[project @ 2003-02-24 12:39:24 by simonpj]

Three Template Haskell improvements

a) Add type synonyms to THSyntax (and DsMeta, Convert)

b) Make Q into a newtype instead of a type synonym

c) Eliminate tiresome and error prone argument to DsMeta.wrapGenSyms
   and similarly addTyVarBinds

docs/building/building.sgml

@@ -4129,6 +4129,36 @@ that Haskell programs compiled by GHC-cygwin can import the (Haskell) Posix libr
 </para>
 </sect3>
 
+<sect3><title>HOST_OS vs TARGET_OS</title>
+
+<para>
+In the source code you'll find various ifdefs looking like:
+<programlisting>
+  #ifdef mingw32_HOST_OS
+    ...blah blah...
+  #endif
+</programlisting>
+and 
+<programlisting>
+  #ifdef mingw32_TARGET_OS
+    ...blah blah...
+  #endif
+</programlisting>
+These macros are set by the configure script (via the file config.h).
+Which is which?  The criterion is this.  In the ifdefs in GHC's source code:
+<itemizedlist>
+  <listitem> <para>
+  The "host" system is the one on which GHC itself will be run.
+  </para> </listitem>
+  <listitem> <para>
+  The "target" system is the one for which the program compiled by GHC will be run.
+  </para> </listitem>
+</itemizedlist>
+For a stage-2 compiler, in which GHCi is available, the "host" and "target" systems must be the same.
+So then it doesn't really matter whether you use the HOST_OS or TARGET_OS cpp macros.
+</para>
+</sect3>
+
 <sect3><title>Summary</title>
 
 <para>Notice that "GHC-mingw" means "GHC that <emphasis>targets</emphasis> MinGW".  It says nothing about 

ghc/compiler/ghci/InteractiveUI.hs

 {-# OPTIONS -#include "Linker.h" #-}
 -----------------------------------------------------------------------------
--- $Id: InteractiveUI.hs,v 1.147 2003/02/20 13:12:40 simonpj Exp $
+-- $Id: InteractiveUI.hs,v 1.148 2003/02/24 12:39:26 simonpj Exp $
 --
 -- GHC Interactive User Interface
 --
@@ -45,7 +45,7 @@ import CmdLineOpts	( DynFlag(..), DynFlags(..), getDynFlags, saveDynFlags,
 import Panic 		hiding ( showException )
 import Config
 
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
 import System.Posix
 #endif
 
@@ -234,7 +234,7 @@ runGHCi paths dflags = do
 	loadModule paths
 
   -- enter the interactive loop
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
    -- always show prompt, since hIsTerminalDevice returns True for Consoles
    -- only, which we may or may not be running under (cf. Emacs sub-shells.)
   interactiveLoop True
@@ -274,7 +274,7 @@ interactiveLoop is_tty = do
 
 checkPerms :: String -> IO Bool
 checkPerms name =
-#ifdef mingw32_TARGET_OS
+#ifdef mingw32_HOST_OS
   return True
 #else
   DriverUtil.handle (\_ -> return False) $ do

ghc/compiler/main/DriverFlags.hs

 -----------------------------------------------------------------------------
--- $Id: DriverFlags.hs,v 1.113 2003/02/21 13:26:58 simonpj Exp $
+-- $Id: DriverFlags.hs,v 1.114 2003/02/24 12:39:26 simonpj Exp $
 --
 -- Driver flags
 --
@@ -362,7 +362,7 @@ dynamic_flags = [
 	-- on all other systems, quoting is necessary, to avoid interpretation
 	-- of shell metacharacters in the arguments (e.g. green-card's
 	-- -DBEGIN_GHC_ONLY='}-' trick).
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
   ,  ( "D",		Prefix (\s -> addOpt_P ("-D'"++s++"'") ) )
   ,  ( "U",		Prefix (\s -> addOpt_P ("-U'"++s++"'") ) )
 #else

ghc/compiler/main/DriverPhases.hs

 -----------------------------------------------------------------------------
--- $Id: DriverPhases.hs,v 1.22 2002/09/13 15:02:34 simonpj Exp $
+-- $Id: DriverPhases.hs,v 1.23 2003/02/24 12:39:27 simonpj Exp $
 --
 -- GHC Driver
 --
@@ -106,6 +106,8 @@ cish_suffix           = (`elem` [ "c", "cpp", "C", "cc", "cxx", "s", "S" ])
 hsbootish_suffix      = (`elem` [ "hs-boot" ])
 extcoreish_suffix     = (`elem` [ "hcr" ])
 
+-- Use the appropriate suffix for the system on which 
+-- the GHC-compiled code will run
 #if mingw32_TARGET_OS || cygwin32_TARGET_OS
 objish_suffix     = (`elem` [ "o", "O", "obj", "OBJ" ])
 #else

ghc/compiler/main/SysTools.lhs

@@ -86,11 +86,11 @@ import Directory	( doesFileExist, removeFile )
 
 -- GHC <= 4.08 didn't have rawSystem, and runs into problems with long command
 -- lines on mingw32, so we disallow it now.
-#if defined(mingw32_TARGET_OS) && (__GLASGOW_HASKELL__ <= 408)
+#if defined(mingw32_HOST_OS) && (__GLASGOW_HASKELL__ <= 408)
 #error GHC <= 4.08 is not supported for bootstrapping GHC on i386-unknown-mingw32
 #endif
 
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
 #if __GLASGOW_HASKELL__ > 504
 import qualified GHC.Posix
 #else
@@ -103,7 +103,7 @@ import Foreign
 import CString		( CString, peekCString )
 #endif
 
-#ifdef mingw32_TARGET_OS
+#ifdef mingw32_HOST_OS
 #if __GLASGOW_HASKELL__ > 504
 import System.Cmd       ( rawSystem )
 #else
@@ -272,7 +272,7 @@ initSysTools minusB_args
 		| am_installed = installed_bin cGHC_MANGLER_PGM
 		| otherwise    = inplace cGHC_MANGLER_DIR_REL cGHC_MANGLER_PGM
 
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
 	-- check whether TMPDIR is set in the environment
 	; IO.try (do dir <- getEnv "TMPDIR" -- fails if not set
 	      	     setTmpDir dir
@@ -314,7 +314,7 @@ initSysTools minusB_args
 	     throwDyn (InstallationError 
 		         ("Can't find package.conf as " ++ pkgconfig_path))
 
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
 	--		WINDOWS-SPECIFIC STUFF
 	-- On Windows, gcc and friends are distributed with GHC,
 	-- 	so when "installed" we look in TopDir/bin
@@ -417,7 +417,7 @@ initSysTools minusB_args
 	; return ()
 	}
 
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
 foreign import stdcall "GetTempPathA" unsafe getTempPath :: Int -> CString -> IO Int32
 #endif
 \end{code}
@@ -701,7 +701,7 @@ runSomething :: String		-- For -v message
 runSomething phase_name pgm args
  = traceCmd phase_name cmd_line $
    do   {
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
 	  exit_code <- system cmd_line
 #else
           exit_code <- rawSystem cmd_line
@@ -772,7 +772,7 @@ pgmPath :: String		-- Directory string in Unix format
 
 
 
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
 
 --------------------- Windows version ------------------
 dosifyPaths xs = map dosifyPath xs
@@ -832,7 +832,7 @@ slash s1 s2 = s1 ++ ('/' : s2)
 -----------------------------------------------------------------------------
 -- Define	getExecDir     :: IO (Maybe String)
 
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
 getExecDir :: IO (Maybe String)
 getExecDir = do let len = (2048::Int) -- plenty, PATH_MAX is 512 under Win32.
 		buf <- mallocArray len
@@ -849,7 +849,7 @@ foreign import stdcall "GetModuleFileNameA" unsafe
 getExecDir :: IO (Maybe String) = do return Nothing
 #endif
 
-#ifdef mingw32_TARGET_OS
+#ifdef mingw32_HOST_OS
 foreign import ccall "_getpid" unsafe getProcessID :: IO Int -- relies on Int == Int32 on Windows
 #elif __GLASGOW_HASKELL__ > 504
 getProcessID :: IO Int
@@ -860,7 +860,7 @@ getProcessID = Posix.getProcessID
 #endif
 
 quote :: String -> String
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
 quote "" = ""
 quote s  = "\"" ++ s ++ "\""
 #else

ghc/compiler/utils/Panic.lhs

@@ -27,7 +27,7 @@ module Panic
 import Config
 import FastTypes
 
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
 # if __GLASGOW_HASKELL__ > 504
 import System.Posix.Signals
 # else
@@ -41,7 +41,7 @@ import EXCEPTION        ( raiseInThread )
 # else
 import EXCEPTION	( throwTo )
 # endif /* GHC < 500 */
-#endif /* mingw32_TARGET_OS */
+#endif /* mingw32_HOST_OS */
 
 import DYNAMIC
 import qualified EXCEPTION as Exception
@@ -185,7 +185,7 @@ thread.
 \begin{code}
 installSignalHandlers :: IO ()
 installSignalHandlers = do
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
   main_thread <- myThreadId
   let sig_handler = Catch (throwTo main_thread 
 				(Exception.DynException (toDyn Interrupted)))