xref: /aosp_15_r20/external/cronet/third_party/libc++/src/test/libcxx/transitive_includes.gen.py (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1#===----------------------------------------------------------------------===##
2#
3# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4# See https://llvm.org/LICENSE.txt for license information.
5# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6#
7#===----------------------------------------------------------------------===##
8
9# Test that we don't remove transitive includes of public C++ headers in the library accidentally.
10# When we remove a transitive public include, clients tend to break because they don't always
11# properly include what they use. Note that we don't check which system (C) headers are
12# included transitively, because that is too unstable across platforms, and hence difficult
13# to test for.
14#
15# This is not meant to block libc++ from removing unused transitive includes
16# forever, however we do try to group removals for a couple of releases
17# to avoid breaking users at every release.
18
19# RUN: %{python} %s %{libcxx-dir}/utils
20
21import sys
22sys.path.append(sys.argv[1])
23from libcxx.header_information import lit_header_restrictions, public_headers
24
25import re
26
27# To re-generate the list of expected headers, temporarily set this to True, and run this test.
28# Note that this needs to be done for all supported language versions of libc++:
29# for std in c++03 c++11 c++14 c++17 c++20 c++23 c++26; do <build>/bin/llvm-lit --param std=$std libcxx/test/libcxx/transitive_includes.gen.py; done
30regenerate_expected_results = False
31
32BLOCKLIT = '' # block Lit from interpreting a RUN/XFAIL/etc inside the generation script
33if regenerate_expected_results:
34  print(f"""\
35//--- generate-transitive-includes.sh.cpp
36// RUN{BLOCKLIT}: mkdir %t
37""")
38
39  all_traces = []
40  for header in sorted(public_headers):
41    if header.endswith('.h'): # Skip C compatibility or detail headers
42      continue
43
44    normalized_header = re.sub('/', '_', header)
45    print(f"""\
46// RUN{BLOCKLIT}: echo "#include <{header}>" | %{{cxx}} -xc++ - %{{flags}} %{{compile_flags}} --trace-includes -fshow-skipped-includes --preprocess > /dev/null 2> %t/trace-includes.{normalized_header}.txt
47""")
48    all_traces.append(f'%t/trace-includes.{normalized_header}.txt')
49
50  print(f"""\
51// RUN{BLOCKLIT}: %{{python}} %{{libcxx-dir}}/test/libcxx/transitive_includes_to_csv.py {' '.join(all_traces)} > %{{libcxx-dir}}/test/libcxx/transitive_includes/%{{cxx_std}}.csv
52""")
53
54else:
55  for header in public_headers:
56    if header.endswith('.h'): # Skip C compatibility or detail headers
57      continue
58
59    # Escape slashes for the awk command below
60    escaped_header = header.replace('/', '\/')
61
62    print(f"""\
63//--- {header}.sh.cpp
64{lit_header_restrictions.get(header, '')}
65
66// TODO: Fix this test to make it work with localization or wide characters disabled
67// UNSUPPORTED{BLOCKLIT}: no-localization, no-wide-characters, no-threads, no-filesystem, libcpp-has-no-incomplete-tzdb, no-tzdb
68
69// When built with modules, this test doesn't work because --trace-includes doesn't
70// report the stack of includes correctly.
71// UNSUPPORTED{BLOCKLIT}: clang-modules-build
72
73// This test uses --trace-includes, which is not supported by GCC.
74// UNSUPPORTED{BLOCKLIT}: gcc
75
76// This test is not supported when we remove the transitive includes provided for backwards
77// compatibility. When we bulk-remove them, we'll adjust the includes that are expected by
78// this test instead.
79// UNSUPPORTED{BLOCKLIT}: transitive-includes-disabled
80
81// TODO: Figure out why <stdatomic.h> doesn't work on FreeBSD
82// UNSUPPORTED{BLOCKLIT}: LIBCXX-FREEBSD-FIXME
83
84// RUN{BLOCKLIT}: mkdir %t
85// RUN{BLOCKLIT}: %{{cxx}} %s %{{flags}} %{{compile_flags}} --trace-includes -fshow-skipped-includes --preprocess > /dev/null 2> %t/trace-includes.txt
86// RUN{BLOCKLIT}: %{{python}} %{{libcxx-dir}}/test/libcxx/transitive_includes_to_csv.py %t/trace-includes.txt > %t/actual_transitive_includes.csv
87// RUN{BLOCKLIT}: cat %{{libcxx-dir}}/test/libcxx/transitive_includes/%{{cxx_std}}.csv | awk '/^{escaped_header} / {{ print }}' > %t/expected_transitive_includes.csv
88// RUN{BLOCKLIT}: diff -w %t/expected_transitive_includes.csv %t/actual_transitive_includes.csv
89#include <{header}>
90""")
91