Generate BuildConfig headers in GN

examples/lighting-app/nrf5/BUILD.gn

@@ -14,6 +14,7 @@
 
 import("//build_overrides/chip.gni")
 import("//build_overrides/nrf5_sdk.gni")
+import("//build_overrides/openthread.gni")
 
 import("${nrf5_sdk_build_root}/nrf5_sdk.gni")
 

examples/lighting-app/nrf5/main/main.cpp

@@ -17,6 +17,8 @@
  *    limitations under the License.
  */
 
+#include <platform/CHIPDeviceConfig.h>
+
 #include <stdbool.h>
 #include <stdint.h>
 

examples/lock-app/nrf5/BUILD.gn

@@ -105,8 +105,6 @@ executable("lock_app") {
   ldscript = "${nrf5_platform_dir}/app/ldscripts/chip-nrf52840-example.ld"
 
   ldflags = [ "-T" + rebase_path(ldscript, root_build_dir) ]
-
-  defines = [ "CHIP_ENABLE_OPENTHREAD=1" ]
 }
 
 group("nrf5") {

examples/lock-app/nrf5/main/main.cpp

@@ -17,6 +17,8 @@
  *    limitations under the License.
  */
 
+#include <platform/CHIPDeviceConfig.h>
+
 #include <stdbool.h>
 #include <stdint.h>
 

examples/platform/nrf528xx/app/chipinit.cpp

@@ -1,5 +1,7 @@
 #include "chipinit.h"
 
+#include <platform/CHIPDeviceConfig.h>
+
 #include <stdbool.h>
 #include <stdint.h>
 

gn/chip/buildconfig_header.gni

@@ -0,0 +1,158 @@
+# Copyright (c) 2020 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Copyright 2015 The Chromium Authors. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#    * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#    * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#    * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Generates a header with preprocessor defines specified by the build file.
+#
+# In the GN template, specify build defines in the template as a list
+# of strings that encode key/value pairs like this:
+#
+#   defines = [ "ENABLE_FOO=1", "ENABLE_BAR=$enable_bar" ]
+#
+# The GN values "true" and "false" will be mapped to 0 and 1 for boolean
+# #if defines to be expressed naturally. This means you can't directly make a
+# define that generates C++ value of true or false for use in code. If you
+# REALLY need this, you can also use the string "(true)" and "(false)" to
+# prevent the rewriting.
+
+# To check the value of the define in C code:
+#
+#   #include "path/to/here/header_file.h"
+#
+#   #if ENABLE_FOO
+#   ...
+#   #endif
+#
+#   const char kSpamServerUrl[] = SPAM_SERVER_URL;
+#
+# Template parameters
+#
+#   defines [required, list of strings]
+#       Defines as described above.
+#
+#   header [required, string]
+#       File name for generated header. By default, this will go in the
+#       generated file directory for this target, and you would include it
+#       with:
+#         #include "<path_to_this_BUILD_file>/<header>"
+#
+#   header_dir [optional, string]
+#       Override the default location of the generated header. The string will
+#       be treated as a subdirectory of the root_gen_dir. For example:
+#         header_dir = "foo/bar"
+#       Then you can include the header as:
+#         #include "foo/bar/baz.h"
+#
+#   deps, public_deps, testonly, visibility
+#       Normal meaning.
+#
+# Example
+#
+#   buildconfig_header("foo_buildconfig") {
+#     header = "foo_buildconfig.h"
+#
+#     defines = [
+#       # This uses the GN build argument enable_doom_melon as the definition.
+#       "ENABLE_DOOM_MELON=$enable_doom_melon",
+#
+#       # This force-enables the define
+#       "ENABLE_SPACE_LASER=true",
+#
+#       # This will expand to the quoted C string when used in source code.
+#       "SPAM_SERVER_URL=\"http://www.example.com/\"",
+#     ]
+#   }
+
+import("//build_overrides/chip.gni")
+
+template("buildconfig_header") {
+  source_set_name = target_name
+  gen_target_name = "gen_${target_name}"
+
+  action(gen_target_name) {
+    script = "${chip_root}/gn/chip/write_buildconfig_header.py"
+
+    if (defined(invoker.header_dir)) {
+      header_file = "${invoker.header_dir}/${invoker.header}"
+    } else {
+      # Compute the path from the root to this file.
+      header_file = rebase_path(".", "//") + "/${invoker.header}"
+    }
+
+    include_dir = "${root_gen_dir}/include"
+
+    outputs = [ "${include_dir}/${header_file}" ]
+
+    # Always write --defines to the file so it's not empty. Empty will confuse GN
+    # into thinking the response file isn't used.
+    response_file_contents = [ "--defines" ]
+    if (defined(invoker.defines)) {
+      response_file_contents += invoker.defines
+    }
+
+    args = [
+      "--output",
+      header_file,  # Not rebased, Python script puts it inside gen-dir.
+      "--rulename",
+      get_label_info(":$target_name", "label_no_toolchain"),
+      "--gen-dir",
+      rebase_path(include_dir, root_build_dir),
+      "--definitions",
+      "{{response_file_name}}",
+    ]
+
+    visibility = [ ":${source_set_name}" ]
+  }
+
+  source_set(source_set_name) {
+    sources = get_target_outputs(":${gen_target_name}")
+
+    deps = [ ":${gen_target_name}" ]
+
+    forward_variables_from(invoker,
+                           [
+                             "deps",
+                             "public_deps",
+                             "testonly",
+                             "visibility",
+                           ])
+  }
+}

gn/chip/write_buildconfig_header.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python
+# Copyright (c) 2020 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Copyright 2015 The Chromium Authors. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#    * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#    * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#    * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# This writes headers for build defines. See buildconfig_header.gni for
+# usage of this system as a whole.
+#
+# The parameters are passed in a response file so we don't have to worry
+# about command line lengths. The name of the response file is passed on the
+# command line.
+#
+# The format of the response file is:
+#    [--defines <list of one or more defines values>]
+
+import optparse
+import os
+import shlex
+import sys
+
+
+class Options:
+  def __init__(self, output, rulename, header_guard, defines):
+    self.output = output
+    self.rulename = rulename
+    self.header_guard = header_guard
+    self.defines = defines
+
+
+def GetOptions():
+  parser = optparse.OptionParser()
+  parser.add_option('--output', help="Output header name inside --gen-dir.")
+  parser.add_option('--rulename',
+                    help="Helpful name of build rule for including in the " +
+                         "comment at the top of the file.")
+  parser.add_option('--gen-dir',
+                    help="Path to root of generated file directory tree.")
+  parser.add_option('--definitions',
+                    help="Name of the response file containing the defines.")
+  cmdline_options, cmdline_flags = parser.parse_args()
+
+  # Compute header guard by replacing some chars with _ and upper-casing.
+  header_guard = cmdline_options.output.upper()
+  header_guard = \
+      header_guard.replace('/', '_').replace('\\', '_').replace('.', '_')
+  header_guard += '_'
+
+  # The actual output file is inside the gen dir.
+  output = os.path.join(cmdline_options.gen_dir, cmdline_options.output)
+
+  # Definition file in GYP is newline separated, in GN they are shell formatted.
+  # shlex can parse both of these.
+  with open(cmdline_options.definitions, 'r') as def_file:
+    defs = shlex.split(def_file.read())
+  defines_index = defs.index('--defines')
+
+  # Everything after --defines are defines. true/false are remapped to 1/0,
+  # everything else is passed through.
+  defines = []
+  for define in defs[defines_index + 1 :]:
+    equals_index = define.index('=')
+    key = define[:equals_index]
+    value = define[equals_index + 1:]
+
+    # Canonicalize and validate the value.
+    if value == 'true':
+      value = '1'
+    elif value == 'false':
+      value = '0'
+    defines.append((key, str(value)))
+
+  return Options(output=output,
+                 rulename=cmdline_options.rulename,
+                 header_guard=header_guard,
+                 defines=defines)
+
+
+def WriteHeader(options):
+  with open(options.output, 'w') as output_file:
+    output_file.write("// Generated by gn/chip/write_buildconfig_header.py\n")
+    if options.rulename:
+      output_file.write('// From "' + options.rulename + '"\n')
+
+    output_file.write('\n#ifndef %s\n' % options.header_guard)
+    output_file.write('#define %s\n\n' % options.header_guard)
+
+    for pair in options.defines:
+      output_file.write('#define %s %s\n' % pair)
+
+    output_file.write('\n#endif  // %s\n' % options.header_guard)
+
+
+options = GetOptions()
+WriteHeader(options)

src/BUILD.gn

@@ -14,12 +14,12 @@
 
 import("//build_overrides/chip.gni")
 
-config("public_includes") {
-  include_dirs = [ "include" ]
-}
-
 config("includes") {
-  include_dirs = [ "." ]
+  include_dirs = [
+    "include",
+    ".",
+    "${root_gen_dir}/include",
+  ]
 
-  configs = [ ":public_includes" ]
+  defines = [ "CHIP_SEPARATE_CONFIG_H=1" ]
 }

src/app/BUILD.gn

@@ -37,7 +37,10 @@ static_library("app") {
     "${chip_root}/src/system",
   ]
 
-  public_configs = [ ":app_config" ]
+  public_configs = [
+    ":app_config",
+    "${chip_root}/src:includes",
+  ]
 }
 
 copy("codec_headers") {