Build nacl_helper_nonsfi with GN

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 6b1e8979e35fe5f1352ff36680b6cb79ddcf7525..d36975d4581f381ab259a50453c751a1afa35a3c 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -450,6 +450,30 @@ config("compiler_cpu_abi") {
         ]
         ldflags += [ "-mips64r2" ]
       }
+    } else if (current_cpu == "pnacl" && is_nacl_nonsfi) {
+      if (target_cpu == "x86" || target_cpu == "x64") {
+        cflags += [
+          "-arch",
+          "x86-32-nonsfi",
+          "--pnacl-bias=x86-32-nonsfi",
+          "--target=i686-unknown-nacl",
+        ]
+        ldflags += [
+          "-arch",
+          "x86-32-nonsfi",
+          "--target=i686-unknown-nacl",
+        ]
+      } else if (target_cpu == "arm") {
+        cflags += [
+          "-arch",
+          "arm-nonsfi",
+          "--pnacl-bias=arm-nonsfi",
+        ]
+        ldflags += [
+          "-arch",
+          "arm-nonsfi",
+        ]
+      }
     }
   }
 
@@ -758,6 +782,19 @@ config("default_warnings") {
         "-Wno-bitfield-width",
       ]
     }
+
+    if (is_nacl_nonsfi) {

[brettw, 2015/10/23 09:38:13]

This block seems very strange to me. Why are we disabling all of these warnings
for this nacl variant? I don't see anything intrinsic in this build that
indicates we should disable things like sign compares or unused functions when
it works well otherwise.

[Petr Hosek, 2015/10/23 17:53:07]

I originally copied the configuration from Gyp but you're right, most of these
are not needed. Actually, it turned it's just the `-Wno-unused-function` and
`-Wno-sign-compare` which is really needed. The first one needs some fixes
inside seccomp-bfp, the second one needs a trivial fix on the NaCl side. I added
appropriate TODOs.

+      cflags += [
+        # Disables
+        "-Wno-c++11-extensions",
+        "-Wno-char-subscripts",
+        "-Wno-extra-semi",
+        "-Wno-unnamed-type-template-args",
+        "-Wno-unused-private-field",
+        "-Wno-unused-function",
+        "-Wno-sign-compare",
+      ]
+    }
   }
 }