Refactor temp files cleanup

Remove filesToNotIntermediateClean from DynFlags, create a data type
FilesToClean, and change filesToClean in DynFlags to be a FilesToClean.

Modify SysTools.newTempName and the Temporary constructor of
PipelineMonad.PipelineOutput to take a TempFileLifetime, which specifies
whether a temp file should live until the end of GhcMonad.withSession,
or until the next time cleanIntermediateTempFiles is called.

These changes allow the cleaning of intermediate files in GhcMake to be
much more efficient.

HscTypes.hptObjs is removed as it is no longer used.

A new performance test T13701 is added, which passes both with and
without -keep-tmp-files.  The test fails by 25% without the patch, and
passes when -keep-tmp-files is added.

Note that there are still at two hotspots caused by
algorithms quadratic in the number of modules, however neither of them
allocate. They are:

* DriverPipeline.compileOne'.needsLinker
* GhcMake.getModLoop

DriverPipeline.compileOne'.needsLinker is changed slightly to improve
the situation.

I don't like adding these Types to DynFlags, but they need to be seen by
Dynflags, SysTools and PipelineMonad. The alternative seems to be to
create a new module.

Reviewers: austin, hvr, bgamari, dfeuer, niteria, simonmar, erikd

Reviewed By: simonmar

Subscribers: rwbarton, thomie

GHC Trac Issues: #13701

Differential Revision: https://phabricator.haskell.org/D3620

1 files changed, 3 insertions, 2 deletions

diff --git a/compiler/main/DriverMkDepend.hs b/compiler/main/DriverMkDepend.hs
index 46fe4e0aad..dc18a31174 100644
--- a/compiler/main/DriverMkDepend.hs
+++ b/compiler/main/DriverMkDepend.hs
@@ -19,7 +19,7 @@ import GhcMonad
 import DynFlags
 import Util
 import HscTypes
-import SysTools         ( newTempName )
+import FileCleanup      ( newTempName )
 import qualified SysTools
 import Module
 import Digraph          ( SCC(..) )
@@ -29,6 +29,7 @@ import Panic
 import SrcLoc
 import Data.List
 import FastString
+import FileCleanup
 
 import Exception
 import ErrUtils
@@ -121,7 +122,7 @@ beginMkDependHS :: DynFlags -> IO MkDepFiles
 beginMkDependHS dflags = do
         -- open a new temp file in which to stuff the dependency info
         -- as we go along.
-  tmp_file <- newTempName dflags "dep"
+  tmp_file <- newTempName dflags TFL_CurrentModule "dep"
   tmp_hdl <- openFile tmp_file WriteMode
 
         -- open the makefile