[libcxx-commits] [libcxx] [libcxx] Use _ftelli64/_fseeki64 on Windows (PR #123128)

[Hubert Tong via libcxx-commits]

Martin =?utf-8?q?Storsjö?= <martin at martin.st>,
Martin =?utf-8?q?Storsjö?= <martin at martin.st>,
Martin =?utf-8?q?Storsjö?= <martin at martin.st>,
Martin =?utf-8?q?Storsjö?= <martin at martin.st>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/123128 at github.com>


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@@ -936,31 +933,42 @@ basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
   default:
     return pos_type(off_type(-1));
   }
-#    if !_LIBCPP_HAS_OFF_T_FUNCTIONS
-  if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
+  if (__fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
     return pos_type(off_type(-1));
-  pos_type __r = ftell(__file_);
-#    else
-  if (::fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
-    return pos_type(off_type(-1));
-  pos_type __r = ftello(__file_);
-#    endif
+  pos_type __r = __ftell(__file_);
   __r.state(__st_);
   return __r;
 }
 
+template <class _CharT, class _Traits>
+int basic_filebuf<_CharT, _Traits>::__fseek(FILE* __file, pos_type __offset, int __whence) {
+#    if defined(_LIBCPP_MSVCRT_LIKE)
+  return _fseeki64(__file, __offset, __whence);
+#    elif defined(_NEWLIB_VERSION)
+  return fseek(__file, __offset, __whence);
+#    else
+  return ::fseeko(__file, __offset, __whence);
----------------
hubert-reinterpretcast wrote:

What is the rationale for the asymmetric use of `::`?

For any possible ADL concern tied to `pos_type`, a more reliable solution would be to cast `__offset` to the type of the intended corresponding function parameter.

https://github.com/llvm/llvm-project/pull/123128