| # Copyright 2014 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. |
| # Deleted from Chromium in https://crrev.com/097f64c631. |
| |
| """Converts a given gypi file to a python scope and writes the result to stdout. |
| |
| USING THIS SCRIPT IN CHROMIUM |
| |
| Forking Python to run this script in the middle of GN is slow, especially on |
| Windows, and it makes both the GYP and GN files harder to follow. You can't |
| use "git grep" to find files in the GN build any more, and tracking everything |
| in GYP down requires a level of indirection. Any calls will have to be removed |
| and cleaned up once the GYP-to-GN transition is complete. |
| |
| As a result, we only use this script when the list of files is large and |
| frequently-changing. In these cases, having one canonical list outweights the |
| downsides. |
| |
| As of this writing, the GN build is basically complete. It's likely that all |
| large and frequently changing targets where this is appropriate use this |
| mechanism already. And since we hope to turn down the GYP build soon, the time |
| horizon is also relatively short. As a result, it is likely that no additional |
| uses of this script should every be added to the build. During this later part |
| of the transition period, we should be focusing more and more on the absolute |
| readability of the GN build. |
| |
| |
| HOW TO USE |
| |
| It is assumed that the file contains a toplevel dictionary, and this script |
| will return that dictionary as a GN "scope" (see example below). This script |
| does not know anything about GYP and it will not expand variables or execute |
| conditions. |
| |
| It will strip conditions blocks. |
| |
| A variables block at the top level will be flattened so that the variables |
| appear in the root dictionary. This way they can be returned to the GN code. |
| |
| Say your_file.gypi looked like this: |
| { |
| 'sources': [ 'a.cc', 'b.cc' ], |
| 'defines': [ 'ENABLE_DOOM_MELON' ], |
| } |
| |
| You would call it like this: |
| gypi_values = exec_script("//build/gypi_to_gn.py", |
| [ rebase_path("your_file.gypi") ], |
| "scope", |
| [ "your_file.gypi" ]) |
| |
| Notes: |
| - The rebase_path call converts the gypi file from being relative to the |
| current build file to being system absolute for calling the script, which |
| will have a different current directory than this file. |
| |
| - The "scope" parameter tells GN to interpret the result as a series of GN |
| variable assignments. |
| |
| - The last file argument to exec_script tells GN that the given file is a |
| dependency of the build so Ninja can automatically re-run GN if the file |
| changes. |
| |
| Read the values into a target like this: |
| component("mycomponent") { |
| sources = gypi_values.sources |
| defines = gypi_values.defines |
| } |
| |
| Sometimes your .gypi file will include paths relative to a different |
| directory than the current .gn file. In this case, you can rebase them to |
| be relative to the current directory. |
| sources = rebase_path(gypi_values.sources, ".", |
| "//path/gypi/input/values/are/relative/to") |
| |
| This script will tolerate a 'variables' in the toplevel dictionary or not. If |
| the toplevel dictionary just contains one item called 'variables', it will be |
| collapsed away and the result will be the contents of that dictinoary. Some |
| .gypi files are written with or without this, depending on how they expect to |
| be embedded into a .gyp file. |
| |
| This script also has the ability to replace certain substrings in the input. |
| Generally this is used to emulate GYP variable expansion. If you passed the |
| argument "--replace=<(foo)=bar" then all instances of "<(foo)" in strings in |
| the input will be replaced with "bar": |
| |
| gypi_values = exec_script("//build/gypi_to_gn.py", |
| [ rebase_path("your_file.gypi"), |
| "--replace=<(foo)=bar"], |
| "scope", |
| [ "your_file.gypi" ]) |
| |
| """ |
| |
| from __future__ import absolute_import |
| from __future__ import print_function |
| from optparse import OptionParser |
| import os |
| import sys |
| |
| try: |
| # May already be in the import path. |
| import gn_helpers |
| except ImportError as e: |
| # Add src/build to import path. |
| cef_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir)) |
| src_dir = os.path.abspath(os.path.join(cef_dir, os.pardir)) |
| sys.path.append(os.path.join(src_dir, 'build')) |
| import gn_helpers |
| |
| |
| def LoadPythonDictionary(path): |
| file_string = open(path).read() |
| try: |
| file_data = eval(file_string, {'__builtins__': None}, None) |
| except SyntaxError as e: |
| e.filename = path |
| raise |
| except Exception as e: |
| raise Exception("Unexpected error while reading %s: %s" % (path, str(e))) |
| |
| assert isinstance(file_data, dict), "%s does not eval to a dictionary" % path |
| |
| # Flatten any variables to the top level. |
| if 'variables' in file_data: |
| file_data.update(file_data['variables']) |
| del file_data['variables'] |
| |
| # Strip all elements that this script can't process. |
| elements_to_strip = [ |
| 'conditions', |
| 'target_conditions', |
| 'target_defaults', |
| 'targets', |
| 'includes', |
| 'actions', |
| ] |
| for element in elements_to_strip: |
| if element in file_data: |
| del file_data[element] |
| |
| return file_data |
| |
| |
| def ReplaceSubstrings(values, search_for, replace_with): |
| """Recursively replaces substrings in a value. |
| |
| Replaces all substrings of the "search_for" with "repace_with" for all |
| strings occurring in "values". This is done by recursively iterating into |
| lists as well as the keys and values of dictionaries.""" |
| if isinstance(values, str): |
| return values.replace(search_for, replace_with) |
| |
| if isinstance(values, list): |
| return [ReplaceSubstrings(v, search_for, replace_with) for v in values] |
| |
| if isinstance(values, dict): |
| # For dictionaries, do the search for both the key and values. |
| result = {} |
| for key, value in values.items(): |
| new_key = ReplaceSubstrings(key, search_for, replace_with) |
| new_value = ReplaceSubstrings(value, search_for, replace_with) |
| result[new_key] = new_value |
| return result |
| |
| # Assume everything else is unchanged. |
| return values |
| |
| def main(): |
| parser = OptionParser() |
| parser.add_option("-r", "--replace", action="append", |
| help="Replaces substrings. If passed a=b, replaces all substrs a with b.") |
| (options, args) = parser.parse_args() |
| |
| if len(args) != 1: |
| raise Exception("Need one argument which is the .gypi file to read.") |
| |
| data = LoadPythonDictionary(args[0]) |
| if options.replace: |
| # Do replacements for all specified patterns. |
| for replace in options.replace: |
| split = replace.split('=') |
| # Allow "foo=" to replace with nothing. |
| if len(split) == 1: |
| split.append('') |
| assert len(split) == 2, "Replacement must be of the form 'key=value'." |
| data = ReplaceSubstrings(data, split[0], split[1]) |
| |
| # Sometimes .gypi files use the GYP syntax with percents at the end of the |
| # variable name (to indicate not to overwrite a previously-defined value): |
| # 'foo%': 'bar', |
| # Convert these to regular variables. |
| for key in data: |
| if len(key) > 1 and key[len(key) - 1] == '%': |
| data[key[:-1]] = data[key] |
| del data[key] |
| |
| print(gn_helpers.ToGNString(data)) |
| |
| if __name__ == '__main__': |
| try: |
| main() |
| except Exception as e: |
| print(str(e)) |
| sys.exit(1) |