Fix ARMv6 Linux cross-build

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/clang.gni")
 import("//build/toolchain/gcc_toolchain.gni")
 import("//build/toolchain/goma.gni")
 
 declare_args() {
   toolchain_prefix = ""
+  # TODO(zra): Add an argument for overriding the host toolchain.
 }
 
 if (use_goma) {
   assert(!use_ccache, "Goma and ccache can't be used together.")
   compiler_prefix = "$goma_dir/gomacc "
 } else if (use_ccache) {
   compiler_prefix = "ccache "
 } else {
   compiler_prefix = ""
 }
@@ skipping 34 matching lines @@
   strip = "${prefix}strip"
 
   toolchain_cpu = "arm64"
   toolchain_os = "linux"
   is_clang = false
 }
 
 gcc_toolchain("clang_x86") {
   prefix = rebase_path("//buildtools/toolchain/clang+llvm-x86_64-linux/bin",
                        root_build_dir)
-  if (toolchain_prefix != "") {
-    prefix = toolchain_prefix
-  }
   cc = "${compiler_prefix}${prefix}/clang"
   cxx = "${compiler_prefix}${prefix}/clang++"
   readelf = "readelf"
   nm = "${prefix}/llvm-nm"
   ar = "${prefix}/llvm-ar"
   ld = cxx
   strip = "${prefix}/strip"
 
   toolchain_cpu = "x86"
   toolchain_os = "linux"
   is_clang = true
 }
 
 gcc_toolchain("x86") {
   prefix = ""
-  if (toolchain_prefix != "") {
-    prefix = toolchain_prefix
-  }
   cc = "${compiler_prefix}${prefix}gcc"
   cxx = "${compiler_prefix}${prefix}g++"
 
   readelf = "${prefix}readelf"
   nm = "${prefix}nm"
   ar = "${prefix}ar"
   ld = cxx
   strip = "${prefix}strip"
 
   toolchain_cpu = "x86"
   toolchain_os = "linux"
   is_clang = false
 }
 
 gcc_toolchain("clang_x64") {
   prefix = rebase_path("//buildtools/toolchain/clang+llvm-x86_64-linux/bin",
                        root_build_dir)
-  if (toolchain_prefix != "") {
-    prefix = toolchain_prefix
-  }
   cc = "${compiler_prefix}${prefix}/clang"
   cxx = "${compiler_prefix}${prefix}/clang++"
 
   readelf = "readelf"
   nm = "${prefix}/llvm-nm"
   ar = "${prefix}/llvm-ar"
   ld = cxx
   strip = "${prefix}/strip"
 
   toolchain_cpu = "x64"
   toolchain_os = "linux"
   is_clang = true
 }
 
 gcc_toolchain("x64") {
   prefix = ""
-  if (toolchain_prefix != "") {
-    prefix = toolchain_prefix
-  }
   cc = "${compiler_prefix}${prefix}gcc"
   cxx = "${compiler_prefix}${prefix}g++"
 
   readelf = "${prefix}readelf"
   nm = "${prefix}nm"
   ar = "${prefix}ar"
   ld = cxx
   strip = "${prefix}strip"
 
   toolchain_cpu = "x64"
   toolchain_os = "linux"
   is_clang = false
 }
 
 gcc_toolchain("mipsel") {
   cc = "${compiler_prefix}${toolchain_prefix}gcc"
   cxx = "${compiler_prefix}${toolchain_prefix}g++"
   ar = "${toolchain_prefix}ar"
   ld = cxx
   readelf = "${toolchain_prefix}readelf"
   nm = "${toolchain_prefix}nm"
   strip = "${toolchain_prefix}strip"
 
   toolchain_cpu = "${target_cpu}"
   toolchain_os = "linux"
   is_clang = is_clang
 }