使用ghc api获取重命名的（具有完全限定的导入）haskell AST

2018-05-31 15:29:44

我可以得到下面的ghc编译器使用ghc api来编译单个文件。我想获得haskell源代码的AST（所有函数调用完全限定）的AST，

ghcmake = defaultErrorHandler defaultFatalMessager defaultFlushOut $ do
  runGhc (Just GP.libdir) $ do
    dflags <- getSessionDynFlags
    setSessionDynFlags dflags
    target <- guessTarget targetFile Nothing
    setTargets [target]
    load LoadAllTargets

从这个简单的演示中，重命名过程应该在“加载”功能中完成。

来源在这里

（文件：///usr/local/haskell/ghc-7.10.2-x86_64/share/doc/ghc/html/libraries/ghc-7.10.2/src/GhcMake.html#load）

load :: GhcMonad m => LoadHowMuch -> m SuccessFlag Source

该功能实现了GHC的核心模式 - 制作模式。它预处理，编译和加载指定的模块，避免在可能的情况下重新编译。根据目标（请参阅hscTarget），编译和加载可能会导致在磁盘上创建文件。

load :: GhcMonad m => LoadHowMuch -> m SuccessFlag
load how_much = do
    mod_graph <- depanal [] False
    guessOutputFile
    hsc_env <- getSession

    let hpt1   = hsc_HPT hsc_env
    let dflags = hsc_dflags hsc_env

    -- The "bad" boot modules are the ones for which we have
    -- B.hs-boot in the module graph, but no B.hs
    -- The downsweep should have ensured this does not happen
    -- (see msDeps)
    let all_home_mods = [ms_mod_name s
                        | s <- mod_graph, not (isBootSummary s)]
        bad_boot_mods = [s        | s <- mod_graph, isBootSummary s,
                                    not (ms_mod_name s `elem` all_home_mods)]
    ASSERT( null bad_boot_mods ) return ()

    -- check that the module given in HowMuch actually exists, otherwise
    -- topSortModuleGraph will bomb later.
    let checkHowMuch (LoadUpTo m)           = checkMod m
        checkHowMuch (LoadDependenciesOf m) = checkMod m
        checkHowMuch _ = id

        checkMod m and_then
            | m `elem` all_home_mods = and_then
            | otherwise = do
                    liftIO $ errorMsg dflags (text "no such module:" <+>
                                     quotes (ppr m))
                    return Failed

    checkHowMuch how_much $ do

    -- mg2_with_srcimps drops the hi-boot nodes, returning a
    -- graph with cycles.  Among other things, it is used for
    -- backing out partially complete cycles following a failed
    -- upsweep, and for removing from hpt all the modules
    -- not in strict downwards closure, during calls to compile.
    let mg2_with_srcimps :: [SCC ModSummary]
        mg2_with_srcimps = topSortModuleGraph True mod_graph Nothing

    -- If we can determine that any of the {-# SOURCE #-} imports
    -- are definitely unnecessary, then emit a warning.
    warnUnnecessarySourceImports mg2_with_srcimps

    let
        -- check the stability property for each module.
        stable_mods@(stable_obj,stable_bco)
            = checkStability hpt1 mg2_with_srcimps all_home_mods

        -- prune bits of the HPT which are definitely redundant now,
        -- to save space.
        pruned_hpt = pruneHomePackageTable hpt1
                            (flattenSCCs mg2_with_srcimps)
                            stable_mods

    _ <- liftIO $ evaluate pruned_hpt

    -- before we unload anything, make sure we don't leave an old
    -- interactive context around pointing to dead bindings.  Also,
    -- write the pruned HPT to allow the old HPT to be GC'd.
    modifySession $ _ -> discardIC $ hsc_env { hsc_HPT = pruned_hpt }

    liftIO $ debugTraceMsg dflags 2 (text "Stable obj:" <+> ppr stable_obj $$
                            text "Stable BCO:" <+> ppr stable_bco)

    -- Unload any modules which are going to be re-linked this time around.
    let stable_linkables = [ linkable
                           | m <- stable_obj++stable_bco,
                             Just hmi <- [lookupUFM pruned_hpt m],
                             Just linkable <- [hm_linkable hmi] ]
    liftIO $ unload hsc_env stable_linkables

    -- We could at this point detect cycles which aren't broken by
    -- a source-import, and complain immediately, but it seems better
    -- to let upsweep_mods do this, so at least some useful work gets
    -- done before the upsweep is abandoned.
    --hPutStrLn stderr "after tsort:n"
    --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))

    -- Now do the upsweep, calling compile for each module in
    -- turn.  Final result is version 3 of everything.

    -- Topologically sort the module graph, this time including hi-boot
    -- nodes, and possibly just including the portion of the graph
    -- reachable from the module specified in the 2nd argument to load.
    -- This graph should be cycle-free.
    -- If we're restricting the upsweep to a portion of the graph, we
    -- also want to retain everything that is still stable.
    let full_mg :: [SCC ModSummary]
        full_mg    = topSortModuleGraph False mod_graph Nothing

        maybe_top_mod = case how_much of
                            LoadUpTo m           -> Just m
                            LoadDependenciesOf m -> Just m
                            _                    -> Nothing

        partial_mg0 :: [SCC ModSummary]
        partial_mg0 = topSortModuleGraph False mod_graph maybe_top_mod

        -- LoadDependenciesOf m: we want the upsweep to stop just
        -- short of the specified module (unless the specified module
        -- is stable).
        partial_mg
            | LoadDependenciesOf _mod <- how_much
            = ASSERT( case last partial_mg0 of
                        AcyclicSCC ms -> ms_mod_name ms == _mod; _ -> False )
              List.init partial_mg0
            | otherwise
            = partial_mg0

        stable_mg =
            [ AcyclicSCC ms
            | AcyclicSCC ms <- full_mg,
              ms_mod_name ms `elem` stable_obj++stable_bco ]

        -- the modules from partial_mg that are not also stable
        -- NB. also keep cycles, we need to emit an error message later
        unstable_mg = filter not_stable partial_mg
          where not_stable (CyclicSCC _) = True
                not_stable (AcyclicSCC ms)
                   = ms_mod_name ms `notElem` stable_obj++stable_bco

        -- Load all the stable modules first, before attempting to load
        -- an unstable module (#7231).
        mg = stable_mg ++ unstable_mg

    -- clean up between compilations
    let cleanup hsc_env = intermediateCleanTempFiles (hsc_dflags hsc_env)
                              (flattenSCCs mg2_with_srcimps)
                              hsc_env

    liftIO $ debugTraceMsg dflags 2 (hang (text "Ready for upsweep")
                               2 (ppr mg))

    n_jobs <- case parMakeCount dflags of
                    Nothing -> liftIO getNumProcessors
                    Just n  -> return n
    let upsweep_fn | n_jobs > 1 = parUpsweep n_jobs
                   | otherwise  = upsweep

    setSession hsc_env{ hsc_HPT = emptyHomePackageTable }
    (upsweep_ok, modsUpswept)
       <- upsweep_fn pruned_hpt stable_mods cleanup mg

    -- Make modsDone be the summaries for each home module now
    -- available; this should equal the domain of hpt3.
    -- Get in in a roughly top .. bottom order (hence reverse).

    let modsDone = reverse modsUpswept

    -- Try and do linking in some form, depending on whether the
    -- upsweep was completely or only partially successful.

    if succeeded upsweep_ok

     then
       -- Easy; just relink it all.
       do liftIO $ debugTraceMsg dflags 2 (text "Upsweep completely successful.")

          -- Clean up after ourselves
          hsc_env1 <- getSession
          liftIO $ intermediateCleanTempFiles dflags modsDone hsc_env1

          -- Issue a warning for the confusing case where the user
          -- said '-o foo' but we're not going to do any linking.
          -- We attempt linking if either (a) one of the modules is
          -- called Main, or (b) the user said -no-hs-main, indicating
          -- that main() is going to come from somewhere else.
          --
          let ofile = outputFile dflags
          let no_hs_main = gopt Opt_NoHsMain dflags
          let
            main_mod = mainModIs dflags
            a_root_is_Main = any ((==main_mod).ms_mod) mod_graph
            do_linking = a_root_is_Main || no_hs_main || ghcLink dflags == LinkDynLib || ghcLink dflags == LinkStaticLib

          when (ghcLink dflags == LinkBinary
                && isJust ofile && not do_linking) $
            liftIO $ debugTraceMsg dflags 1 $
                text ("Warning: output was redirected with -o, " ++
                      "but no output will be generatedn" ++
                      "because there is no " ++
                      moduleNameString (moduleName main_mod) ++ " module.")

          -- link everything together
          linkresult <- liftIO $ link (ghcLink dflags) dflags do_linking (hsc_HPT hsc_env1)

          loadFinish Succeeded linkresult

上面的代码片断检查模块依赖性是否正常，但在此之后，它似乎直接跳转到链接？我无法找到链接功能的位置。

linkresult <- liftIO $ link (ghcLink dflags) dflags do_linking (hsc_HPT hsc_env1)

  loadFinish Succeeded linkresult