[MonoPosixHelper] Allow MmapFlags.MAP_ANON use on OS X.

Fixes: https://bugzilla.xamarin.com/show_bug.cgi?id=3419

The problem is that OS X defines MAP_ANON but not MAP_ANONYMOUS, AND
MAP_ANON and MAP_ANONYMOUS have the same value. Furthermore,
create-native-map doesn't have any special support for constants with
the same value, so it emits the validation independently.

The result is that the following fails on OS X:

	$ csharp -r:Mono.Posix.dll
	csharp> int r;
	csharp> using Mono.Unix.Native;
	csharp> NativeConvert.TryFromMmapFlags(MmapFlags.MAP_ANONYMOUS, out r);
	false
	csharp> r;

The (hackish) fix is to provide MAP_ANONYMOUS on OS X, thus allowing
the existing validation logic to work as expected.

diff --git a/support/mph.h b/support/mph.h
index 8a61999942641e4e81bb5c953e5c04f494510c4f..aedff01b7f32d6f8ce7f2a570c0472afa6e48c6e 100644 (file)
--- a/support/mph.h
+++ b/support/mph.h
@@ -74,6 +74,16 @@
 #define L_XTND SEEK_END
 #endif /* ndef L_XTND */
 
+/*
+ * OS X doesn't define MAP_ANONYMOUS, but it does define MAP_ANON.
+ * Alias them to fix: https://bugzilla.xamarin.com/show_bug.cgi?id=3419
+ */
+#ifdef PLATFORM_MACOSX
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif  /* ndef MAP_ANONYMOUS */
+#endif  /* ndef PLATFORM_MACOSX */
+
 /*
  * XATTR_AUTO is a synonym for 0 within XattrFlags, but most systems don't
  * define it.  map.c doesn't know that, though, so we ensure that it's defined