Re: [committed] libstdc++: Reset filesystem::recursive_directory_iterator on error

[Jonathan Wakely via Gcc-patches]

On Tue, 1 Feb 2022 at 22:00, Jonathan Wakely via Libstdc++
<libstd...@gcc.gnu.org> wrote:
>
> The standard requires directory iterators to become equal to the end
> iterator value if they report an error. Some members functions of
> filesystem::recursive_directory_iterator fail to do that.
>
> libstdc++-v3/ChangeLog:
>
>         * src/c++17/fs_dir.cc (recursive_directory_iterator::increment):
>         Reset state to past-the-end iterator on error.
>         (fs::recursive_directory_iterator::pop(error_code&)): Likewise.
>         (fs::recursive_directory_iterator::pop()): Check _M_dirs before
>         it might get reset.
>         * src/filesystem/dir.cc (recursive_directory_iterator): Likewise,
>         for the TS implementation.
>         * testsuite/27_io/filesystem/iterators/error_reporting.cc: New test.
>         * testsuite/experimental/filesystem/iterators/error_reporting.cc: New 
> test.
> ---
>  libstdc++-v3/src/c++17/fs_dir.cc              |  12 +-
>  libstdc++-v3/src/filesystem/dir.cc            |  12 +-
>  .../filesystem/iterators/error_reporting.cc   | 135 +++++++++++++++++
>  .../filesystem/iterators/error_reporting.cc   | 136 ++++++++++++++++++
>  4 files changed, 291 insertions(+), 4 deletions(-)
>  create mode 100644 
> libstdc++-v3/testsuite/27_io/filesystem/iterators/error_reporting.cc
>  create mode 100644 
> libstdc++-v3/testsuite/experimental/filesystem/iterators/error_reporting.cc
>
[...]
> +
> +extern "C" struct dirent* readdir(DIR*)
> +{
> +  switch (choice)
> +  {
> +  case 1:
> +    global_dirent.d_ino = 999;
> +    global_dirent.d_type = DT_REG;

These new tests should not use the d_type member unless it's actually
present on the OS. Fixed by the attached patch.

Tested x86_64-linux and mingw-w64, pushed to trunk.

commit d98668eb06f532b2dbe0c721fa1b9ed6e643df27
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Tue Feb 1 23:58:08 2022

    libstdc++: Do not use dirent::d_type unconditionally
    
    These new tests should not use the d_type member unless it's actually
    present on the OS.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/27_io/filesystem/iterators/error_reporting.cc: Use
            autoconf macro to check whether d_type is present.
            * testsuite/experimental/filesystem/iterators/error_reporting.cc:
            Likewise.

diff --git 
a/libstdc++-v3/testsuite/27_io/filesystem/iterators/error_reporting.cc 
b/libstdc++-v3/testsuite/27_io/filesystem/iterators/error_reporting.cc
index 81ef1069367..1f297a731a3 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/iterators/error_reporting.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/iterators/error_reporting.cc
@@ -36,14 +36,18 @@ extern "C" struct dirent* readdir(DIR*)
   {
   case 1:
     global_dirent.d_ino = 999;
+#if defined _GLIBCXX_HAVE_STRUCT_DIRENT_D_TYPE && defined DT_REG
     global_dirent.d_type = DT_REG;
+#endif
     global_dirent.d_reclen = 0;
     std::char_traits<char>::copy(global_dirent.d_name, "file", 5);
     choice = 0;
     return &global_dirent;
   case 2:
     global_dirent.d_ino = 111;
+#if defined _GLIBCXX_HAVE_STRUCT_DIRENT_D_TYPE && defined DT_DIR
     global_dirent.d_type = DT_DIR;
+#endif
     global_dirent.d_reclen = 60;
     std::char_traits<char>::copy(global_dirent.d_name, "subdir", 7);
     choice = 1;
diff --git 
a/libstdc++-v3/testsuite/experimental/filesystem/iterators/error_reporting.cc 
b/libstdc++-v3/testsuite/experimental/filesystem/iterators/error_reporting.cc
index ade62732028..806c511ebef 100644
--- 
a/libstdc++-v3/testsuite/experimental/filesystem/iterators/error_reporting.cc
+++ 
b/libstdc++-v3/testsuite/experimental/filesystem/iterators/error_reporting.cc
@@ -37,14 +37,18 @@ extern "C" struct dirent* readdir(DIR*)
   {
   case 1:
     global_dirent.d_ino = 999;
+#if defined _GLIBCXX_HAVE_STRUCT_DIRENT_D_TYPE && defined DT_REG
     global_dirent.d_type = DT_REG;
+#endif
     global_dirent.d_reclen = 0;
     std::char_traits<char>::copy(global_dirent.d_name, "file", 5);
     choice = 0;
     return &global_dirent;
   case 2:
     global_dirent.d_ino = 111;
+#if defined _GLIBCXX_HAVE_STRUCT_DIRENT_D_TYPE && defined DT_DIR
     global_dirent.d_type = DT_DIR;
+#endif
     global_dirent.d_reclen = 60;
     std::char_traits<char>::copy(global_dirent.d_name, "subdir", 7);
     choice = 1;