GN: Generate appropriate .dSYMs for .frameworks and .apps

build/toolchain/mac/BUILD.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.
 
 # TODO(brettw) Use "gcc_toolchain.gni" like the Linux toolchains. This requires
 # some enhancements since the commands on Mac are slightly different than on
 # Linux.
 
 import("../goma.gni")
 import("//build/config/clang/clang.gni")
@@ skipping 154 matching lines @@
     lib_switch = "-l"
     lib_dir_switch = "-L"
 
     # Object files go in this directory. Use label_name instead of
     # target_output_name since labels will generally have no spaces and will be
     # unique in the directory.
     object_subdir = "{{target_out_dir}}/{{label_name}}"
 
     # If dSYMs are enabled, this flag will be added to the link tools.
     if (_enable_dsyms) {
-      dsym_switch = " -Wcrl,dsym,{{root_out_dir}} "
-      dsym_output_dir =
-          "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM"
+      if (defined(invoker.dsym_name)) {

[themblsha, 2017/03/17 15:50:58]

This doesn't actually work, as it seems that I need to forward the |dsym_name|
through all the templates. But the template("mac_toolchain") seems to be
instantiated through the "tool" and I'm not sure how to achieve that.

Maybe you could advice? :-)

[Robert Sesek, 2017/03/17 16:59:36]

I think this is because tool()s are actually special entities in GN that only
inherit specific tool variables (see `gn help tool`).

This may be fairly tricky to pipe through, because technically the link
tool/step doesn't actually know where in the output bundle structure the binary
goes. That's handled by the bundle_data/create_bundle steps, which occur after.

+        dsym_name = invoker.dsym_name
+      } else {
+        dsym_name = "{{target_output_name}}{{output_extension}}.dSYM"
+      }
+      dsym_switch = " -Wcrl,dsym,\{{root_out_dir}},\"$dsym_name\" "
+      dsym_output_dir = "{{root_out_dir}}/$dsym_name"
       dsym_output = [
         "$dsym_output_dir/",
         "$dsym_output_dir/Contents/Info.plist",
         "$dsym_output_dir/Contents/Resources/DWARF/" +
             "{{target_output_name}}{{output_extension}}",
       ]
     } else {
       dsym_switch = ""
     }
 
@@ skipping 333 matching lines @@
     }
   }
 
   mac_toolchain("ios_clang_x64") {
     toolchain_args = {
       current_cpu = "x64"
       current_os = "ios"
     }
   }
 }