--- ---------------------------------------------------------------------------
--- Unloading
-
-unload :: HscEnv -> [Linkable] -> IO ()
-unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
- = case ghcLink (hsc_dflags hsc_env) of
-#ifdef GHCI
- LinkInMemory -> Linker.unload (hsc_dflags hsc_env) stable_linkables
-#else
- LinkInMemory -> panic "unload: no interpreter"
- -- urgh. avoid warnings:
- hsc_env stable_linkables
-#endif
- _other -> return ()
-
--- -----------------------------------------------------------------------------
-
-{- |
-
- Stability tells us which modules definitely do not need to be recompiled.
- There are two main reasons for having stability:
-
- - avoid doing a complete upsweep of the module graph in GHCi when
- modules near the bottom of the tree have not changed.
-
- - to tell GHCi when it can load object code: we can only load object code
- for a module when we also load object code fo all of the imports of the
- module. So we need to know that we will definitely not be recompiling
- any of these modules, and we can use the object code.
-
- The stability check is as follows. Both stableObject and
- stableBCO are used during the upsweep phase later.
-
-@
- stable m = stableObject m || stableBCO m
-
- stableObject m =
- all stableObject (imports m)
- && old linkable does not exist, or is == on-disk .o
- && date(on-disk .o) > date(.hs)
-
- stableBCO m =
- all stable (imports m)
- && date(BCO) > date(.hs)
-@
-
- These properties embody the following ideas:
-
- - if a module is stable, then:
-
- - if it has been compiled in a previous pass (present in HPT)
- then it does not need to be compiled or re-linked.
-
- - if it has not been compiled in a previous pass,
- then we only need to read its .hi file from disk and
- link it to produce a 'ModDetails'.
-
- - if a modules is not stable, we will definitely be at least
- re-linking, and possibly re-compiling it during the 'upsweep'.
- All non-stable modules can (and should) therefore be unlinked
- before the 'upsweep'.
-
- - Note that objects are only considered stable if they only depend
- on other objects. We can't link object code against byte code.
--}
-
-checkStability
- :: HomePackageTable -- HPT from last compilation
- -> [SCC ModSummary] -- current module graph (cyclic)
- -> [ModuleName] -- all home modules
- -> ([ModuleName], -- stableObject
- [ModuleName]) -- stableBCO
-
-checkStability hpt sccs all_home_mods = foldl checkSCC ([],[]) sccs
- where
- checkSCC (stable_obj, stable_bco) scc0
- | stableObjects = (scc_mods ++ stable_obj, stable_bco)
- | stableBCOs = (stable_obj, scc_mods ++ stable_bco)
- | otherwise = (stable_obj, stable_bco)
- where
- scc = flattenSCC scc0
- scc_mods = map ms_mod_name scc
- home_module m = m `elem` all_home_mods && m `notElem` scc_mods
-
- scc_allimps = nub (filter home_module (concatMap ms_home_allimps scc))
- -- all imports outside the current SCC, but in the home pkg
-
- stable_obj_imps = map (`elem` stable_obj) scc_allimps
- stable_bco_imps = map (`elem` stable_bco) scc_allimps
-
- stableObjects =
- and stable_obj_imps
- && all object_ok scc
-
- stableBCOs =
- and (zipWith (||) stable_obj_imps stable_bco_imps)
- && all bco_ok scc
-
- object_ok ms
- | Just t <- ms_obj_date ms = t >= ms_hs_date ms
- && same_as_prev t
- | otherwise = False
- where
- same_as_prev t = case lookupUFM hpt (ms_mod_name ms) of
- Just hmi | Just l <- hm_linkable hmi
- -> isObjectLinkable l && t == linkableTime l
- _other -> True
- -- why '>=' rather than '>' above? If the filesystem stores
- -- times to the nearset second, we may occasionally find that
- -- the object & source have the same modification time,
- -- especially if the source was automatically generated
- -- and compiled. Using >= is slightly unsafe, but it matches
- -- make's behaviour.
-
- bco_ok ms
- = case lookupUFM hpt (ms_mod_name ms) of
- Just hmi | Just l <- hm_linkable hmi ->
- not (isObjectLinkable l) &&
- linkableTime l >= ms_hs_date ms
- _other -> False
-
--- -----------------------------------------------------------------------------
-
--- | Prune the HomePackageTable
---
--- Before doing an upsweep, we can throw away:
---
--- - For non-stable modules:
--- - all ModDetails, all linked code
--- - all unlinked code that is out of date with respect to
--- the source file
---
--- This is VERY IMPORTANT otherwise we'll end up requiring 2x the
--- space at the end of the upsweep, because the topmost ModDetails of the
--- old HPT holds on to the entire type environment from the previous
--- compilation.
-
-pruneHomePackageTable
- :: HomePackageTable
- -> [ModSummary]
- -> ([ModuleName],[ModuleName])
- -> HomePackageTable
-
-pruneHomePackageTable hpt summ (stable_obj, stable_bco)
- = mapUFM prune hpt
- where prune hmi
- | is_stable modl = hmi'
- | otherwise = hmi'{ hm_details = emptyModDetails }
- where
- modl = moduleName (mi_module (hm_iface hmi))
- hmi' | Just l <- hm_linkable hmi, linkableTime l < ms_hs_date ms
- = hmi{ hm_linkable = Nothing }
- | otherwise
- = hmi
- where ms = expectJust "prune" (lookupUFM ms_map modl)
-
- ms_map = listToUFM [(ms_mod_name ms, ms) | ms <- summ]
-
- is_stable m = m `elem` stable_obj || m `elem` stable_bco
-
--- -----------------------------------------------------------------------------
-
--- Return (names of) all those in modsDone who are part of a cycle
--- as defined by theGraph.
-findPartiallyCompletedCycles :: [Module] -> [SCC ModSummary] -> [Module]
-findPartiallyCompletedCycles modsDone theGraph
- = chew theGraph
- where
- chew [] = []
- chew ((AcyclicSCC _):rest) = chew rest -- acyclic? not interesting.
- chew ((CyclicSCC vs):rest)
- = let names_in_this_cycle = nub (map ms_mod vs)
- mods_in_this_cycle
- = nub ([done | done <- modsDone,
- done `elem` names_in_this_cycle])
- chewed_rest = chew rest
- in
- if notNull mods_in_this_cycle
- && length mods_in_this_cycle < length names_in_this_cycle
- then mods_in_this_cycle ++ chewed_rest
- else chewed_rest
-
--- -----------------------------------------------------------------------------
-
--- | The upsweep
---
--- This is where we compile each module in the module graph, in a pass
--- from the bottom to the top of the graph.
---
--- There better had not be any cyclic groups here -- we check for them.
-
-upsweep
- :: GhcMonad m =>
- HscEnv -- ^ Includes initially-empty HPT
- -> HomePackageTable -- ^ HPT from last time round (pruned)
- -> ([ModuleName],[ModuleName]) -- ^ stable modules (see checkStability)
- -> IO () -- ^ How to clean up unwanted tmp files
- -> [SCC ModSummary] -- ^ Mods to do (the worklist)
- -> m (SuccessFlag,
- HscEnv,
- [ModSummary])
- -- ^ Returns:
- --
- -- 1. A flag whether the complete upsweep was successful.
- -- 2. The 'HscEnv' with an updated HPT
- -- 3. A list of modules which succeeded loading.
-
-upsweep hsc_env old_hpt stable_mods cleanup sccs = do
- (res, hsc_env, done) <- upsweep' hsc_env old_hpt [] sccs 1 (length sccs)
- return (res, hsc_env, reverse done)
- where
-
- upsweep' hsc_env _old_hpt done
- [] _ _
- = return (Succeeded, hsc_env, done)
-
- upsweep' hsc_env _old_hpt done
- (CyclicSCC ms:_) _ _
- = do liftIO $ fatalErrorMsg (hsc_dflags hsc_env) (cyclicModuleErr ms)
- return (Failed, hsc_env, done)
-
- upsweep' hsc_env old_hpt done
- (AcyclicSCC mod:mods) mod_index nmods
- = do -- putStrLn ("UPSWEEP_MOD: hpt = " ++
- -- show (map (moduleUserString.moduleName.mi_module.hm_iface)
- -- (moduleEnvElts (hsc_HPT hsc_env)))
- let logger = reportModuleCompilationResult (hsc_callbacks hsc_env)
-
- mb_mod_info
- <- handleSourceError
- (\err -> do logger mod (Just err); return Nothing) $ do
- mod_info <- upsweep_mod hsc_env old_hpt stable_mods
- mod mod_index nmods
- logger mod Nothing -- log warnings
- return (Just mod_info)
-
- liftIO cleanup -- Remove unwanted tmp files between compilations
-
- case mb_mod_info of
- Nothing -> return (Failed, hsc_env, done)
- Just mod_info -> do
- let this_mod = ms_mod_name mod
-
- -- Add new info to hsc_env
- hpt1 = addToUFM (hsc_HPT hsc_env) this_mod mod_info
- hsc_env1 = hsc_env { hsc_HPT = hpt1 }
-
- -- Space-saving: delete the old HPT entry
- -- for mod BUT if mod is a hs-boot
- -- node, don't delete it. For the
- -- interface, the HPT entry is probaby for the
- -- main Haskell source file. Deleting it
- -- would force the real module to be recompiled
- -- every time.
- old_hpt1 | isBootSummary mod = old_hpt
- | otherwise = delFromUFM old_hpt this_mod
-
- done' = mod:done
-
- -- fixup our HomePackageTable after we've finished compiling
- -- a mutually-recursive loop. See reTypecheckLoop, below.
- hsc_env2 <- liftIO $ reTypecheckLoop hsc_env1 mod done'
-
- upsweep' hsc_env2 old_hpt1 done' mods (mod_index+1) nmods
-
--- | Compile a single module. Always produce a Linkable for it if
--- successful. If no compilation happened, return the old Linkable.
-upsweep_mod :: GhcMonad m =>
- HscEnv
- -> HomePackageTable
- -> ([ModuleName],[ModuleName])
- -> ModSummary
- -> Int -- index of module
- -> Int -- total number of modules
- -> m HomeModInfo
-
-upsweep_mod hsc_env old_hpt (stable_obj, stable_bco) summary mod_index nmods
- = let
- this_mod_name = ms_mod_name summary
- this_mod = ms_mod summary
- mb_obj_date = ms_obj_date summary
- obj_fn = ml_obj_file (ms_location summary)
- hs_date = ms_hs_date summary
-
- is_stable_obj = this_mod_name `elem` stable_obj
- is_stable_bco = this_mod_name `elem` stable_bco
-
- old_hmi = lookupUFM old_hpt this_mod_name
-
- -- We're using the dflags for this module now, obtained by
- -- applying any options in its LANGUAGE & OPTIONS_GHC pragmas.
- dflags = ms_hspp_opts summary
- prevailing_target = hscTarget (hsc_dflags hsc_env)
- local_target = hscTarget dflags
-
- -- If OPTIONS_GHC contains -fasm or -fvia-C, be careful that
- -- we don't do anything dodgy: these should only work to change
- -- from -fvia-C to -fasm and vice-versa, otherwise we could
- -- end up trying to link object code to byte code.
- target = if prevailing_target /= local_target
- && (not (isObjectTarget prevailing_target)
- || not (isObjectTarget local_target))
- then prevailing_target
- else local_target
-
- -- store the corrected hscTarget into the summary
- summary' = summary{ ms_hspp_opts = dflags { hscTarget = target } }
-
- -- The old interface is ok if
- -- a) we're compiling a source file, and the old HPT
- -- entry is for a source file
- -- b) we're compiling a hs-boot file
- -- Case (b) allows an hs-boot file to get the interface of its
- -- real source file on the second iteration of the compilation
- -- manager, but that does no harm. Otherwise the hs-boot file
- -- will always be recompiled
-
- mb_old_iface
- = case old_hmi of
- Nothing -> Nothing
- Just hm_info | isBootSummary summary -> Just iface
- | not (mi_boot iface) -> Just iface
- | otherwise -> Nothing
- where
- iface = hm_iface hm_info
-
- compile_it :: GhcMonad m => Maybe Linkable -> m HomeModInfo
- compile_it = compile hsc_env summary' mod_index nmods mb_old_iface
-
- compile_it_discard_iface :: GhcMonad m =>
- Maybe Linkable -> m HomeModInfo
- compile_it_discard_iface
- = compile hsc_env summary' mod_index nmods Nothing
-
- -- With the HscNothing target we create empty linkables to avoid
- -- recompilation. We have to detect these to recompile anyway if
- -- the target changed since the last compile.
- is_fake_linkable
- | Just hmi <- old_hmi, Just l <- hm_linkable hmi =
- null (linkableUnlinked l)
- | otherwise =
- -- we have no linkable, so it cannot be fake
- False
-
- implies False _ = True
- implies True x = x
-
- in
- case () of
- _
- -- Regardless of whether we're generating object code or
- -- byte code, we can always use an existing object file
- -- if it is *stable* (see checkStability).
- | is_stable_obj, Just hmi <- old_hmi -> do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "skipping stable obj mod:" <+> ppr this_mod_name)
- return hmi
- -- object is stable, and we have an entry in the
- -- old HPT: nothing to do
-
- | is_stable_obj, isNothing old_hmi -> do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "compiling stable on-disk mod:" <+> ppr this_mod_name)
- linkable <- liftIO $ findObjectLinkable this_mod obj_fn
- (expectJust "upsweep1" mb_obj_date)
- compile_it (Just linkable)
- -- object is stable, but we need to load the interface
- -- off disk to make a HMI.
-
- | not (isObjectTarget target), is_stable_bco,
- (target /= HscNothing) `implies` not is_fake_linkable ->
- ASSERT(isJust old_hmi) -- must be in the old_hpt
- let Just hmi = old_hmi in do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "skipping stable BCO mod:" <+> ppr this_mod_name)
- return hmi
- -- BCO is stable: nothing to do
-
- | not (isObjectTarget target),
- Just hmi <- old_hmi,
- Just l <- hm_linkable hmi,
- not (isObjectLinkable l),
- (target /= HscNothing) `implies` not is_fake_linkable,
- linkableTime l >= ms_hs_date summary -> do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "compiling non-stable BCO mod:" <+> ppr this_mod_name)
- compile_it (Just l)
- -- we have an old BCO that is up to date with respect
- -- to the source: do a recompilation check as normal.
-
- -- When generating object code, if there's an up-to-date
- -- object file on the disk, then we can use it.
- -- However, if the object file is new (compared to any
- -- linkable we had from a previous compilation), then we
- -- must discard any in-memory interface, because this
- -- means the user has compiled the source file
- -- separately and generated a new interface, that we must
- -- read from the disk.
- --
- | isObjectTarget target,
- Just obj_date <- mb_obj_date,
- obj_date >= hs_date -> do
- case old_hmi of
- Just hmi
- | Just l <- hm_linkable hmi,
- isObjectLinkable l && linkableTime l == obj_date -> do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "compiling mod with new on-disk obj:" <+> ppr this_mod_name)
- compile_it (Just l)
- _otherwise -> do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "compiling mod with new on-disk obj2:" <+> ppr this_mod_name)
- linkable <- liftIO $ findObjectLinkable this_mod obj_fn obj_date
- compile_it_discard_iface (Just linkable)
-
- _otherwise -> do
- liftIO $ debugTraceMsg (hsc_dflags hsc_env) 5
- (text "compiling mod:" <+> ppr this_mod_name)
- compile_it Nothing
-
-
-
--- Filter modules in the HPT
-retainInTopLevelEnvs :: [ModuleName] -> HomePackageTable -> HomePackageTable
-retainInTopLevelEnvs keep_these hpt
- = listToUFM [ (mod, expectJust "retain" mb_mod_info)
- | mod <- keep_these
- , let mb_mod_info = lookupUFM hpt mod
- , isJust mb_mod_info ]
-
--- ---------------------------------------------------------------------------
--- Typecheck module loops
-
-{-
-See bug #930. This code fixes a long-standing bug in --make. The
-problem is that when compiling the modules *inside* a loop, a data
-type that is only defined at the top of the loop looks opaque; but
-after the loop is done, the structure of the data type becomes
-apparent.
-
-The difficulty is then that two different bits of code have
-different notions of what the data type looks like.
-
-The idea is that after we compile a module which also has an .hs-boot
-file, we re-generate the ModDetails for each of the modules that
-depends on the .hs-boot file, so that everyone points to the proper
-TyCons, Ids etc. defined by the real module, not the boot module.
-Fortunately re-generating a ModDetails from a ModIface is easy: the
-function TcIface.typecheckIface does exactly that.
-
-Picking the modules to re-typecheck is slightly tricky. Starting from
-the module graph consisting of the modules that have already been
-compiled, we reverse the edges (so they point from the imported module
-to the importing module), and depth-first-search from the .hs-boot
-node. This gives us all the modules that depend transitively on the
-.hs-boot module, and those are exactly the modules that we need to
-re-typecheck.
-
-Following this fix, GHC can compile itself with --make -O2.
--}
-
-reTypecheckLoop :: HscEnv -> ModSummary -> ModuleGraph -> IO HscEnv
-reTypecheckLoop hsc_env ms graph
- | not (isBootSummary ms) &&
- any (\m -> ms_mod m == this_mod && isBootSummary m) graph
- = do
- let mss = reachableBackwards (ms_mod_name ms) graph
- non_boot = filter (not.isBootSummary) mss
- debugTraceMsg (hsc_dflags hsc_env) 2 $
- text "Re-typechecking loop: " <> ppr (map ms_mod_name non_boot)
- typecheckLoop hsc_env (map ms_mod_name non_boot)
- | otherwise
- = return hsc_env
- where
- this_mod = ms_mod ms
-
-typecheckLoop :: HscEnv -> [ModuleName] -> IO HscEnv
-typecheckLoop hsc_env mods = do
- new_hpt <-
- fixIO $ \new_hpt -> do
- let new_hsc_env = hsc_env{ hsc_HPT = new_hpt }
- mds <- initIfaceCheck new_hsc_env $
- mapM (typecheckIface . hm_iface) hmis
- let new_hpt = addListToUFM old_hpt
- (zip mods [ hmi{ hm_details = details }
- | (hmi,details) <- zip hmis mds ])
- return new_hpt
- return hsc_env{ hsc_HPT = new_hpt }
- where
- old_hpt = hsc_HPT hsc_env
- hmis = map (expectJust "typecheckLoop" . lookupUFM old_hpt) mods
-
-reachableBackwards :: ModuleName -> [ModSummary] -> [ModSummary]
-reachableBackwards mod summaries
- = [ ms | (ms,_,_) <- reachableG (transposeG graph) root ]
- where -- the rest just sets up the graph:
- (graph, lookup_node) = moduleGraphNodes False summaries
- root = expectJust "reachableBackwards" (lookup_node HsBootFile mod)
-
--- ---------------------------------------------------------------------------
--- Topological sort of the module graph
-
-type SummaryNode = (ModSummary, Int, [Int])
-
-topSortModuleGraph
- :: Bool
- -- ^ Drop hi-boot nodes? (see below)
- -> [ModSummary]
- -> Maybe ModuleName
- -- ^ Root module name. If @Nothing@, use the full graph.
- -> [SCC ModSummary]
--- ^ Calculate SCCs of the module graph, possibly dropping the hi-boot nodes
--- The resulting list of strongly-connected-components is in topologically
--- sorted order, starting with the module(s) at the bottom of the
--- dependency graph (ie compile them first) and ending with the ones at
--- the top.
---
--- Drop hi-boot nodes (first boolean arg)?
---
--- - @False@: treat the hi-boot summaries as nodes of the graph,
--- so the graph must be acyclic
---
--- - @True@: eliminate the hi-boot nodes, and instead pretend
--- the a source-import of Foo is an import of Foo
--- The resulting graph has no hi-boot nodes, but can be cyclic
-
-topSortModuleGraph drop_hs_boot_nodes summaries mb_root_mod
- = map (fmap summaryNodeSummary) $ stronglyConnCompG initial_graph
- where
- (graph, lookup_node) = moduleGraphNodes drop_hs_boot_nodes summaries
-
- initial_graph = case mb_root_mod of
- Nothing -> graph
- Just root_mod ->
- -- restrict the graph to just those modules reachable from
- -- the specified module. We do this by building a graph with
- -- the full set of nodes, and determining the reachable set from
- -- the specified node.
- let root | Just node <- lookup_node HsSrcFile root_mod, graph `hasVertexG` node = node
- | otherwise = ghcError (ProgramError "module does not exist")
- in graphFromEdgedVertices (seq root (reachableG graph root))
-
-summaryNodeKey :: SummaryNode -> Int
-summaryNodeKey (_, k, _) = k
-
-summaryNodeSummary :: SummaryNode -> ModSummary
-summaryNodeSummary (s, _, _) = s
-
-moduleGraphNodes :: Bool -> [ModSummary]
- -> (Graph SummaryNode, HscSource -> ModuleName -> Maybe SummaryNode)
-moduleGraphNodes drop_hs_boot_nodes summaries = (graphFromEdgedVertices nodes, lookup_node)
- where
- numbered_summaries = zip summaries [1..]
-
- lookup_node :: HscSource -> ModuleName -> Maybe SummaryNode
- lookup_node hs_src mod = lookupFM node_map (mod, hs_src)
-
- lookup_key :: HscSource -> ModuleName -> Maybe Int
- lookup_key hs_src mod = fmap summaryNodeKey (lookup_node hs_src mod)
-
- node_map :: NodeMap SummaryNode
- node_map = listToFM [ ((moduleName (ms_mod s), ms_hsc_src s), node)
- | node@(s, _, _) <- nodes ]
-
- -- We use integers as the keys for the SCC algorithm
- nodes :: [SummaryNode]
- nodes = [ (s, key, out_keys)
- | (s, key) <- numbered_summaries
- -- Drop the hi-boot ones if told to do so
- , not (isBootSummary s && drop_hs_boot_nodes)
- , let out_keys = out_edge_keys hs_boot_key (map unLoc (ms_home_srcimps s)) ++
- out_edge_keys HsSrcFile (map unLoc (ms_home_imps s)) ++
- (-- see [boot-edges] below
- if drop_hs_boot_nodes || ms_hsc_src s == HsBootFile
- then []
- else case lookup_key HsBootFile (ms_mod_name s) of
- Nothing -> []
- Just k -> [k]) ]
-
- -- [boot-edges] if this is a .hs and there is an equivalent
- -- .hs-boot, add a link from the former to the latter. This
- -- has the effect of detecting bogus cases where the .hs-boot
- -- depends on the .hs, by introducing a cycle. Additionally,
- -- it ensures that we will always process the .hs-boot before
- -- the .hs, and so the HomePackageTable will always have the
- -- most up to date information.
-
- -- Drop hs-boot nodes by using HsSrcFile as the key
- hs_boot_key | drop_hs_boot_nodes = HsSrcFile
- | otherwise = HsBootFile
-
- out_edge_keys :: HscSource -> [ModuleName] -> [Int]
- out_edge_keys hi_boot ms = mapCatMaybes (lookup_key hi_boot) ms
- -- If we want keep_hi_boot_nodes, then we do lookup_key with
- -- the IsBootInterface parameter True; else False
-
-
-type NodeKey = (ModuleName, HscSource) -- The nodes of the graph are
-type NodeMap a = FiniteMap NodeKey a -- keyed by (mod, src_file_type) pairs
-
-msKey :: ModSummary -> NodeKey
-msKey (ModSummary { ms_mod = mod, ms_hsc_src = boot }) = (moduleName mod,boot)
-
-mkNodeMap :: [ModSummary] -> NodeMap ModSummary
-mkNodeMap summaries = listToFM [ (msKey s, s) | s <- summaries]
-
-nodeMapElts :: NodeMap a -> [a]
-nodeMapElts = eltsFM
-
--- | If there are {-# SOURCE #-} imports between strongly connected
--- components in the topological sort, then those imports can
--- definitely be replaced by ordinary non-SOURCE imports: if SOURCE
--- were necessary, then the edge would be part of a cycle.
-warnUnnecessarySourceImports :: GhcMonad m => [SCC ModSummary] -> m ()
-warnUnnecessarySourceImports sccs =
- logWarnings (listToBag (concatMap (check.flattenSCC) sccs))
- where check ms =
- let mods_in_this_cycle = map ms_mod_name ms in
- [ warn i | m <- ms, i <- ms_home_srcimps m,
- unLoc i `notElem` mods_in_this_cycle ]
-
- warn :: Located ModuleName -> WarnMsg
- warn (L loc mod) =
- mkPlainErrMsg loc
- (ptext (sLit "Warning: {-# SOURCE #-} unnecessary in import of ")
- <+> quotes (ppr mod))
-
------------------------------------------------------------------------------
--- Downsweep (dependency analysis)
-
--- Chase downwards from the specified root set, returning summaries
--- for all home modules encountered. Only follow source-import
--- links.
-
--- We pass in the previous collection of summaries, which is used as a
--- cache to avoid recalculating a module summary if the source is
--- unchanged.
---
--- The returned list of [ModSummary] nodes has one node for each home-package
--- module, plus one for any hs-boot files. The imports of these nodes
--- are all there, including the imports of non-home-package modules.
-
-downsweep :: GhcMonad m =>
- HscEnv
- -> [ModSummary] -- Old summaries
- -> [ModuleName] -- Ignore dependencies on these; treat
- -- them as if they were package modules
- -> Bool -- True <=> allow multiple targets to have
- -- the same module name; this is
- -- very useful for ghc -M
- -> m [ModSummary]
- -- The elts of [ModSummary] all have distinct
- -- (Modules, IsBoot) identifiers, unless the Bool is true
- -- in which case there can be repeats
-downsweep hsc_env old_summaries excl_mods allow_dup_roots
- = do -- catch error messages and return them
- --handleErrMsg -- should be covered by GhcMonad now
- -- (\err_msg -> printBagOfErrors (hsc_dflags hsc_env) (unitBag err_msg) >> return Nothing) $ do
- rootSummaries <- mapM getRootSummary roots
- let root_map = mkRootMap rootSummaries
- checkDuplicates root_map
- summs <- loop (concatMap msDeps rootSummaries) root_map
- return summs
- where
- roots = hsc_targets hsc_env
-
- old_summary_map :: NodeMap ModSummary
- old_summary_map = mkNodeMap old_summaries
-
- getRootSummary :: GhcMonad m => Target -> m ModSummary
- getRootSummary (Target (TargetFile file mb_phase) obj_allowed maybe_buf)
- = do exists <- liftIO $ doesFileExist file
- if exists
- then summariseFile hsc_env old_summaries file mb_phase
- obj_allowed maybe_buf
- else throwOneError $ mkPlainErrMsg noSrcSpan $
- text "can't find file:" <+> text file
- getRootSummary (Target (TargetModule modl) obj_allowed maybe_buf)
- = do maybe_summary <- summariseModule hsc_env old_summary_map False
- (L rootLoc modl) obj_allowed
- maybe_buf excl_mods
- case maybe_summary of
- Nothing -> packageModErr modl
- Just s -> return s
-
- rootLoc = mkGeneralSrcSpan (fsLit "<command line>")
-
- -- In a root module, the filename is allowed to diverge from the module
- -- name, so we have to check that there aren't multiple root files
- -- defining the same module (otherwise the duplicates will be silently
- -- ignored, leading to confusing behaviour).
- checkDuplicates :: GhcMonad m => NodeMap [ModSummary] -> m ()
- checkDuplicates root_map
- | allow_dup_roots = return ()
- | null dup_roots = return ()
- | otherwise = liftIO $ multiRootsErr (head dup_roots)
- where
- dup_roots :: [[ModSummary]] -- Each at least of length 2
- dup_roots = filterOut isSingleton (nodeMapElts root_map)
-
- loop :: GhcMonad m =>
- [(Located ModuleName,IsBootInterface)]
- -- Work list: process these modules
- -> NodeMap [ModSummary]
- -- Visited set; the range is a list because
- -- the roots can have the same module names
- -- if allow_dup_roots is True
- -> m [ModSummary]
- -- The result includes the worklist, except
- -- for those mentioned in the visited set
- loop [] done = return (concat (nodeMapElts done))
- loop ((wanted_mod, is_boot) : ss) done
- | Just summs <- lookupFM done key
- = if isSingleton summs then
- loop ss done
- else
- do { liftIO $ multiRootsErr summs; return [] }
- | otherwise
- = do mb_s <- summariseModule hsc_env old_summary_map
- is_boot wanted_mod True
- Nothing excl_mods
- case mb_s of
- Nothing -> loop ss done
- Just s -> loop (msDeps s ++ ss) (addToFM done key [s])
- where
- key = (unLoc wanted_mod, if is_boot then HsBootFile else HsSrcFile)
-
-mkRootMap :: [ModSummary] -> NodeMap [ModSummary]
-mkRootMap summaries = addListToFM_C (++) emptyFM
- [ (msKey s, [s]) | s <- summaries ]
-
-msDeps :: ModSummary -> [(Located ModuleName, IsBootInterface)]
--- (msDeps s) returns the dependencies of the ModSummary s.
--- A wrinkle is that for a {-# SOURCE #-} import we return
--- *both* the hs-boot file
--- *and* the source file
--- as "dependencies". That ensures that the list of all relevant
--- modules always contains B.hs if it contains B.hs-boot.
--- Remember, this pass isn't doing the topological sort. It's
--- just gathering the list of all relevant ModSummaries
-msDeps s =
- concat [ [(m,True), (m,False)] | m <- ms_home_srcimps s ]
- ++ [ (m,False) | m <- ms_home_imps s ]
-
-home_imps :: [Located (ImportDecl RdrName)] -> [Located ModuleName]
-home_imps imps = [ ideclName i | L _ i <- imps, isLocal (ideclPkgQual i) ]
- where isLocal Nothing = True
- isLocal (Just pkg) | pkg == fsLit "this" = True -- "this" is special
- isLocal _ = False
-
-ms_home_allimps :: ModSummary -> [ModuleName]
-ms_home_allimps ms = map unLoc (ms_home_srcimps ms ++ ms_home_imps ms)
-
-ms_home_srcimps :: ModSummary -> [Located ModuleName]
-ms_home_srcimps = home_imps . ms_srcimps
-
-ms_home_imps :: ModSummary -> [Located ModuleName]
-ms_home_imps = home_imps . ms_imps
-
------------------------------------------------------------------------------
--- Summarising modules
-
--- We have two types of summarisation:
---
--- * Summarise a file. This is used for the root module(s) passed to
--- cmLoadModules. The file is read, and used to determine the root
--- module name. The module name may differ from the filename.
---
--- * Summarise a module. We are given a module name, and must provide
--- a summary. The finder is used to locate the file in which the module
--- resides.
-
-summariseFile
- :: GhcMonad m =>
- HscEnv
- -> [ModSummary] -- old summaries
- -> FilePath -- source file name
- -> Maybe Phase -- start phase
- -> Bool -- object code allowed?
- -> Maybe (StringBuffer,ClockTime)
- -> m ModSummary
-
-summariseFile hsc_env old_summaries file mb_phase obj_allowed maybe_buf
- -- we can use a cached summary if one is available and the
- -- source file hasn't changed, But we have to look up the summary
- -- by source file, rather than module name as we do in summarise.
- | Just old_summary <- findSummaryBySourceFile old_summaries file
- = do
- let location = ms_location old_summary
-
- -- return the cached summary if the source didn't change
- src_timestamp <- case maybe_buf of
- Just (_,t) -> return t
- Nothing -> liftIO $ getModificationTime file
- -- The file exists; we checked in getRootSummary above.
- -- If it gets removed subsequently, then this
- -- getModificationTime may fail, but that's the right
- -- behaviour.
-
- if ms_hs_date old_summary == src_timestamp
- then do -- update the object-file timestamp
- obj_timestamp <-
- if isObjectTarget (hscTarget (hsc_dflags hsc_env))
- || obj_allowed -- bug #1205
- then liftIO $ getObjTimestamp location False
- else return Nothing
- return old_summary{ ms_obj_date = obj_timestamp }
- else
- new_summary
-
- | otherwise
- = new_summary
- where
- new_summary = do
- let dflags = hsc_dflags hsc_env
-
- (dflags', hspp_fn, buf)
- <- preprocessFile hsc_env file mb_phase maybe_buf
-
- (srcimps,the_imps, L _ mod_name) <- getImports dflags' buf hspp_fn file
-
- -- Make a ModLocation for this file
- location <- liftIO $ mkHomeModLocation dflags mod_name file
-
- -- Tell the Finder cache where it is, so that subsequent calls
- -- to findModule will find it, even if it's not on any search path
- mod <- liftIO $ addHomeModuleToFinder hsc_env mod_name location
-
- src_timestamp <- case maybe_buf of
- Just (_,t) -> return t
- Nothing -> liftIO $ getModificationTime file
- -- getMofificationTime may fail
-
- -- when the user asks to load a source file by name, we only
- -- use an object file if -fobject-code is on. See #1205.
- obj_timestamp <-
- if isObjectTarget (hscTarget (hsc_dflags hsc_env))
- || obj_allowed -- bug #1205
- then liftIO $ modificationTimeIfExists (ml_obj_file location)
- else return Nothing
-
- return (ModSummary { ms_mod = mod, ms_hsc_src = HsSrcFile,
- ms_location = location,
- ms_hspp_file = hspp_fn,
- ms_hspp_opts = dflags',
- ms_hspp_buf = Just buf,
- ms_srcimps = srcimps, ms_imps = the_imps,
- ms_hs_date = src_timestamp,
- ms_obj_date = obj_timestamp })
-
-findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
-findSummaryBySourceFile summaries file
- = case [ ms | ms <- summaries, HsSrcFile <- [ms_hsc_src ms],
- expectJust "findSummaryBySourceFile" (ml_hs_file (ms_location ms)) == file ] of
- [] -> Nothing
- (x:_) -> Just x
-
--- Summarise a module, and pick up source and timestamp.
-summariseModule
- :: GhcMonad m =>
- HscEnv
- -> NodeMap ModSummary -- Map of old summaries
- -> IsBootInterface -- True <=> a {-# SOURCE #-} import
- -> Located ModuleName -- Imported module to be summarised
- -> Bool -- object code allowed?
- -> Maybe (StringBuffer, ClockTime)
- -> [ModuleName] -- Modules to exclude
- -> m (Maybe ModSummary) -- Its new summary
-
-summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod)
- obj_allowed maybe_buf excl_mods
- | wanted_mod `elem` excl_mods
- = return Nothing
-
- | Just old_summary <- lookupFM old_summary_map (wanted_mod, hsc_src)
- = do -- Find its new timestamp; all the
- -- ModSummaries in the old map have valid ml_hs_files
- let location = ms_location old_summary
- src_fn = expectJust "summariseModule" (ml_hs_file location)
-
- -- check the modification time on the source file, and
- -- return the cached summary if it hasn't changed. If the
- -- file has disappeared, we need to call the Finder again.
- case maybe_buf of
- Just (_,t) -> check_timestamp old_summary location src_fn t
- Nothing -> do
- m <- liftIO $ System.IO.Error.try (getModificationTime src_fn)
- case m of
- Right t -> check_timestamp old_summary location src_fn t
- Left e | isDoesNotExistError e -> find_it
- | otherwise -> liftIO $ ioError e
-
- | otherwise = find_it
- where
- dflags = hsc_dflags hsc_env
-
- hsc_src = if is_boot then HsBootFile else HsSrcFile
-
- check_timestamp old_summary location src_fn src_timestamp
- | ms_hs_date old_summary == src_timestamp = do
- -- update the object-file timestamp
- obj_timestamp <- liftIO $
- if isObjectTarget (hscTarget (hsc_dflags hsc_env))
- || obj_allowed -- bug #1205
- then getObjTimestamp location is_boot
- else return Nothing
- return (Just old_summary{ ms_obj_date = obj_timestamp })
- | otherwise =
- -- source changed: re-summarise.
- new_summary location (ms_mod old_summary) src_fn src_timestamp
-
- find_it = do
- -- Don't use the Finder's cache this time. If the module was
- -- previously a package module, it may have now appeared on the
- -- search path, so we want to consider it to be a home module. If
- -- the module was previously a home module, it may have moved.
- liftIO $ uncacheModule hsc_env wanted_mod
- found <- liftIO $ findImportedModule hsc_env wanted_mod Nothing
- case found of
- Found location mod
- | isJust (ml_hs_file location) ->
- -- Home package
- just_found location mod
- | otherwise ->
- -- Drop external-pkg
- ASSERT(modulePackageId mod /= thisPackage dflags)
- return Nothing
-
- err -> liftIO $ noModError dflags loc wanted_mod err
- -- Not found
-
- just_found location mod = do
- -- Adjust location to point to the hs-boot source file,
- -- hi file, object file, when is_boot says so
- let location' | is_boot = addBootSuffixLocn location
- | otherwise = location
- src_fn = expectJust "summarise2" (ml_hs_file location')
-
- -- Check that it exists
- -- It might have been deleted since the Finder last found it
- maybe_t <- liftIO $ modificationTimeIfExists src_fn
- case maybe_t of
- Nothing -> noHsFileErr loc src_fn
- Just t -> new_summary location' mod src_fn t
-
-
- new_summary location mod src_fn src_timestamp
- = do
- -- Preprocess the source file and get its imports
- -- The dflags' contains the OPTIONS pragmas
- (dflags', hspp_fn, buf) <- preprocessFile hsc_env src_fn Nothing maybe_buf
- (srcimps, the_imps, L mod_loc mod_name) <- getImports dflags' buf hspp_fn src_fn
-
- when (mod_name /= wanted_mod) $
- throwOneError $ mkPlainErrMsg mod_loc $
- text "File name does not match module name:"
- $$ text "Saw:" <+> quotes (ppr mod_name)
- $$ text "Expected:" <+> quotes (ppr wanted_mod)
-
- -- Find the object timestamp, and return the summary
- obj_timestamp <- liftIO $
- if isObjectTarget (hscTarget (hsc_dflags hsc_env))
- || obj_allowed -- bug #1205
- then getObjTimestamp location is_boot
- else return Nothing
-
- return (Just (ModSummary { ms_mod = mod,
- ms_hsc_src = hsc_src,
- ms_location = location,
- ms_hspp_file = hspp_fn,
- ms_hspp_opts = dflags',
- ms_hspp_buf = Just buf,
- ms_srcimps = srcimps,
- ms_imps = the_imps,
- ms_hs_date = src_timestamp,
- ms_obj_date = obj_timestamp }))
-
-
-getObjTimestamp :: ModLocation -> Bool -> IO (Maybe ClockTime)
-getObjTimestamp location is_boot
- = if is_boot then return Nothing
- else modificationTimeIfExists (ml_obj_file location)
-
-
-preprocessFile :: GhcMonad m =>
- HscEnv
- -> FilePath
- -> Maybe Phase -- ^ Starting phase
- -> Maybe (StringBuffer,ClockTime)
- -> m (DynFlags, FilePath, StringBuffer)
-preprocessFile hsc_env src_fn mb_phase Nothing
- = do
- (dflags', hspp_fn) <- preprocess hsc_env (src_fn, mb_phase)
- buf <- liftIO $ hGetStringBuffer hspp_fn
- return (dflags', hspp_fn, buf)
-
-preprocessFile hsc_env src_fn mb_phase (Just (buf, _time))
- = do
- let dflags = hsc_dflags hsc_env
- -- case we bypass the preprocessing stage?
- let
- local_opts = getOptions dflags buf src_fn
- --
- (dflags', leftovers, warns)
- <- parseDynamicNoPackageFlags dflags local_opts
- checkProcessArgsResult leftovers
- handleFlagWarnings dflags' warns
-
- let
- needs_preprocessing
- | Just (Unlit _) <- mb_phase = True
- | Nothing <- mb_phase, Unlit _ <- startPhase src_fn = True
- -- note: local_opts is only required if there's no Unlit phase
- | dopt Opt_Cpp dflags' = True
- | dopt Opt_Pp dflags' = True
- | otherwise = False
-
- when needs_preprocessing $
- ghcError (ProgramError "buffer needs preprocesing; interactive check disabled")
-
- return (dflags', src_fn, buf)
-
-
------------------------------------------------------------------------------
--- Error messages
------------------------------------------------------------------------------
-
-noModError :: DynFlags -> SrcSpan -> ModuleName -> FindResult -> IO ab
--- ToDo: we don't have a proper line number for this error
-noModError dflags loc wanted_mod err
- = throwOneError $ mkPlainErrMsg loc $ cannotFindModule dflags wanted_mod err
-
-noHsFileErr :: GhcMonad m => SrcSpan -> String -> m a
-noHsFileErr loc path
- = throwOneError $ mkPlainErrMsg loc $ text "Can't find" <+> text path
-
-packageModErr :: GhcMonad m => ModuleName -> m a
-packageModErr mod
- = throwOneError $ mkPlainErrMsg noSrcSpan $
- text "module" <+> quotes (ppr mod) <+> text "is a package module"
-
-multiRootsErr :: [ModSummary] -> IO ()
-multiRootsErr [] = panic "multiRootsErr"
-multiRootsErr summs@(summ1:_)
- = throwOneError $ mkPlainErrMsg noSrcSpan $
- text "module" <+> quotes (ppr mod) <+>
- text "is defined in multiple files:" <+>
- sep (map text files)
- where
- mod = ms_mod summ1
- files = map (expectJust "checkDup" . ml_hs_file . ms_location) summs
-
-cyclicModuleErr :: [ModSummary] -> SDoc
-cyclicModuleErr ms
- = hang (ptext (sLit "Module imports form a cycle for modules:"))
- 2 (vcat (map show_one ms))
- where
- mods_in_cycle = map ms_mod_name ms
- imp_modname = unLoc . ideclName . unLoc
- just_in_cycle = filter ((`elem` mods_in_cycle) . imp_modname)
-
- show_one ms =
- vcat [ show_mod (ms_hsc_src ms) (ms_mod_name ms) <+>
- maybe empty (parens . text) (ml_hs_file (ms_location ms)),
- nest 2 $ ptext (sLit "imports:") <+> vcat [
- pp_imps HsBootFile (just_in_cycle $ ms_srcimps ms),
- pp_imps HsSrcFile (just_in_cycle $ ms_imps ms) ]
- ]
- show_mod hsc_src mod = ppr mod <> text (hscSourceString hsc_src)
- pp_imps src imps = fsep (map (show_mod src . unLoc . ideclName . unLoc) imps)
-
-
--- | Inform GHC that the working directory has changed. GHC will flush
--- its cache of module locations, since it may no longer be valid.
---
--- Note: Before changing the working directory make sure all threads running
--- in the same session have stopped. If you change the working directory,
--- you should also unload the current program (set targets to empty,
--- followed by load).
-workingDirectoryChanged :: GhcMonad m => m ()
-workingDirectoryChanged = withSession $ (liftIO . flushFinderCaches)
-
--- -----------------------------------------------------------------------------
--- inspecting the session