Interop: Compiling with C++17 or higher on Ubuntu 22.04 fails with cyclic header dependencies in libstdc++

[ADKaster]

Description

When building on a Linux system with libstdc++ higher than version 10 (the current version is 14, and Ubuntu Jammy ships 11) there is a cyclic dependency in the clang module graph for the standard library.

The check in <prefix>//lib/swift/linux/libstdcxx.h includes <execution> in c++17 or higher modes. With libstdc++-11-dev or higher and libtbb-dev, installed, this introduces a cyclic dependency between the _Builtin_intrinsics module and std.

Reproduction

With the following 3 files, the issue is easy to see with the official swift 6.0 snapshot docker containers:

Lib.h

#include <memory>

#include <stdio.h>

void foo() { puts("hi");  }

module.modulemap

module lib {
    header "Lib.h"
}

main.swift

import lib

print("hi")

After putting all these 4 files in one directory, the error can be reproduced with the following shell commands that launch a swift nightly docker container, and installs libtbb-dev.

docker run -it --rm -v $PWD:/workspace swiftlang/swift:nightly-6.0-jammy
apt update && apt install -y libtbb-dev
swiftc -emit-executable -o test -Xcc -std=c++17 -cxx-interoperability-mode=default -I /workspace /workspace/main.swift

The error is as follows:

- error: cyclic dependency in module 'std': std -> _Builtin_intrinsics -> std

/workspace/Lib.h:1:10: note: while building module 'std' imported from /workspace/Lib.h:1:
1 | #include <memory>
  |          `- note: while building module 'std' imported from /workspace/Lib.h:1:
2 | 
3 | #include <stdio.h>

/usr/include/tbb/../oneapi/tbb/detail/_machine.h:42:10: note: while building module '_Builtin_intrinsics' imported from /usr/include/tbb/../oneapi/tbb/detail/_machine.h:42:
 40 | #endif
 41 | #if __TBB_x86_64 || __TBB_x86_32
 42 | #include <immintrin.h> // _mm_pause
    |          `- note: while building module '_Builtin_intrinsics' imported from /usr/include/tbb/../oneapi/tbb/detail/_machine.h:42:
 43 | #endif
 44 | #if (_WIN32)

<module-includes>:2:10: note: in file included from <module-includes>:2:
 1 | extern "C" {
 2 | #include "immintrin.h"
   |          `- note: in file included from <module-includes>:2:
 3 | }
 4 | extern "C" {

/usr/lib/swift/clang/include/immintrin.h:26:10: note: in file included from /usr/lib/swift/clang/include/immintrin.h:26:
 24 | #if !(defined(_MSC_VER) || defined(__SCE__)) || __has_feature(modules) ||      \
 25 |     defined(__SSE__)
 26 | #include <xmmintrin.h>
    |          `- note: in file included from /usr/lib/swift/clang/include/immintrin.h:26:
 27 | #endif
 28 | 

/usr/lib/swift/clang/include/xmmintrin.h:31:10: note: in file included from /usr/lib/swift/clang/include/xmmintrin.h:31:
  29 |  * a standard library to provide allocation routines. */
  30 | #if __STDC_HOSTED__
  31 | #include <mm_malloc.h>
     |          `- note: in file included from /usr/lib/swift/clang/include/xmmintrin.h:31:
  32 | #endif
  33 | 

/usr/lib/swift/clang/include/mm_malloc.h:13:10: note: in file included from /usr/lib/swift/clang/include/mm_malloc.h:13:
11 | #define __MM_MALLOC_H
12 | 
13 | #include <stdlib.h>
   |          `- note: in file included from /usr/lib/swift/clang/include/mm_malloc.h:13:
14 | 
15 | #ifdef _WIN32

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/stdlib.h:36:11: error: cyclic dependency in module 'std': std -> _Builtin_intrinsics -> std
34 | #define _GLIBCXX_STDLIB_H 1
35 | 
36 | # include <cstdlib>
   |           `- error: cyclic dependency in module 'std': std -> _Builtin_intrinsics -> std
37 | 
38 | using std::abort;

/workspace/Lib.h:1:10: note: while building module 'std' imported from /workspace/Lib.h:1:
1 | #include <memory>
  |          `- note: while building module 'std' imported from /workspace/Lib.h:1:
2 | 
3 | #include <stdio.h>

<module-includes>:1:10: note: in file included from <module-includes>:1:
  1 | #include "libstdcxx.h"
    |          `- note: in file included from <module-includes>:1:
  2 | #include "algorithm"
  3 | #include "bitset"

/usr/lib/swift/linux/libstdcxx.h:6:10: note: in file included from /usr/lib/swift/linux/libstdcxx.h:6:
4 | // Only include <execution> if tbb is installed.
5 | #if __has_include("execution") && __has_include(<tbb/blocked_range.h>)
6 | #include "execution"
  |          `- note: in file included from /usr/lib/swift/linux/libstdcxx.h:6:
7 | #endif
8 | 

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/execution:32:11: note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/execution:32:
30 | #if __cplusplus >= 201703L
31 | # include <bits/c++config.h>
32 | # include <pstl/glue_execution_defs.h>
   |           `- note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/execution:32:
33 | 
34 | # define _PSTL_EXECUTION_POLICIES_DEFINED 1

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/glue_execution_defs.h:50:10: note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/glue_execution_defs.h:50:
48 | } // namespace std
49 | 
50 | #include "algorithm_impl.h"
   |          `- note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/glue_execution_defs.h:50:
51 | #include "numeric_impl.h"
52 | #include "parallel_backend.h"

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/algorithm_impl.h:22:10: note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/algorithm_impl.h:22:
  20 | #include "memory_impl.h"
  21 | #include "parallel_backend_utils.h"
  22 | #include "parallel_backend.h"
     |          `- note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/algorithm_impl.h:22:
  23 | #include "parallel_impl.h"
  24 | #include "unseq_backend_simd.h"

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/parallel_backend.h:20:14: note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/parallel_backend.h:20:
18 | }
19 | #elif defined(_PSTL_PAR_BACKEND_TBB)
20 | #    include "parallel_backend_tbb.h"
   |              `- note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/parallel_backend.h:20:
21 | namespace __pstl
22 | {

/usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/parallel_backend_tbb.h:19:10: note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/parallel_backend_tbb.h:19:
  17 | 
  18 | // Bring in minimal required subset of Intel TBB
  19 | #include <tbb/blocked_range.h>
     |          `- note: in file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/pstl/parallel_backend_tbb.h:19:
  20 | #include <tbb/parallel_for.h>
  21 | #include <tbb/parallel_reduce.h>

/usr/include/tbb/blocked_range.h:17:10: note: in file included from /usr/include/tbb/blocked_range.h:17:
15 | */
16 | 
17 | #include "../oneapi/tbb/blocked_range.h"
   |          `- note: in file included from /usr/include/tbb/blocked_range.h:17:
18 | 

/usr/include/tbb/../oneapi/tbb/blocked_range.h:22:10: note: in file included from /usr/include/tbb/../oneapi/tbb/blocked_range.h:22:
 20 | #include <cstddef>
 21 | 
 22 | #include "detail/_range_common.h"
    |          `- note: in file included from /usr/include/tbb/../oneapi/tbb/blocked_range.h:22:
 23 | #include "detail/_namespace_injection.h"
 24 | 

/usr/include/tbb/../oneapi/tbb/detail/_range_common.h:21:10: note: in file included from /usr/include/tbb/../oneapi/tbb/detail/_range_common.h:21:
 19 | 
 20 | #include "_config.h"
 21 | #include "_utils.h"
    |          `- note: in file included from /usr/include/tbb/../oneapi/tbb/detail/_range_common.h:21:
 22 | #if __TBB_CPP20_CONCEPTS_PRESENT
 23 | #include <concepts>

/usr/include/tbb/../oneapi/tbb/detail/_utils.h:26:10: note: in file included from /usr/include/tbb/../oneapi/tbb/detail/_utils.h:26:
 24 | #include "_config.h"
 25 | #include "_assert.h"
 26 | #include "_machine.h"
    |          `- note: in file included from /usr/include/tbb/../oneapi/tbb/detail/_utils.h:26:
 27 | 
 28 | namespace tbb {

/usr/include/tbb/../oneapi/tbb/detail/_machine.h:42:10: error: could not build module '_Builtin_intrinsics'
 40 | #endif
 41 | #if __TBB_x86_64 || __TBB_x86_32
 42 | #include <immintrin.h> // _mm_pause
    |          `- error: could not build module '_Builtin_intrinsics'
 43 | #endif
 44 | #if (_WIN32)

<module-includes>:1:10: note: in file included from <module-includes>:1:
1 | #include "Lib.h"
  |          `- note: in file included from <module-includes>:1:
2 | 

/workspace/Lib.h:1:10: error: could not build module 'std'
1 | #include <memory>
  |          `- error: could not build module 'std'
2 | 
3 | #include <stdio.h>

/workspace/main.swift:1:8: error: could not build C module 'lib'
1 | import lib
  |        `- error: could not build C module 'lib'
2 | 
3 | print("hi")

Removing the -Xcc -std=c++17 causes the error to go away, because we are no longer trying to use tbb/execution

Expected behavior

including any C++ standard library header in C++17, C++20, C++23 or C++26 mode should not error out the swift compiler.

The support for <execution> on Linux should either be removed or fixed for Swift 6.0.

Note that this was not an issue in the Ubuntu 20.04 containers, because they only ship libstdc++-10-dev.

Environment

swiftc -version:
Swift version 6.0-dev (LLVM d83ae228657c9e1, Swift 0382996)
Target: x86_64-unknown-linux-gnu

docker image list:
swiftlang/swift nightly-6.0-jammy dbdffe58b5a0 13 hours ago 3.51GB

Additional information

https://forums.swift.org/t/swift-5-9-release-on-ubuntu-22-04-fails-to-build-std-module/67659/4

[egorzhdan]

I extracted #76166 to track the future fix for this.
Since this has a workaround and isn't blocking anymore, I am closing this issue.