Added 32-bit version of nonsfi monacl shell

mojo/nacl/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Trusted code
 if (!is_nacl) {
   # A simple shell for running untrusted binaries that talk to the Mojo
   # embedder. (No services.)
   executable("monacl_shell") {
     testonly = true
     sources = [
       "monacl_shell.cc",
     ]
     deps = [
       "//base:base",
       "//mojo/edk/system:system",
       "//nacl_bindings:monacl_sel",
     ]
 
     data_deps = [ "//nacl_bindings:irt_mojo(//native_client/build/toolchain/nacl:irt_${target_cpu})" ]
   }
 
-  executable("monacl_shell_nonsfi") {
-    testonly = true
-    sources = [
-      "monacl_shell_nonsfi.cc",
-    ]
-    deps = [
-      ":irt_mojo_nonsfi",
-      "//mojo/edk/system",
-      "//native_client/src/nonsfi/loader:elf_loader",
-    ]
+  if (current_cpu == "x86") {

[Mark Seaborn, 2015/09/09 19:13:14]

Can you add a comment to explain the conditional?  e.g. Non-SFI NaCl currently
supports x86-32 but not x86-64 (and PNaCl pexes assume 32-bit pointers).

[Sean Klein, 2015/09/09 19:32:33]

Done.

+    executable("monacl_shell_nonsfi") {
+      testonly = true
+      sources = [
+        "monacl_shell_nonsfi.cc",
+      ]
+      deps = [
+        ":irt_mojo_nonsfi",
+        "//mojo/edk/system",
+        "//native_client/src/nonsfi/loader:elf_loader",
+      ]
+    }
   }
 }
 
+group("monacl_shell_nonsfi_x86") {
+  testonly = true
+  deps = []
+  if ((target_cpu == "x64" || target_cpu == "x86") && is_linux) {

[Mark Seaborn, 2015/09/09 19:13:14]

A similar explanatory comment would be good here:  Even when Mojo is built for
x86-64 by default, we want to use x86-32 for running programs under Non-SFI
NaCl.

[Sean Klein, 2015/09/09 19:32:33]

Done.

+    # The toolchain is hardcoded as 32-bit clang here -- although it must
+    # be 32 bit (for nonsfi), it assumes clang. Ideally, the toolchain would
+    # be defined as the 32 bit variant of whatever is being used (be it clang,
+    # gcc, or something else).
+    deps += [ ":monacl_shell_nonsfi(//build/toolchain/linux:clang_x86)" ]
+  }
+}
+
 # Untrusted code
 if (is_nacl) {
   # Unit test for the Mojo public API.
   executable("monacl_test") {
     testonly = true
     sources = [
       "//mojo/public/cpp/system/tests/core_unittest.cc",
       "//mojo/public/cpp/system/tests/macros_unittest.cc",
     ]
     deps = [
@@ skipping 51 matching lines @@
   deps = [
     ":monacl_test(//native_client/build/toolchain/nacl:newlib_pnacl)",
   ]
 }
 
 group("mojo_nacl_tests") {
   testonly = true
   deps = [
     ":mojo_nacl_tests_untrusted(//native_client/build/toolchain/nacl:clang_newlib_${current_cpu})",
     ":monacl_shell",
+    ":monacl_shell_nonsfi_x86",
     ":mojo_pnacl_tests",
   ]
 }