cross gn

build/config/BUILDCONFIG.gn

 # Copyright (c) 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.
 
 # =============================================================================
 # PLATFORM SELECTION
 # =============================================================================
 #
 # There are two main things to set: "os" and "cpu". The "toolchain" is the name
 # of the GN thing that encodes combinations of these things.
@@ skipping 207 matching lines @@
   if (is_clang) {
     _default_toolchain = "//build/toolchain/linux:clang_$target_cpu"
   } else {
     _default_toolchain = "//build/toolchain/linux:$target_cpu"
   }
 } else if (target_os == "mac") {
   assert(host_os == "mac", "Mac cross-compiles are unsupported.")
   _default_toolchain = host_toolchain
 } else if (target_os == "win") {
   # On Windows we use the same toolchain for host and target by default.
-  assert(target_os == host_os, "Win cross-compiles only work on win hosts.")
+  #assert(target_os == host_os, "Win cross-compiles only work on win hosts.")
+  # TODO(thakis): Getting this working requires definiting a clang_x86 toolchain
+  # on mac.
+  assert(host_os != "mac" || target_cpu != "x86",
+         "Doing 32-bit Windows builds on Mac does not yet work, target 64-bit")
   if (is_clang) {
     _default_toolchain = "//build/toolchain/win:clang_$target_cpu"
   } else {
     _default_toolchain = "//build/toolchain/win:$target_cpu"
   }
 } else if (target_os == "winrt_81" || target_os == "winrt_81_phone" ||
            target_os == "winrt_10") {
   _default_toolchain = "//build/toolchain/win:winrt_$target_cpu"
 } else {
   assert(false, "Unsupported target_os: $target_os")
@@ skipping 419 matching lines @@
     forward_variables_from(invoker, "*", [ "visibility" ])
 
     # All shared libraries must have the sanitizer deps to properly link in
     # asan mode (this target will be empty in other cases).
     if (!defined(deps)) {
       deps = []
     }
     deps += [ "//build/config/sanitizers:deps" ]
   }
 }