HscMain.hs 68.2 KB
Newer Older
1 2
{-# LANGUAGE BangPatterns, CPP, MagicHash, NondecreasingIndentation #-}

dterei's avatar
dterei committed
3 4
-------------------------------------------------------------------------------
--
5
-- | Main API for compiling plain Haskell source code.
6
--
dterei's avatar
dterei committed
7
-- This module implements compilation of a Haskell source. It is
8 9 10 11 12
-- /not/ concerned with preprocessing of source files; this is handled
-- in "DriverPipeline".
--
-- There are various entry points depending on what mode we're in:
-- "batch" mode (@--make@), "one-shot" mode (@-c@, @-S@ etc.), and
dterei's avatar
dterei committed
13
-- "interactive" mode (GHCi). There are also entry points for
14 15 16 17 18 19 20 21 22 23 24 25
-- individual passes: parsing, typechecking/renaming, desugaring, and
-- simplification.
--
-- All the functions here take an 'HscEnv' as a parameter, but none of
-- them return a new one: 'HscEnv' is treated as an immutable value
-- from here on in (although it has mutable components, for the
-- caches).
--
-- Warning messages are dealt with consistently throughout this API:
-- during compilation warnings are collected, and before any function
-- in @HscMain@ returns, the warnings are either printed, or turned
-- into a real compialtion error if the @-Werror@ flag is enabled.
26
--
dterei's avatar
dterei committed
27 28 29 30
-- (c) The GRASP/AQUA Project, Glasgow University, 1993-2000
--
-------------------------------------------------------------------------------

31
module HscMain
dterei's avatar
dterei committed
32
    (
33 34 35 36
    -- * Making an HscEnv
      newHscEnv

    -- * Compiling complete source files
37 38
    , Messager, batchMsg
    , HscStatus (..)
39 40 41 42
    , hscCompileOneShot
    , hscCompileCmmFile
    , hscCompileCore

43 44 45 46 47 48 49 50 51
    , genericHscCompileGetFrontendResult

    , genModDetails
    , hscSimpleIface
    , hscWriteIface
    , hscNormalIface
    , hscGenHardCode
    , hscInteractive

52
    -- * Running passes separately
Thomas Schilling's avatar
Thomas Schilling committed
53 54 55
    , hscParse
    , hscTypecheckRename
    , hscDesugar
Simon Marlow's avatar
Simon Marlow committed
56 57
    , makeSimpleIface
    , makeSimpleDetails
58 59 60 61 62 63
    , hscSimplify -- ToDo, shouldn't really export this

    -- * Support for interactive evaluation
    , hscParseIdentifier
    , hscTcRcLookupName
    , hscTcRnGetInfo
64
    , hscCheckSafe
dterei's avatar
dterei committed
65
    , hscGetSafe
66
#ifdef GHCI
dterei's avatar
dterei committed
67
    , hscIsGHCiMonad
68
    , hscGetModuleInterface
69
    , hscRnImportDecls
70
    , hscTcRnLookupRdrName
vivian's avatar
vivian committed
71
    , hscStmt, hscStmtWithLocation
72
    , hscDecls, hscDeclsWithLocation
vivian's avatar
vivian committed
73
    , hscTcExpr, hscImport, hscKcType
74
    , hscCompileCoreExpr
75 76
    -- * Low-level exports for hooks
    , hscCompileCoreExpr'
77
#endif
Edsko de Vries's avatar
Edsko de Vries committed
78 79
      -- We want to make sure that we export enough to be able to redefine
      -- hscFileFrontEnd in client code
80
    , hscParse', hscSimplify', hscDesugar', tcRnModule'
Edsko de Vries's avatar
Edsko de Vries committed
81
    , getHscEnv
82 83 84
    , hscSimpleIface', hscNormalIface'
    , oneShotMsg
    , hscFileFrontEnd, genericHscFrontend, dumpIfaceStats
85
    ) where
86

87
#ifdef GHCI
Simon Marlow's avatar
Simon Marlow committed
88
import Id
89
import BasicTypes       ( HValue )
90
import ByteCodeGen      ( byteCodeGen, coreExprToBCOs )
91
import Linker
92 93
import CoreTidy         ( tidyExpr )
import Type             ( Type )
94
import PrelNames
95
import {- Kind parts of -} Type         ( Kind )
96
import CoreLint         ( lintInteractiveExpr )
97 98
import DsMeta           ( templateHaskellNames )
import VarEnv           ( emptyTidyEnv )
simonpj@microsoft.com's avatar
simonpj@microsoft.com committed
99
import Panic
100
import ConLike
101 102

import GHC.Exts
103 104
#endif

105 106
import Module
import Packages
Simon Marlow's avatar
Simon Marlow committed
107 108
import RdrName
import HsSyn
109
import CoreSyn
Ian Lynagh's avatar
Ian Lynagh committed
110
import StringBuffer
111
import Parser
112
import Lexer
113 114
import SrcLoc
import TcRnDriver
115
import TcIface          ( typecheckIface )
116
import TcRnMonad
117 118
import IfaceEnv         ( initNameCache )
import LoadIface        ( ifaceStats, initExternalPackageState )
119
import PrelInfo
Simon Marlow's avatar
Simon Marlow committed
120
import MkIface
121 122
import Desugar
import SimplCore
Simon Marlow's avatar
Simon Marlow committed
123
import TidyPgm
124
import CorePrep
125 126
import CoreToStg        ( coreToStg )
import qualified StgCmm ( codeGen )
127 128
import StgSyn
import CostCentre
129
import ProfInit
130 131
import TyCon
import Name
132
import SimplStg         ( stg2stg )
133
import Cmm
134
import CmmParse         ( parseCmmFile )
135
import CmmBuildInfoTables
Edward Z. Yang's avatar
Edward Z. Yang committed
136
import CmmPipeline
137
import CmmInfo
138
import CodeOutput
139
import NameEnv          ( emptyNameEnv )
140 141
import NameSet          ( emptyNameSet )
import InstEnv
142
import FamInstEnv
Thomas Schilling's avatar
Thomas Schilling committed
143
import Fingerprint      ( Fingerprint )
144
import Hooks
145

146
import DynFlags
147
import ErrUtils
148

149
import Outputable
150
import HscStats         ( ppSourceStats )
151
import HscTypes
152
import FastString
153
import UniqFM           ( emptyUFM )
154
import UniqSupply
155
import Bag
Thomas Schilling's avatar
Thomas Schilling committed
156
import Exception
157 158 159
import qualified Stream
import Stream (Stream)

160
import Util
Simon Marlow's avatar
Simon Marlow committed
161

162
import Data.List
Simon Marlow's avatar
Simon Marlow committed
163
import Control.Monad
164
import Data.Maybe
Simon Marlow's avatar
Simon Marlow committed
165
import Data.IORef
166
import System.FilePath as FilePath
167
import System.Directory
Alan Zimmerman's avatar
Alan Zimmerman committed
168
import qualified Data.Map as Map
dterei's avatar
dterei committed
169

Thomas Schilling's avatar
Thomas Schilling committed
170
#include "HsVersions.h"
171

172

dterei's avatar
dterei committed
173 174 175 176 177
{- **********************************************************************
%*                                                                      *
                Initialisation
%*                                                                      *
%********************************************************************* -}
178

179
newHscEnv :: DynFlags -> IO HscEnv
180
newHscEnv dflags = do
dterei's avatar
dterei committed
181 182 183 184 185
    eps_var <- newIORef initExternalPackageState
    us      <- mkSplitUniqSupply 'r'
    nc_var  <- newIORef (initNameCache us knownKeyNames)
    fc_var  <- newIORef emptyUFM
    mlc_var <- newIORef emptyModuleEnv
186
    return HscEnv {  hsc_dflags       = dflags,
dterei's avatar
dterei committed
187 188
                     hsc_targets      = [],
                     hsc_mod_graph    = [],
189
                     hsc_IC           = emptyInteractiveContext dflags,
dterei's avatar
dterei committed
190 191 192 193 194
                     hsc_HPT          = emptyHomePackageTable,
                     hsc_EPS          = eps_var,
                     hsc_NC           = nc_var,
                     hsc_FC           = fc_var,
                     hsc_MLC          = mlc_var,
195
                     hsc_type_env_var = Nothing }
Thomas Schilling's avatar
Thomas Schilling committed
196

197

198
knownKeyNames :: [Name]      -- Put here to avoid loops involving DsMeta,
199
knownKeyNames =              -- where templateHaskellNames are defined
dterei's avatar
dterei committed
200
    map getName wiredInThings
dterei's avatar
dterei committed
201
        ++ basicKnownKeyNames
202
#ifdef GHCI
dterei's avatar
dterei committed
203
        ++ templateHaskellNames
204 205
#endif

206
-- -----------------------------------------------------------------------------
207

208
getWarnings :: Hsc WarningMessages
dterei's avatar
dterei committed
209
getWarnings = Hsc $ \_ w -> return (w, w)
210 211

clearWarnings :: Hsc ()
dterei's avatar
dterei committed
212
clearWarnings = Hsc $ \_ _ -> return ((), emptyBag)
213 214

logWarnings :: WarningMessages -> Hsc ()
dterei's avatar
dterei committed
215
logWarnings w = Hsc $ \_ w0 -> return ((), w0 `unionBags` w)
216 217

getHscEnv :: Hsc HscEnv
dterei's avatar
dterei committed
218
getHscEnv = Hsc $ \e w -> return (e, w)
219 220 221

handleWarnings :: Hsc ()
handleWarnings = do
dterei's avatar
dterei committed
222 223 224 225
    dflags <- getDynFlags
    w <- getWarnings
    liftIO $ printOrThrowWarnings dflags w
    clearWarnings
226 227 228 229 230

-- | log warning in the monad, and if there are errors then
-- throw a SourceError exception.
logWarningsReportErrors :: Messages -> Hsc ()
logWarningsReportErrors (warns,errs) = do
dterei's avatar
dterei committed
231 232
    logWarnings warns
    when (not $ isEmptyBag errs) $ throwErrors errs
233 234 235 236

-- | Throw some errors.
throwErrors :: ErrorMessages -> Hsc a
throwErrors = liftIO . throwIO . mkSrcErr
237 238 239 240 241

-- | Deal with errors and warnings returned by a compilation step
--
-- In order to reduce dependencies to other parts of the compiler, functions
-- outside the "main" parts of GHC return warnings and errors as a parameter
dterei's avatar
dterei committed
242
-- and signal success via by wrapping the result in a 'Maybe' type. This
243 244 245 246 247 248 249 250 251
-- function logs the returned warnings and propagates errors as exceptions
-- (of type 'SourceError').
--
-- This function assumes the following invariants:
--
--  1. If the second result indicates success (is of the form 'Just x'),
--     there must be no error messages in the first result.
--
--  2. If there are no error messages, but the second result indicates failure
dterei's avatar
dterei committed
252
--     there should be warnings in the first result. That is, if the action
253 254 255
--     failed, it must have been due to the warnings (i.e., @-Werror@).
ioMsgMaybe :: IO (Messages, Maybe a) -> Hsc a
ioMsgMaybe ioA = do
256
    ((warns,errs), mb_r) <- liftIO ioA
dterei's avatar
dterei committed
257 258 259 260
    logWarnings warns
    case mb_r of
        Nothing -> throwErrors errs
        Just r  -> ASSERT( isEmptyBag errs ) return r
261 262 263 264 265

-- | like ioMsgMaybe, except that we ignore error messages and return
-- 'Nothing' instead.
ioMsgMaybe' :: IO (Messages, Maybe a) -> Hsc (Maybe a)
ioMsgMaybe' ioA = do
dterei's avatar
dterei committed
266 267 268
    ((warns,_errs), mb_r) <- liftIO $ ioA
    logWarnings warns
    return mb_r
269 270 271 272 273

-- -----------------------------------------------------------------------------
-- | Lookup things in the compiler's environment

#ifdef GHCI
274 275 276 277 278
hscTcRnLookupRdrName :: HscEnv -> Located RdrName -> IO [Name]
hscTcRnLookupRdrName hsc_env0 rdr_name 
  = runInteractiveHsc hsc_env0 $ 
    do { hsc_env <- getHscEnv
       ; ioMsgMaybe $ tcRnLookupRdrName hsc_env rdr_name }
279 280 281
#endif

hscTcRcLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
282 283 284
hscTcRcLookupName hsc_env0 name = runInteractiveHsc hsc_env0 $ do
  hsc_env <- getHscEnv
  ioMsgMaybe' $ tcRnLookupName hsc_env name
dterei's avatar
dterei committed
285 286 287
      -- ignore errors: the only error we're likely to get is
      -- "name not found", and the Maybe in the return type
      -- is used to indicate that.
288

289
hscTcRnGetInfo :: HscEnv -> Name -> IO (Maybe (TyThing, Fixity, [ClsInst], [FamInst]))
290 291 292 293
hscTcRnGetInfo hsc_env0 name
  = runInteractiveHsc hsc_env0 $
    do { hsc_env <- getHscEnv
       ; ioMsgMaybe' $ tcRnGetInfo hsc_env name }
294 295

#ifdef GHCI
dterei's avatar
dterei committed
296
hscIsGHCiMonad :: HscEnv -> String -> IO Name
Edsko de Vries's avatar
Edsko de Vries committed
297
hscIsGHCiMonad hsc_env name
298
  = runHsc hsc_env $ ioMsgMaybe $ isGHCiMonad hsc_env name
dterei's avatar
dterei committed
299

300
hscGetModuleInterface :: HscEnv -> Module -> IO ModIface
301 302 303
hscGetModuleInterface hsc_env0 mod = runInteractiveHsc hsc_env0 $ do
  hsc_env <- getHscEnv
  ioMsgMaybe $ getModuleInterface hsc_env mod
304 305 306

-- -----------------------------------------------------------------------------
-- | Rename some import declarations
307
hscRnImportDecls :: HscEnv -> [LImportDecl RdrName] -> IO GlobalRdrEnv
308 309 310
hscRnImportDecls hsc_env0 import_decls = runInteractiveHsc hsc_env0 $ do
  hsc_env <- getHscEnv
  ioMsgMaybe $ tcRnImportDecls hsc_env import_decls
311 312
#endif

313
-- -----------------------------------------------------------------------------
Simon Marlow's avatar
Simon Marlow committed
314
-- | parse a file, returning the abstract syntax
315

316
hscParse :: HscEnv -> ModSummary -> IO HsParsedModule
317 318 319
hscParse hsc_env mod_summary = runHsc hsc_env $ hscParse' mod_summary

-- internal version, that doesn't fail due to -Werror
320
hscParse' :: ModSummary -> Hsc HsParsedModule
321
hscParse' mod_summary = do
dterei's avatar
dterei committed
322 323 324
    dflags <- getDynFlags
    let src_filename  = ms_hspp_file mod_summary
        maybe_src_buf = ms_hspp_buf  mod_summary
325

dterei's avatar
dterei committed
326 327 328
    --------------------------  Parser  ----------------
    liftIO $ showPass dflags "Parser"
    {-# SCC "Parser" #-} do
329 330 331 332

    -- sometimes we already have the buffer in memory, perhaps
    -- because we needed to parse the imports out of it, or get the
    -- module name.
dterei's avatar
dterei committed
333 334 335
    buf <- case maybe_src_buf of
               Just b  -> return b
               Nothing -> liftIO $ hGetStringBuffer src_filename
336

dterei's avatar
dterei committed
337
    let loc = mkRealSrcLoc (mkFastString src_filename) 1 1
338

dterei's avatar
dterei committed
339 340
    case unP parseModule (mkPState dflags buf loc) of
        PFailed span err ->
Ian Lynagh's avatar
Ian Lynagh committed
341
            liftIO $ throwOneError (mkPlainErrMsg dflags span err)
342

dterei's avatar
dterei committed
343 344 345 346 347 348
        POk pst rdr_module -> do
            logWarningsReportErrors (getMessages pst)
            liftIO $ dumpIfSet_dyn dflags Opt_D_dump_parsed "Parser" $
                                   ppr rdr_module
            liftIO $ dumpIfSet_dyn dflags Opt_D_source_stats "Source Statistics" $
                                   ppSourceStats False rdr_module
349 350 351 352 353 354 355 356 357 358 359 360 361 362 363

            -- To get the list of extra source files, we take the list
            -- that the parser gave us,
            --   - eliminate files beginning with '<'.  gcc likes to use
            --     pseudo-filenames like "<built-in>" and "<command-line>"
            --   - normalise them (elimiante differences between ./f and f)
            --   - filter out the preprocessed source file
            --   - filter out anything beginning with tmpdir
            --   - remove duplicates
            --   - filter out the .hs/.lhs source filename if we have one
            --
            let n_hspp  = FilePath.normalise src_filename
                srcs0 = nub $ filter (not . (tmpDir dflags `isPrefixOf`))
                            $ filter (not . (== n_hspp))
                            $ map FilePath.normalise
364
                            $ filter (not . (isPrefixOf "<"))
365 366 367 368 369 370
                            $ map unpackFS
                            $ srcfiles pst
                srcs1 = case ml_hs_file (ms_location mod_summary) of
                          Just f  -> filter (/= FilePath.normalise f) srcs0
                          Nothing -> srcs0

371 372 373 374 375
            -- sometimes we see source files from earlier
            -- preprocessing stages that cannot be found, so just
            -- filter them out:
            srcs2 <- liftIO $ filterM doesFileExist srcs1

376 377
            return HsParsedModule {
                      hpm_module    = rdr_module,
Alan Zimmerman's avatar
Alan Zimmerman committed
378 379 380 381 382
                      hpm_src_files = srcs2,
                      hpm_annotations
                              = (Map.fromListWith (++) $ annotations pst,
                                 Map.fromList $ ((noSrcSpan,comment_q pst)
                                                 :(annotations_comments pst)))
383
                   }
Simon Marlow's avatar
Simon Marlow committed
384

Thomas Schilling's avatar
Thomas Schilling committed
385 386 387
-- XXX: should this really be a Maybe X?  Check under which circumstances this
-- can become a Nothing and decide whether this should instead throw an
-- exception/signal an error.
dterei's avatar
dterei committed
388
type RenamedStuff =
Simon Marlow's avatar
Simon Marlow committed
389
        (Maybe (HsGroup Name, [LImportDecl Name], Maybe [LIE Name],
390
                Maybe LHsDocString))
Simon Marlow's avatar
Simon Marlow committed
391

Thomas Schilling's avatar
Thomas Schilling committed
392
-- | Rename and typecheck a module, additionally returning the renamed syntax
393
hscTypecheckRename :: HscEnv -> ModSummary -> HsParsedModule
394
                   -> IO (TcGblEnv, RenamedStuff)
dterei's avatar
dterei committed
395
hscTypecheckRename hsc_env mod_summary rdr_module = runHsc hsc_env $ do
396
    tc_result <- tcRnModule' hsc_env mod_summary True rdr_module
Thomas Schilling's avatar
Thomas Schilling committed
397

398 399 400 401 402 403
        -- This 'do' is in the Maybe monad!
    let rn_info = do decl <- tcg_rn_decls tc_result
                     let imports = tcg_rn_imports tc_result
                         exports = tcg_rn_exports tc_result
                         doc_hdr = tcg_doc_hdr tc_result
                     return (decl,imports,exports,doc_hdr)
Thomas Schilling's avatar
Thomas Schilling committed
404

405
    return (tc_result, rn_info)
Simon Marlow's avatar
Simon Marlow committed
406

407 408 409 410 411 412 413 414 415 416
-- wrapper around tcRnModule to handle safe haskell extras
tcRnModule' :: HscEnv -> ModSummary -> Bool -> HsParsedModule
            -> Hsc TcGblEnv
tcRnModule' hsc_env sum save_rn_syntax mod = do
    tcg_res <- {-# SCC "Typecheck-Rename" #-}
               ioMsgMaybe $
                   tcRnModule hsc_env (ms_hsc_src sum) save_rn_syntax mod

    tcSafeOK <- liftIO $ readIORef (tcg_safeInfer tcg_res)
    dflags   <- getDynFlags
417
    let allSafeOK = safeInferred dflags && tcSafeOK
418

419 420 421
    -- end of the safe haskell line, how to respond to user?
    if not (safeHaskellOn dflags) || (safeInferOn dflags && not allSafeOK)
        -- if safe Haskell off or safe infer failed, mark unsafe
422
        then markUnsafeInfer tcg_res emptyBag
423

424
        -- module (could be) safe, throw warning if needed
425 426 427
        else do
            tcg_res' <- hscCheckSafeImports tcg_res
            safe <- liftIO $ readIORef (tcg_safeInfer tcg_res')
428 429 430 431 432 433 434 435 436
            when safe $ do
              case wopt Opt_WarnSafe dflags of
                True -> (logWarnings $ unitBag $ mkPlainWarnMsg dflags
                       (warnSafeOnLoc dflags) $ errSafe tcg_res')
                False | safeHaskell dflags == Sf_Trustworthy &&
                        wopt Opt_WarnTrustworthySafe dflags ->
                  (logWarnings $ unitBag $ mkPlainWarnMsg dflags
                    (trustworthyOnLoc dflags) $ errTwthySafe tcg_res')
                False -> return ()
437 438 439
            return tcg_res'
  where
    pprMod t  = ppr $ moduleName $ tcg_mod t
440
    errSafe t = quotes (pprMod t) <+> text "has been inferred as safe!"
441 442
    errTwthySafe t = quotes (pprMod t)
      <+> text "is marked as Trustworthy but has been inferred as safe!"
443

Simon Marlow's avatar
Simon Marlow committed
444
-- | Convert a typechecked module to Core
445
hscDesugar :: HscEnv -> ModSummary -> TcGblEnv -> IO ModGuts
446
hscDesugar hsc_env mod_summary tc_result =
Ian Lynagh's avatar
Ian Lynagh committed
447
    runHsc hsc_env $ hscDesugar' (ms_location mod_summary) tc_result
448

Ian Lynagh's avatar
Ian Lynagh committed
449 450
hscDesugar' :: ModLocation -> TcGblEnv -> Hsc ModGuts
hscDesugar' mod_location tc_result = do
dterei's avatar
dterei committed
451
    hsc_env <- getHscEnv
Simon Marlow's avatar
Simon Marlow committed
452 453
    r <- ioMsgMaybe $
      {-# SCC "deSugar" #-}
Ian Lynagh's avatar
Ian Lynagh committed
454
      deSugar hsc_env mod_location tc_result
455

dterei's avatar
dterei committed
456 457 458 459
    -- always check -Werror after desugaring, this is the last opportunity for
    -- warnings to arise before the backend.
    handleWarnings
    return r
Simon Marlow's avatar
Simon Marlow committed
460

dterei's avatar
dterei committed
461
-- | Make a 'ModIface' from the results of typechecking. Used when
Simon Marlow's avatar
Simon Marlow committed
462 463 464 465
-- not optimising, and the interface doesn't need to contain any
-- unfoldings or other cross-module optimisation info.
-- ToDo: the old interface is only needed to get the version numbers,
-- we should use fingerprint versions instead.
466
makeSimpleIface :: HscEnv -> Maybe ModIface -> TcGblEnv -> ModDetails
467
                -> IO (ModIface,Bool)
468 469 470 471 472
makeSimpleIface hsc_env maybe_old_iface tc_result details = runHsc hsc_env $ do
    safe_mode <- hscGetSafeMode tc_result
    ioMsgMaybe $ do
        mkIfaceTc hsc_env (fmap mi_iface_hash maybe_old_iface) safe_mode
                  details tc_result
Simon Marlow's avatar
Simon Marlow committed
473

dterei's avatar
dterei committed
474
-- | Make a 'ModDetails' from the results of typechecking. Used when
Simon Marlow's avatar
Simon Marlow committed
475
-- typechecking only, as opposed to full compilation.
476 477
makeSimpleDetails :: HscEnv -> TcGblEnv -> IO ModDetails
makeSimpleDetails hsc_env tc_result = mkBootModDetailsTc hsc_env tc_result
Simon Marlow's avatar
Simon Marlow committed
478

479

dterei's avatar
dterei committed
480 481 482 483 484 485 486
{- **********************************************************************
%*                                                                      *
                The main compiler pipeline
%*                                                                      *
%********************************************************************* -}

{-
487 488 489 490
                   --------------------------------
                        The compilation proper
                   --------------------------------

dterei's avatar
dterei committed
491 492 493 494 495 496
It's the task of the compilation proper to compile Haskell, hs-boot and core
files to either byte-code, hard-code (C, asm, LLVM, ect) or to nothing at all
(the module is still parsed and type-checked. This feature is mostly used by
IDE's and the likes). Compilation can happen in either 'one-shot', 'batch',
'nothing', or 'interactive' mode. 'One-shot' mode targets hard-code, 'batch'
mode targets hard-code, 'nothing' mode targets nothing and 'interactive' mode
497
targets byte-code.
dterei's avatar
dterei committed
498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522

The modes are kept separate because of their different types and meanings:

 * In 'one-shot' mode, we're only compiling a single file and can therefore
 discard the new ModIface and ModDetails. This is also the reason it only
 targets hard-code; compiling to byte-code or nothing doesn't make sense when
 we discard the result.

 * 'Batch' mode is like 'one-shot' except that we keep the resulting ModIface
 and ModDetails. 'Batch' mode doesn't target byte-code since that require us to
 return the newly compiled byte-code.

 * 'Nothing' mode has exactly the same type as 'batch' mode but they're still
 kept separate. This is because compiling to nothing is fairly special: We
 don't output any interface files, we don't run the simplifier and we don't
 generate any code.

 * 'Interactive' mode is similar to 'batch' mode except that we return the
 compiled byte-code together with the ModIface and ModDetails.

Trying to compile a hs-boot file to byte-code will result in a run-time error.
This is the only thing that isn't caught by the type-system.
-}


523 524 525 526 527 528 529 530 531 532 533 534 535
type Messager = HscEnv -> (Int,Int) -> RecompileRequired -> ModSummary -> IO ()

genericHscCompileGetFrontendResult ::
                     Bool -- always do basic recompilation check?
                  -> Maybe TcGblEnv
                  -> Maybe Messager
                  -> HscEnv
                  -> ModSummary
                  -> SourceModified
                  -> Maybe ModIface  -- Old interface, if available
                  -> (Int,Int)       -- (i,n) = module i of n (for msgs)
                  -> IO (Either ModIface (TcGblEnv, Maybe Fingerprint))

Simon Marlow's avatar
Simon Marlow committed
536 537 538
genericHscCompileGetFrontendResult
  always_do_basic_recompilation_check m_tc_result
  mHscMessage hsc_env mod_summary source_modified mb_old_iface mod_index
539 540 541 542 543
    = do

    let msg what = case mHscMessage of
                   Just hscMessage -> hscMessage hsc_env mod_index what mod_summary
                   Nothing -> return ()
dterei's avatar
dterei committed
544

545 546 547
        skip iface = do
            msg UpToDate
            return $ Left iface
dterei's avatar
dterei committed
548

549 550 551 552
        compile mb_old_hash reason = do
            msg reason
            tc_result <- runHsc hsc_env $ genericHscFrontend mod_summary
            return $ Right (tc_result, mb_old_hash)
dterei's avatar
dterei committed
553 554 555 556

        stable = case source_modified of
                     SourceUnmodifiedAndStable -> True
                     _                         -> False
557

558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
    case m_tc_result of
         Just tc_result
          | not always_do_basic_recompilation_check ->
             return $ Right (tc_result, Nothing)
         _ -> do
            (recomp_reqd, mb_checked_iface)
                <- {-# SCC "checkOldIface" #-}
                   checkOldIface hsc_env mod_summary
                                source_modified mb_old_iface
            -- save the interface that comes back from checkOldIface.
            -- In one-shot mode we don't have the old iface until this
            -- point, when checkOldIface reads it from the disk.
            let mb_old_hash = fmap mi_iface_hash mb_checked_iface

            case mb_checked_iface of
                Just iface | not (recompileRequired recomp_reqd) ->
Simon Marlow's avatar
Simon Marlow committed
574 575 576 577 578 579 580 581 582 583 584 585 586
                    -- If the module used TH splices when it was last
                    -- compiled, then the recompilation check is not
                    -- accurate enough (#481) and we must ignore
                    -- it.  However, if the module is stable (none of
                    -- the modules it depends on, directly or
                    -- indirectly, changed), then we *can* skip
                    -- recompilation. This is why the SourceModified
                    -- type contains SourceUnmodifiedAndStable, and
                    -- it's pretty important: otherwise ghc --make
                    -- would always recompile TH modules, even if
                    -- nothing at all has changed. Stability is just
                    -- the same check that make is doing for us in
                    -- one-shot mode.
587 588 589 590 591 592 593 594 595 596 597 598 599
                    case m_tc_result of
                    Nothing
                     | mi_used_th iface && not stable ->
                        compile mb_old_hash (RecompBecause "TH")
                    _ ->
                        skip iface
                _ ->
                    case m_tc_result of
                    Nothing -> compile mb_old_hash recomp_reqd
                    Just tc_result ->
                        return $ Right (tc_result, mb_old_hash)

genericHscFrontend :: ModSummary -> Hsc TcGblEnv
600 601 602 603
genericHscFrontend mod_summary =
  getHooked hscFrontendHook genericHscFrontend' >>= ($ mod_summary)

genericHscFrontend' :: ModSummary -> Hsc TcGblEnv
Austin Seipp's avatar
Austin Seipp committed
604
genericHscFrontend' mod_summary = hscFileFrontEnd mod_summary
605

606 607 608 609
--------------------------------------------------------------
-- Compilers
--------------------------------------------------------------

610 611 612
hscCompileOneShot :: HscEnv
                  -> ModSummary
                  -> SourceModified
613
                  -> IO HscStatus
614 615 616
hscCompileOneShot env =
  lookupHook hscCompileOneShotHook hscCompileOneShot' (hsc_dflags env) env

Austin Seipp's avatar
Austin Seipp committed
617
-- Compile Haskell/boot in OneShot mode.
618 619 620 621
hscCompileOneShot' :: HscEnv
                   -> ModSummary
                   -> SourceModified
                   -> IO HscStatus
Austin Seipp's avatar
Austin Seipp committed
622
hscCompileOneShot' hsc_env mod_summary src_changed
623
  = do
dterei's avatar
dterei committed
624 625 626 627 628
    -- One-shot mode needs a knot-tying mutable variable for interface
    -- files. See TcRnTypes.TcGblEnv.tcg_type_env_var.
    type_env_var <- newIORef emptyNameEnv
    let mod = ms_mod mod_summary
        hsc_env' = hsc_env{ hsc_type_env_var = Just (mod, type_env_var) }
629

630 631 632 633
        msg what = oneShotMsg hsc_env' what

        skip = do msg UpToDate
                  dumpIfaceStats hsc_env'
634
                  return HscUpToDate
635 636 637 638

        compile mb_old_hash reason = runHsc hsc_env' $ do
            liftIO $ msg reason
            tc_result <- genericHscFrontend mod_summary
639
            guts0 <- hscDesugar' (ms_location mod_summary) tc_result
640 641
            dflags <- getDynFlags
            case hscTarget dflags of
642
                HscNothing -> do
643 644 645
                    when (gopt Opt_WriteInterface dflags) $ liftIO $ do
                        (iface, changed, _details) <- hscSimpleIface hsc_env tc_result mb_old_hash
                        hscWriteIface dflags iface changed mod_summary
646
                    return HscNotGeneratingCode
647 648
                _ ->
                    case ms_hsc_src mod_summary of
649
                    t | isHsBootOrSig t ->
650 651
                        do (iface, changed, _) <- hscSimpleIface' tc_result mb_old_hash
                           liftIO $ hscWriteIface dflags iface changed mod_summary
652 653 654 655
                           return (case t of
                                    HsBootFile -> HscUpdateBoot
                                    HsigFile -> HscUpdateSig
                                    HsSrcFile -> panic "hscCompileOneShot Src")
656
                    _ ->
657
                        do guts <- hscSimplify' guts0
Austin Seipp's avatar
Austin Seipp committed
658
                           (iface, changed, _details, cgguts) <- hscNormalIface' guts mb_old_hash
659
                           liftIO $ hscWriteIface dflags iface changed mod_summary
660
                           return $ HscRecomp cgguts mod_summary
661

Simon Marlow's avatar
Comment  
Simon Marlow committed
662 663 664
        -- XXX This is always False, because in one-shot mode the
        -- concept of stability does not exist.  The driver never
        -- passes SourceUnmodifiedAndStable in here.
665 666 667
        stable = case src_changed of
                     SourceUnmodifiedAndStable -> True
                     _                         -> False
668

669 670 671 672 673 674 675
    (recomp_reqd, mb_checked_iface)
        <- {-# SCC "checkOldIface" #-}
           checkOldIface hsc_env' mod_summary src_changed Nothing
    -- save the interface that comes back from checkOldIface.
    -- In one-shot mode we don't have the old iface until this
    -- point, when checkOldIface reads it from the disk.
    let mb_old_hash = fmap mi_iface_hash mb_checked_iface
676

677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
    case mb_checked_iface of
        Just iface | not (recompileRequired recomp_reqd) ->
            -- If the module used TH splices when it was last compiled,
            -- then the recompilation check is not accurate enough (#481)
            -- and we must ignore it. However, if the module is stable
            -- (none of the modules it depends on, directly or indirectly,
            -- changed), then we *can* skip recompilation. This is why
            -- the SourceModified type contains SourceUnmodifiedAndStable,
            -- and it's pretty important: otherwise ghc --make would
            -- always recompile TH modules, even if nothing at all has
            -- changed. Stability is just the same check that make is
            -- doing for us in one-shot mode.
            if mi_used_th iface && not stable
            then compile mb_old_hash (RecompBecause "TH")
            else skip
        _ ->
            compile mb_old_hash recomp_reqd
694

695 696 697 698
--------------------------------------------------------------
-- NoRecomp handlers
--------------------------------------------------------------

699 700
genModDetails :: HscEnv -> ModIface -> IO ModDetails
genModDetails hsc_env old_iface
701
  = do
dterei's avatar
dterei committed
702
    new_details <- {-# SCC "tcRnIface" #-}
703 704
                   initIfaceCheck hsc_env (typecheckIface old_iface)
    dumpIfaceStats hsc_env
dterei's avatar
dterei committed
705
    return new_details
706

707 708 709 710
--------------------------------------------------------------
-- Progress displayers.
--------------------------------------------------------------

711 712
oneShotMsg :: HscEnv -> RecompileRequired -> IO ()
oneShotMsg hsc_env recomp =
dterei's avatar
dterei committed
713
    case recomp of
714
        UpToDate ->
715 716
            compilationProgressMsg (hsc_dflags hsc_env) $
                   "compilation IS NOT required"
717
        _ ->
718 719
            return ()

720 721
batchMsg :: Messager
batchMsg hsc_env mod_index recomp mod_summary =
dterei's avatar
dterei committed
722
    case recomp of
723 724 725
        MustCompile -> showMsg "Compiling " ""
        UpToDate
            | verbosity (hsc_dflags hsc_env) >= 2 -> showMsg "Skipping  " ""
dterei's avatar
dterei committed
726
            | otherwise -> return ()
727
        RecompBecause reason -> showMsg "Compiling " (" [" ++ reason ++ "]")
dterei's avatar
dterei committed
728
    where
Ian Lynagh's avatar
Ian Lynagh committed
729
        dflags = hsc_dflags hsc_env
730
        showMsg msg reason =
Ian Lynagh's avatar
Ian Lynagh committed
731
            compilationProgressMsg dflags $
732
            (showModuleIndex mod_index ++
Ian Lynagh's avatar
Ian Lynagh committed
733
            msg ++ showModMsg dflags (hscTarget dflags)
734 735
                              (recompileRequired recomp) mod_summary)
                ++ reason
736

737 738 739
--------------------------------------------------------------
-- FrontEnds
--------------------------------------------------------------
740 741

hscFileFrontEnd :: ModSummary -> Hsc TcGblEnv
742
hscFileFrontEnd mod_summary = do
743
    hpm <- hscParse' mod_summary
744
    hsc_env <- getHscEnv
745 746
    tcg_env <- tcRnModule' hsc_env mod_summary False hpm
    return tcg_env
747 748

--------------------------------------------------------------
749
-- Safe Haskell
750 751
--------------------------------------------------------------

752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771
-- Note [Safe Haskell Trust Check]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Safe Haskell checks that an import is trusted according to the following
-- rules for an import of module M that resides in Package P:
--
--   * If M is recorded as Safe and all its trust dependencies are OK
--     then M is considered safe.
--   * If M is recorded as Trustworthy and P is considered trusted and
--     all M's trust dependencies are OK then M is considered safe.
--
-- By trust dependencies we mean that the check is transitive. So if
-- a module M that is Safe relies on a module N that is trustworthy,
-- importing module M will first check (according to the second case)
-- that N is trusted before checking M is trusted.
--
-- This is a minimal description, so please refer to the user guide
-- for more details. The user guide is also considered the authoritative
-- source in this matter, not the comments or code.


772 773 774 775 776 777 778 779 780 781 782
-- Note [Safe Haskell Inference]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Safe Haskell does Safe inference on modules that don't have any specific
-- safe haskell mode flag. The basic aproach to this is:
--   * When deciding if we need to do a Safe language check, treat
--     an unmarked module as having -XSafe mode specified.
--   * For checks, don't throw errors but return them to the caller.
--   * Caller checks if there are errors:
--     * For modules explicitly marked -XSafe, we throw the errors.
--     * For unmarked modules (inference mode), we drop the errors
--       and mark the module as being Unsafe.
783 784 785 786 787 788 789 790 791 792 793 794
--
-- It used to be that we only did safe inference on modules that had no Safe
-- Haskell flags, but now we perform safe inference on all modules as we want
-- to allow users to set the `--fwarn-safe`, `--fwarn-unsafe` and
-- `--fwarn-trustworthy-safe` flags on Trustworthy and Unsafe modules so that a
-- user can ensure their assumptions are correct and see reasons for why a
-- module is safe or unsafe.
--
-- This is tricky as we must be careful when we should throw an error compared
-- to just warnings. For checking safe imports we manage it as two steps. First
-- we check any imports that are required to be safe, then we check all other
-- imports to see if we can infer them to be safe.
795 796 797 798 799 800 801 802 803


-- | Check that the safe imports of the module being compiled are valid.
-- If not we either issue a compilation error if the module is explicitly
-- using Safe Haskell, or mark the module as unsafe if we're in safe
-- inference mode.
hscCheckSafeImports :: TcGblEnv -> Hsc TcGblEnv
hscCheckSafeImports tcg_env = do
    dflags   <- getDynFlags
804
    tcg_env' <- checkSafeImports dflags tcg_env
805
    checkRULES dflags tcg_env'
806

dterei's avatar
dterei committed
807
  where
808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
    checkRULES dflags tcg_env' = do
      case safeLanguageOn dflags of
          True -> do
              -- XSafe: we nuke user written RULES
              logWarnings $ warns dflags (tcg_rules tcg_env')
              return tcg_env' { tcg_rules = [] }
          False
                -- SafeInferred: user defined RULES, so not safe
              | safeInferOn dflags && not (null $ tcg_rules tcg_env')
              -> markUnsafeInfer tcg_env' $ warns dflags (tcg_rules tcg_env')

                -- Trustworthy OR SafeInferred: with no RULES
              | otherwise
              -> return tcg_env'

Ian Lynagh's avatar
Ian Lynagh committed
823 824 825
    warns dflags rules = listToBag $ map (warnRules dflags) rules
    warnRules dflags (L loc (HsRule n _ _ _ _ _ _)) =
        mkPlainWarnMsg dflags loc $
826
            text "Rule \"" <> ftext (unLoc n) <> text "\" ignored" $+$
dterei's avatar
dterei committed
827
            text "User defined rules are disabled under Safe Haskell"
828

829 830 831 832 833 834
-- | Validate that safe imported modules are actually safe.  For modules in the
-- HomePackage (the package the module we are compiling in resides) this just
-- involves checking its trust type is 'Safe' or 'Trustworthy'. For modules
-- that reside in another package we also must check that the external pacakge
-- is trusted. See the Note [Safe Haskell Trust Check] above for more
-- information.
835
--
836 837 838 839 840
-- The code for this is quite tricky as the whole algorithm is done in a few
-- distinct phases in different parts of the code base. See
-- RnNames.rnImportDecl for where package trust dependencies for a module are
-- collected and unioned.  Specifically see the Note [RnNames . Tracking Trust
-- Transitively] and the Note [RnNames . Trust Own Package].
841 842
checkSafeImports :: DynFlags -> TcGblEnv -> Hsc TcGblEnv
checkSafeImports dflags tcg_env
843
    = do
844 845 846
        imps <- mapM condense imports'
        let (safeImps, regImps) = partition (\(_,_,s) -> s) imps

847 848 849 850 851
        -- We want to use the warning state specifically for detecting if safe
        -- inference has failed, so store and clear any existing warnings.
        oldErrs <- getWarnings
        clearWarnings

852 853 854
        -- Check safe imports are correct
        safePkgs <- mapM checkSafe safeImps
        safeErrs <- getWarnings
dterei's avatar
dterei committed
855 856
        clearWarnings

857
        -- Check non-safe imports are correct if inferring safety
858
        -- See the Note [Safe Haskell Inference]
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881
        (infErrs, infPkgs) <- case (safeInferOn dflags) of
          False -> return (emptyBag, [])
          True -> do infPkgs <- mapM checkSafe regImps
                     infErrs <- getWarnings
                     clearWarnings
                     return (infErrs, infPkgs)

        -- restore old errors
        logWarnings oldErrs

        case (isEmptyBag safeErrs) of
          -- Failed safe check
          False -> liftIO . throwIO . mkSrcErr $ safeErrs

          -- Passed safe check
          True -> do
            let infPassed = isEmptyBag infErrs
            tcg_env' <- case (not infPassed) of
              True  -> markUnsafeInfer tcg_env infErrs
              False -> return tcg_env
            when (packageTrustOn dflags) $ checkPkgTrust dflags pkgReqs
            let newTrust = pkgTrustReqs safePkgs infPkgs infPassed
            return tcg_env' { tcg_imports = impInfo `plusImportAvails` newTrust }
882

dterei's avatar
dterei committed
883
  where
884 885
    impInfo  = tcg_imports tcg_env     -- ImportAvails
    imports  = imp_mods impInfo        -- ImportedMods
dterei's avatar
dterei committed
886
    imports' = moduleEnvToList imports -- (Module, [ImportedModsVal])
887
    pkgReqs  = imp_trust_pkgs impInfo  -- [PackageKey]
dterei's avatar
dterei committed
888 889 890 891

    condense :: (Module, [ImportedModsVal]) -> Hsc (Module, SrcSpan, IsSafeImport)
    condense (_, [])   = panic "HscMain.condense: Pattern match failure!"
    condense (m, x:xs) = do (_,_,l,s) <- foldlM cond' x xs
892
                            return (m, l, s)
dterei's avatar
dterei committed
893

dterei's avatar
dterei committed
894 895 896 897
    -- ImportedModsVal = (ModuleName, Bool, SrcSpan, IsSafeImport)
    cond' :: ImportedModsVal -> ImportedModsVal -> Hsc ImportedModsVal
    cond' v1@(m1,_,l1,s1) (_,_,_,s2)
        | s1 /= s2
Ian Lynagh's avatar
Ian Lynagh committed
898
        = throwErrors $ unitBag $ mkPlainErrMsg dflags l1
dterei's avatar
dterei committed
899 900 901 902
              (text "Module" <+> ppr m1 <+>
              (text $ "is imported both as a safe and unsafe import!"))
        | otherwise
        = return v1
Jan Stolarek's avatar
Jan Stolarek committed
903

904
    -- easier interface to work with
905 906 907 908 909 910 911 912 913 914 915
    checkSafe (m, l, _) = fst `fmap` hscCheckSafe' dflags m l

    -- what pkg's to add to our trust requirements
    pkgTrustReqs req inf infPassed | safeInferOn dflags
                                  && safeHaskell dflags == Sf_None && infPassed
                                   = emptyImportAvails {
                                       imp_trust_pkgs = catMaybes req ++ catMaybes inf
                                   }
    pkgTrustReqs _   _ _ | safeHaskell dflags == Sf_Unsafe
                         = emptyImportAvails
    pkgTrustReqs req _ _ = emptyImportAvails { imp_trust_pkgs = catMaybes req }
dterei's avatar
dterei committed
916

917 918
-- | Check that a module is safe to import.
--
dterei's avatar
dterei committed
919 920 921
-- We return True to indicate the import is safe and False otherwise
-- although in the False case an exception may be thrown first.
hscCheckSafe :: HscEnv -> Module -> SrcSpan -> IO Bool
922 923
hscCheckSafe hsc_env m l = runHsc hsc_env $ do
    dflags <- getDynFlags
dterei's avatar
dterei committed
924 925 926 927
    pkgs <- snd `fmap` hscCheckSafe' dflags m l
    when (packageTrustOn dflags) $ checkPkgTrust dflags pkgs
    errs <- getWarnings
    return $ isEmptyBag errs
928

dterei's avatar
dterei committed
929
-- | Return if a module is trusted and the pkgs it depends on to be trusted.
930
hscGetSafe :: HscEnv -> Module -> SrcSpan -> IO (Bool, [PackageKey])
dterei's avatar
dterei committed
931 932 933 934 935 936 937 938
hscGetSafe hsc_env m l = runHsc hsc_env $ do
    dflags       <- getDynFlags
    (self, pkgs) <- hscCheckSafe' dflags m l
    good         <- isEmptyBag `fmap` getWarnings
    clearWarnings -- don't want them printed...
    let pkgs' | Just p <- self = p:pkgs
              | otherwise      = pkgs
    return (good, pkgs')
Jan Stolarek's avatar
Jan Stolarek committed
939

dterei's avatar
dterei committed
940 941 942 943
-- | Is a module trusted? If not, throw or log errors depending on the type.
-- Return (regardless of trusted or not) if the trust type requires the modules
-- own package be trusted and a list of other packages required to be trusted
-- (these later ones haven't been checked) but the own package trust has been.
944
hscCheckSafe' :: DynFlags -> Module -> SrcSpan -> Hsc (Maybe PackageKey, [PackageKey])
945
hscCheckSafe' dflags m l = do
dterei's avatar
dterei committed
946
    (tw, pkgs) <- isModSafe m l
947
    case tw of
dterei's avatar
dterei committed
948 949
        False              -> return (Nothing, pkgs)
        True | isHomePkg m -> return (Nothing, pkgs)
950
             | otherwise   -> return (Just $ modulePackageKey m, pkgs)
951
  where
952
    isModSafe :: Module -> SrcSpan -> Hsc (Bool, [PackageKey])
dterei's avatar
dterei committed
953 954 955 956
    isModSafe m l = do
        iface <- lookup' m
        case iface of
            -- can't load iface to check trust!
Ian Lynagh's avatar
Ian Lynagh committed
957
            Nothing -> throwErrors $ unitBag $ mkPlainErrMsg dflags l
958 959
                         $ text "Can't load the interface file for" <+> ppr m
                           <> text ", to check that it can be safely imported"
dterei's avatar
dterei committed
960 961

            -- got iface, check trust
962
            Just iface' ->
dterei's avatar
dterei committed
963 964 965
                let trust = getSafeMode $ mi_trust iface'
                    trust_own_pkg = mi_trust_pkg iface'
                    -- check module is trusted
966
                    safeM = trust `elem` [Sf_Safe, Sf_Trustworthy]
dterei's avatar
dterei committed
967 968
                    -- check package is trusted
                    safeP = packageTrusted trust trust_own_pkg m
dterei's avatar
dterei committed
969 970
                    -- pkg trust reqs
                    pkgRs = map fst $ filter snd $ dep_pkgs $ mi_deps iface'
dterei's avatar
dterei committed
971
                    -- General errors we throw but Safe errors we log
972 973 974 975 976 977 978
                    errs = case (safeM, safeP) of
                        (True, True ) -> emptyBag
                        (True, False) -> pkgTrustErr
                        (False, _   ) -> modTrustErr
                in do
                    logWarnings errs
                    return (trust == Sf_Trustworthy