llvm-capstone/libcxx/modules/std/functional.inc
Mark de Wever 4d4c70c91c [libc++][modules] Removes the module partitions.
This patch is based on the suggestion by @ChuanqiXu on discourse
(https://discourse.llvm.org/t/alternatives-to-the-implementation-of-std-modules/71958)

Instead of making a module partition per header every header gets an inc
file which contains the exports per header. The std module then includes
all public headers and these inc files. The one file per header is
useful for testing purposes. The CI tests whether the exports of a
header's module partition matches the "public" named declarations in the
header. With one file per header this can still be done.

The patch improves compilation time of files using "import std;" and the
size of the std module.

A comparision of the compilation speed using a libc++ test
  build/bin/llvm-lit -a -Dstd=c++23 -Denable_modules=std libcxx/test/std/modules/std.pass.cpp

Which boils down to
  import std;

  int main(int, char**) {
    std::println("Hello modular world");
    return 0;
  }
and has -ftime-report enabled

Before
===-------------------------------------------------------------------------===
                          Clang front-end time report
===-------------------------------------------------------------------------===
  Total Execution Time: 8.6585 seconds (8.6619 wall clock)

   ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Name ---
   4.5041 ( 57.2%)   0.4264 ( 54.4%)   4.9305 ( 56.9%)   4.9331 ( 57.0%)  Clang front-end timer
   3.2037 ( 40.7%)   0.2408 ( 30.7%)   3.4445 ( 39.8%)   3.4452 ( 39.8%)  Reading modules
   0.1665 (  2.1%)   0.1170 ( 14.9%)   0.2835 (  3.3%)   0.2837 (  3.3%)  Loading .../build/test/__config_module__/CMakeFiles/std.dir/std.pcm
   7.8744 (100.0%)   0.7842 (100.0%)   8.6585 (100.0%)   8.6619 (100.0%)  Total

After
===-------------------------------------------------------------------------===
                          Clang front-end time report
===-------------------------------------------------------------------------===
  Total Execution Time: 1.2420 seconds (1.2423 wall clock)

   ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Name ---
   0.8892 ( 84.6%)   0.1698 ( 88.8%)   1.0590 ( 85.3%)   1.0590 ( 85.2%)  Clang front-end timer
   0.1533 ( 14.6%)   0.0168 (  8.8%)   0.1701 ( 13.7%)   0.1704 ( 13.7%)  Reading modules
   0.0082 (  0.8%)   0.0047 (  2.5%)   0.0129 (  1.0%)   0.0129 (  1.0%)  Loading .../build/test/__config_module__/CMakeFiles/std.dir/std.pcm
   1.0507 (100.0%)   0.1913 (100.0%)   1.2420 (100.0%)   1.2423 (100.0%)  Total

Using "include <print>" instead of "import module;"
===-------------------------------------------------------------------------===
                          Clang front-end time report
===-------------------------------------------------------------------------===
  Total Execution Time: 2.1507 seconds (2.1517 wall clock)

   ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Name ---
   1.9714 (100.0%)   0.1793 (100.0%)   2.1507 (100.0%)   2.1517 (100.0%)  Clang front-end timer
   1.9714 (100.0%)   0.1793 (100.0%)   2.1507 (100.0%)   2.1517 (100.0%)  Total

It's possible to use the std module in external projects
(https://libcxx.llvm.org/Modules.html#using-in-external-projects)

Tested this with a private project to validate the size of the generated files:

Before
$ du -sch std-*
448M	std-build
508K	std-src
120K	std-subbuild
449M	total

After
$ du -sch std-*
29M	std-build
1004K	std-src
132K	std-subbuild
30M	total

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D156907
2023-08-09 19:39:08 +02:00

117 lines
2.9 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
export namespace std {
// [func.invoke], invoke
using std::invoke;
using std::invoke_r;
// [refwrap], reference_wrapper
using std::reference_wrapper;
using std::cref;
using std::ref;
// [arithmetic.operations], arithmetic operations
using std::divides;
using std::minus;
using std::modulus;
using std::multiplies;
using std::negate;
using std::plus;
// [comparisons], comparisons
using std::equal_to;
using std::greater;
using std::greater_equal;
using std::less;
using std::less_equal;
using std::not_equal_to;
// [comparisons.three.way], class compare_three_way
using std::compare_three_way;
// [logical.operations], logical operations
using std::logical_and;
using std::logical_not;
using std::logical_or;
// [bitwise.operations], bitwise operations
using std::bit_and;
using std::bit_not;
using std::bit_or;
using std::bit_xor;
// [func.identity], identity
using std::identity;
// [func.not.fn], function template not_fn
using std::not_fn;
// [func.bind.partial], function templates bind_front and bind_back
// using std::bind_back;
using std::bind_front;
// [func.bind], bind
using std::is_bind_expression;
using std::is_bind_expression_v;
using std::is_placeholder;
using std::is_placeholder_v;
using std::bind;
namespace placeholders {
// M is the implementation-defined number of placeholders
using std::placeholders::_1;
using std::placeholders::_10;
using std::placeholders::_2;
using std::placeholders::_3;
using std::placeholders::_4;
using std::placeholders::_5;
using std::placeholders::_6;
using std::placeholders::_7;
using std::placeholders::_8;
using std::placeholders::_9;
} // namespace placeholders
// [func.memfn], member function adaptors
using std::mem_fn;
// [func.wrap], polymorphic function wrappers
using std::bad_function_call;
using std::function;
using std::swap;
using std::operator==;
// [func.wrap.move], move only wrapper
// using std::move_only_function;
// [func.search], searchers
using std::default_searcher;
using std::boyer_moore_searcher;
using std::boyer_moore_horspool_searcher;
// [unord.hash], class template hash
using std::hash;
namespace ranges {
// [range.cmp], concept-constrained comparisons
using std::ranges::equal_to;
using std::ranges::greater;
using std::ranges::greater_equal;
using std::ranges::less;
using std::ranges::less_equal;
using std::ranges::not_equal_to;
} // namespace ranges
} // namespace std