Introduce OS_NACL_SFI and OS_NACL_NONSFI macros.

PNaCl toolchain starts to support "Non-SFI build binary" mode.
Some sources are built both for SFI binary and for Non-SFI binary, but, in some
cases, there are small diffs which need to be guarded by #ifdef.
In "Non-SFI build binary" mode, __native_client_nonsfi__ is defined.
This CL introduce OS_NACL_SFI and OS_NACL_NONSFI which can be used among the
chrome code, to slightly simplify the #ifdef conditions.

This CL is the follow up of crrev.com/659243002

BUG=358465
TEST=Ran trybot.

Review URL: https://codereview.chromium.org/664373003

Cr-Commit-Position: refs/heads/master@{#301603}

5 files changed, 16 insertions, 8 deletions

diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 8ec7f53..2c40565 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -265,6 +265,8 @@ _VALID_OS_MACROS = (
     'OS_LINUX',
     'OS_MACOSX',
     'OS_NACL',
+    'OS_NACL_NONSFI',
+    'OS_NACL_SFI',
     'OS_OPENBSD',
     'OS_POSIX',
     'OS_QNX',
diff --git a/build/build_config.h b/build/build_config.h
index 5534846..b07660d 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 +19,14 @@
 #if defined(__native_client__)
 // __native_client__ must be first, so that other OS_ defines are not set.
 #define OS_NACL 1
+// OS_NACL comes in two sandboxing technology flavors, SFI or Non-SFI.
+// PNaCl toolchain defines __native_client_nonsfi__ macro in Non-SFI build
+// mode, while it does not in SFI build mode.
+#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__)
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
index 3ed5e6a..f077def 100644
--- a/ipc/ipc_channel.h
+++ b/ipc/ipc_channel.h
@@ -182,8 +182,7 @@ class IPC_EXPORT Channel : public Sender {
   // NaCl in Non-SFI mode runs on Linux directly, and the following functions
   // compiled on Linux are also needed. Please see also comments in
   // components/nacl_nonsfi.gyp for more details.
-#if defined(OS_POSIX) && \
-    (!defined(OS_NACL) || defined(__native_client_nonsfi__))
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
   // On POSIX an IPC::Channel wraps a socketpair(), this method returns the
   // FD # for the client end of the socket.
   // This method may only be called on the server side of a channel.
@@ -200,7 +199,7 @@ class IPC_EXPORT Channel : public Sender {
   // ID. Even if true, the server may have already accepted a connection.
   static bool IsNamedServerInitialized(const std::string& channel_id);
 
-#if !defined(OS_NACL) || defined(__native_client_nonsfi__)
+#if !defined(OS_NACL_SFI)
   // Generates a channel ID that's non-predictable and unique.
   static std::string GenerateUniqueRandomChannelID();
 
diff --git a/ipc/ipc_channel_proxy.cc b/ipc/ipc_channel_proxy.cc
index 07f9552..64fab8f 100644
--- a/ipc/ipc_channel_proxy.cc
+++ b/ipc/ipc_channel_proxy.cc
@@ -434,8 +434,7 @@ void ChannelProxy::ClearIPCTaskRunner() {
   context()->ClearIPCTaskRunner();
 }
 
-#if defined(OS_POSIX) && \
-    (!defined(OS_NACL) || defined(__native_client_nonsfi__))
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
 // See the TODO regarding lazy initialization of the channel in
 // ChannelProxy::Init().
 int ChannelProxy::GetClientFileDescriptor() {
diff --git a/ipc/ipc_channel_proxy.h b/ipc/ipc_channel_proxy.h
index e2ad4a9..dda5fa5 100644
--- a/ipc/ipc_channel_proxy.h
+++ b/ipc/ipc_channel_proxy.h
@@ -119,8 +119,7 @@ class IPC_EXPORT ChannelProxy : public Sender, public base::NonThreadSafe {
   // Returns base::kNullProcessId if the peer is not connected yet.
   base::ProcessId GetPeerPID() const { return context_->peer_pid_; }
 
-#if defined(OS_POSIX) && \
-    (!defined(OS_NACL) || defined(__native_client_nonsfi__))
+#if defined(OS_POSIX) && !defined(OS_NACL_SFI)
   // Calls through to the underlying channel's methods.
   int GetClientFileDescriptor();
   base::ScopedFD TakeClientFileDescriptor();