[iOS/GN] Fix generation of .dSYM for fat binary builds.

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 74 matching lines @@
     # concurrent_links is picked up from the declare_arg().
 
     cc = "${compiler_prefix}clang"
     cxx = "${compiler_prefix}clang++"
     ld = cxx
 
     linker_driver =
         "TOOL_VERSION=${tool_versions.linker_driver} " +
         rebase_path("//build/toolchain/mac/linker_driver.py", root_build_dir)
 
+    if (is_ios && additional_toolchains != []) {
+      # For a fat build, the generation of dSYM needs to be performed after the
+      # generation of the fat binaries using "lipo". So disable the generation
+      # of the dSYM for intermediate architecture specific binaries.
+      _enable_dsyms = false
+      _save_unstripped_output = false
+    } else {
+      _enable_dsyms = enable_dsyms
+      _save_unstripped_output = save_unstripped_output
+    }
+
     # Make these apply to all tools below.
     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) {
+    if (_enable_dsyms) {
       dsym_switch = " -Wcrl,dsym," + rebase_path(root_out_dir) + " "
       _dsym_output =
           "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/"
     } else {
       dsym_switch = ""
     }
 
-    if (save_unstripped_output) {
+    if (_save_unstripped_output) {
       _unstripped_output = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.unstripped"
     }
 
     tool("cc") {
       depfile = "{{output}}.d"
       precompiled_header_type = "gcc"
       command = "$cc -MMD -MF $depfile {{defines}} {{include_dirs}} {{cflags}} {{cflags_c}} -c {{source}} -o {{output}}"
       depsformat = "gcc"
       description = "CC {{output}}"
       outputs = [
@@ skipping 106 matching lines @@
 
       # Tell GN about the output files. It will link to the dylib but use the
       # tocname for dependency management.
       outputs = [
         dylib,
         tocname,
       ]
       link_output = dylib
       depend_output = tocname
 
-      if (enable_dsyms) {
+      if (_enable_dsyms) {
         outputs += [ _dsym_output ]
       }
-      if (save_unstripped_output) {
+      if (_save_unstripped_output) {
         outputs += [ _unstripped_output ]
       }
     }
 
     tool("solink_module") {
       sofile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.so"
       rspfile = sofile + ".rsp"
 
       link_command = "$linker_driver $ld -bundle {{ldflags}} -o \"$sofile\" -Wl,-filelist,\"$rspfile\""
       if (is_component_build) {
@@ skipping 10 matching lines @@
       # Use this for {{output_extension}} expansions unless a target manually
       # overrides it (in which case {{output_extension}} will be what the target
       # specifies).
       default_output_dir = "{{root_out_dir}}"
       default_output_extension = ".so"
 
       outputs = [
         sofile,
       ]
 
-      if (enable_dsyms) {
+      if (_enable_dsyms) {
         outputs += [ _dsym_output ]
       }
-      if (save_unstripped_output) {
+      if (_save_unstripped_output) {
         outputs += [ _unstripped_output ]
       }
     }
 
     tool("link") {
       outfile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"
       rspfile = "$outfile.rsp"
 
       # Note about --filelist: Apple's linker reads the file list file and
       # interprets each newline-separated chunk of text as a file name. It
       # doesn't do the things one would expect from the shell like unescaping
       # or handling quotes. In contrast, when Ninja finds a file name with
       # spaces, it single-quotes them in $inputs_newline as it would normally
       # do for command-line arguments. Thus any source names with spaces, or
       # label names with spaces (which GN bases the output paths on) will be
       # corrupted by this process. Don't use spaces for source files or labels.
       command = "$linker_driver $ld $dsym_switch {{ldflags}} -o \"$outfile\" -Wl,-filelist,\"$rspfile\" {{solibs}} {{libs}}"
       description = "LINK $outfile"
       rspfile_content = "{{inputs_newline}}"
       outputs = [
         outfile,
       ]
 
-      if (enable_dsyms) {
+      if (_enable_dsyms) {
         outputs += [ _dsym_output ]
       }
-      if (save_unstripped_output) {
+      if (_save_unstripped_output) {
         outputs += [ _unstripped_output ]
       }
 
       default_output_dir = "{{root_out_dir}}"
     }
 
     # These two are really entirely generic, but have to be repeated in
     # each toolchain because GN doesn't allow a template to be used here.
     # See //build/toolchain/toolchain.gni for details.
     tool("stamp") {
@@ skipping 86 matching lines @@
 
 mac_toolchain("ios_clang_x86") {
   toolchain_cpu = "x86"
   toolchain_os = "ios"
 }
 
 mac_toolchain("ios_clang_x64") {
   toolchain_cpu = "x64"
   toolchain_os = "ios"
 }