More windows woe

[Edward Z. Yang]

I think this is reasonable, with the added caveat that
the macros should be placed in includes/rts/Linker.h, because that is
where pathchar is defined.  So how about something like:

diff --git a/includes/rts/Linker.h b/includes/rts/Linker.h
index e900e85..871b8cd 100644
--- a/includes/rts/Linker.h
+++ b/includes/rts/Linker.h
@@ -16,8 +16,10 @@

 #if defined(mingw32_HOST_OS)
 typedef wchar_t pathchar;
+#define FMT_PATH "%S"
 #else
 typedef char    pathchar;
+#define FMT_PATH "%s"
 #endif

 /* initialize the object linker */
diff --git a/rts/CheckUnload.c b/rts/CheckUnload.c
index a758b06..8dc8fdc 100644
--- a/rts/CheckUnload.c
+++ b/rts/CheckUnload.c
@@ -254,7 +254,7 @@ void checkUnload (StgClosure *static_objects)

   // Mark every unloadable object as unreferenced initially
   for (oc = unloaded_objects; oc; oc = oc->next) {
-      IF_DEBUG(linker, debugBelch("Checking whether to unload %s\n",
+      IF_DEBUG(linker, debugBelch("Checking whether to unload " FMT_PATH "\n",
                                   oc->fileName));
       oc->referenced = rtsFalse;
   }
@@ -290,11 +290,11 @@ void checkUnload (StgClosure *static_objects)
           } else {
               prev->next = oc->next;
           }
-          IF_DEBUG(linker, debugBelch("Unloading object file %s\n",
+          IF_DEBUG(linker, debugBelch("Unloading object file " FMT_PATH "\n",
                                       oc->fileName));
           freeObjectCode(oc);
       } else {
-          IF_DEBUG(linker, debugBelch("Object file still in use: %s\n",
+          IF_DEBUG(linker, debugBelch("Object file still in use: " FMT_PATH "\n",
                                       oc->fileName));
       }
   }
diff --git a/rts/Linker.c b/rts/Linker.c
index 6490242..4f0a1c4 100644
--- a/rts/Linker.c
+++ b/rts/Linker.c
@@ -2790,7 +2790,7 @@ unloadObj( pathchar *path )

     initLinker();

-    IF_DEBUG(linker, debugBelch("unloadObj: %s\n", path));
+    IF_DEBUG(linker, debugBelch("unloadObj: " FMT_PATH "\n", path));

     prev = NULL;
     for (oc = objects; oc; prev = oc, oc = next) {

Excerpts from Jost Berthold's message of Tue Sep 03 12:56:03 -0700 2013:
> > From: Simon Peyton-Jones <simonpj at microsoft.com>
> > To: "Edward Z. Yang" <ezyang at MIT.EDU>, Simon Marlow
> >     <marlowsd at gmail.com>
> > Cc: "ghc-devs at haskell.org" <ghc-devs at haskell.org>
> > Subject: RE: More windows woe
> > Message-ID:
> >     <59543203684B2244980D7E4057D5FBC1485BB7AB at DB3EX14MBXC308.europe.corp.microsoft.com>
> >     
> > Content-Type: text/plain; charset="utf-8"
> >
> > Simon Marlow: please help!
> > At the moment windows builds are hosed, which is a Bad Situation.
> >
> > Actually it turns out that what want is
> >
> >    debugBelch("Checking whether to unload %S\n", oc->fileName));
> >
> > That is, use "%S" rather than "%s" as format specifier for wide chars.
> >
> > Sadly, this works on Windows, but not on Linux:
> > rts/CheckUnload.c:260:13:
> >       error: format ?%S? expects argument of type ?wchar_t *?, but argument 2 has type ?pathchar *? [-Werror=format]
> >
> >
> > So what I need guidance on, please!, is what the approved way to deal with this is.  I suppose that I could identify each use of %s on a filepath and say
> >
> > #ifdef mingw32_HOST_OS
> >    debugBelch("Checking whether to unload %S\n", oc->fileName));
> > #else
> >    debugBelch("Checking whether to unload %s\n", oc->fileName));
> > #endif
> >
> > But that seems deeply unsatisfactory doesn't it?
> >
> > If not that, then what?
> >
> >
> > Simon
> 
> Similar code is in place to distinguish between 32-bit and 64-bit StgWords:
> 
>  > grep -r -e FMT_Word includes/
> includes/stg/Types.h:#define FMT_Word32    "u"
> includes/stg/Types.h:#define FMT_Word32    "lu"
> includes/stg/Types.h:#define FMT_Word64    "lu"
> includes/stg/Types.h:#define FMT_Word64    "llu"
> includes/stg/Types.h:#define FMT_Word     FMT_Word64
> includes/stg/Types.h:#define FMT_Word     FMT_Word32
> 
> and format strings like "blabla " FMT_Word " ..blabla" are used inside 
> rts/. One could do the same for FMT_Path and introduce it where required.
> 
> Maybe this would be acceptable?
> 
> / Jost
>