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Fix overwriting files with fs::copy_file on windows

Message ID 20240324213401.47870-1-gcc@hazardy.de
State New
Headers
Series Fix overwriting files with fs::copy_file on windows |

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Commit Message

Björn Schäpers March 24, 2024, 9:34 p.m. UTC 
  From: Björn Schäpers <bjoern@hazardy.de>

This fixes i.e. https://github.com/msys2/MSYS2-packages/issues/1937
I don't know if I picked the right way to do it.

When acceptable I think the declaration should be moved into
ops-common.h, since then we could use stat_type and also use that in the
commonly used function.

Manually tested on i686-w64-mingw32.

-- >8 --
libstdc++: Fix overwriting files on windows

The inodes have no meaning on windows, thus all files have an inode of
0. Use a differenz approach to identify equivalent files. As a result
std::filesystem::copy_file did not honor
copy_options::overwrite_existing. Factored the method out of
std::filesystem::equivalent.

libstdc++-v3/Changelog:

	* include/bits/fs_ops.h: Add declaration of
	  __detail::equivalent_win32.
	* src/c++17/fs_ops.cc (__detail::equivalent_win32): Implement it
	(fs::equivalent): Use __detail::equivalent_win32, factored the
	old test out.
	* src/filesystem/ops-common.h (_GLIBCXX_FILESYSTEM_IS_WINDOWS):
	  Use the function.

Signed-off-by: Björn Schäpers <bjoern@hazardy.de>
---
 libstdc++-v3/include/bits/fs_ops.h       |  8 +++
 libstdc++-v3/src/c++17/fs_ops.cc         | 79 +++++++++++++-----------
 libstdc++-v3/src/filesystem/ops-common.h | 10 ++-
 3 files changed, 60 insertions(+), 37 deletions(-)

Comments

Björn Schäpers April 25, 2024, 8:16 p.m. UTC | #1 
Am 24.03.2024 um 22:34 schrieb Björn Schäpers:
> From: Björn Schäpers <bjoern@hazardy.de>
> 
> This fixes i.e. https://github.com/msys2/MSYS2-packages/issues/1937
> I don't know if I picked the right way to do it.
> 
> When acceptable I think the declaration should be moved into
> ops-common.h, since then we could use stat_type and also use that in the
> commonly used function.
> 
> Manually tested on i686-w64-mingw32.
> 
> -- >8 --
> libstdc++: Fix overwriting files on windows
> 
> The inodes have no meaning on windows, thus all files have an inode of
> 0. Use a differenz approach to identify equivalent files. As a result
> std::filesystem::copy_file did not honor
> copy_options::overwrite_existing. Factored the method out of
> std::filesystem::equivalent.
> 
> libstdc++-v3/Changelog:
> 
> 	* include/bits/fs_ops.h: Add declaration of
> 	  __detail::equivalent_win32.
> 	* src/c++17/fs_ops.cc (__detail::equivalent_win32): Implement it
> 	(fs::equivalent): Use __detail::equivalent_win32, factored the
> 	old test out.
> 	* src/filesystem/ops-common.h (_GLIBCXX_FILESYSTEM_IS_WINDOWS):
> 	  Use the function.
> 
> Signed-off-by: Björn Schäpers <bjoern@hazardy.de>
> ---
>   libstdc++-v3/include/bits/fs_ops.h       |  8 +++
>   libstdc++-v3/src/c++17/fs_ops.cc         | 79 +++++++++++++-----------
>   libstdc++-v3/src/filesystem/ops-common.h | 10 ++-
>   3 files changed, 60 insertions(+), 37 deletions(-)
> 
> diff --git a/libstdc++-v3/include/bits/fs_ops.h b/libstdc++-v3/include/bits/fs_ops.h
> index 90650c47b46..d10b78a4bdd 100644
> --- a/libstdc++-v3/include/bits/fs_ops.h
> +++ b/libstdc++-v3/include/bits/fs_ops.h
> @@ -40,6 +40,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>   
>   namespace filesystem
>   {
> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
> +namespace __detail
> +{
> +  bool
> +  equivalent_win32(const wchar_t* p1, const wchar_t* p2, error_code& ec);
> +} // namespace __detail
> +#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
> +
>     /** @addtogroup filesystem
>      *  @{
>      */
> diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc
> index 61df19753ef..3cc87d45237 100644
> --- a/libstdc++-v3/src/c++17/fs_ops.cc
> +++ b/libstdc++-v3/src/c++17/fs_ops.cc
> @@ -67,6 +67,49 @@
>   namespace fs = std::filesystem;
>   namespace posix = std::filesystem::__gnu_posix;
>   
> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
> +bool
> +fs::__detail::equivalent_win32(const wchar_t* p1, const wchar_t* p2,
> +			       error_code& ec)
> +{
> +  struct auto_handle {
> +    explicit auto_handle(const path& p_)
> +    : handle(CreateFileW(p_.c_str(), 0,
> +	FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
> +	0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
> +    { }
> +
> +    ~auto_handle()
> +    { if (*this) CloseHandle(handle); }
> +
> +    explicit operator bool() const
> +    { return handle != INVALID_HANDLE_VALUE; }
> +
> +    bool get_info()
> +    { return GetFileInformationByHandle(handle, &info); }
> +
> +    HANDLE handle;
> +    BY_HANDLE_FILE_INFORMATION info;
> +  };
> +  auto_handle h1(p1);
> +  auto_handle h2(p2);
> +  if (!h1 || !h2)
> +    {
> +      if (!h1 && !h2)
> +	ec = __last_system_error();
> +      return false;
> +    }
> +  if (!h1.get_info() || !h2.get_info())
> +    {
> +      ec = __last_system_error();
> +      return false;
> +    }
> +  return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
> +    && h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
> +    && h1.info.nFileIndexLow == h2.info.nFileIndexLow;
> +}
> +#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
> +
>   fs::path
>   fs::absolute(const path& p)
>   {
> @@ -858,41 +901,7 @@ fs::equivalent(const path& p1, const path& p2, error_code& ec) noexcept
>         if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev)
>   	return false;
>   
> -      struct auto_handle {
> -	explicit auto_handle(const path& p_)
> -	: handle(CreateFileW(p_.c_str(), 0,
> -	      FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
> -	      0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
> -	{ }
> -
> -	~auto_handle()
> -	{ if (*this) CloseHandle(handle); }
> -
> -	explicit operator bool() const
> -	{ return handle != INVALID_HANDLE_VALUE; }
> -
> -	bool get_info()
> -	{ return GetFileInformationByHandle(handle, &info); }
> -
> -	HANDLE handle;
> -	BY_HANDLE_FILE_INFORMATION info;
> -      };
> -      auto_handle h1(p1);
> -      auto_handle h2(p2);
> -      if (!h1 || !h2)
> -	{
> -	  if (!h1 && !h2)
> -	    ec = __last_system_error();
> -	  return false;
> -	}
> -      if (!h1.get_info() || !h2.get_info())
> -	{
> -	  ec = __last_system_error();
> -	  return false;
> -	}
> -      return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
> -	&& h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
> -	&& h1.info.nFileIndexLow == h2.info.nFileIndexLow;
> +      return __detail::equivalent_win32(p1.c_str(), p2.c_str(), ec);
>   #else
>         return st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino;
>   #endif
> diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
> index d917fddbeb1..7e67286bd01 100644
> --- a/libstdc++-v3/src/filesystem/ops-common.h
> +++ b/libstdc++-v3/src/filesystem/ops-common.h
> @@ -489,8 +489,14 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
>   	    return false;
>   	  }
>   
> -	if (to_st->st_dev == from_st->st_dev
> -	    && to_st->st_ino == from_st->st_ino)
> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
> +	// st_ino is not set, so can't be used to distinguish files
> +	std::error_code not_used;
> +	if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev ||
> +	    fs::__detail::equivalent_win32(from, to, not_used))
> +#else
> +	if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
> +#endif
>   	  {
>   	    ec = std::make_error_code(std::errc::file_exists);
>   	    return false;

A friendly ping.
One of your IPs tried to hack me May 16, 2024, 6:49 p.m. UTC | #2 
Am 25.04.2024 um 22:16 schrieb Björn Schäpers:
> Am 24.03.2024 um 22:34 schrieb Björn Schäpers:
>> From: Björn Schäpers <bjoern@hazardy.de>
>>
>> This fixes i.e. https://github.com/msys2/MSYS2-packages/issues/1937
>> I don't know if I picked the right way to do it.
>>
>> When acceptable I think the declaration should be moved into
>> ops-common.h, since then we could use stat_type and also use that in the
>> commonly used function.
>>
>> Manually tested on i686-w64-mingw32.
>>
>> -- >8 --
>> libstdc++: Fix overwriting files on windows
>>
>> The inodes have no meaning on windows, thus all files have an inode of
>> 0. Use a differenz approach to identify equivalent files. As a result
>> std::filesystem::copy_file did not honor
>> copy_options::overwrite_existing. Factored the method out of
>> std::filesystem::equivalent.
>>
>> libstdc++-v3/Changelog:
>>
>>     * include/bits/fs_ops.h: Add declaration of
>>       __detail::equivalent_win32.
>>     * src/c++17/fs_ops.cc (__detail::equivalent_win32): Implement it
>>     (fs::equivalent): Use __detail::equivalent_win32, factored the
>>     old test out.
>>     * src/filesystem/ops-common.h (_GLIBCXX_FILESYSTEM_IS_WINDOWS):
>>       Use the function.
>>
>> Signed-off-by: Björn Schäpers <bjoern@hazardy.de>
>> ---
>>   libstdc++-v3/include/bits/fs_ops.h       |  8 +++
>>   libstdc++-v3/src/c++17/fs_ops.cc         | 79 +++++++++++++-----------
>>   libstdc++-v3/src/filesystem/ops-common.h | 10 ++-
>>   3 files changed, 60 insertions(+), 37 deletions(-)
>>
>> diff --git a/libstdc++-v3/include/bits/fs_ops.h 
>> b/libstdc++-v3/include/bits/fs_ops.h
>> index 90650c47b46..d10b78a4bdd 100644
>> --- a/libstdc++-v3/include/bits/fs_ops.h
>> +++ b/libstdc++-v3/include/bits/fs_ops.h
>> @@ -40,6 +40,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>>   namespace filesystem
>>   {
>> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
>> +namespace __detail
>> +{
>> +  bool
>> +  equivalent_win32(const wchar_t* p1, const wchar_t* p2, error_code& ec);
>> +} // namespace __detail
>> +#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
>> +
>>     /** @addtogroup filesystem
>>      *  @{
>>      */
>> diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc
>> index 61df19753ef..3cc87d45237 100644
>> --- a/libstdc++-v3/src/c++17/fs_ops.cc
>> +++ b/libstdc++-v3/src/c++17/fs_ops.cc
>> @@ -67,6 +67,49 @@
>>   namespace fs = std::filesystem;
>>   namespace posix = std::filesystem::__gnu_posix;
>> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
>> +bool
>> +fs::__detail::equivalent_win32(const wchar_t* p1, const wchar_t* p2,
>> +                   error_code& ec)
>> +{
>> +  struct auto_handle {
>> +    explicit auto_handle(const path& p_)
>> +    : handle(CreateFileW(p_.c_str(), 0,
>> +    FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
>> +    0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
>> +    { }
>> +
>> +    ~auto_handle()
>> +    { if (*this) CloseHandle(handle); }
>> +
>> +    explicit operator bool() const
>> +    { return handle != INVALID_HANDLE_VALUE; }
>> +
>> +    bool get_info()
>> +    { return GetFileInformationByHandle(handle, &info); }
>> +
>> +    HANDLE handle;
>> +    BY_HANDLE_FILE_INFORMATION info;
>> +  };
>> +  auto_handle h1(p1);
>> +  auto_handle h2(p2);
>> +  if (!h1 || !h2)
>> +    {
>> +      if (!h1 && !h2)
>> +    ec = __last_system_error();
>> +      return false;
>> +    }
>> +  if (!h1.get_info() || !h2.get_info())
>> +    {
>> +      ec = __last_system_error();
>> +      return false;
>> +    }
>> +  return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
>> +    && h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
>> +    && h1.info.nFileIndexLow == h2.info.nFileIndexLow;
>> +}
>> +#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
>> +
>>   fs::path
>>   fs::absolute(const path& p)
>>   {
>> @@ -858,41 +901,7 @@ fs::equivalent(const path& p1, const path& p2, 
>> error_code& ec) noexcept
>>         if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev)
>>       return false;
>> -      struct auto_handle {
>> -    explicit auto_handle(const path& p_)
>> -    : handle(CreateFileW(p_.c_str(), 0,
>> -          FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
>> -          0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
>> -    { }
>> -
>> -    ~auto_handle()
>> -    { if (*this) CloseHandle(handle); }
>> -
>> -    explicit operator bool() const
>> -    { return handle != INVALID_HANDLE_VALUE; }
>> -
>> -    bool get_info()
>> -    { return GetFileInformationByHandle(handle, &info); }
>> -
>> -    HANDLE handle;
>> -    BY_HANDLE_FILE_INFORMATION info;
>> -      };
>> -      auto_handle h1(p1);
>> -      auto_handle h2(p2);
>> -      if (!h1 || !h2)
>> -    {
>> -      if (!h1 && !h2)
>> -        ec = __last_system_error();
>> -      return false;
>> -    }
>> -      if (!h1.get_info() || !h2.get_info())
>> -    {
>> -      ec = __last_system_error();
>> -      return false;
>> -    }
>> -      return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
>> -    && h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
>> -    && h1.info.nFileIndexLow == h2.info.nFileIndexLow;
>> +      return __detail::equivalent_win32(p1.c_str(), p2.c_str(), ec);
>>   #else
>>         return st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino;
>>   #endif
>> diff --git a/libstdc++-v3/src/filesystem/ops-common.h 
>> b/libstdc++-v3/src/filesystem/ops-common.h
>> index d917fddbeb1..7e67286bd01 100644
>> --- a/libstdc++-v3/src/filesystem/ops-common.h
>> +++ b/libstdc++-v3/src/filesystem/ops-common.h
>> @@ -489,8 +489,14 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
>>           return false;
>>         }
>> -    if (to_st->st_dev == from_st->st_dev
>> -        && to_st->st_ino == from_st->st_ino)
>> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
>> +    // st_ino is not set, so can't be used to distinguish files
>> +    std::error_code not_used;
>> +    if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev ||
>> +        fs::__detail::equivalent_win32(from, to, not_used))
>> +#else
>> +    if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
>> +#endif
>>         {
>>           ec = std::make_error_code(std::errc::file_exists);
>>           return false;
> 
> A friendly ping.

Ping.
Jonathan Wakely May 17, 2024, 2:34 p.m. UTC | #3 
On Sun, 24 Mar 2024 at 21:34, Björn Schäpers <gcc@hazardy.de> wrote:
>
> From: Björn Schäpers <bjoern@hazardy.de>
>
> This fixes i.e. https://github.com/msys2/MSYS2-packages/issues/1937
> I don't know if I picked the right way to do it.
>
> When acceptable I think the declaration should be moved into
> ops-common.h, since then we could use stat_type and also use that in the
> commonly used function.
>
> Manually tested on i686-w64-mingw32.
>
> -- >8 --
> libstdc++: Fix overwriting files on windows
>
> The inodes have no meaning on windows, thus all files have an inode of
> 0. Use a differenz approach to identify equivalent files. As a result
> std::filesystem::copy_file did not honor
> copy_options::overwrite_existing. Factored the method out of
> std::filesystem::equivalent.
>
> libstdc++-v3/Changelog:
>
>         * include/bits/fs_ops.h: Add declaration of
>           __detail::equivalent_win32.
>         * src/c++17/fs_ops.cc (__detail::equivalent_win32): Implement it
>         (fs::equivalent): Use __detail::equivalent_win32, factored the
>         old test out.
>         * src/filesystem/ops-common.h (_GLIBCXX_FILESYSTEM_IS_WINDOWS):
>           Use the function.
>
> Signed-off-by: Björn Schäpers <bjoern@hazardy.de>
> ---
>  libstdc++-v3/include/bits/fs_ops.h       |  8 +++
>  libstdc++-v3/src/c++17/fs_ops.cc         | 79 +++++++++++++-----------
>  libstdc++-v3/src/filesystem/ops-common.h | 10 ++-
>  3 files changed, 60 insertions(+), 37 deletions(-)
>
> diff --git a/libstdc++-v3/include/bits/fs_ops.h b/libstdc++-v3/include/bits/fs_ops.h
> index 90650c47b46..d10b78a4bdd 100644
> --- a/libstdc++-v3/include/bits/fs_ops.h
> +++ b/libstdc++-v3/include/bits/fs_ops.h
> @@ -40,6 +40,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>
>  namespace filesystem
>  {
> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
> +namespace __detail
> +{
> +  bool
> +  equivalent_win32(const wchar_t* p1, const wchar_t* p2, error_code& ec);

I don't think we want this declared in the public header, it should be
internal to the library.

Can it just be declared in ops-common.h instead?


> +} // namespace __detail
> +#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
> +
>    /** @addtogroup filesystem
>     *  @{
>     */
> diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc
> index 61df19753ef..3cc87d45237 100644
> --- a/libstdc++-v3/src/c++17/fs_ops.cc
> +++ b/libstdc++-v3/src/c++17/fs_ops.cc
> @@ -67,6 +67,49 @@
>  namespace fs = std::filesystem;
>  namespace posix = std::filesystem::__gnu_posix;
>
> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
> +bool
> +fs::__detail::equivalent_win32(const wchar_t* p1, const wchar_t* p2,
> +                              error_code& ec)
> +{
> +  struct auto_handle {
> +    explicit auto_handle(const path& p_)
> +    : handle(CreateFileW(p_.c_str(), 0,
> +       FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
> +       0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
> +    { }
> +
> +    ~auto_handle()
> +    { if (*this) CloseHandle(handle); }
> +
> +    explicit operator bool() const
> +    { return handle != INVALID_HANDLE_VALUE; }
> +
> +    bool get_info()
> +    { return GetFileInformationByHandle(handle, &info); }
> +
> +    HANDLE handle;
> +    BY_HANDLE_FILE_INFORMATION info;
> +  };
> +  auto_handle h1(p1);

This creates a new filesystem::path, just to call c_str() on it
immediately. The auto_handle ctor should be changed to just take const
wchar_t* so we don't need to allocate and parse new path objects.

> +  auto_handle h2(p2);
> +  if (!h1 || !h2)
> +    {
> +      if (!h1 && !h2)
> +       ec = __last_system_error();
> +      return false;
> +    }
> +  if (!h1.get_info() || !h2.get_info())
> +    {
> +      ec = __last_system_error();
> +      return false;
> +    }
> +  return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
> +    && h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
> +    && h1.info.nFileIndexLow == h2.info.nFileIndexLow;
> +}
> +#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
> +
>  fs::path
>  fs::absolute(const path& p)
>  {
> @@ -858,41 +901,7 @@ fs::equivalent(const path& p1, const path& p2, error_code& ec) noexcept
>        if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev)
>         return false;
>
> -      struct auto_handle {
> -       explicit auto_handle(const path& p_)
> -       : handle(CreateFileW(p_.c_str(), 0,
> -             FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
> -             0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
> -       { }
> -
> -       ~auto_handle()
> -       { if (*this) CloseHandle(handle); }
> -
> -       explicit operator bool() const
> -       { return handle != INVALID_HANDLE_VALUE; }
> -
> -       bool get_info()
> -       { return GetFileInformationByHandle(handle, &info); }
> -
> -       HANDLE handle;
> -       BY_HANDLE_FILE_INFORMATION info;
> -      };
> -      auto_handle h1(p1);
> -      auto_handle h2(p2);
> -      if (!h1 || !h2)
> -       {
> -         if (!h1 && !h2)
> -           ec = __last_system_error();
> -         return false;
> -       }
> -      if (!h1.get_info() || !h2.get_info())
> -       {
> -         ec = __last_system_error();
> -         return false;
> -       }
> -      return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
> -       && h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
> -       && h1.info.nFileIndexLow == h2.info.nFileIndexLow;
> +      return __detail::equivalent_win32(p1.c_str(), p2.c_str(), ec);
>  #else
>        return st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino;
>  #endif
> diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
> index d917fddbeb1..7e67286bd01 100644
> --- a/libstdc++-v3/src/filesystem/ops-common.h
> +++ b/libstdc++-v3/src/filesystem/ops-common.h
> @@ -489,8 +489,14 @@ _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
>             return false;
>           }
>
> -       if (to_st->st_dev == from_st->st_dev
> -           && to_st->st_ino == from_st->st_ino)
> +#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
> +       // st_ino is not set, so can't be used to distinguish files
> +       std::error_code not_used;
> +       if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev ||
> +           fs::__detail::equivalent_win32(from, to, not_used))
> +#else
> +       if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
> +#endif
>           {
>             ec = std::make_error_code(std::errc::file_exists);
>             return false;
> --
> 2.44.0
>
diff mbox series

Patch

diff --git a/libstdc++-v3/include/bits/fs_ops.h b/libstdc++-v3/include/bits/fs_ops.h
index 90650c47b46..d10b78a4bdd 100644
--- a/libstdc++-v3/include/bits/fs_ops.h
+++ b/libstdc++-v3/include/bits/fs_ops.h
@@ -40,6 +40,14 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 namespace filesystem
 {
+#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
+namespace __detail
+{
+  bool
+  equivalent_win32(const wchar_t* p1, const wchar_t* p2, error_code& ec);
+} // namespace __detail
+#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
+
   /** @addtogroup filesystem
    *  @{
    */
diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc
index 61df19753ef..3cc87d45237 100644
--- a/libstdc++-v3/src/c++17/fs_ops.cc
+++ b/libstdc++-v3/src/c++17/fs_ops.cc
@@ -67,6 +67,49 @@ 
 namespace fs = std::filesystem;
 namespace posix = std::filesystem::__gnu_posix;
 
+#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
+bool
+fs::__detail::equivalent_win32(const wchar_t* p1, const wchar_t* p2,
+			       error_code& ec)
+{
+  struct auto_handle {
+    explicit auto_handle(const path& p_)
+    : handle(CreateFileW(p_.c_str(), 0,
+	FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
+	0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
+    { }
+
+    ~auto_handle()
+    { if (*this) CloseHandle(handle); }
+
+    explicit operator bool() const
+    { return handle != INVALID_HANDLE_VALUE; }
+
+    bool get_info()
+    { return GetFileInformationByHandle(handle, &info); }
+
+    HANDLE handle;
+    BY_HANDLE_FILE_INFORMATION info;
+  };
+  auto_handle h1(p1);
+  auto_handle h2(p2);
+  if (!h1 || !h2)
+    {
+      if (!h1 && !h2)
+	ec = __last_system_error();
+      return false;
+    }
+  if (!h1.get_info() || !h2.get_info())
+    {
+      ec = __last_system_error();
+      return false;
+    }
+  return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
+    && h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
+    && h1.info.nFileIndexLow == h2.info.nFileIndexLow;
+}
+#endif //_GLIBCXX_FILESYSTEM_IS_WINDOWS
+
 fs::path
 fs::absolute(const path& p)
 {
@@ -858,41 +901,7 @@  fs::equivalent(const path& p1, const path& p2, error_code& ec) noexcept
       if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev)
 	return false;
 
-      struct auto_handle {
-	explicit auto_handle(const path& p_)
-	: handle(CreateFileW(p_.c_str(), 0,
-	      FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE,
-	      0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0))
-	{ }
-
-	~auto_handle()
-	{ if (*this) CloseHandle(handle); }
-
-	explicit operator bool() const
-	{ return handle != INVALID_HANDLE_VALUE; }
-
-	bool get_info()
-	{ return GetFileInformationByHandle(handle, &info); }
-
-	HANDLE handle;
-	BY_HANDLE_FILE_INFORMATION info;
-      };
-      auto_handle h1(p1);
-      auto_handle h2(p2);
-      if (!h1 || !h2)
-	{
-	  if (!h1 && !h2)
-	    ec = __last_system_error();
-	  return false;
-	}
-      if (!h1.get_info() || !h2.get_info())
-	{
-	  ec = __last_system_error();
-	  return false;
-	}
-      return h1.info.dwVolumeSerialNumber == h2.info.dwVolumeSerialNumber
-	&& h1.info.nFileIndexHigh == h2.info.nFileIndexHigh
-	&& h1.info.nFileIndexLow == h2.info.nFileIndexLow;
+      return __detail::equivalent_win32(p1.c_str(), p2.c_str(), ec);
 #else
       return st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino;
 #endif
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index d917fddbeb1..7e67286bd01 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -489,8 +489,14 @@  _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
 	    return false;
 	  }
 
-	if (to_st->st_dev == from_st->st_dev
-	    && to_st->st_ino == from_st->st_ino)
+#ifdef _GLIBCXX_FILESYSTEM_IS_WINDOWS
+	// st_ino is not set, so can't be used to distinguish files
+	std::error_code not_used;
+	if (st1.st_mode != st2.st_mode || st1.st_dev != st2.st_dev ||
+	    fs::__detail::equivalent_win32(from, to, not_used))
+#else
+	if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
+#endif
 	  {
 	    ec = std::make_error_code(std::errc::file_exists);
 	    return false;