GN: Harmonize ARM compiler settings with GYP

build/toolchain/linux/BUILD.gn

 # Copyright 2013 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/config/sysroot.gni")
 import("//build/toolchain/ccache.gni")
 import("//build/toolchain/gcc_toolchain.gni")
 import("//build/toolchain/goma.gni")
 
 if (use_goma) {
   assert(!use_ccache, "Goma and ccache can't be used together.")
   compiler_prefix = "$goma_dir/gomacc "
 } else if (use_ccache) {
   compiler_prefix = "ccache "
 } else {
   compiler_prefix = ""
 }
 
-gcc_toolchain("arm") {
-  cc = "${compiler_prefix}arm-linux-gnueabi-gcc"
-  cxx = "${compiler_prefix}arm-linux-gnueabi-g++"
+gcc_toolchain("clang_arm") {
+  prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
+                       root_build_dir)
+  cc = "${compiler_prefix}$prefix/clang"
+  cxx = "${compiler_prefix}$prefix/clang++"
 
-  ar = "arm-linux-gnueabi-ar"
+  toolprefix = "arm-linux-gnueabihf-"
+  readelf = "${toolprefix}readelf"
+  ar = "${toolprefix}ar"
   ld = cxx
-  readelf = "arm-linux-gnueabi-readelf"
-  nm = "arm-linux-gnueabi-nm"
+  readelf = "${toolprefix}readelf"
+  nm = "${toolprefix}nm"
 
   toolchain_cpu = "arm"
   toolchain_os = "linux"
+  is_clang = true
+}
+
+gcc_toolchain("arm") {
+  toolprefix = "arm-linux-gnueabihf-"
+
+  cc = "${compiler_prefix}${toolprefix}gcc"
+  cxx = "${compiler_prefix}${toolprefix}g++"
+
+  ar = "${toolprefix}ar"
+  ld = cxx
+  readelf = "${toolprefix}readelf"
+  nm = "${toolprefix}nm"
+
+  toolchain_cpu = "arm"
+  toolchain_os = "linux"
   is_clang = false
 }
 
 gcc_toolchain("clang_x86") {
   prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
                        root_build_dir)
   cc = "${compiler_prefix}$prefix/clang"
   cxx = "${compiler_prefix}$prefix/clang++"
   readelf = "readelf"
   nm = "nm"
@@ skipping 54 matching lines @@
   cxx = "mipsel-linux-gnu-g++"
   ar = "mipsel-linux-gnu-ar"
   ld = cxx
   readelf = "mipsel-linux-gnu-readelf"
   nm = "mipsel-linux-gnu-nm"
 
   toolchain_cpu = "mipsel"
   toolchain_os = "linux"
   is_clang = false
 }