[project @ 2001-01-15 20:55:14 by qrczak]

[ghc-hetmet.git] / ghc / lib / std / PrelCError.lhs

diff --git a/ghc/lib/std/PrelCError.lhs b/ghc/lib/std/PrelCError.lhs
index 8455321..9792030 100644 (file)
--- a/ghc/lib/std/PrelCError.lhs
+++ b/ghc/lib/std/PrelCError.lhs
@@ -1,5 +1,5 @@
 % -----------------------------------------------------------------------------
-% $Id: PrelCError.lhs,v 1.1 2001/01/11 17:25:57 simonmar Exp $
+% $Id: PrelCError.lhs,v 1.3 2001/01/15 20:55:14 qrczak Exp $
 %
 % (c) The FFI task force, 2000
 %
@@ -19,7 +19,7 @@ module PrelCError (
   -- Haskell representation for "errno" values
   --
   Errno(..),           -- instance: Eq
-  e2BIG, eACCES, eADDRINUSE, eADDRNOTAVAIL, eADV, eAFNOSUPPORT, eAGAIN, 
+  eOK, e2BIG, eACCES, eADDRINUSE, eADDRNOTAVAIL, eADV, eAFNOSUPPORT, eAGAIN, 
   eALREADY, eBADF, eBADMSG, eBADRPC, eBUSY, eCHILD, eCOMM, eCONNABORTED, 
   eCONNREFUSED, eCONNRESET, eDEADLK, eDESTADDRREQ, eDIRTY, eDOM, eDQUOT, 
   eEXIST, eFAULT, eFBIG, eFTYPE, eHOSTDOWN, eHOSTUNREACH, eIDRM, eILSEQ, 
@@ -39,6 +39,7 @@ module PrelCError (
   -- access to the current thread's "errno" value
   --
   getErrno,             -- :: IO Errno
+  resetErrno,           -- :: IO ()
 
   -- conversion of an "errno" value into IO error
   --
@@ -145,7 +146,7 @@ instance Eq Errno where
 
 -- common "errno" symbols
 --
-e2BIG, eACCES, eADDRINUSE, eADDRNOTAVAIL, eADV, eAFNOSUPPORT, eAGAIN, 
+eOK, e2BIG, eACCES, eADDRINUSE, eADDRNOTAVAIL, eADV, eAFNOSUPPORT, eAGAIN, 
   eALREADY, eBADF, eBADMSG, eBADRPC, eBUSY, eCHILD, eCOMM, eCONNABORTED, 
   eCONNREFUSED, eCONNRESET, eDEADLK, eDESTADDRREQ, eDIRTY, eDOM, eDQUOT, 
   eEXIST, eFAULT, eFBIG, eFTYPE, eHOSTDOWN, eHOSTUNREACH, eIDRM, eILSEQ, 
@@ -163,6 +164,7 @@ e2BIG, eACCES, eADDRINUSE, eADDRNOTAVAIL, eADV, eAFNOSUPPORT, eAGAIN,
 -- the CCONST_XXX identifiers are cpp symbols whose value is computed by
 -- configure 
 --
+eOK             = Errno 0
 e2BIG           = Errno CCONST_E2BIG
 eACCES         = Errno CCONST_EACCES
 eADDRINUSE     = Errno CCONST_EADDRINUSE
@@ -267,9 +269,9 @@ eXDEV               = Errno CCONST_EXDEV
 --
 isValidErrno               :: Errno -> Bool
 --
--- the configure script sets all invalid "errno"s to 0
+-- the configure script sets all invalid "errno"s to -1
 --
-isValidErrno (Errno errno)  = errno /= 0
+isValidErrno (Errno errno)  = errno /= -1
 
 
 -- access to the current thread's "errno" value
@@ -281,6 +283,12 @@ getErrno :: IO Errno
 getErrno  = liftM Errno (peek _errno)
 
 
+-- set the current thread's "errno" value to 0
+--
+resetErrno :: IO ()
+resetErrno  = poke _errno 0
+
+
 -- throw current "errno" value
 -- ---------------------------
 
@@ -379,7 +387,7 @@ errnoToIOError loc errno@(Errno no) maybeHdl maybeName =
 #endif
   where
     (errType, str)
-      | no == 0                   = (OtherError,
+      | errno == eOK              = (OtherError,
                                     "no error")
       | errno == e2BIG            = (ResourceExhausted,
                                     "argument list too long")