From 64eab5d02c8ac0685f94e00d452f7dfda03e45d9 Mon Sep 17 00:00:00 2001
From: qrczak <unknown>
Date: Sat, 19 May 2001 20:20:56 +0000
Subject: [PATCH] [project @ 2001-05-19 20:20:56 by qrczak] Make ghc
 compilable with itself after the implementation of handle
 IO changed, by changing an ugly mess of #ifdefs and
 low-level ghc-internals-specific kludges into a yet uglier
 mess with more #ifdefs and kludges.

Wouldn't Haskell 98 implementation of a lexer be fast enough? :-)

This won't compile with older versions of ghc-5.01. You may temporarily
change 501 to 502 in #ifdefs here, or use an older ghc.

The compiler still doesn't work at all when compiled with itself:
it writes complete nonsense into .hc files.

A remaining error: ghc/lib/std doesn't link PrelHandle_hsc.o into
libHSstd.a. Function read_wrap is inline but for some reason it's
needed for linking some programs (e.g. ghc itself).
---
 ghc/compiler/utils/FastString.lhs   |    5 +--
 ghc/compiler/utils/StringBuffer.lhs |   69 +++++++++++++++++++++++++++--------
 2 files changed, 55 insertions(+), 19 deletions(-)

diff --git a/ghc/compiler/utils/FastString.lhs b/ghc/compiler/utils/FastString.lhs
index bb0a02f..6913539 100644
--- a/ghc/compiler/utils/FastString.lhs
+++ b/ghc/compiler/utils/FastString.lhs
@@ -78,10 +78,9 @@ import PrelIOBase	( Handle__(..), IOError, IOErrorType(..),
 		  	  IOResult(..), 
 #endif
 			  IO(..),
-#if __GLASGOW_HASKELL__ >= 303
-			  Handle__Type(..),
-#endif
+#if __GLASGOW_HASKELL__ >= 301 && __GLASGOW_HASKELL__ <= 302
 		  	  constructError
+#endif
 			)
 #endif
 
diff --git a/ghc/compiler/utils/StringBuffer.lhs b/ghc/compiler/utils/StringBuffer.lhs
index 8f79d2b..2f0d532 100644
--- a/ghc/compiler/utils/StringBuffer.lhs
+++ b/ghc/compiler/utils/StringBuffer.lhs
@@ -77,9 +77,6 @@ import Foreign
 import Char		( chr )
 import Panic		( panic )
 
--- urk!
-#include "../lib/std/cbits/stgerror.h"
-
 #if __GLASGOW_HASKELL__ >= 303
 import IO		( openFile
 #if __GLASGOW_HASKELL__ < 407
@@ -88,6 +85,9 @@ import IO		( openFile
                         )
 import PrelIOBase
 import PrelHandle
+#if __GLASGOW_HASKELL__ >= 501
+import IOExts		( slurpFile )
+#endif
 import Addr
 #else
 import IO		( openFile, hFileSize, hClose, IOMode(..) )
@@ -110,6 +110,11 @@ import PrelHandle	( readHandle, writeHandle, filePtr )
 # endif
 import PrelPack		( unpackCStringBA )
 #endif
+#if __GLASGOW_HASKELL__ >= 501
+import PrelIO		( hGetcBuffered )
+import PrelCError	( throwErrnoIfMinus1RetryMayBlock )
+import PrelConc		( threadWaitRead )
+#endif
 
 #if __GLASGOW_HASKELL__ < 402
 import Util 		( bracket )
@@ -260,15 +265,19 @@ slurpFileExpandTabs fname = do
 
 trySlurp :: Handle -> Int -> Addr -> IO (Addr, Int)
 trySlurp handle sz_i chunk =
-#if __GLASGOW_HASKELL__ == 303
+#if __GLASGOW_HASKELL__ < 303
+  readHandle handle        >>= \ handle_ ->
+  let fo = filePtr handle_ in
+#elif __GLASGOW_HASKELL__ == 303
   wantReadableHandle "hGetChar" handle >>= \ handle_ ->
   let fo = haFO__ handle_ in
-#elif __GLASGOW_HASKELL__ > 303
+#elif __GLASGOW_HASKELL__ < 501
   wantReadableHandle "hGetChar" handle $ \ handle_ ->
   let fo = haFO__ handle_ in
 #else
-  readHandle handle        >>= \ handle_ ->
-  let fo = filePtr handle_ in
+  wantReadableHandle "hGetChar" handle $ \handle_ ->
+  let fd = haFD handle_
+      ref = haBuffer handle_ in
 #endif
   let
 	(I# chunk_sz) = sz_i
@@ -285,13 +294,42 @@ trySlurp handle sz_i chunk =
 	     	chunk' <- reAllocMem chunk (I# new_sz)
 	     	slurpFile c off chunk' new_sz (new_sz -# (tAB_SIZE +# 1#))
     	  slurp c off = do
+#if __GLASGOW_HASKELL__ < 501
     		intc <- mayBlock fo (_ccall_ fileGetc fo)
     		if intc == ((-1)::Int)
      		  then do errtype <- getErrType
-			  if errtype == (ERR_EOF :: Int)
+			  if errtype == (19{-ERR_EOF-} :: Int)
 			    then return (chunk, I# off)
 			    else constructErrorAndFail "slurpFile"
      		  else case chr intc of
+#else
+		buf <- readIORef ref
+		ch <- (if not (bufferEmpty buf)
+		      then hGetcBuffered fd ref buf
+		      else -- buffer is empty.
+			   case haBufferMode handle_ of
+		  LineBuffering    -> do
+		      new_buf <- fillReadBuffer fd True buf
+		      hGetcBuffered fd ref new_buf
+		  BlockBuffering _ -> do
+		      new_buf <- fillReadBuffer fd False buf
+		      hGetcBuffered fd ref new_buf
+		  NoBuffering -> do
+		      -- make use of the minimal buffer we already have
+		      let raw = bufBuf buf
+		      r <- throwErrnoIfMinus1RetryMayBlock "hGetChar"
+		              (read_off (fromIntegral fd) raw 0 1)
+		              (threadWaitRead fd)
+		      if r == 0
+		         then ioe_EOF
+		         else do (c,_) <- readCharFromBuffer raw 0
+		                 return c)
+		    `catch` \e -> if isEOFError e
+			then return '\xFFFF'
+			else ioError e
+		case ch of
+			 '\xFFFF' -> return (chunk, I# off)
+#endif
 			 '\t' -> tabIt c off
 			 ch   -> do  writeCharOffAddr chunk (I# off) ch
 				     let c' | ch == '\n' = 0#
@@ -318,9 +356,7 @@ trySlurp handle sz_i chunk =
 #if __GLASGOW_HASKELL__ < 404
   writeHandle handle handle_
 #endif
-  if rc < (0::Int)
-	then constructErrorAndFail "slurpFile"
-	else return (chunk', rc+1 {-room for sentinel-})
+  return (chunk', rc+1 {-room for sentinel-})
 
 
 reAllocMem :: Addr -> Int -> IO Addr
@@ -337,15 +373,16 @@ reAllocMem ptr sz = do
 allocMem :: Int -> IO Addr
 allocMem sz = do
    chunk <- _ccall_ malloc sz
-#if __GLASGOW_HASKELL__ < 303
    if chunk == nullAddr 
+#if __GLASGOW_HASKELL__ < 303
       then fail (userError "allocMem")
-      else return chunk
-#else
-   if chunk == nullAddr 
+#elif __GLASGOW_HASKELL__ < 501
       then constructErrorAndFail "allocMem"
-      else return chunk
+#else
+      then ioException (IOError Nothing ResourceExhausted "malloc"
+					"out of memory" Nothing)
 #endif
+      else return chunk
 \end{code}
 
 Lookup
-- 
1.7.10.4