkg_configs <-
569
    if isdir
570
       then readDirStyleUnitInfo conf_file
571
       else do
572
            isfile <- doesFileExist conf_file
573
            if isfile
574
               then do
575
                 mpkgs <- tryReadOldFileStyleUnitInfo
576 577 578
                 case mpkgs of
                   Just pkgs -> return pkgs
                   Nothing   -> throwGhcExceptionIO $ InstallationError $
579 580 581 582
                      "ghc no longer supports single-file style package " ++
                      "databases (" ++ conf_file ++
                      ") use 'ghc-pkg init' to create the database with " ++
                      "the correct format."
583 584
               else throwGhcExceptionIO $ InstallationError $
                      "can't find a package database at " ++ conf_file
585

586
  let
587
      -- Fix #16360: remove trailing slash from conf_file before calculating pkgroot
588
      conf_file' = dropTrailingPathSeparator conf_file
589
      top_dir = topDir dflags
590
      pkgroot = takeDirectory conf_file'
591
      pkg_configs1 = map (mungeUnitInfo top_dir pkgroot . mapUnitInfo (\(UnitKey x) -> UnitId x) unitIdFS . mkUnitKeyInfo)
592
                         proto_pkg_configs
593
  --
594
  return $ PackageDatabase conf_file' pkg_configs1
595
  where
596
    readDirStyleUnitInfo conf_dir = do
597
      let filename = conf_dir </> "package.cache"
598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624
      cache_exists <- doesFileExist filename
      if cache_exists
        then do
          debugTraceMsg dflags 2 $ text "Using binary package database:"
                                    <+> text filename
          readPackageDbForGhc filename
        else do
          -- If there is no package.cache file, we check if the database is not
          -- empty by inspecting if the directory contains any .conf file. If it
          -- does, something is wrong and we fail. Otherwise we assume that the
          -- database is empty.
          debugTraceMsg dflags 2 $ text "There is no package.cache in"
                               <+> text conf_dir
                                <> text ", checking if the database is empty"
          db_empty <- all (not . isSuffixOf ".conf")
                   <$> getDirectoryContents conf_dir
          if db_empty
            then do
              debugTraceMsg dflags 3 $ text "There are no .conf files in"
                                   <+> text conf_dir <> text ", treating"
                                   <+> text "package database as empty"
              return []
            else do
              throwGhcExceptionIO $ InstallationError $
                "there is no package.cache in " ++ conf_dir ++
                " even though package database is not empty"

625 626 627 628 629 630 631 632 633

    -- Single-file style package dbs have been deprecated for some time, but
    -- it turns out that Cabal was using them in one place. So this is a
    -- workaround to allow older Cabal versions to use this newer ghc.
    -- We check if the file db contains just "[]" and if so, we look for a new
    -- dir-style db in conf_file.d/, ie in a dir next to the given file.
    -- We cannot just replace the file with a new dir style since Cabal still
    -- assumes it's a file and tries to overwrite with 'writeFile'.
    -- ghc-pkg also cooperates with this workaround.
634
    tryReadOldFileStyleUnitInfo = do
635 636 637 638 639 640 641
      content <- readFile conf_file `catchIO` \_ -> return ""
      if take 2 content == "[]"
        then do
          let conf_dir = conf_file <.> "d"
          direxists <- doesDirectoryExist conf_dir
          if direxists
             then do debugTraceMsg dflags 2 (text "Ignoring old file-style db and trying:" <+> text conf_dir)
642
                     liftM Just (readDirStyleUnitInfo conf_dir)
643 644
             else return (Just []) -- ghc-pkg will create it when it's updated
        else return Nothing
645

646 647
distrustAllUnits :: [UnitInfo] -> [UnitInfo]
distrustAllUnits pkgs = map distrust pkgs
648
  where
Sylvain Henry's avatar
Sylvain Henry committed
649
    distrust pkg = pkg{ unitIsTrusted = False }
650

651 652 653
mungeUnitInfo :: FilePath -> FilePath
                   -> UnitInfo -> UnitInfo
mungeUnitInfo top_dir pkgroot =
654
    mungeDynLibFields
655
  . mungeUnitInfoPaths top_dir pkgroot
656

657
mungeDynLibFields :: UnitInfo -> UnitInfo
658 659
mungeDynLibFields pkg =
    pkg {
Sylvain Henry's avatar
Sylvain Henry committed
660 661 662
      unitLibraryDynDirs = case unitLibraryDynDirs pkg of
         [] -> unitLibraryDirs pkg
         ds -> ds
663 664
    }

665
-- -----------------------------------------------------------------------------
666 667 668 669 670
-- Modify our copy of the package database based on trust flags,
-- -trust and -distrust.

applyTrustFlag
   :: DynFlags
671
   -> PackagePrecedenceIndex
672
   -> UnusablePackages
673
   -> [UnitInfo]
674
   -> TrustFlag
675
   -> IO [UnitInfo]
676
applyTrustFlag dflags prec_map unusable pkgs flag =
677 678 679 680
  case flag of
    -- we trust all matching packages. Maybe should only trust first one?
    -- and leave others the same or set them untrusted
    TrustPackage str ->
681
       case selectPackages prec_map (PackageArg str) pkgs unusable of
682 683
         Left ps       -> trustFlagErr dflags flag ps
         Right (ps,qs) -> return (map trust ps ++ qs)
Sylvain Henry's avatar
Sylvain Henry committed
684
          where trust p = p {unitIsTrusted=True}
685 686

    DistrustPackage str ->
687
       case selectPackages prec_map (PackageArg str) pkgs unusable of
688
         Left ps       -> trustFlagErr dflags flag ps
689
         Right (ps,qs) -> return (distrustAllUnits ps ++ qs)
690

Sylvain Henry's avatar
Sylvain Henry committed
691
-- | A little utility to tell if the home unit is indefinite
Edward Z. Yang's avatar
Edward Z. Yang committed
692
-- (if it is not, we should never use on-the-fly renaming.)
Sylvain Henry's avatar
Sylvain Henry committed
693 694 695 696 697 698 699
homeUnitIsIndefinite :: DynFlags -> Bool
homeUnitIsIndefinite dflags = not (homeUnitIsDefinite dflags)

-- | A little utility to tell if the home unit is definite
-- (if it is, we should never use on-the-fly renaming.)
homeUnitIsDefinite :: DynFlags -> Bool
homeUnitIsDefinite dflags = unitIsDefinite (homeUnit dflags)
Edward Z. Yang's avatar
Edward Z. Yang committed
700

701
applyPackageFlag
Ian Lynagh's avatar
Ian Lynagh committed
702
   :: DynFlags
703
   -> PackagePrecedenceIndex
704
   -> UnitInfoMap
Ian Lynagh's avatar
Ian Lynagh committed
705
   -> UnusablePackages
706 707
   -> Bool -- if False, if you expose a package, it implicitly hides
           -- any previously exposed packages with the same name
708
   -> [UnitInfo]
709
   -> VisibilityMap           -- Initially exposed
710
   -> PackageFlag               -- flag to apply
711
   -> IO VisibilityMap        -- Now exposed
712

713
applyPackageFlag dflags prec_map pkg_db unusable no_hide_others pkgs vm flag =
714
  case flag of
715
    ExposePackage _ arg (ModRenaming b rns) ->
716
       case findPackages prec_map pkg_db arg pkgs unusable of
717
         Left ps         -> packageFlagErr dflags flag ps
Edward Z. Yang's avatar
Edward Z. Yang committed
718
         Right (p:_) -> return vm'
719 720
          where
           n = fsPackageName p
Edward Z. Yang's avatar
Edward Z. Yang committed
721 722 723 724 725 726 727 728 729

           -- If a user says @-unit-id p[A=<A>]@, this imposes
           -- a requirement on us: whatever our signature A is,
           -- it must fulfill all of p[A=<A>]:A's requirements.
           -- This method is responsible for computing what our
           -- inherited requirements are.
           reqs | UnitIdArg orig_uid <- arg = collectHoles orig_uid
                | otherwise                 = Map.empty

730 731 732 733
           collectHoles uid = case uid of
             HoleUnit       -> Map.empty
             RealUnit {}    -> Map.empty -- definite units don't have holes
             VirtUnit indef ->
734
                  let local = [ Map.singleton
Edward Z. Yang's avatar
Edward Z. Yang committed
735
                                  (moduleName mod)
736 737
                                  (Set.singleton $ Module indef mod_name)
                              | (mod_name, mod) <- instUnitInsts indef
Edward Z. Yang's avatar
Edward Z. Yang committed
738
                              , isHoleModule mod ]
739 740
                      recurse = [ collectHoles (moduleUnit mod)
                                | (_, mod) <- instUnitInsts indef ]
Edward Z. Yang's avatar
Edward Z. Yang committed
741 742 743 744 745 746 747 748 749
                  in Map.unionsWith Set.union $ local ++ recurse

           uv = UnitVisibility
                { uv_expose_all = b
                , uv_renamings = rns
                , uv_package_name = First (Just n)
                , uv_requirements = reqs
                , uv_explicit = True
                }
750
           vm' = Map.insertWith mappend (mkUnit p) uv vm_cleared
751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771
           -- In the old days, if you said `ghc -package p-0.1 -package p-0.2`
           -- (or if p-0.1 was registered in the pkgdb as exposed: True),
           -- the second package flag would override the first one and you
           -- would only see p-0.2 in exposed modules.  This is good for
           -- usability.
           --
           -- However, with thinning and renaming (or Backpack), there might be
           -- situations where you legitimately want to see two versions of a
           -- package at the same time, and this behavior would make it
           -- impossible to do so.  So we decided that if you pass
           -- -hide-all-packages, this should turn OFF the overriding behavior
           -- where an exposed package hides all other packages with the same
           -- name.  This should not affect Cabal at all, which only ever
           -- exposes one package at a time.
           --
           -- NB: Why a variable no_hide_others?  We have to apply this logic to
           -- -plugin-package too, and it's more consistent if the switch in
           -- behavior is based off of
           -- -hide-all-packages/-hide-all-plugin-packages depending on what
           -- flag is in question.
           vm_cleared | no_hide_others = vm
Edward Z. Yang's avatar
Edward Z. Yang committed
772 773 774
                      -- NB: renamings never clear
                      | (_:_) <- rns = vm
                      | otherwise = Map.filterWithKey
775
                            (\k uv -> k == mkUnit p
Edward Z. Yang's avatar
Edward Z. Yang committed
776
                                   || First (Just n) /= uv_package_name uv) vm
777 778
         _ -> panic "applyPackageFlag"

779
    HidePackage str ->
780
       case findPackages prec_map pkg_db (PackageArg str) pkgs unusable of
Edward Z. Yang's avatar
Edward Z. Yang committed
781 782
         Left ps  -> packageFlagErr dflags flag ps
         Right ps -> return vm'
783
          where vm' = foldl' (flip Map.delete) vm (map mkUnit ps)
Edward Z. Yang's avatar
Edward Z. Yang committed
784 785 786 787

-- | Like 'selectPackages', but doesn't return a list of unmatched
-- packages.  Furthermore, any packages it returns are *renamed*
-- if the 'UnitArg' has a renaming associated with it.
788
findPackages :: PackagePrecedenceIndex
789
             -> UnitInfoMap -> PackageArg -> [UnitInfo]
Edward Z. Yang's avatar
Edward Z. Yang committed
790
             -> UnusablePackages
791 792
             -> Either [(UnitInfo, UnusablePackageReason)]
                [UnitInfo]
793
findPackages prec_map pkg_db arg pkgs unusable
Edward Z. Yang's avatar
Edward Z. Yang committed
794 795 796 797
  = let ps = mapMaybe (finder arg) pkgs
    in if null ps
        then Left (mapMaybe (\(x,y) -> finder arg x >>= \x' -> return (x',y))
                            (Map.elems unusable))
798
        else Right (sortByPreference prec_map ps)
Edward Z. Yang's avatar
Edward Z. Yang committed
799 800
  where
    finder (PackageArg str) p
Sylvain Henry's avatar
Sylvain Henry committed
801
      = if str == unitPackageIdString p || str == unitPackageNameString p
Edward Z. Yang's avatar
Edward Z. Yang committed
802 803 804
          then Just p
          else Nothing
    finder (UnitIdArg uid) p
805 806 807 808 809 810 811 812
      = case uid of
          RealUnit (Definite iuid)
            | iuid == unitId p
            -> Just p
          VirtUnit inst
            | indefUnit (instUnitInstanceOf inst) == unitId p
            -> Just (renamePackage pkg_db (instUnitInsts inst) p)
          _ -> Nothing
Edward Z. Yang's avatar
Edward Z. Yang committed
813

814
selectPackages :: PackagePrecedenceIndex -> PackageArg -> [UnitInfo]
815
               -> UnusablePackages
816 817
               -> Either [(UnitInfo, UnusablePackageReason)]
                  ([UnitInfo], [UnitInfo])
818
selectPackages prec_map arg pkgs unusable
Edward Z. Yang's avatar
Edward Z. Yang committed
819 820
  = let matches = matching arg
        (ps,rest) = partition matches pkgs
821 822
    in if null ps
        then Left (filter (matches.fst) (Map.elems unusable))
823
        else Right (sortByPreference prec_map ps, rest)
824

825 826 827
-- | Rename a 'UnitInfo' according to some module instantiation.
renamePackage :: UnitInfoMap -> [(ModuleName, Module)]
              -> UnitInfo -> UnitInfo
Edward Z. Yang's avatar
Edward Z. Yang committed
828 829
renamePackage pkg_map insts conf =
    let hsubst = listToUFM insts
830
        smod  = renameHoleModule' pkg_map hsubst
Sylvain Henry's avatar
Sylvain Henry committed
831
        new_insts = map (\(k,v) -> (k,smod v)) (unitInstantiations conf)
Edward Z. Yang's avatar
Edward Z. Yang committed
832
    in conf {
Sylvain Henry's avatar
Sylvain Henry committed
833 834 835
        unitInstantiations = new_insts,
        unitExposedModules = map (\(mod_name, mb_mod) -> (mod_name, fmap smod mb_mod))
                             (unitExposedModules conf)
Edward Z. Yang's avatar
Edward Z. Yang committed
836 837 838
    }


839 840
-- A package named on the command line can either include the
-- version, or just the name if it is unambiguous.
841
matchingStr :: String -> UnitInfo -> Bool
842
matchingStr str p
Sylvain Henry's avatar
Sylvain Henry committed
843 844
        =  str == unitPackageIdString p
        || str == unitPackageNameString p
845

846 847
matchingId :: UnitId -> UnitInfo -> Bool
matchingId uid p = uid == unitId p
848

849
matching :: PackageArg -> UnitInfo -> Bool
850
matching (PackageArg str) = matchingStr str
851
matching (UnitIdArg (RealUnit (Definite uid))) = matchingId uid
852
matching (UnitIdArg _)  = \_ -> False -- TODO: warn in this case
853

854 855
-- | This sorts a list of packages, putting "preferred" packages first.
-- See 'compareByPreference' for the semantics of "preference".
856
sortByPreference :: PackagePrecedenceIndex -> [UnitInfo] -> [UnitInfo]
857 858 859 860 861 862 863 864 865 866 867
sortByPreference prec_map = sortBy (flip (compareByPreference prec_map))

-- | Returns 'GT' if @pkg@ should be preferred over @pkg'@ when picking
-- which should be "active".  Here is the order of preference:
--
--      1. First, prefer the latest version
--      2. If the versions are the same, prefer the package that
--      came in the latest package database.
--
-- Pursuant to #12518, we could change this policy to, for example, remove
-- the version preference, meaning that we would always prefer the packages
868
-- in later package database.
869
--
870 871 872 873 874 875
-- Instead, we use that preference based policy only when one of the packages
-- is integer-gmp and the other is integer-simple.
-- This currently only happens when we're looking up which concrete
-- package to use in place of @integer-wired-in@ and that two different
-- package databases supply a different integer library. For more about
-- the fake @integer-wired-in@ package, see Note [The integer library]
Sylvain Henry's avatar
Sylvain Henry committed
876
-- in the @GHC.Builtin.Names@ module.
877 878
compareByPreference
    :: PackagePrecedenceIndex
879 880
    -> UnitInfo
    -> UnitInfo
881
    -> Ordering
882 883 884 885 886 887 888
compareByPreference prec_map pkg pkg'
  | Just prec  <- Map.lookup (unitId pkg)  prec_map
  , Just prec' <- Map.lookup (unitId pkg') prec_map
  , differentIntegerPkgs pkg pkg'
  = compare prec prec'

  | otherwise
Sylvain Henry's avatar
Sylvain Henry committed
889
  = case comparing unitPackageVersion pkg pkg' of
890 891 892 893 894 895 896 897 898
        GT -> GT
        EQ | Just prec  <- Map.lookup (unitId pkg)  prec_map
           , Just prec' <- Map.lookup (unitId pkg') prec_map
           -- Prefer the package from the later DB flag (i.e., higher
           -- precedence)
           -> compare prec prec'
           | otherwise
           -> EQ
        LT -> LT
Ian Lynagh's avatar
Ian Lynagh committed
899

Sylvain Henry's avatar
Sylvain Henry committed
900
  where isIntegerPkg p = unitPackageNameString p `elem`
901 902 903
          ["integer-simple", "integer-gmp"]
        differentIntegerPkgs p p' =
          isIntegerPkg p && isIntegerPkg p' &&
Sylvain Henry's avatar
Sylvain Henry committed
904
          (unitPackageName p /= unitPackageName p')
905

Ian Lynagh's avatar
Ian Lynagh committed
906
comparing :: Ord a => (t -> a) -> t -> t -> Ordering
907 908
comparing f a b = f a `compare` f b

Ian Lynagh's avatar
Ian Lynagh committed
909 910
packageFlagErr :: DynFlags
               -> PackageFlag
911
               -> [(UnitInfo, UnusablePackageReason)]
912
               -> IO a
913
packageFlagErr dflags flag reasons
914 915 916 917
  = packageFlagErr' dflags (pprFlag flag) reasons

trustFlagErr :: DynFlags
             -> TrustFlag
918
             -> [(UnitInfo, UnusablePackageReason)]
919 920 921 922 923 924
             -> IO a
trustFlagErr dflags flag reasons
  = packageFlagErr' dflags (pprTrustFlag flag) reasons

packageFlagErr' :: DynFlags
               -> SDoc
925
               -> [(UnitInfo, UnusablePackageReason)]
926 927
               -> IO a
packageFlagErr' dflags flag_doc reasons
928
  = throwGhcExceptionIO (CmdLineError (showSDoc dflags $ err))
929
  where err = text "cannot satisfy " <> flag_doc <>
930
                (if null reasons then Outputable.empty else text ": ") $$
931 932 933
              nest 4 (ppr_reasons $$
                      text "(use -v for more information)")
        ppr_reasons = vcat (map ppr_reason reasons)
934
        ppr_reason (p, reason) =
935
            pprReason (ppr (unitId p) <+> text "is") reason
936

937 938 939
pprFlag :: PackageFlag -> SDoc
pprFlag flag = case flag of
    HidePackage p   -> text "-hide-package " <> text p
940
    ExposePackage doc _ _ -> text doc
941

942 943 944 945 946
pprTrustFlag :: TrustFlag -> SDoc
pprTrustFlag flag = case flag of
    TrustPackage p    -> text "-trust " <> text p
    DistrustPackage p -> text "-distrust " <> text p

947
-- -----------------------------------------------------------------------------
948
-- Wired-in units
949
--
950
-- See Note [Wired-in units] in GHC.Unit.Module
951

Sylvain Henry's avatar
Sylvain Henry committed
952
type WiredInUnitId = UnitId
953
type WiredPackagesMap = Map WiredUnitId WiredUnitId
954

955 956
findWiredInPackages
   :: DynFlags
957
   -> PackagePrecedenceIndex
958
   -> [UnitInfo]           -- database
959
   -> VisibilityMap             -- info on what packages are visible
960
                                -- for wired in selection
961
   -> IO ([UnitInfo],  -- package database updated for wired in
962
          WiredPackagesMap) -- map from unit id to wired identity
963

964
findWiredInPackages dflags prec_map pkgs vis_map = do
Simon Marlow's avatar
Simon Marlow committed
965
  -- Now we must find our wired-in packages, and rename them to
966
  -- their canonical names (eg. base-1.0 ==> base), as described
967
  -- in Note [Wired-in units] in GHC.Unit.Module
Simon Marlow's avatar
Simon Marlow committed
968
  let
969
        matches :: UnitInfo -> WiredInUnitId -> Bool
970
        pc `matches` pid
Sylvain Henry's avatar
Sylvain Henry committed
971
            -- See Note [The integer library] in GHC.Builtin.Names
Sylvain Henry's avatar
Sylvain Henry committed
972
            | pid == integerUnitId
Sylvain Henry's avatar
Sylvain Henry committed
973
            = unitPackageNameString pc `elem` ["integer-gmp", "integer-simple"]
Sylvain Henry's avatar
Sylvain Henry committed
974
        pc `matches` pid = unitPackageName pc == PackageName (unitIdFS pid)