Add fnl build target

build/toolchain/fnl/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/toolchain/clang.gni")
 import("//build/toolchain/gcc_toolchain.gni")
+import("//build/config/sysroot.gni")
 
 declare_args() {
   # The CrOS build system supports many different kinds of targets across

[viettrungluu, 2015/09/15 23:48:22]

Update this comment for FNL?

[cdotstout, 2015/09/16 22:01:00]

Done.

   # many different architectures. Bringing your own toolchain is also supported,
   # so it's actually impossible to enumerate all toolchains for all targets
   # as GN toolchain specifications.
   # These arguments provide a mechanism for specifying your CC, CXX and AR at
   # buildfile-generation time, allowing the CrOS build system to always use
   # the right tools for the current target.
-  cros_target_cc = ""
-  cros_target_cxx = ""
-  cros_target_ar = ""
+  compiler_prefix = "${sysroot}/../../bin/x86_64-linux-"

[viettrungluu, 2015/09/15 23:48:22]

It seems odd to be going outside the sysroot, but I don't know what's going
on....

[cdotstout, 2015/09/16 22:01:00]

Right, this is a buildroot specific hack.  Reworked.

+  cros_target_cc = "${compiler_prefix}gcc"

[viettrungluu, 2015/09/15 23:48:22]

Can you rename these from cros_... to fnl_...?

[cdotstout, 2015/09/16 22:01:00]

Done.

+  cros_target_cxx = "${compiler_prefix}g++"
+  cros_target_ar = "${compiler_prefix}ar"
+  cros_target_readelf = "${compiler_prefix}readelf"
+  cros_target_nm = "${compiler_prefix}nm"
 }
 
 gcc_toolchain("target") {
   assert(cros_target_cc != "", "Must provide target CC.")
   assert(cros_target_cxx != "", "Must provide target CXX.")
   assert(cros_target_ar != "", "Must provide target AR.")
 
   cc = "${cros_target_cc}"
   cxx = "${cros_target_cxx}"
 
   ar = "${cros_target_ar}"
   ld = cxx
+  readelf = "${cros_target_readelf}"
+  nm = "${cros_target_nm}"
 
   toolchain_cpu = "${target_cpu}"
   toolchain_os = "linux"
   is_clang = is_clang
 }