Reorganisation of the source tree

Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.

The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level.  The build system now makes no
pretense at being multi-project, it is just the GHC build system.

No doubt this will break many things, and there will be a period of
instability while we fix the dependencies.  A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.

1 files changed, 540 insertions, 0 deletions

diff --git a/compiler/utils/Outputable.lhs b/compiler/utils/Outputable.lhs
new file mode 100644
index 0000000000..cf99e12bcf
--- /dev/null
+++ b/compiler/utils/Outputable.lhs
@@ -0,0 +1,540 @@
+%
+% (c) The GRASP Project, Glasgow University, 1992-1998
+%
+\section[Outputable]{Classes for pretty-printing}
+
+Defines classes for pretty-printing and forcing, both forms of
+``output.''
+
+\begin{code}
+
+module Outputable (
+	Outputable(..), OutputableBndr(..),	-- Class
+
+	BindingSite(..),
+
+	PprStyle, CodeStyle(..), PrintUnqualified, alwaysQualify,
+	getPprStyle, withPprStyle, withPprStyleDoc, pprDeeper, pprSetDepth,
+	codeStyle, userStyle, debugStyle, dumpStyle, asmStyle,
+	ifPprDebug, unqualStyle, 
+	mkErrStyle, defaultErrStyle, defaultDumpStyle, defaultUserStyle,
+
+	SDoc, 		-- Abstract
+	docToSDoc,
+	interppSP, interpp'SP, pprQuotedList, pprWithCommas,
+	empty, nest,
+	text, char, ftext, ptext,
+	int, integer, float, double, rational,
+	parens, brackets, braces, quotes, doubleQuotes, angleBrackets,
+	semi, comma, colon, dcolon, space, equals, dot, arrow,
+	lparen, rparen, lbrack, rbrack, lbrace, rbrace, underscore,
+	(<>), (<+>), hcat, hsep, 
+	($$), ($+$), vcat, 
+	sep, cat, 
+	fsep, fcat, 
+	hang, punctuate,
+	speakNth, speakNTimes, speakN, speakNOf, plural,
+
+	printSDoc, printErrs, printDump,
+	printForC, printForAsm, printForUser,
+	pprCode, mkCodeStyle,
+	showSDoc, showSDocForUser, showSDocDebug, showSDocDump,
+	showSDocUnqual, showsPrecSDoc,
+	pprHsChar, pprHsString,
+
+	-- error handling
+	pprPanic, assertPprPanic, pprPanic#, pprPgmError, 
+	pprTrace, warnPprTrace,
+	trace, pgmError, panic, panic#, assertPanic
+    ) where
+
+#include "HsVersions.h"
+
+
+import {-# SOURCE #-} 	Module( Module )
+import {-# SOURCE #-} 	OccName( OccName )
+
+import StaticFlags	( opt_PprStyle_Debug, opt_PprUserLength )
+import PackageConfig	( PackageId, packageIdString )
+import FastString
+import qualified Pretty
+import Pretty		( Doc, Mode(..) )
+import Panic
+
+import DATA_WORD	( Word32 )
+
+import IO		( Handle, stderr, stdout, hFlush )
+import Char             ( ord )
+\end{code}
+
+
+%************************************************************************
+%*									*
+\subsection{The @PprStyle@ data type}
+%*									*
+%************************************************************************
+
+\begin{code}
+data PprStyle
+  = PprUser PrintUnqualified Depth
+		-- Pretty-print in a way that will make sense to the
+		-- ordinary user; must be very close to Haskell
+		-- syntax, etc.
+		-- Assumes printing tidied code: non-system names are
+		-- printed without uniques.
+
+  | PprCode CodeStyle
+		-- Print code; either C or assembler
+
+  | PprDump	-- For -ddump-foo; less verbose than PprDebug.
+		-- Does not assume tidied code: non-external names
+		-- are printed with uniques.
+
+  | PprDebug	-- Full debugging output
+
+data CodeStyle = CStyle		-- The format of labels differs for C and assembler
+	       | AsmStyle
+
+data Depth = AllTheWay
+           | PartWay Int	-- 0 => stop
+
+
+type PrintUnqualified = Module -> OccName -> Bool
+	-- This function tells when it's ok to print 
+	-- a (Global) name unqualified
+
+alwaysQualify,neverQualify :: PrintUnqualified
+alwaysQualify m n = False
+neverQualify  m n = True
+
+defaultUserStyle = mkUserStyle alwaysQualify AllTheWay
+
+defaultDumpStyle |  opt_PprStyle_Debug = PprDebug
+		 |  otherwise          = PprDump
+
+mkErrStyle :: PrintUnqualified -> PprStyle
+-- Style for printing error messages
+mkErrStyle print_unqual = mkUserStyle print_unqual (PartWay opt_PprUserLength)
+
+defaultErrStyle :: PprStyle
+-- Default style for error messages
+-- It's a bit of a hack because it doesn't take into account what's in scope
+-- Only used for desugarer warnings, and typechecker errors in interface sigs
+defaultErrStyle 
+  | opt_PprStyle_Debug = mkUserStyle alwaysQualify AllTheWay
+  | otherwise	       = mkUserStyle alwaysQualify  (PartWay opt_PprUserLength)
+
+mkUserStyle unqual depth |  opt_PprStyle_Debug = PprDebug
+	          	 |  otherwise          = PprUser unqual depth
+\end{code}
+
+Orthogonal to the above printing styles are (possibly) some
+command-line flags that affect printing (often carried with the
+style).  The most likely ones are variations on how much type info is
+shown.
+
+The following test decides whether or not we are actually generating
+code (either C or assembly), or generating interface files.
+
+%************************************************************************
+%*									*
+\subsection{The @SDoc@ data type}
+%*									*
+%************************************************************************
+
+\begin{code}
+type SDoc = PprStyle -> Doc
+
+withPprStyle :: PprStyle -> SDoc -> SDoc
+withPprStyle sty d sty' = d sty
+
+withPprStyleDoc :: PprStyle -> SDoc -> Doc
+withPprStyleDoc sty d = d sty
+
+pprDeeper :: SDoc -> SDoc
+pprDeeper d (PprUser unqual (PartWay 0)) = Pretty.text "..."
+pprDeeper d (PprUser unqual (PartWay n)) = d (PprUser unqual (PartWay (n-1)))
+pprDeeper d other_sty        		 = d other_sty
+
+pprSetDepth :: Int -> SDoc -> SDoc
+pprSetDepth n d (PprUser unqual _) = d (PprUser unqual (PartWay n))
+pprSetDepth n d other_sty	   = d other_sty
+
+getPprStyle :: (PprStyle -> SDoc) -> SDoc
+getPprStyle df sty = df sty sty
+\end{code}
+
+\begin{code}
+unqualStyle :: PprStyle -> PrintUnqualified
+unqualStyle (PprUser    unqual _) m n = unqual m n
+unqualStyle other		  m n = False
+
+codeStyle :: PprStyle -> Bool
+codeStyle (PprCode _)	  = True
+codeStyle _		  = False
+
+asmStyle :: PprStyle -> Bool
+asmStyle (PprCode AsmStyle)  = True
+asmStyle other               = False
+
+dumpStyle :: PprStyle -> Bool
+dumpStyle PprDump = True
+dumpStyle other   = False
+
+debugStyle :: PprStyle -> Bool
+debugStyle PprDebug	  = True
+debugStyle other	  = False
+
+userStyle ::  PprStyle -> Bool
+userStyle (PprUser _ _) = True
+userStyle other         = False
+
+ifPprDebug :: SDoc -> SDoc	  -- Empty for non-debug style
+ifPprDebug d sty@PprDebug = d sty
+ifPprDebug d sty	  = Pretty.empty
+\end{code}
+
+\begin{code}
+-- Unused [7/02 sof]
+printSDoc :: SDoc -> PprStyle -> IO ()
+printSDoc d sty = do
+  Pretty.printDoc PageMode stdout (d sty)
+  hFlush stdout
+
+-- I'm not sure whether the direct-IO approach of Pretty.printDoc
+-- above is better or worse than the put-big-string approach here
+printErrs :: Doc -> IO ()
+printErrs doc = do Pretty.printDoc PageMode stderr doc
+		   hFlush stderr
+
+printDump :: SDoc -> IO ()
+printDump doc = do
+   Pretty.printDoc PageMode stdout (better_doc defaultDumpStyle)
+   hFlush stdout
+ where
+   better_doc = doc $$ text ""
+
+printForUser :: Handle -> PrintUnqualified -> SDoc -> IO ()
+printForUser handle unqual doc 
+  = Pretty.printDoc PageMode handle (doc (mkUserStyle unqual AllTheWay))
+
+-- printForC, printForAsm do what they sound like
+printForC :: Handle -> SDoc -> IO ()
+printForC handle doc = Pretty.printDoc LeftMode handle (doc (PprCode CStyle))
+
+printForAsm :: Handle -> SDoc -> IO ()
+printForAsm handle doc = Pretty.printDoc LeftMode handle (doc (PprCode AsmStyle))
+
+pprCode :: CodeStyle -> SDoc -> SDoc
+pprCode cs d = withPprStyle (PprCode cs) d
+
+mkCodeStyle :: CodeStyle -> PprStyle
+mkCodeStyle = PprCode
+
+-- Can't make SDoc an instance of Show because SDoc is just a function type
+-- However, Doc *is* an instance of Show
+-- showSDoc just blasts it out as a string
+showSDoc :: SDoc -> String
+showSDoc d = show (d defaultUserStyle)
+
+showSDocForUser :: PrintUnqualified -> SDoc -> String
+showSDocForUser unqual doc = show (doc (mkUserStyle unqual AllTheWay))
+
+showSDocUnqual :: SDoc -> String
+-- Only used in the gruesome HsExpr.isOperator
+showSDocUnqual d = show (d (mkUserStyle neverQualify AllTheWay))
+
+showsPrecSDoc :: Int -> SDoc -> ShowS
+showsPrecSDoc p d = showsPrec p (d defaultUserStyle)
+
+showSDocDump :: SDoc -> String
+showSDocDump d = show (d PprDump)
+
+showSDocDebug :: SDoc -> String
+showSDocDebug d = show (d PprDebug)
+\end{code}
+
+\begin{code}
+docToSDoc :: Doc -> SDoc
+docToSDoc d = \_ -> d
+
+empty sty      = Pretty.empty
+text s sty     = Pretty.text s
+char c sty     = Pretty.char c
+ftext s sty    = Pretty.ftext s
+ptext s sty    = Pretty.ptext s
+int n sty      = Pretty.int n
+integer n sty  = Pretty.integer n
+float n sty    = Pretty.float n
+double n sty   = Pretty.double n
+rational n sty = Pretty.rational n
+
+parens d sty       = Pretty.parens (d sty)
+braces d sty       = Pretty.braces (d sty)
+brackets d sty     = Pretty.brackets (d sty)
+doubleQuotes d sty = Pretty.doubleQuotes (d sty)
+angleBrackets d    = char '<' <> d <> char '>'
+
+-- quotes encloses something in single quotes...
+-- but it omits them if the thing ends in a single quote
+-- so that we don't get `foo''.  Instead we just have foo'.
+quotes d sty = case show pp_d of
+		 ('\'' : _) -> pp_d
+		 other	    -> Pretty.quotes pp_d
+	     where
+	       pp_d = d sty
+
+semi sty   = Pretty.semi
+comma sty  = Pretty.comma
+colon sty  = Pretty.colon
+equals sty = Pretty.equals
+space sty  = Pretty.space
+lparen sty = Pretty.lparen
+rparen sty = Pretty.rparen
+lbrack sty = Pretty.lbrack
+rbrack sty = Pretty.rbrack
+lbrace sty = Pretty.lbrace
+rbrace sty = Pretty.rbrace
+dcolon sty = Pretty.ptext SLIT("::")
+arrow  sty = Pretty.ptext SLIT("->")
+underscore = char '_'
+dot	   = char '.'
+
+nest n d sty    = Pretty.nest n (d sty)
+(<>) d1 d2 sty  = (Pretty.<>)  (d1 sty) (d2 sty)
+(<+>) d1 d2 sty = (Pretty.<+>) (d1 sty) (d2 sty)
+($$) d1 d2 sty  = (Pretty.$$)  (d1 sty) (d2 sty)
+($+$) d1 d2 sty = (Pretty.$+$) (d1 sty) (d2 sty)
+
+hcat ds sty = Pretty.hcat [d sty | d <- ds]
+hsep ds sty = Pretty.hsep [d sty | d <- ds]
+vcat ds sty = Pretty.vcat [d sty | d <- ds]
+sep ds sty  = Pretty.sep  [d sty | d <- ds]
+cat ds sty  = Pretty.cat  [d sty | d <- ds]
+fsep ds sty = Pretty.fsep [d sty | d <- ds]
+fcat ds sty = Pretty.fcat [d sty | d <- ds]
+
+hang d1 n d2 sty   = Pretty.hang (d1 sty) n (d2 sty)
+
+punctuate :: SDoc -> [SDoc] -> [SDoc]
+punctuate p []     = []
+punctuate p (d:ds) = go d ds
+		   where
+		     go d [] = [d]
+		     go d (e:es) = (d <> p) : go e es
+\end{code}
+
+
+%************************************************************************
+%*									*
+\subsection[Outputable-class]{The @Outputable@ class}
+%*									*
+%************************************************************************
+
+\begin{code}
+class Outputable a where
+	ppr :: a -> SDoc
+\end{code}
+
+\begin{code}
+instance Outputable Bool where
+    ppr True  = ptext SLIT("True")
+    ppr False = ptext SLIT("False")
+
+instance Outputable Int where
+   ppr n = int n
+
+instance Outputable () where
+   ppr _ = text "()"
+
+instance (Outputable a) => Outputable [a] where
+    ppr xs = brackets (fsep (punctuate comma (map ppr xs)))
+
+instance (Outputable a, Outputable b) => Outputable (a, b) where
+    ppr (x,y) = parens (sep [ppr x <> comma, ppr y])
+
+instance Outputable a => Outputable (Maybe a) where
+  ppr Nothing = ptext SLIT("Nothing")
+  ppr (Just x) = ptext SLIT("Just") <+> ppr x
+
+-- ToDo: may not be used
+instance (Outputable a, Outputable b, Outputable c) => Outputable (a, b, c) where
+    ppr (x,y,z) =
+      parens (sep [ppr x <> comma,
+		   ppr y <> comma,
+		   ppr z ])
+
+instance (Outputable a, Outputable b, Outputable c, Outputable d) =>
+	 Outputable (a, b, c, d) where
+    ppr (x,y,z,w) =
+      parens (sep [ppr x <> comma,
+		   ppr y <> comma,
+		   ppr z <> comma,
+		   ppr w])
+
+instance Outputable FastString where
+    ppr fs = ftext fs		-- Prints an unadorned string,
+				-- no double quotes or anything
+
+instance Outputable PackageId where
+   ppr pid = text (packageIdString pid)
+\end{code}
+
+
+%************************************************************************
+%*									*
+\subsection{The @OutputableBndr@ class}
+%*									*
+%************************************************************************
+
+When we print a binder, we often want to print its type too.
+The @OutputableBndr@ class encapsulates this idea.
+
+@BindingSite@ is used to tell the thing that prints binder what
+language construct is binding the identifier.  This can be used
+to decide how much info to print.
+
+\begin{code}
+data BindingSite = LambdaBind | CaseBind | LetBind
+
+class Outputable a => OutputableBndr a where
+   pprBndr :: BindingSite -> a -> SDoc
+   pprBndr b x = ppr x
+\end{code}
+
+
+
+%************************************************************************
+%*									*
+\subsection{Random printing helpers}
+%*									*
+%************************************************************************
+
+\begin{code}
+-- We have 31-bit Chars and will simply use Show instances
+-- of Char and String.
+
+pprHsChar :: Char -> SDoc
+pprHsChar c | c > '\x10ffff' = char '\\' <> text (show (fromIntegral (ord c) :: Word32))
+            | otherwise      = text (show c)
+
+pprHsString :: FastString -> SDoc
+pprHsString fs = text (show (unpackFS fs))
+\end{code}
+
+
+%************************************************************************
+%*									*
+\subsection{Other helper functions}
+%*									*
+%************************************************************************
+
+\begin{code}
+pprWithCommas :: (a -> SDoc) -> [a] -> SDoc
+pprWithCommas pp xs = fsep (punctuate comma (map pp xs))
+
+interppSP  :: Outputable a => [a] -> SDoc
+interppSP  xs = sep (map ppr xs)
+
+interpp'SP :: Outputable a => [a] -> SDoc
+interpp'SP xs = sep (punctuate comma (map ppr xs))
+
+pprQuotedList :: Outputable a => [a] -> SDoc
+-- [x,y,z]  ==>  `x', `y', `z'
+pprQuotedList xs = hsep (punctuate comma (map (quotes . ppr) xs))
+\end{code}
+
+
+%************************************************************************
+%*									*
+\subsection{Printing numbers verbally}
+%*									*
+%************************************************************************
+
+@speakNth@ converts an integer to a verbal index; eg 1 maps to
+``first'' etc.
+
+\begin{code}
+speakNth :: Int -> SDoc
+speakNth 1 = ptext SLIT("first")
+speakNth 2 = ptext SLIT("second")
+speakNth 3 = ptext SLIT("third")
+speakNth 4 = ptext SLIT("fourth")
+speakNth 5 = ptext SLIT("fifth")
+speakNth 6 = ptext SLIT("sixth")
+speakNth n = hcat [ int n, text suffix ]
+  where
+    suffix | n <= 20       = "th"	-- 11,12,13 are non-std
+	   | last_dig == 1 = "st"
+	   | last_dig == 2 = "nd"
+	   | last_dig == 3 = "rd"
+	   | otherwise     = "th"
+
+    last_dig = n `rem` 10
+
+speakN :: Int -> SDoc
+speakN 0 = ptext SLIT("none")	-- E.g.  "he has none"
+speakN 1 = ptext SLIT("one")	-- E.g.  "he has one"
+speakN 2 = ptext SLIT("two")
+speakN 3 = ptext SLIT("three")
+speakN 4 = ptext SLIT("four")
+speakN 5 = ptext SLIT("five")
+speakN 6 = ptext SLIT("six")
+speakN n = int n
+
+speakNOf :: Int -> SDoc -> SDoc
+speakNOf 0 d = ptext SLIT("no") <+> d <> char 's'	-- E.g. "no arguments"
+speakNOf 1 d = ptext SLIT("one") <+> d			-- E.g. "one argument"
+speakNOf n d = speakN n <+> d <> char 's'		-- E.g. "three arguments"
+
+speakNTimes :: Int {- >=1 -} -> SDoc
+speakNTimes t | t == 1 	   = ptext SLIT("once")
+              | t == 2 	   = ptext SLIT("twice")
+              | otherwise  = speakN t <+> ptext SLIT("times")
+
+plural [x] = empty
+plural xs  = char 's'
+\end{code}
+
+
+%************************************************************************
+%*									*
+\subsection{Error handling}
+%*									*
+%************************************************************************
+
+\begin{code}
+pprPanic, pprPgmError :: String -> SDoc -> a
+pprTrace :: String -> SDoc -> a -> a
+pprPanic    = pprAndThen panic		-- Throw an exn saying "bug in GHC"
+
+pprPgmError = pprAndThen pgmError	-- Throw an exn saying "bug in pgm being compiled"
+					--	(used for unusual pgm errors)
+pprTrace    = pprAndThen trace
+
+pprPanic# heading pretty_msg = panic# (show (doc PprDebug))
+			     where
+			       doc = text heading <+> pretty_msg
+
+pprAndThen :: (String -> a) -> String -> SDoc -> a
+pprAndThen cont heading pretty_msg = cont (show (doc PprDebug))
+    where
+     doc = sep [text heading, nest 4 pretty_msg]
+
+assertPprPanic :: String -> Int -> SDoc -> a
+assertPprPanic file line msg
+  = panic (show (doc PprDebug))
+  where
+    doc = sep [hsep[text "ASSERT failed! file", 
+		 	   text file, 
+			   text "line", int line], 
+		    msg]
+
+warnPprTrace :: Bool -> String -> Int -> SDoc -> a -> a
+warnPprTrace False file line msg x = x
+warnPprTrace True  file line msg x
+  = trace (show (doc PprDebug)) x
+  where
+    doc = sep [hsep [text "WARNING: file", text file, text "line", int line],
+	       msg]
+\end{code}