xref: /aosp_15_r20/external/skia/gn/find_headers.py (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17) 
1#!/usr/bin/env python
2#
3# Copyright 2016 Google Inc.
4#
5# Use of this source code is governed by a BSD-style license that can be
6# found in the LICENSE file.
7
8from __future__ import print_function
9
10import collections
11import json
12import os
13import subprocess
14import sys
15
16# Finds all public sources in include directories then write them to skia.h.
17
18# Also write skia.h.deps, which Ninja uses to track dependencies. It's the
19# very same mechanism Ninja uses to know which .h files affect which .cpp files.
20
21gn              = sys.argv[1]
22absolute_source = sys.argv[2]
23skia_h          = sys.argv[3]
24include_dirs    = sys.argv[4:]
25
26absolute_source = os.path.normpath(absolute_source)
27
28include_dirs = [os.path.join(os.path.normpath(include_dir), '')
29                for include_dir in include_dirs]
30include_dirs.sort(key=len, reverse=True)
31
32gn_desc_cmd = [gn, 'desc', '.', '--root=%s' % absolute_source, '--format=json',
33               '*']
34
35desc_json_txt = ''
36try:
37  desc_json_txt = subprocess.check_output(gn_desc_cmd).decode('utf-8')
38except subprocess.CalledProcessError as e:
39  print(e.output.decode('utf-8'))
40  raise
41
42if desc_json_txt.startswith('WARNING'):
43   print('\ngn generated a warning when we asked for JSON output.',
44         'To see the warning, run this command from the out_dir:',
45         '(you may need to quote the * argument)\n',
46         ' '.join(gn_desc_cmd),
47         '\n', sep='\n')
48   sys.exit(-1)
49
50desc_json = {}
51try:
52  desc_json = json.loads(desc_json_txt)
53except ValueError:
54  print(desc_json_txt)
55  raise
56
57sources = set()
58
59for target in desc_json.values():
60  # We'll use `public` headers if they're listed, or pull them from `sources`
61  # if not.  GN sneaks in a default "public": "*" into the JSON if you don't
62  # set one explicitly.
63  search_list = target.get('public')
64  if search_list == '*':
65    search_list = target.get('sources', [])
66
67  for name in search_list:
68    sources.add(os.path.join(absolute_source, os.path.normpath(name[2:])))
69
70Header = collections.namedtuple('Header', ['absolute', 'include'])
71headers = {}
72for source in sources:
73  source_as_include = [os.path.relpath(source, absolute_source)
74                       for include_dir in include_dirs
75                       if source.startswith(include_dir)]
76  if not source_as_include:
77    continue
78  statinfo = os.stat(source)
79  key = str(statinfo.st_ino) + ':' + str(statinfo.st_dev)
80  # On Windows os.stat st_ino is 0 until 3.3.4 and st_dev is 0 until 3.4.0.
81  if key == '0:0':
82    key = source
83  include_path = source_as_include[0]
84  if key not in headers or len(include_path) < len(headers[key].include):
85    headers[key] = Header(source, include_path)
86
87headers = sorted(headers.values(), key=lambda x: x.include)
88
89with open(skia_h, 'w') as f:
90  f.write('// skia.h generated by GN.\n')
91  f.write('#ifndef skia_h_DEFINED\n')
92  f.write('#define skia_h_DEFINED\n')
93  for header in headers:
94    f.write('#include "' + header.include + '"\n')
95  f.write('#endif//skia_h_DEFINED\n')
96
97with open(skia_h + '.deps', 'w') as f:
98  f.write(skia_h + ':')
99  for header in headers:
100    f.write(' ' + header.absolute)
101  f.write(' build.ninja.d')
102  f.write('\n')
103
104# Temporary: during development this file wrote skia.h.d, not skia.h.deps,
105# and I think we have some bad versions of those files laying around.
106if os.path.exists(skia_h + '.d'):
107  os.remove(skia_h + '.d')
108