Add fnl build target

build/toolchain/fnl/BUILD.gn

Index: build/toolchain/fnl/BUILD.gn
diff --git a/build/toolchain/cros/BUILD.gn b/build/toolchain/fnl/BUILD.gn
similarity index 74%
copy from build/toolchain/cros/BUILD.gn
copy to build/toolchain/fnl/BUILD.gn
index 140958b5b93e6870ac744decdcd5d939acfebdd6..076aa5825bec296bfa8a89245b1fb3a50b689c55 100644
--- a/build/toolchain/cros/BUILD.gn
+++ b/build/toolchain/fnl/BUILD.gn
@@ -4,6 +4,7 @@
 
 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.

@@ -13,9 +14,12 @@ declare_args() {
   # 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") {
@@ -28,6 +32,8 @@ gcc_toolchain("target") {
 
   ar = "${cros_target_ar}"
   ld = cxx
+  readelf = "${cros_target_readelf}"
+  nm = "${cros_target_nm}"
 
   toolchain_cpu = "${target_cpu}"
   toolchain_os = "linux"