Introduce OS_NACL_SFI and OS_NACL_NONSFI macros.

build/build_config.h

Index: build/build_config.h
diff --git a/build/build_config.h b/build/build_config.h
index 553484605a857baa66d252ba5df4286ce89b53c7..38b2110695944f9d1d3d8b50af383f145294563f 100644
--- a/build/build_config.h
+++ b/build/build_config.h
@@ -4,7 +4,8 @@
 
 // This file adds defines about the platform we're currently building on.
 //  Operating System:
-//    OS_WIN / OS_MACOSX / OS_LINUX / OS_POSIX (MACOSX or LINUX) / OS_NACL
+//    OS_WIN / OS_MACOSX / OS_LINUX / OS_POSIX (MACOSX or LINUX) /
+//    OS_NACL (NACL_SFI or NACL_NONSFI) / OS_NACL_SFI / OS_NACL_NONSFI
 //  Compiler:
 //    COMPILER_MSVC / COMPILER_GCC
 //  Processor:
@@ -18,6 +19,13 @@
 #if defined(__native_client__)
 // __native_client__ must be first, so that other OS_ defines are not set.
 #define OS_NACL 1
+// In __native_client__ build, we also define one more macro depends on the
+// build is for Non-SFI binary or SFI binary.

[Junichi Uekawa, 2014/10/27 12:14:08]

This file is read by many people when they port things.
When a reader reads this document, I would expect to be able to distinguish what
they are.
Since it's something that we've defined as opposed to someone else, it might be
our duty to try to explain it succinctly.

ala "OS_NACL comes in two sandboxing technology flavors, SFI or Non-SFI. See XXX
for details."

[hidehiko, 2014/10/27 13:11:53]

Indeed. Updated the comment.

+#if defined(__native_client_nonsfi__)
+#define OS_NACL_NONSFI
+#else
+#define OS_NACL_SFI
+#endif
 #elif defined(ANDROID)
 #define OS_ANDROID 1
 #elif defined(__APPLE__)