当包含 <iostream> 时，在 CYGWIN 下与 GCC 的交叉编译失败

Question

我使用 https://preshing.com/20141119/how-to-build-a-gcc-cross-compiler/ 上的文章作为源，在 CYGWIN 环境下为 Linux 构建了交叉工具链。

编译安装成功。

使用的组件是：

binutils-2.35
cloog-0.18.1
gcc-10.2.0
glibc-2.32
gmp-6.1.2
isl-0.20
linux-5.9.3
mpc-1.1.0
mpfr-4.0.2

GCC 配置为：

$ x86_64-unknown-linux-gnu-g++ --verbose
Using built-in specs.
COLLECT_GCC=x86_64-unknown-linux-gnu-g++
COLLECT_LTO_WRAPPER=/opt/cross/x86_64-unknown-linux-gnu/libexec/gcc/x86_64-unknown-linux- 
gnu/10.2.0/lto-wrapper.exe
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-10.2.0/configure --prefix=/opt/cross/x86_64-unknown-linux-gnu -- 
target=x86_64-unknown-linux-gnu --enable-languages=c,c++ --disable-nls --disable-multilib --with- 
headers=/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/linux
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.2.0 (GCC)

但是当我尝试编译简单的 Hello World 应用程序时，我遇到了很多不同的错误：

$ x86_64-unknown-linux-gnu-g++ main.cpp
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr-default.h:35,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr.h:148,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/atomicity.h:35,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:39,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:240:34: error: 'clockid_t' has not been declared
  240 |                                  clockid_t __clockid,
      |                                  ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:375:12: error: 'cpu_set_t' does not name a type
  375 |      const cpu_set_t *__cpuset)
      |            ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:382:6: error: 'cpu_set_t' has not been declared
  382 |      cpu_set_t *__cpuset)
      |      ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:466:14: error: 'cpu_set_t' does not name a type
  466 |        const cpu_set_t *__cpuset)
      |              ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:471:8: error: 'cpu_set_t' has not been declared
  471 |        cpu_set_t *__cpuset)
      |        ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:765:9: error: 'clockid_t' has not been declared
  765 |         clockid_t __clockid,
      |         ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:911:12: error: 'clockid_t' has not been declared
  911 |            clockid_t __clockid,
      |            ^~~~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:933:12: error: 'clockid_t' has not been declared
  933 |            clockid_t __clockid,
      |            ^~~~~~~~~
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr.h:148,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/atomicity.h:35,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:39,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr-default.h:114:1: error: 'sched_yield' was not declared in this scope; did you mean 'pthread_yield'?
  114 | __gthrw(sched_yield)
      | ^~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr-default.h:114:1: error: 'sched_yield' was not declared in this scope; did you mean 'pthread_yield'?
  114 | __gthrw(sched_yield)
      | ^~~~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr-default.h: In function 'int __gthread_yield()':
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr-default.h:693:33: error: '__gthrw_sched_yield' cannot be used as a function
  693 |   return __gthrw_(sched_yield) ();
      |                                 ^
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/sys/select.h:37,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/sys/types.h:179,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/stdlib.h:394,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/cstdlib:75,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:41,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/basic_string.h:6535,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/string:55,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/locale_classes.h:40,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:41,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/bits/types/struct_timeval.h: At global scope:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/bits/types/struct_timeval.h:8:8: error: redefinition of 'struct timeval'
    8 | struct timeval
      |        ^~~~~~~
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/pthread.h:23,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr-default.h:35,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/gthr.h:148,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/atomicity.h:35,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:39,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/sys-include/time.h:16:8: note: previous definition of 'struct timeval'
   16 | struct timeval {
      |        ^~~~~~~
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:44,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/basic_string.h:6535,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/string:55,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/locale_classes.h:40,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:41,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h: In constructor '__gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, std::size_t*, _Base ...)::_Save_errno::_Save_errno()':
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:63:27: error: 'errno' was not declared in this scope
   63 |  _Save_errno() : _M_errno(errno) { errno = 0; }
      |                           ^~~~~
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/basic_string.h:6535,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/string:55,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/locale_classes.h:40,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:41,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:45:1: note: 'errno' is defined in header '<cerrno>'; did you forget to '#include <cerrno>'?
   44 | #include <cerrno>
  +++ |+#include <cerrno>
   45 |
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:44,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/basic_string.h:6535,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/string:55,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/locale_classes.h:40,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:41,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h: In destructor '__gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, std::size_t*, _Base ...)::_Save_errno::~_Save_errno()':
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:64:23: error: 'errno' was not declared in this scope
   64 |  ~_Save_errno() { if (errno == 0) errno = _M_errno; }
      |                       ^~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:64:23: note: 'errno' is defined in header '<cerrno>'; did you forget to '#include <cerrno>'?
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h: In function '_Ret __gnu_cxx::__stoa(_TRet (*)(const _CharT*, _CharT**, _Base ...), const char*, const _CharT*, std::size_t*, _Base ...)':
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:84:16: error: 'errno' was not declared in this scope
   84 |       else if (errno == ERANGE
      |                ^~~~~
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ext/string_conversions.h:84:16: note: 'errno' is defined in header '<cerrno>'; did you forget to '#include <cerrno>'?
In file included from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/system_error:39,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/bits/ios_base.h:46,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ios:42,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/ostream:38,
                 from /opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/iostream:39,
                 from main.cpp:1:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/error_constants.h: At global scope:
/opt/cross/x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu/include/c++/10.2.0/x86_64-unknown-linux-gnu/bits/error_constants.h:122:27: error: 'ENOTSUP' was not declared in this scope
  122 |       not_supported =     ENOTSUP,
      |

UPD：WSL 和虚拟机不是我的选择

Answer 1

我已经解决了这个问题。

问题出在 sys-include 目录
opt/cross/x86_64-unknown-linux-gnu/sys-include

此目录包含与来自
的文件同名的文件 opt/cross/x86_64-unknown-linux-gnu/include
但内容不同。

编译器在 include 之前搜索了 sys-include 目录。

重命名或删除 sys-include 问题解决，代码可以编译。

我不知道sys-include目录的用途，创建时间以及为什么这个目录中的重复文件有其他内容。

接受我自己的post作为答案，表明问题可以解决。

当包含 <iostream> 时，在 CYGWIN 下与 GCC 的交叉编译失败

cross-compilation with GCC fails under CYGWIN when <iostream> is included

c++

linux

gcc

cygwin

cross-compiling