$NetBSD$

--- rts/Linker.c.orig	2010-11-12 18:10:05.000000000 +0000
+++ rts/Linker.c
@@ -69,7 +69,15 @@
 #include <sys/wait.h>
 #endif
 
-#if defined(linux_HOST_OS) || defined(freebsd_HOST_OS) || defined(dragonfly_HOST_OS) || defined(netbsd_HOST_OS) || defined(openbsd_HOST_OS) || defined(darwin_HOST_OS)
+#if defined(linux_HOST_OS    ) || defined(freebsd_HOST_OS) || \
+    defined(dragonfly_HOST_OS) || defined(netbsd_HOST_OS ) || \
+    defined(openbsd_HOST_OS  ) || \
+    ( defined(darwin_HOST_OS ) && !defined(powerpc_HOST_ARCH) )
+/* Don't use mmap on powerpc-apple-darwin as mmap doesn't support
+ * reallocating but we need to allocate jump islands just after each
+ * object images. Otherwise relative branches to jump islands can fail
+ * due to 24-bits displacement overflow.
+ */
 #define USE_MMAP
 #include <fcntl.h>
 #include <sys/mman.h>
@@ -1684,6 +1692,9 @@ loadArchive( char *path )
    size_t fileSize;
    int isObject;
    char tmp[12];
+#if !defined(USE_MMAP) && defined(darwin_HOST_OS)
+   int misalignment;
+#endif
 
    IF_DEBUG(linker, debugBelch("loadArchive `%s'\n", path));
 
@@ -1763,6 +1774,7 @@ loadArchive( char *path )
        if (isObject) {
            char *archiveMemberName;
 
+#if defined(USE_MMAP)
            /* We can't mmap from the archive directly, as object
               files need to be 8-byte aligned but files in .ar
               archives are 2-byte aligned, and if we malloc the
@@ -1770,9 +1782,17 @@ loadArchive( char *path )
               mmap some anonymous memory and use that. We could
               do better here. */
            image = mmapForLinker(imageSize, MAP_ANONYMOUS, -1);
+#elif defined(darwin_HOST_OS)
+           // See loadObj()
+           misalignment = machoGetMisalignment(f);
+           image = stgMallocBytes(imageSize + misalignment, "loadArchive(file)");
+           image += misalignment;
+#else
+           image = stgMallocBytes(imageSize, "loadArchive(file)");
+#endif
            n = fread ( image, 1, imageSize, f );
            if (n != imageSize)
-               barf("loadObj: error whilst reading `%s'", path);
+               barf("loadArchive: error whilst reading `%s'", path);
 
            archiveMemberName = stgMallocBytes(strlen(path) + fileNameSize + 3, "loadArchive(file)");
            sprintf(archiveMemberName, "%s(%.*s)", path, (int)fileNameSize, file);
@@ -1780,7 +1800,7 @@ loadArchive( char *path )
            oc = mkOc(path, image, imageSize, archiveMemberName
 #ifndef USE_MMAP
 #ifdef darwin_HOST_OS
-                    , 0
+                    , misalignment
 #endif
 #endif
                     );
@@ -1841,7 +1861,11 @@ loadObj( char *path )
    int fd;
 #else
    FILE *f;
+#  if defined(darwin_HOST_OS)
+   int misalignment;
+#  endif
 #endif
+
    IF_DEBUG(linker, debugBelch("loadObj %s\n", path));
 
    initLinker();
@@ -1914,12 +1938,12 @@ loadObj( char *path )
     // We calculate the correct alignment from the header before
     // reading the file, and then we misalign image on purpose so
     // that the actual sections end up aligned again.
-   misalignment = machoGetMisalignment(f);
-   image = stgMallocBytes(fileSize + misalignment, "loadObj(image)");
-   image += misalignment;
-#  else
-   image = stgMallocBytes(fileSize, "loadObj(image)");
-#  endif
+    misalignment = machoGetMisalignment(f);
+    image = stgMallocBytes(fileSize + misalignment, "loadObj(image)");
+    image += misalignment;
+#   else
+    image = stgMallocBytes(fileSize, "loadObj(image)");
+#   endif
 
    {
        int n;
@@ -2203,6 +2227,12 @@ static int ocAllocateSymbolExtras( Objec
      */
     if( m > n ) // we need to allocate more pages
     {
+#if !defined(x86_64_HOST_ARCH)
+        errorBelch("%s: WARNING: Allocating jump islands separately from "
+                   "the object image itself. This may interfere with "
+                   "relative branches to them.",
+                   OC_INFORMATIVE_FILENAME(oc));
+#endif
         oc->symbol_extras = mmapForLinker(sizeof(SymbolExtra) * count, 
                                           MAP_ANONYMOUS, -1);
     }
@@ -5211,20 +5241,23 @@ static int machoGetMisalignment( FILE * 
     struct mach_header header;
     int misalignment;
     
-    fread(&header, sizeof(header), 1, f);
-    rewind(f);
+    {
+        int n = fread(&header, sizeof(header), 1, f);
+        if (n != 1) {
+            barf("machoGetMisalignment: can't read the Mach-O header");
+        }
+    }
+    fseek(f, -sizeof(header), SEEK_CUR);
 
 #if x86_64_HOST_ARCH || powerpc64_HOST_ARCH
     if(header.magic != MH_MAGIC_64) {
-        errorBelch("Bad magic. Expected: %08x, got: %08x.\n",
-                   MH_MAGIC_64, header->magic);
-        return 0;
+        barf("Bad magic. Expected: %08x, got: %08x.",
+             MH_MAGIC_64, header.magic);
     }
 #else
     if(header.magic != MH_MAGIC) {
-        errorBelch("Bad magic. Expected: %08x, got: %08x.\n",
-                   MH_MAGIC, header->magic);
-        return 0;
+        barf("Bad magic. Expected: %08x, got: %08x.",
+             MH_MAGIC, header.magic);
     }
 #endif