On Fri, Sep 25, 2026 at 7:07 PM Jonathan Wakely <[email protected]> wrote:
> The config/os/mingw32-w64/error_constants.h and
> config/os/mingw32/error_constants.h headers check `#ifdef EPERM` before
> using it, but I think that's completely redundant. Windows and all
> versions of MinGW and mingw-w64 define EPERM and always have done as far
> as I can tell. And all UNIX-like and POSIX-based targets define it.
>
> We already have other code that uses EPERM without checking if it's
> defined, and that would not compile if it wasn't present for the target.
>
> Remove the #ifdef from those headers so that we use it unconditionally,
> and remove some other checks and comments that assume it can be absent.
>
> libstdc++-v3/ChangeLog:
>
> * config/os/mingw32-w64/error_constants.h: Use EPERM without
> checking if it's defined.
> * config/os/mingw32/error_constants.h: Likewise.
> * src/c++11/system_error.cc: Likewise.
> * src/c++17/fs_dir.cc (fs::recursive_directory_iterator::__erase):
> Likewise.
> * testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc:
> Use errc::operation_not_permitted without checking if EPERM is
> defined.
> ---
>
> Tested x86_64-linux and x86_64-w64-mingw32.
>
LGTM
>
> libstdc++-v3/config/os/mingw32-w64/error_constants.h | 2 --
> libstdc++-v3/config/os/mingw32/error_constants.h | 2 --
> libstdc++-v3/src/c++11/system_error.cc | 4 ----
> libstdc++-v3/src/c++17/fs_dir.cc | 6 +-----
> .../19_diagnostics/headers/system_error/errc_std_c++0x.cc | 4 ----
> 5 files changed, 1 insertion(+), 17 deletions(-)
>
> diff --git a/libstdc++-v3/config/os/mingw32-w64/error_constants.h
> b/libstdc++-v3/config/os/mingw32-w64/error_constants.h
> index f2a4fb579042..eca02eeecc76 100644
> --- a/libstdc++-v3/config/os/mingw32-w64/error_constants.h
> +++ b/libstdc++-v3/config/os/mingw32-w64/error_constants.h
> @@ -118,9 +118,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> #endif
> operation_canceled = ECANCELED,
> operation_in_progress = EINPROGRESS,
> -#ifdef EPERM
> operation_not_permitted = EPERM,
> -#endif
> operation_not_supported = EOPNOTSUPP,
> #ifdef EWOULDBLOCK
> operation_would_block = EWOULDBLOCK,
> diff --git a/libstdc++-v3/config/os/mingw32/error_constants.h
> b/libstdc++-v3/config/os/mingw32/error_constants.h
> index 2586eed5b037..eeeeedc5c611 100644
> --- a/libstdc++-v3/config/os/mingw32/error_constants.h
> +++ b/libstdc++-v3/config/os/mingw32/error_constants.h
> @@ -104,9 +104,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> #endif
> // operation_canceled = ECANCELED,
> // operation_in_progress = EINPROGRESS,
> -#ifdef EPERM
> operation_not_permitted = EPERM,
> -#endif
> // operation_not_supported = EOPNOTSUPP,
> #ifdef EWOULDBLOCK
> operation_would_block = EWOULDBLOCK,
> diff --git a/libstdc++-v3/src/c++11/system_error.cc
> b/libstdc++-v3/src/c++11/system_error.cc
> index 851f51acd404..a251fe6a50e2 100644
> --- a/libstdc++-v3/src/c++11/system_error.cc
> +++ b/libstdc++-v3/src/c++11/system_error.cc
> @@ -275,11 +275,7 @@ namespace
> X (NONPAGED_SYSTEM_RESOURCES, EAGAIN);
> X (NOT_ENOUGH_MEMORY, ENOMEM);
> X (NOT_ENOUGH_QUOTA, EIO);
> -#ifdef EPERM
> X (NOT_OWNER, EPERM);
> -#else
> - X (NOT_OWNER, EACCES);
> -#endif
> X (NOT_SAME_DEVICE, EXDEV);
> X (NOT_SUPPORTED, ENOSYS);
> X (NO_DATA, EPIPE);
> diff --git a/libstdc++-v3/src/c++17/fs_dir.cc
> b/libstdc++-v3/src/c++17/fs_dir.cc
> index f6860e264110..f1eca0bbd51c 100644
> --- a/libstdc++-v3/src/c++17/fs_dir.cc
> +++ b/libstdc++-v3/src/c++17/fs_dir.cc
> @@ -514,13 +514,9 @@ fs::recursive_directory_iterator::__erase(error_code*
> ecptr)
> {
> // We did not have a cached type, so it's possible that top.entry
> // is actually a directory, and that's why the unlink above
> failed.
> -#ifdef EPERM
> // POSIX.1-2017 says unlink on a directory returns EPERM,
> - // but LSB allows EISDIR too. Some targets don't even define
> EPERM.
> + // but LSB allows EISDIR too.
> if (ec.value() == EPERM || ec.value() == EISDIR)
> -#else
> - if (ec.value() == EISDIR)
> -#endif
> {
> // Retry, treating it as a directory.
> top.entry._M_type = file_type::directory;
> diff --git
> a/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
> b/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
> index 1b1a950c2b0b..13f4b385e385 100644
> ---
> a/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
> +++
> b/libstdc++-v3/testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc
> @@ -121,11 +121,7 @@ void test01()
> #endif
>
> TEST_ERRC(operation_in_progress);
> -
> -#ifdef EPERM
> TEST_ERRC(operation_not_permitted);
> -#endif
> -
> TEST_ERRC(operation_not_supported);
>
> #ifdef EWOULDBLOCK
> --
> 2.55.0
>
>
