[Mac/iOS/GN] Allow targets to override the output directory.

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/ios/ios_sdk.gni")
@@ skipping 96 matching lines @@
       description = "OBJCXX {{output}}"
       outputs = [
         "$object_subdir/{{source_name_part}}.o",
       ]
     }
 
     tool("alink") {
       command = "rm -f {{output}} && ./gyp-mac-tool filter-libtool libtool -static -o {{output}} {{inputs}}"
       description = "LIBTOOL-STATIC {{output}}"
       outputs = [
-        "{{target_out_dir}}/{{target_output_name}}{{output_extension}}",
+        "{{output_dir}}/{{target_output_name}}{{output_extension}}",
       ]
+      default_output_dir = "{{target_out_dir}}"
       default_output_extension = ".a"
       output_prefix = "lib"
     }
 
     tool("solink") {
-      dylib = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.dylib"
+      dylib = "{{output_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.dylib"
       rspfile = dylib + ".rsp"
 
       # These variables are not built into GN but are helpers that implement
       # (1) linking to produce a .dylib, (2) extracting the symbols from that
       # file to a temporary file, (3) if the temporary file has differences from
       # the existing .TOC file, overwrite it, otherwise, don't change it.
       #
       # As a special case, if the library reexports symbols from other dynamic
       # libraries, we always update the .TOC and skip the temporary file and
       # diffing steps, since that library always needs to be re-linked.
@@ skipping 14 matching lines @@
 
       command = "if $does_reexport_command ; then $link_command && $extract_toc_command > \"$tocname\"; else $link_command && $extract_toc_command > \"$temporary_tocname\" && $replace_command ; fi; fi"
 
       rspfile_content = "{{inputs_newline}}"
 
       description = "SOLINK {{output}}"
 
       # 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 = ".dylib"
 
       output_prefix = "lib"
 
       # Since the above commands only updates the .TOC file when it changes, ask
       # Ninja to check if the timestamp actually changed to know if downstream
       # dependencies should be recompiled.
       restat = true
 
       # 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
     }
 
     tool("solink_module") {
-      sofile = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.so"
+      sofile = "{{output_dir}}/{{target_output_name}}{{output_extension}}"  # eg "./libfoo.so"
       rspfile = sofile + ".rsp"
 
       link_command =
           "$ld -bundle {{ldflags}} -o \"$sofile\" -Wl,-filelist,\"$rspfile\""
       if (is_component_build) {
         link_command += " -Wl,-install_name,@rpath/{{target_output_name}}{{output_extension}}"
       }
       link_command += " {{solibs}} {{libs}}"
       command = link_command
 
       rspfile_content = "{{inputs_newline}}"
 
       description = "SOLINK_MODULE {{output}}"
 
       # 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,
       ]
     }
 
     tool("link") {
-      outfile = "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"
+      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 $inputs_newline as it would normally
       # do for command-line arguments. Thus any source names with spaces, or
       # label names with spaces (which GN bases the output paths on) will be
       # corrupted by this process. Don't use spaces for source files or labels.
       command = "$ld {{ldflags}} -o \"$outfile\" -Wl,-filelist,\"$rspfile\" {{solibs}} {{libs}}"
       description = "LINK $outfile"
       rspfile_content = "{{inputs_newline}}"
       outputs = [
         outfile,
       ]
+
+      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") {
       command = stamp_command
       description = stamp_description
     }
     tool("copy") {
@@ skipping 119 matching lines @@
 }
 
 mac_toolchain("x64") {
   toolchain_cpu = "x64"
   toolchain_os = "mac"
   cc = "${goma_prefix}/gcc"
   cxx = "${goma_prefix}/g++"
   ld = cxx
   is_clang = false
 }