From 8a994e17e7502f31ce2d830ace2f00c305619fa3 Mon Sep 17 00:00:00 2001
From: Ian Lynagh <igloo@earth.li>
Date: Mon, 10 Jul 2006 20:44:24 +0000
Subject: [PATCH] Create our own directory in the temporary directory to avoid
 various races

---
 compiler/main/GHC.hs       |   19 ++++++++-------
 compiler/main/SysTools.lhs |   57 +++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 62 insertions(+), 14 deletions(-)

diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs
index 5fcfd1d..207f5a3 100644
--- a/compiler/main/GHC.hs
+++ b/compiler/main/GHC.hs
@@ -226,7 +226,8 @@ import Finder
 import HscMain		( newHscEnv, hscFileCheck, HscChecked(..) )
 import HscTypes
 import DynFlags
-import SysTools		( initSysTools, cleanTempFiles, cleanTempFilesExcept )
+import SysTools     ( initSysTools, cleanTempFiles, cleanTempFilesExcept,
+                      cleanTempDirs )
 import Module
 import UniqFM
 import PackageConfig    ( PackageId )
@@ -309,13 +310,15 @@ defaultErrorHandler dflags inner =
 -- handling, but still get the ordinary cleanup behaviour.
 defaultCleanupHandler :: DynFlags -> IO a -> IO a
 defaultCleanupHandler dflags inner = 
-   -- make sure we clean up after ourselves
-   later (unless (dopt Opt_KeepTmpFiles dflags) $ 
-	    cleanTempFiles dflags) 
-	-- exceptions will be blocked while we clean the temporary files,
-	-- so there shouldn't be any difficulty if we receive further
-	-- signals.
-   inner
+    -- make sure we clean up after ourselves
+    later (unless (dopt Opt_KeepTmpFiles dflags) $
+               do cleanTempFiles dflags
+                  cleanTempDirs dflags
+          )
+          -- exceptions will be blocked while we clean the temporary files,
+          -- so there shouldn't be any difficulty if we receive further
+          -- signals.
+    inner
 
 
 -- | Initialises GHC.  This must be done /once/ only.  Takes the
diff --git a/compiler/main/SysTools.lhs b/compiler/main/SysTools.lhs
index 4e5c583..a377427 100644
--- a/compiler/main/SysTools.lhs
+++ b/compiler/main/SysTools.lhs
@@ -29,7 +29,7 @@ module SysTools (
 	-- Temporary-file management
 	setTmpDir,
 	newTempName,
-	cleanTempFiles, cleanTempFilesExcept,
+	cleanTempDirs, cleanTempFiles, cleanTempFilesExcept,
 	addFilesToClean,
 
 	-- System interface
@@ -62,10 +62,13 @@ import Monad		( when, unless )
 import System		( ExitCode(..), getEnv, system )
 import IO		( try, catch, hGetContents,
 			  openFile, hPutStr, hClose, hFlush, IOMode(..), 
-			  stderr, ioError, isDoesNotExistError )
-import Directory	( doesFileExist, removeFile )
+			  stderr, ioError, isDoesNotExistError,
+			  isAlreadyExistsError )
+import Directory	( doesFileExist, removeFile,
+			  createDirectory, removeDirectory )
 import Maybe		( isJust )
 import List             ( partition )
+import FiniteMap ( FiniteMap, emptyFM, lookupFM, addToFM, eltsFM )
 
 -- GHC <= 4.08 didn't have rawSystem, and runs into problems with long command
 -- lines on mingw32, so we disallow it now.
@@ -543,9 +546,16 @@ getUsageMsgPaths = readIORef v_Path_usages
 
 \begin{code}
 GLOBAL_VAR(v_FilesToClean, [],               [String] )
+GLOBAL_VAR(v_DirsToClean, emptyFM, FiniteMap FilePath FilePath )
 \end{code}
 
 \begin{code}
+cleanTempDirs :: DynFlags -> IO ()
+cleanTempDirs dflags
+   = do ds <- readIORef v_DirsToClean
+        removeTmpDirs dflags (eltsFM ds)
+        writeIORef v_DirsToClean emptyFM
+
 cleanTempFiles :: DynFlags -> IO ()
 cleanTempFiles dflags
    = do fs <- readIORef v_FilesToClean
@@ -562,9 +572,10 @@ cleanTempFilesExcept dflags dont_delete
 
 -- find a temporary name that doesn't already exist.
 newTempName :: DynFlags -> Suffix -> IO FilePath
-newTempName DynFlags{tmpDir=tmp_dir} extn
-  = do x <- getProcessID
-       findTempName (tmp_dir ++ "/ghc" ++ show x ++ "_") 0
+newTempName dflags extn
+  = do d <- getTempDir dflags
+       x <- getProcessID
+       findTempName (d ++ "/ghc" ++ show x ++ "_") 0
   where 
     findTempName prefix x
       = do let filename = (prefix ++ show x) `joinFileExt` extn
@@ -573,10 +584,44 @@ newTempName DynFlags{tmpDir=tmp_dir} extn
 		else do consIORef v_FilesToClean filename -- clean it up later
 		        return filename
 
+-- return our temporary directory within tmp_dir, creating one if we
+-- don't have one yet
+getTempDir :: DynFlags -> IO FilePath
+getTempDir dflags@(DynFlags{tmpDir=tmp_dir})
+  = do mapping <- readIORef v_DirsToClean
+       case lookupFM mapping tmp_dir of
+           Nothing ->
+               do x <- getProcessID
+                  let prefix = tmp_dir ++ "/ghc" ++ show x ++ "_"
+                      mkTempDir x
+                       = let dirname = prefix ++ show x
+                         in do createDirectory dirname
+                               let mapping' = addToFM mapping tmp_dir dirname
+                               writeIORef v_DirsToClean mapping'
+                               debugTraceMsg dflags 2 (ptext SLIT("Created temporary directory:") <+> text dirname)
+                               return dirname
+                            `IO.catch` \e ->
+                                    if isAlreadyExistsError e
+                                    then mkTempDir (x+1)
+                                    else ioError e
+                  mkTempDir 0
+           Just d -> return d
+
 addFilesToClean :: [FilePath] -> IO ()
 -- May include wildcards [used by DriverPipeline.run_phase SplitMangle]
 addFilesToClean files = mapM_ (consIORef v_FilesToClean) files
 
+removeTmpDirs :: DynFlags -> [FilePath] -> IO ()
+removeTmpDirs dflags ds
+  = traceCmd dflags "Deleting temp dirs"
+	     ("Deleting: " ++ unwords ds)
+	     (mapM_ rmdir ds)
+  where
+    rmdir d = removeDirectory d `IO.catch`
+		(\_ignored ->
+		    debugTraceMsg dflags 2 (ptext SLIT("Warning: deleting") <+> text d <+> ptext SLIT("raised exception"))
+		)
+
 removeTmpFiles :: DynFlags -> [FilePath] -> IO ()
 removeTmpFiles dflags fs
   = warnNon $
-- 
1.7.10.4