Loading interface files
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module LoadIface (
loadInterface, loadInterfaceForName, loadWiredInHomeIface,
loadSrcInterface, loadSysInterface, loadOrphanModules,
#include "HsVersions.h"
import {-# SOURCE #-} TcIface( tcIfaceDecl, tcIfaceRules, tcIfaceInst,
- tcIfaceFamInst )
+ tcIfaceFamInst, tcIfaceVectInfo )
import DynFlags
import IfaceSyn
import Maybes
import ErrUtils
import Finder
-import UniqFM
+import LazyUniqFM
import StaticFlags
import Outputable
import BinIface
-- interface; it will call the Finder again, but the ModLocation will be
-- cached from the first search.
hsc_env <- getTopEnv
- res <- ioToIOEnv $ findImportedModule hsc_env mod Nothing
+ res <- liftIO $ findImportedModule hsc_env mod Nothing
case res of
Found _ mod -> do
mb_iface <- initIfaceTcRn $ loadInterface doc mod (ImportByUser want_boot)
-> Bool -- these are family instance-modules
-> TcM ()
loadOrphanModules mods isFamInstMod
- | null mods = returnM ()
+ | null mods = return ()
| otherwise = initIfaceTcRn $
do { traceIf (text "Loading orphan modules:" <+>
fsep (map ppr mods))
- ; mappM_ load mods
- ; returnM () }
+ ; mapM_ load mods
+ ; return () }
where
load mod = loadSysInterface (mk_doc mod) mod
mk_doc mod
-- | An 'IfM' function to load the home interface for a wired-in thing,
-- so that we're sure that we see its instance declarations and rules
+-- See Note [Loading instances]
loadWiredInHomeIface :: Name -> IfM lcl ()
loadWiredInHomeIface name
= ASSERT( isWiredInName name )
Succeeded iface -> return iface }
\end{code}
+Note [Loading instances]
+~~~~~~~~~~~~~~~~~~~~~~~~
+We need to make sure that we have at least *read* the interface files
+for any module with an instance decl or RULE that we might want.
+
+* If the instance decl is an orphan, we have a whole separate mechanism
+ (loadOprhanModules)
+
+* If the instance decl not an orphan, then the act of looking at the
+ TyCon or Class will force in the defining module for the
+ TyCon/Class, and hence the instance decl
+
+* BUT, if the TyCon is a wired-in TyCon, we don't really need its interface;
+ but we must make sure we read its interface in case it has instances or
+ rules. That is what LoadIface.loadWiredInHomeInterface does. It's called
+ from TcIface.{tcImportDecl, checkWiredInTyCon, ifCHeckWiredInThing}
+
+All of this is done by the type checker. The renamer plays no role.
+(It used to, but no longer.)
+
+
%*********************************************************
%* *
; dflags <- getDOpts
; case lookupIfaceByModule dflags hpt (eps_PIT eps) mod of {
Just iface
- -> returnM (Succeeded iface) ; -- Already loaded
+ -> return (Succeeded iface) ; -- Already loaded
-- The (src_imp == mi_boot iface) test checks that the already-loaded
-- interface isn't a boot iface. This can conceivably happen,
-- if an earlier import had a before we got to real imports. I think.
- other -> do
+ other -> do {
- { let { hi_boot_file = case from of
+ let { hi_boot_file = case from of
ImportByUser usr_boot -> usr_boot
ImportBySystem -> sys_boot
-- Not found, so add an empty iface to
-- the EPS map so that we don't look again
- ; returnM (Failed err) } ;
+ ; return (Failed err) } ;
-- Found and parsed!
Succeeded (iface, file_path) -- Sanity check:
modulePackageId (mi_module iface) == thisPackage dflags,
-- a home-package module...
Nothing <- mb_dep -- that we know nothing about
- -> returnM (Failed (badDepMsg mod))
+ -> return (Failed (badDepMsg mod))
| otherwise ->
--
-- The main thing is to add the ModIface to the PIT, but
-- we also take the
- -- IfaceDecls, IfaceInst, IfaceRules
+ -- IfaceDecls, IfaceInst, IfaceFamInst, IfaceRules, IfaceVectInfo
-- out of the ModIface and put them into the big EPS pools
-- NB: *first* we do loadDecl, so that the provenance of all the locally-defined
; new_eps_insts <- mapM tcIfaceInst (mi_insts iface)
; new_eps_fam_insts <- mapM tcIfaceFamInst (mi_fam_insts iface)
; new_eps_rules <- tcIfaceRules ignore_prags (mi_rules iface)
+ ; new_eps_vect_info <- tcIfaceVectInfo mod (mkNameEnv new_eps_decls)
+ (mi_vect_info iface)
; let { final_iface = iface {
mi_decls = panic "No mi_decls in PIT",
mi_insts = panic "No mi_insts in PIT",
mi_fam_insts = panic "No mi_fam_insts in PIT",
mi_rules = panic "No mi_rules in PIT"
- } }
+ }
+ }
; updateEps_ $ \ eps ->
eps {
new_eps_insts,
eps_fam_inst_env = extendFamInstEnvList (eps_fam_inst_env eps)
new_eps_fam_insts,
+ eps_vect_info = plusVectInfo (eps_vect_info eps)
+ new_eps_vect_info,
eps_mod_fam_inst_env
= let
fam_inst_env =
fam_inst_env,
eps_stats = addEpsInStats (eps_stats eps)
(length new_eps_decls)
- (length new_eps_insts) (length new_eps_rules) }
+ (length new_eps_insts)
+ (length new_eps_rules) }
; return (Succeeded final_iface)
}}}}
badDepMsg mod
= hang (ptext SLIT("Interface file inconsistency:"))
- 2 (sep [ptext SLIT("home-package module") <+> quotes (ppr mod) <+> ptext SLIT("is mentioned is needed,"),
- ptext SLIT("but is not among the dependencies of interfaces directly imported by the module being compiled")])
+ 2 (sep [ptext SLIT("home-package module") <+> quotes (ppr mod) <+> ptext SLIT("is needed,"),
+ ptext SLIT("but is not listed in the dependencies of the interfaces directly imported by the module being compiled")])
-----------------------------------------------------
-- Loading type/class/value decls
loadDecl ignore_prags mod (_version, decl)
= do { -- Populate the name cache with final versions of all
-- the names associated with the decl
- main_name <- mk_new_bndr mod (ifName decl)
- ; traceIf (text "Loading decl for " <> ppr main_name)
- ; implicit_names <- mapM (mk_new_bndr mod) (ifaceDeclSubBndrs decl)
+ main_name <- lookupOrig mod (ifName decl)
+-- ; traceIf (text "Loading decl for " <> ppr main_name)
+ ; implicit_names <- mapM (lookupOrig mod) (ifaceDeclSubBndrs decl)
-- Typecheck the thing, lazily
-- NB. Firstly, the laziness is there in case we never need the
; thing <- forkM doc $ do { bumpDeclStats main_name
; tcIfaceDecl ignore_prags decl }
- -- Populate the type environment with the implicitTyThings too
+ -- Populate the type environment with the implicitTyThings too.
+ --
+ -- Note [Tricky iface loop]
+ -- ~~~~~~~~~~~~~~~~~~~~~~~~
+ -- Summary: The delicate point here is that 'mini-env' must be
+ -- buildable from 'thing' without demanding any of the things
+ -- 'forkM'd by tcIfaceDecl.
+ --
+ -- In more detail: Consider the example
+ -- data T a = MkT { x :: T a }
+ -- The implicitTyThings of T are: [ <datacon MkT>, <selector x>]
+ -- (plus their workers, wrappers, coercions etc etc)
+ --
+ -- We want to return an environment
+ -- [ "MkT" -> <datacon MkT>, "x" -> <selector x>, ... ]
+ -- (where the "MkT" is the *Name* associated with MkT, etc.)
+ --
+ -- We do this by mapping the implict_names to the associated
+ -- TyThings. By the invariant on ifaceDeclSubBndrs and
+ -- implicitTyThings, we can use getOccName on the implicit
+ -- TyThings to make this association: each Name's OccName should
+ -- be the OccName of exactly one implictTyThing. So the key is
+ -- to define a "mini-env"
+ --
+ -- [ 'MkT' -> <datacon MkT>, 'x' -> <selector x>, ... ]
+ -- where the 'MkT' here is the *OccName* associated with MkT.
+ --
+ -- However, there is a subtlety: due to how type checking needs
+ -- to be staged, we can't poke on the forkM'd thunks inside the
+ -- implictTyThings while building this mini-env.
+ -- If we poke these thunks too early, two problems could happen:
+ -- (1) When processing mutually recursive modules across
+ -- hs-boot boundaries, poking too early will do the
+ -- type-checking before the recursive knot has been tied,
+ -- so things will be type-checked in the wrong
+ -- environment, and necessary variables won't be in
+ -- scope.
+ --
+ -- (2) Looking up one OccName in the mini_env will cause
+ -- others to be looked up, which might cause that
+ -- original one to be looked up again, and hence loop.
+ --
+ -- The code below works because of the following invariant:
+ -- getOccName on a TyThing does not force the suspended type
+ -- checks in order to extract the name. For example, we don't
+ -- poke on the "T a" type of <selector x> on the way to
+ -- extracting <selector x>'s OccName. Of course, there is no
+ -- reason in principle why getting the OccName should force the
+ -- thunks, but this means we need to be careful in
+ -- implicitTyThings and its helper functions.
+ --
+ -- All a bit too finely-balanced for my liking.
+
+ -- This mini-env and lookup function mediates between the
+ -- *Name*s n and the map from *OccName*s to the implicit TyThings
; let mini_env = mkOccEnv [(getOccName t, t) | t <- implicitTyThings thing]
lookup n = case lookupOccEnv mini_env (getOccName n) of
Just thing -> thing
Nothing ->
pprPanic "loadDecl" (ppr main_name <+> ppr n $$ ppr (decl))
- ; returnM $ (main_name, thing) : [(n, lookup n) | n <- implicit_names]
+ ; return $ (main_name, thing) :
+ -- uses the invariant that implicit_names and
+ -- implictTyThings are bijective
+ [(n, lookup n) | n <- implicit_names]
}
- -- We build a list from the *known* names, with (lookup n) thunks
- -- as the TyThings. That way we can extend the PTE without poking the
- -- thunks
where
- -- mk_new_bndr allocates in the name cache the final canonical
- -- name for the thing, with the correct
- -- * parent
- -- * location
- -- imported name, to fix the module correctly in the cache
- mk_new_bndr mod occ
- = newGlobalBinder mod occ
- (importedSrcLoc (showSDoc (ppr (moduleName mod))))
- -- ToDo: qualify with the package name if necessary
-
doc = ptext SLIT("Declaration for") <+> ppr (ifName decl)
bumpDeclStats :: Name -> IfL () -- Record that one more declaration has actually been used
-- Check for GHC.Prim, and return its static interface
; dflags <- getDOpts
; if mod == gHC_PRIM
- then returnM (Succeeded (ghcPrimIface,
+ then return (Succeeded (ghcPrimIface,
"<built in interface for GHC.Prim>"))
else do
-- Look for the file
; hsc_env <- getTopEnv
- ; mb_found <- ioToIOEnv (findHiFile hsc_env mod hi_boot_file)
+ ; mb_found <- liftIO (findExactModule hsc_env mod)
; case mb_found of {
- Failed err -> do
+
+ err | notFound err -> do
{ traceIf (ptext SLIT("...not found"))
; dflags <- getDOpts
- ; returnM (Failed (cannotFindInterface dflags
+ ; return (Failed (cannotFindInterface dflags
(moduleName mod) err)) } ;
-
- Succeeded file_path -> do
+ Found loc mod -> do
-- Found file, so read it
- { traceIf (ptext SLIT("readIFace") <+> text file_path)
+ { let { file_path = addBootSuffix_maybe hi_boot_file (ml_hi_file loc) }
+
+ ; if thisPackage dflags == modulePackageId mod
+ && not (isOneShot (ghcMode dflags))
+ then return (Failed (homeModError mod loc))
+ else do {
+
+ ; traceIf (ptext SLIT("readIFace") <+> text file_path)
; read_result <- readIface mod file_path hi_boot_file
; case read_result of
- Failed err -> returnM (Failed (badIfaceFile file_path err))
+ Failed err -> return (Failed (badIfaceFile file_path err))
Succeeded iface
| mi_module iface /= mod ->
return (Failed (wrongIfaceModErr iface mod file_path))
| otherwise ->
- returnM (Succeeded (iface, file_path))
+ return (Succeeded (iface, file_path))
-- Don't forget to fill in the package name...
- }}}
-
-findHiFile :: HscEnv -> Module -> IsBootInterface
- -> IO (MaybeErr FindResult FilePath)
-findHiFile hsc_env mod hi_boot_file
- = do
- maybe_found <- findExactModule hsc_env mod
- case maybe_found of
- Found loc mod -> return (Succeeded path)
- where
- path = addBootSuffix_maybe hi_boot_file (ml_hi_file loc)
- err -> return (Failed err)
+ }}}}
+
+notFound (Found _ _) = False
+notFound _ = True
\end{code}
@readIface@ tries just the one file.
readIface wanted_mod file_path is_hi_boot_file
= do { dflags <- getDOpts
- ; res <- tryMostM $ readBinIface file_path
+ ; res <- tryMostM $
+ readBinIface CheckHiWay QuietBinIFaceReading file_path
; case res of
Right iface
| wanted_mod == actual_mod -> return (Succeeded iface)
-- Initialise the EPS rule pool with the built-in rules
eps_mod_fam_inst_env
= emptyModuleEnv,
+ eps_vect_info = noVectInfo,
eps_stats = EpsStats { n_ifaces_in = 0, n_decls_in = 0, n_decls_out = 0
, n_insts_in = 0, n_insts_out = 0
, n_rules_in = length builtinRules, n_rules_out = 0 }
hsep [ int (n_rules_out stats), text "rule decls imported, out of",
int (n_rules_in stats), text "read"]
]
-\end{code}
+\end{code}
%************************************************************************
-- | Read binary interface, and print it out
showIface :: HscEnv -> FilePath -> IO ()
showIface hsc_env filename = do
- -- skip the version check; we don't want to worry about profiled vs.
+ -- skip the hi way check; we don't want to worry about profiled vs.
-- non-profiled interfaces, for example.
- writeIORef v_IgnoreHiWay True
- iface <- initTcRnIf 's' hsc_env () () $ readBinIface filename
+ iface <- initTcRnIf 's' hsc_env () () $
+ readBinIface IgnoreHiWay TraceBinIFaceReading filename
printDump (pprModIface iface)
\end{code}
<+> ppr (mi_mod_vers iface) <+> pp_sub_vers
<+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
<+> (if mi_finsts iface then ptext SLIT("[family instance module]") else empty)
- <+> int opt_HiVersion
+ <+> (if mi_hpc iface then ptext SLIT("[hpc]") else empty)
+ <+> integer opt_HiVersion
<+> ptext SLIT("where")
, vcat (map pprExport (mi_exports iface))
, pprDeps (mi_deps iface)
, pprFixities (mi_fixities iface)
, vcat (map pprIfaceDecl (mi_decls iface))
, vcat (map ppr (mi_insts iface))
+ , vcat (map ppr (mi_fam_insts iface))
, vcat (map ppr (mi_rules iface))
+ , pprVectInfo (mi_vect_info iface)
, pprDeprecs (mi_deprecs iface)
- ]
+ ]
where
pp_boot | mi_boot iface = ptext SLIT("[boot]")
| otherwise = empty
where
pprFix (occ,fix) = ppr fix <+> ppr occ
+pprVectInfo :: IfaceVectInfo -> SDoc
+pprVectInfo (IfaceVectInfo { ifaceVectInfoVar = vars
+ , ifaceVectInfoTyCon = tycons
+ , ifaceVectInfoTyConReuse = tyconsReuse
+ }) =
+ vcat
+ [ ptext SLIT("vectorised variables:") <+> hsep (map ppr vars)
+ , ptext SLIT("vectorised tycons:") <+> hsep (map ppr tycons)
+ , ptext SLIT("vectorised reused tycons:") <+> hsep (map ppr tyconsReuse)
+ ]
+
pprDeprecs NoDeprecs = empty
pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
]
]
where iface_file = doubleQuotes (text file_path)
+
+homeModError mod location
+ = ptext SLIT("attempting to use module ") <> quotes (ppr mod)
+ <> (case ml_hs_file location of
+ Just file -> space <> parens (text file)
+ Nothing -> empty)
+ <+> ptext SLIT("which is not loaded")
\end{code}