[[project @ 2003-02-24 12:39:24 by simonpj]
simonpj**20030224123927
 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
] {
hunk ./docs/building/building.sgml 4131
+
+<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>
hunk ./ghc/compiler/ghci/InteractiveUI.hs 3
--- $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 $
hunk ./ghc/compiler/ghci/InteractiveUI.hs 48
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
hunk ./ghc/compiler/ghci/InteractiveUI.hs 237
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
hunk ./ghc/compiler/ghci/InteractiveUI.hs 277
-#ifdef mingw32_TARGET_OS
+#ifdef mingw32_HOST_OS
hunk ./ghc/compiler/main/DriverFlags.hs 2
--- $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 $
hunk ./ghc/compiler/main/DriverFlags.hs 365
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
hunk ./ghc/compiler/main/DriverPhases.hs 2
--- $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 $
hunk ./ghc/compiler/main/DriverPhases.hs 109
+-- Use the appropriate suffix for the system on which 
+-- the GHC-compiled code will run
hunk ./ghc/compiler/main/SysTools.lhs 89
-#if defined(mingw32_TARGET_OS) && (__GLASGOW_HASKELL__ <= 408)
+#if defined(mingw32_HOST_OS) && (__GLASGOW_HASKELL__ <= 408)
hunk ./ghc/compiler/main/SysTools.lhs 93
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
hunk ./ghc/compiler/main/SysTools.lhs 106
-#ifdef mingw32_TARGET_OS
+#ifdef mingw32_HOST_OS
hunk ./ghc/compiler/main/SysTools.lhs 275
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
hunk ./ghc/compiler/main/SysTools.lhs 317
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
hunk ./ghc/compiler/main/SysTools.lhs 420
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
hunk ./ghc/compiler/main/SysTools.lhs 704
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
hunk ./ghc/compiler/main/SysTools.lhs 775
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
hunk ./ghc/compiler/main/SysTools.lhs 835
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
hunk ./ghc/compiler/main/SysTools.lhs 852
-#ifdef mingw32_TARGET_OS
+#ifdef mingw32_HOST_OS
hunk ./ghc/compiler/main/SysTools.lhs 863
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
hunk ./ghc/compiler/utils/Panic.lhs 30
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
hunk ./ghc/compiler/utils/Panic.lhs 44
-#endif /* mingw32_TARGET_OS */
+#endif /* mingw32_HOST_OS */
hunk ./ghc/compiler/utils/Panic.lhs 188
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
}