[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/lowio/lseek.cpp

@@ -0,0 +1,171 @@
+//
+// lseek.cpp
+//
+//      Copyright (c) Microsoft Corporation. All rights reserved.
+//
+// Defines _lseek(), which seeks the file pointer of a file.
+//
+#include <corecrt_internal_lowio.h>
+#include <corecrt_internal_ptd_propagation.h>
+#include <stdlib.h>
+
+#if SEEK_SET != FILE_BEGIN || SEEK_CUR != FILE_CURRENT || SEEK_END != FILE_END
+    #error Xenix and Win32 seek constants not compatible
+#endif
+
+
+
+// These functions actually seek the underlying operating system file handle.
+// The logic is different for 32-bit and 64-bit seek values because a seek may
+// end up moving out of range of 32-bit values.
+static long __cdecl common_lseek_do_seek_nolock(HANDLE const os_handle, long const offset, int const origin, __crt_cached_ptd_host& ptd) throw()
+{
+    LARGE_INTEGER const origin_pos = { 0 };
+
+    LARGE_INTEGER saved_pos;
+    if (!SetFilePointerEx(os_handle, origin_pos, &saved_pos, FILE_CURRENT))
+    {
+        __acrt_errno_map_os_error_ptd(GetLastError(), ptd);
+        return -1;
+    }
+
+    LARGE_INTEGER seek_pos = { 0 };
+    seek_pos.QuadPart = offset;
+
+    LARGE_INTEGER new_pos = { 0 };
+    if (!SetFilePointerEx(os_handle, seek_pos, &new_pos, origin))
+    {
+        __acrt_errno_map_os_error_ptd(GetLastError(), ptd);
+        return -1;
+    }
+
+    // The call succeeded, but the new file pointer location is too large for
+    // the return type or is a negative value.  So, restore the file pointer
+    // to the saved location and return an error:
+    if (new_pos.QuadPart > LONG_MAX)
+    {
+        SetFilePointerEx(os_handle, saved_pos, nullptr, FILE_BEGIN);
+        ptd.get_errno().set(EINVAL);
+        return -1;
+    }
+
+    return static_cast<long>(new_pos.LowPart);
+}
+
+static __int64 __cdecl common_lseek_do_seek_nolock(HANDLE const os_handle, __int64 const offset, int const origin, __crt_cached_ptd_host& ptd) throw()
+{
+    LARGE_INTEGER new_pos;
+    if (!SetFilePointerEx(os_handle, *reinterpret_cast<LARGE_INTEGER const*>(&offset), &new_pos, origin))
+    {
+        __acrt_errno_map_os_error_ptd(GetLastError(), ptd);
+        return -1;
+    }
+
+    return new_pos.QuadPart;
+}
+
+
+template <typename Integer>
+static Integer __cdecl common_lseek_nolock(int const fh, Integer const offset, int const origin, __crt_cached_ptd_host& ptd) throw()
+{
+    HANDLE const os_handle = reinterpret_cast<HANDLE>(_get_osfhandle(fh));
+    if (os_handle == reinterpret_cast<HANDLE>(-1))
+    {
+        ptd.get_errno().set(EBADF);
+        _ASSERTE(("Invalid file descriptor",0));
+        return -1;
+    }
+
+    Integer const new_position = common_lseek_do_seek_nolock(os_handle, offset, origin, ptd);
+    if (new_position == -1)
+    {
+        return -1;
+    }
+
+    // The call succeeded, so return success:
+    _osfile(fh) &= ~FEOFLAG; // Clear the Ctrl-Z flag
+    return new_position;
+}
+
+// Moves the file pointer associated with the given file to a new position.  The
+// new position is 'offset' bytes (the offset may be negative) away from the
+// origin specified by 'origin'.
+//
+//     If origin == SEEK_SET, the origin in the beginning of file
+//     If origin == SEEK_CUR, the origin is the current file pointer position
+//     If origin == SEEK_END, the origin is the end of the file
+//
+// Returns the offset, in bytes, of the new position, from the beginning of the
+// file.  Returns -1 and sets errno on failure.  Note that seeking beyond the
+// end of the file is not an error, but seeking before the beginning is.
+template <typename Integer>
+static Integer __cdecl common_lseek(int const fh, Integer const offset, int const origin, __crt_cached_ptd_host& ptd) throw()
+{
+    _UCRT_CHECK_FH_CLEAR_OSSERR_RETURN(ptd, fh, EBADF, -1);
+    _UCRT_VALIDATE_CLEAR_OSSERR_RETURN(ptd, fh >= 0 && (unsigned)fh < (unsigned)_nhandle, EBADF, -1);
+    _UCRT_VALIDATE_CLEAR_OSSERR_RETURN(ptd, _osfile(fh) & FOPEN, EBADF, -1);
+
+    __acrt_lowio_lock_fh(fh);
+    Integer result = -1;
+    __try
+    {
+        if ((_osfile(fh) & FOPEN) == 0)
+        {
+            ptd.get_errno().set(EBADF);
+            ptd.get_doserrno().set(0);
+            _ASSERTE(("Invalid file descriptor. File possibly closed by a different thread",0));
+            __leave;
+        }
+
+        result = common_lseek_nolock(fh, offset, origin, ptd);
+    }
+    __finally
+    {
+        __acrt_lowio_unlock_fh(fh);
+    }
+    return result;
+}
+
+extern "C" long __cdecl _lseek_internal(int const fh, long const offset, int const origin, __crt_cached_ptd_host& ptd)
+{
+    return common_lseek(fh, offset, origin, ptd);
+}
+
+extern "C" __int64 __cdecl _lseeki64_internal(int const fh, __int64 const offset, int const origin, __crt_cached_ptd_host& ptd)
+{
+    return common_lseek(fh, offset, origin, ptd);
+}
+
+extern "C" long __cdecl _lseek_nolock_internal(int const fh, long const offset, int const origin, __crt_cached_ptd_host& ptd)
+{
+    return common_lseek_nolock(fh, offset, origin, ptd);
+}
+
+extern "C" __int64 __cdecl _lseeki64_nolock_internal(int const fh, __int64 const offset, int const origin, __crt_cached_ptd_host& ptd)
+{
+    return common_lseek_nolock(fh, offset, origin, ptd);
+}
+
+extern "C" long __cdecl _lseek(int const fh, long const offset, int const origin)
+{
+    __crt_cached_ptd_host ptd;
+    return common_lseek(fh, offset, origin, ptd);
+}
+
+extern "C" __int64 __cdecl _lseeki64(int const fh, __int64 const offset, int const origin)
+{
+    __crt_cached_ptd_host ptd;
+    return common_lseek(fh, offset, origin, ptd);
+}
+
+extern "C" long __cdecl _lseek_nolock(int const fh, long const offset, int const origin)
+{
+    __crt_cached_ptd_host ptd;
+    return common_lseek_nolock(fh, offset, origin, ptd);
+}
+
+extern "C" __int64 __cdecl _lseeki64_nolock(int const fh, __int64 const offset, int const origin)
+{
+    __crt_cached_ptd_host ptd;
+    return common_lseek_nolock(fh, offset, origin, ptd);
+}