[project @ 2005-01-27 10:45:47 by simonpj]

--------------------------------------------
          Replace hi-boot files with hs-boot files
  	--------------------------------------------

This major commit completely re-organises the way that recursive modules
are dealt with.

  * It should have NO EFFECT if you do not use recursive modules

  * It is a BREAKING CHANGE if you do

====== Warning: .hi-file format has changed, so if you are
======		updating into an existing HEAD build, you'll
======		need to make clean and re-make


The details:  [documentation still to be done]

* Recursive loops are now broken with Foo.hs-boot (or Foo.lhs-boot),
  not Foo.hi-boot

* An hs-boot files is a proper source file.  It is compiled just like
  a regular Haskell source file:
	ghc Foo.hs		generates Foo.hi, Foo.o
	ghc Foo.hs-boot		generates Foo.hi-boot, Foo.o-boot

* hs-boot files are precisely a subset of Haskell. In particular:
	- they have the same import, export, and scoping rules
	- errors (such as kind errors) in hs-boot files are checked
  You do *not* need to mention the "original" name of something in
  an hs-boot file, any more than you do in any other Haskell module.

* The Foo.hi-boot file generated by compiling Foo.hs-boot is a machine-
  generated interface file, in precisely the same format as Foo.hi

* When compiling Foo.hs, its exports are checked for compatibility with
  Foo.hi-boot (previously generated by compiling Foo.hs-boot)

* The dependency analyser (ghc -M) knows about Foo.hs-boot files, and
  generates appropriate dependencies.  For regular source files it
  generates
	Foo.o : Foo.hs
	Foo.o : Baz.hi		-- Foo.hs imports Baz
	Foo.o : Bog.hi-boot	-- Foo.hs source-imports Bog

  For a hs-boot file it generates similar dependencies
	Bog.o-boot : Bog.hs-boot
	Bog.o-boot : Nib.hi	-- Bog.hs-boto imports Nib

* ghc -M is also enhanced to use the compilation manager dependency
  chasing, so that
	ghc -M Main
  will usually do the job.  No need to enumerate all the source files.

* The -c flag is no longer a "compiler mode". It simply means "omit the
  link step", and synonymous with -no-link.

7 files changed, 41 insertions, 36 deletions

diff --git a/libraries/base/Data/Dynamic.hi-boot b/libraries/base/Data/Dynamic.hs-boot
index 7ab9f6a4b0..822ef67c7d 100644
--- a/libraries/base/Data/Dynamic.hi-boot
+++ b/libraries/base/Data/Dynamic.hs-boot
@@ -1,2 +1,3 @@
+{-# OPTIONS -fno-implicit-prelude #-}
 module Data.Dynamic where
 data Dynamic
diff --git a/libraries/base/Foreign/Ptr.hs b/libraries/base/Foreign/Ptr.hs
index 7ab3c02451..ad20da4a5a 100644
--- a/libraries/base/Foreign/Ptr.hs
+++ b/libraries/base/Foreign/Ptr.hs
@@ -42,7 +42,6 @@ module Foreign.Ptr (
 #ifdef __GLASGOW_HASKELL__
 import GHC.Ptr
 import GHC.IOBase
-import GHC.Err
 import GHC.Base
 import GHC.Num
 import GHC.List
diff --git a/libraries/base/GHC/Err.hi-boot b/libraries/base/GHC/Err.hi-boot
deleted file mode 100644
index 4ae901a99f..0000000000
--- a/libraries/base/GHC/Err.hi-boot
+++ /dev/null
@@ -1,20 +0,0 @@
----------------------------------------------------------------------------
---                              PrelErr.hi-boot
--- 
---      This hand-written interface file is the initial bootstrap version
---	for PrelErr.hi.
---	It doesn't need to give "error" a type signature, 
---	because it's wired into the compiler
----------------------------------------------------------------------------
-
-module GHC.Err where
-
--- We can't give an accurate type for error, because it mentions an open
--- type variable, but fortunately it doesn't matter what type we
--- give here because the compiler will use its wired-in version.  But we have
--- to mention 'error' so that it gets exported from this .hi-boot
--- file.
-error    :: GHC.Base.String -> a
-
--- divide by zero is needed quite early
-divZeroError :: a
diff --git a/libraries/base/GHC/Err.lhs-boot b/libraries/base/GHC/Err.lhs-boot
new file mode 100644
index 0000000000..70afbb9121
--- /dev/null
+++ b/libraries/base/GHC/Err.lhs-boot
@@ -0,0 +1,23 @@
+\begin{code}
+{-# OPTIONS -fno-implicit-prelude #-}
+---------------------------------------------------------------------------
+--                  Ghc.Err.hs-boot
+---------------------------------------------------------------------------
+
+module GHC.Err( error, divZeroError ) where
+
+-- The type signature for 'error' is a gross hack.
+-- First, we can't give an accurate type for error, because it mentions 
+-- an open type variable.
+-- Second, we can't even say error :: [Char] -> a, because Char is defined
+-- in GHC.Base, and that would make Err.lhs-boot mutually recursive 
+-- with GHC.Base.
+-- Fortunately it doesn't matter what type we give here because the 
+-- compiler will use its wired-in version.  But we have
+-- to mention 'error' so that it gets exported from this .hi-boot
+-- file.
+error    :: a
+
+-- divide by zero is needed quite early
+divZeroError :: a
+\end{code}
diff --git a/libraries/base/GHC/Num.lhs b/libraries/base/GHC/Num.lhs
index 5d559469fe..76d6c8b1f1 100644
--- a/libraries/base/GHC/Num.lhs
+++ b/libraries/base/GHC/Num.lhs
@@ -27,7 +27,6 @@ module GHC.Num where
 
 import {-# SOURCE #-} GHC.Err
 import GHC.Base
-import GHC.List
 import GHC.Enum
 import GHC.Show
 
diff --git a/libraries/base/GHC/Unicode.hi-boot b/libraries/base/GHC/Unicode.hi-boot
deleted file mode 100644
index 43204df6f4..0000000000
--- a/libraries/base/GHC/Unicode.hi-boot
+++ /dev/null
@@ -1,14 +0,0 @@
-module GHC.Unicode where
-
-isAscii		:: GHC.Base.Char -> GHC.Base.Bool
-isLatin1	:: GHC.Base.Char -> GHC.Base.Bool
-isControl	:: GHC.Base.Char -> GHC.Base.Bool
-isPrint		:: GHC.Base.Char -> GHC.Base.Bool
-isSpace		:: GHC.Base.Char -> GHC.Base.Bool
-isUpper		:: GHC.Base.Char -> GHC.Base.Bool
-isLower		:: GHC.Base.Char -> GHC.Base.Bool
-isAlpha		:: GHC.Base.Char -> GHC.Base.Bool
-isDigit		:: GHC.Base.Char -> GHC.Base.Bool
-isOctDigit	:: GHC.Base.Char -> GHC.Base.Bool
-isHexDigit	:: GHC.Base.Char -> GHC.Base.Bool
-isAlphaNum	:: GHC.Base.Char -> GHC.Base.Bool
diff --git a/libraries/base/GHC/Unicode.hs-boot b/libraries/base/GHC/Unicode.hs-boot
new file mode 100644
index 0000000000..169011060d
--- /dev/null
+++ b/libraries/base/GHC/Unicode.hs-boot
@@ -0,0 +1,17 @@
+{-# OPTIONS -fno-implicit-prelude #-}
+
+module GHC.Unicode where
+import GHC.Base( Char, Bool )
+
+isAscii		:: Char -> Bool
+isLatin1	:: Char -> Bool
+isControl	:: Char -> Bool
+isPrint		:: Char -> Bool
+isSpace		:: Char -> Bool
+isUpper		:: Char -> Bool
+isLower		:: Char -> Bool
+isAlpha		:: Char -> Bool
+isDigit		:: Char -> Bool
+isOctDigit	:: Char -> Bool
+isHexDigit	:: Char -> Bool
+isAlphaNum	:: Char -> Bool