Generate shim headers for libpng

build/shim_headers.gypi

+# Copyright (c) 2012 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.
+
+# This file is meant to be included into a target to handle shim headers
+# in a consistent manner. To use this the following variables need to be
+# defined:
+#   headers_root_path: string: path to directory containing headers
+#   header_filenames: list: list of header file names
+
+{
+  'variables': {
+    'shim_headers_path': '<(SHARED_INTERMEDIATE_DIR)/shim_headers',

[Mark Mentovai, 2012/12/17 23:02:41]

I don’t think you should use the shared dir. Since you’re going to be pushing
the include dir out to dependents in direct_dependent_settings (below), it’s
fine (safer) to use INTERMEDIATE_DIR.

[Paweł Hajdan Jr., 2012/12/17 23:18:26]

Done.

+  },
+  'direct_dependent_settings': {
+    'include_dirs+': [

[Mark Mentovai, 2012/12/17 23:02:41]

WIth the previous suggestion, this right here might also help flush out targets
that depend on targets without declaring that dependency in GYP. Consider that a
positive.

+      '<(shim_headers_path)',
+    ],
+  },
+  'actions': [
+    {
+      'variables': {
+        'generator_path': '<(DEPTH)/tools/generate_shim_headers/generate_shim_headers.py',
+        'generator_args': [
+          '--headers-root', '<(headers_root_path)',
+          '--output-directory', '<(shim_headers_path)',
+          '<@(header_filenames)',
+        ],
+      },
+      'action_name': 'generate_<(_target_name)_shim_headers',
+      'inputs': [
+        '<(generator_path)',
+      ],
+      'outputs': [
+        '<!@pymod_do_main(generate_shim_headers <@(generator_args) --outputs)',
+      ],
+      'action': ['python',
+                 '<(generator_path)',
+                 '<@(generator_args)',
+                 '--generate',
+      ],
+      'message': 'Generating <(_target_name) shim headers.',
+    },
+  ],
+}