[v3,2/7] Use SCANF_ISOC99_A instead of _IO_FLAGS2_SCANF_STD.

Message ID 20181115214449.19262-3-gabriel@inconstante.eti.br
State New
Headers show
Series
  • Use more flags parameters instead of global bits in stdio
Related show

Commit Message

Gabriel F. T. Gomes Nov. 15, 2018, 9:44 p.m.
From: Zack Weinberg <zackw@panix.com>


Changes since v2

  - None, but dependent on previous patch in the set, thus resending.

Changes since v1:

  - Cleared VARGARSn comments.
  - Added signed-off-by statements.

-- 8< --
Change the callers of __vfscanf_internal and __vfwscanf_internal that
want C99-compliant behavior to communicate this via the new flags
argument, rather than setting bits on the FILE object.  This also
means these functions do not need to do their own locking.

Tested for powerpc and powerpc64le.

2018-10-16  Zack Weinberg  <zackw@panix.com>
	    Gabriel F. T. Gomes  <gabriel@inconstante.eti.br>

	* stdio-common/isoc99_scanf.c
	* stdio-common/isoc99_fscanf.c
	* stdio-common/isoc99_sscanf.c
	* stdio-common/isoc99_vscanf.c
	* stdio-common/isoc99_vfscanf.c
	* stdio-common/isoc99_vsscanf.c
	* wcsmbs/isoc99_wscanf.c
	* wcsmbs/isoc99_fwscanf.c
	* wcsmbs/isoc99_swscanf.c
	* wcsmbs/isoc99_vwscanf.c
	* wcsmbs/isoc99_vfwscanf.c
	* wcsmbs/isoc99_vswscanf.c:
	Pass SCANF_ISOC99_A to __vfscanf_internal and/or __vfwscanf_internal.
	Do not set _IO_FLAGS2_SCANF_STD on the FILE passed to that function.
	No need to lock and unlock the FILE passed to that function.

	* stdio-common/vfscanf-internal.c
	(__vfscanf_internal, __vfwscanf_internal):
	Don't look at _IO_FLAGS2_SCANF_STD.
	* libio/libioP.h (_IO_acquire_lock_clear_flags2_fct)
	(_IO_release_lock): Don't clear _IO_FLAGS2_SCANF_STD.
	* libio/libio.h (_IO_FLAGS2_SCANF_STD): Delete.
---
 libio/libio.h                   |  1 -
 libio/libioP.h                  |  5 ++---
 stdio-common/isoc99_fscanf.c    |  7 +------
 stdio-common/isoc99_scanf.c     | 12 +-----------
 stdio-common/isoc99_sscanf.c    |  3 +--
 stdio-common/isoc99_vfscanf.c   |  9 +--------
 stdio-common/isoc99_vscanf.c    |  9 +--------
 stdio-common/isoc99_vsscanf.c   |  3 +--
 stdio-common/vfscanf-internal.c |  2 --
 wcsmbs/isoc99_fwscanf.c         |  7 +------
 wcsmbs/isoc99_swscanf.c         |  3 +--
 wcsmbs/isoc99_vfwscanf.c        |  9 +--------
 wcsmbs/isoc99_vswscanf.c        |  3 +--
 wcsmbs/isoc99_vwscanf.c         |  9 +--------
 wcsmbs/isoc99_wscanf.c          |  7 +------
 15 files changed, 14 insertions(+), 75 deletions(-)

-- 
2.14.5

Comments

Adhemerval Zanella Nov. 22, 2018, 5:38 p.m. | #1
On 15/11/2018 19:44, Gabriel F. T. Gomes wrote:
> From: Zack Weinberg <zackw@panix.com>

> 

> Changes since v2

> 

>   - None, but dependent on previous patch in the set, thus resending.


LGTM.

> 

> Changes since v1:

> 

>   - Cleared VARGARSn comments.

>   - Added signed-off-by statements.

> 

> -- 8< --

> Change the callers of __vfscanf_internal and __vfwscanf_internal that

> want C99-compliant behavior to communicate this via the new flags

> argument, rather than setting bits on the FILE object.  This also

> means these functions do not need to do their own locking.

> 

> Tested for powerpc and powerpc64le.

> 

> 2018-10-16  Zack Weinberg  <zackw@panix.com>

> 	    Gabriel F. T. Gomes  <gabriel@inconstante.eti.br>

> 

> 	* stdio-common/isoc99_scanf.c

> 	* stdio-common/isoc99_fscanf.c

> 	* stdio-common/isoc99_sscanf.c

> 	* stdio-common/isoc99_vscanf.c

> 	* stdio-common/isoc99_vfscanf.c

> 	* stdio-common/isoc99_vsscanf.c

> 	* wcsmbs/isoc99_wscanf.c

> 	* wcsmbs/isoc99_fwscanf.c

> 	* wcsmbs/isoc99_swscanf.c

> 	* wcsmbs/isoc99_vwscanf.c

> 	* wcsmbs/isoc99_vfwscanf.c

> 	* wcsmbs/isoc99_vswscanf.c:

> 	Pass SCANF_ISOC99_A to __vfscanf_internal and/or __vfwscanf_internal.

> 	Do not set _IO_FLAGS2_SCANF_STD on the FILE passed to that function.

> 	No need to lock and unlock the FILE passed to that function.

> 

> 	* stdio-common/vfscanf-internal.c

> 	(__vfscanf_internal, __vfwscanf_internal):

> 	Don't look at _IO_FLAGS2_SCANF_STD.

> 	* libio/libioP.h (_IO_acquire_lock_clear_flags2_fct)

> 	(_IO_release_lock): Don't clear _IO_FLAGS2_SCANF_STD.

> 	* libio/libio.h (_IO_FLAGS2_SCANF_STD): Delete.

> ---

>  libio/libio.h                   |  1 -

>  libio/libioP.h                  |  5 ++---

>  stdio-common/isoc99_fscanf.c    |  7 +------

>  stdio-common/isoc99_scanf.c     | 12 +-----------

>  stdio-common/isoc99_sscanf.c    |  3 +--

>  stdio-common/isoc99_vfscanf.c   |  9 +--------

>  stdio-common/isoc99_vscanf.c    |  9 +--------

>  stdio-common/isoc99_vsscanf.c   |  3 +--

>  stdio-common/vfscanf-internal.c |  2 --

>  wcsmbs/isoc99_fwscanf.c         |  7 +------

>  wcsmbs/isoc99_swscanf.c         |  3 +--

>  wcsmbs/isoc99_vfwscanf.c        |  9 +--------

>  wcsmbs/isoc99_vswscanf.c        |  3 +--

>  wcsmbs/isoc99_vwscanf.c         |  9 +--------

>  wcsmbs/isoc99_wscanf.c          |  7 +------

>  15 files changed, 14 insertions(+), 75 deletions(-)

> 

> diff --git a/libio/libio.h b/libio/libio.h

> index d4eba2df54..30cb7d784f 100644

> --- a/libio/libio.h

> +++ b/libio/libio.h

> @@ -92,7 +92,6 @@ typedef union

>  #define _IO_FLAGS2_NOTCANCEL 2

>  #define _IO_FLAGS2_FORTIFY 4

>  #define _IO_FLAGS2_USER_WBUF 8

> -#define _IO_FLAGS2_SCANF_STD 16

>  #define _IO_FLAGS2_NOCLOSE 32

>  #define _IO_FLAGS2_CLOEXEC 64

>  #define _IO_FLAGS2_NEED_LOCK 128

> diff --git a/libio/libioP.h b/libio/libioP.h

> index 525dce19ee..9e971cb96b 100644

> --- a/libio/libioP.h

> +++ b/libio/libioP.h

> @@ -786,7 +786,7 @@ __attribute__ ((__always_inline__))

>  _IO_acquire_lock_clear_flags2_fct (FILE **p)

>  {

>    FILE *fp = *p;

> -  fp->_flags2 &= ~(_IO_FLAGS2_FORTIFY | _IO_FLAGS2_SCANF_STD);

> +  fp->_flags2 &= ~(_IO_FLAGS2_FORTIFY);

>    if ((fp->_flags & _IO_USER_LOCK) == 0)

>      _IO_funlockfile (fp);

>  }

> @@ -800,8 +800,7 @@ _IO_acquire_lock_clear_flags2_fct (FILE **p)

>      FILE *_IO_acquire_lock_file = (_fp)

>  # define _IO_release_lock(_fp)						      \

>      if (_IO_acquire_lock_file != NULL)					      \

> -      _IO_acquire_lock_file->_flags2 &= ~(_IO_FLAGS2_FORTIFY		      \

> -                                          | _IO_FLAGS2_SCANF_STD);	      \

> +      _IO_acquire_lock_file->_flags2 &= ~(_IO_FLAGS2_FORTIFY);		      \

>    } while (0)

>  #endif

>  

> diff --git a/stdio-common/isoc99_fscanf.c b/stdio-common/isoc99_fscanf.c

> index 4210d11f2b..d7b5993f3e 100644

> --- a/stdio-common/isoc99_fscanf.c

> +++ b/stdio-common/isoc99_fscanf.c

> @@ -20,20 +20,15 @@

>  #include <stdio.h>

>  

>  /* Read formatted input from STREAM according to the format string FORMAT.  */

> -/* VARARGS2 */

>  int

>  __isoc99_fscanf (FILE *stream, const char *format, ...)

>  {

>    va_list arg;

>    int done;

>  

> -  _IO_acquire_lock_clear_flags2 (stream);

> -  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -

>    va_start (arg, format);

> -  done = __vfscanf_internal (stream, format, arg, 0);

> +  done = __vfscanf_internal (stream, format, arg, SCANF_ISOC99_A);

>    va_end (arg);

>  

> -  _IO_release_lock (stream);

>    return done;

>  }

> diff --git a/stdio-common/isoc99_scanf.c b/stdio-common/isoc99_scanf.c

> index 64c873eed9..3998322ea1 100644

> --- a/stdio-common/isoc99_scanf.c

> +++ b/stdio-common/isoc99_scanf.c

> @@ -19,26 +19,16 @@

>  #include <stdio.h>

>  #include <libioP.h>

>  

> -

>  /* Read formatted input from stdin according to the format string FORMAT.  */

> -/* VARARGS1 */

>  int

>  __isoc99_scanf (const char *format, ...)

>  {

>    va_list arg;

>    int done;

>  

> -#ifdef _IO_MTSAFE_IO

> -  _IO_acquire_lock_clear_flags2 (stdin);

> -#endif

> -  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -

>    va_start (arg, format);

> -  done = __vfscanf_internal (stdin, format, arg, 0);

> +  done = __vfscanf_internal (stdin, format, arg, SCANF_ISOC99_A);

>    va_end (arg);

>  

> -#ifdef _IO_MTSAFE_IO

> -  _IO_release_lock (stdin);

> -#endif

>    return done;

>  }

> diff --git a/stdio-common/isoc99_sscanf.c b/stdio-common/isoc99_sscanf.c

> index 2c89a03fe9..c9e5103b81 100644

> --- a/stdio-common/isoc99_sscanf.c

> +++ b/stdio-common/isoc99_sscanf.c

> @@ -26,10 +26,9 @@ __isoc99_sscanf (const char *s, const char *format, ...)

>    int done;

>    _IO_strfile sf;

>    FILE *f = _IO_strfile_read (&sf, s);

> -  f->_flags2 |= _IO_FLAGS2_SCANF_STD;

>  

>    va_start (arg, format);

> -  done = __vfscanf_internal (f, format, arg, 0);

> +  done = __vfscanf_internal (f, format, arg, SCANF_ISOC99_A);

>    va_end (arg);

>  

>    return done;

> diff --git a/stdio-common/isoc99_vfscanf.c b/stdio-common/isoc99_vfscanf.c

> index c96ca831ae..3c59c60b3e 100644

> --- a/stdio-common/isoc99_vfscanf.c

> +++ b/stdio-common/isoc99_vfscanf.c

> @@ -19,16 +19,9 @@

>  #include <stdio.h>

>  

>  /* Read formatted input from STREAM according to the format string FORMAT.  */

> -/* VARARGS2 */

>  int

>  __isoc99_vfscanf (FILE *stream, const char *format, va_list args)

>  {

> -  int done;

> -

> -  _IO_acquire_lock_clear_flags2 (stream);

> -  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -  done = __vfscanf_internal (stream, format, args, 0);

> -  _IO_release_lock (stream);

> -  return done;

> +  return __vfscanf_internal (stream, format, args, SCANF_ISOC99_A);

>  }

>  libc_hidden_def (__isoc99_vfscanf)

> diff --git a/stdio-common/isoc99_vscanf.c b/stdio-common/isoc99_vscanf.c

> index 72ae72ddee..fc5d609ae7 100644

> --- a/stdio-common/isoc99_vscanf.c

> +++ b/stdio-common/isoc99_vscanf.c

> @@ -19,15 +19,8 @@

>  #include <stdio.h>

>  

>  /* Read formatted input from STDIN according to the format string FORMAT.  */

> -/* VARARGS2 */

>  int

>  __isoc99_vscanf (const char *format, va_list args)

>  {

> -  int done;

> -

> -  _IO_acquire_lock_clear_flags2 (stdin);

> -  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -  done = __vfscanf_internal (stdin, format, args, 0);

> -  _IO_release_lock (stdin);

> -  return done;

> +  return __vfscanf_internal (stdin, format, args, SCANF_ISOC99_A);

>  }

> diff --git a/stdio-common/isoc99_vsscanf.c b/stdio-common/isoc99_vsscanf.c

> index 02bc0f50e6..dfc394bb51 100644

> --- a/stdio-common/isoc99_vsscanf.c

> +++ b/stdio-common/isoc99_vsscanf.c

> @@ -31,7 +31,6 @@ __isoc99_vsscanf (const char *string, const char *format, va_list args)

>  {

>    _IO_strfile sf;

>    FILE *f = _IO_strfile_read (&sf, string);

> -  f->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -  return __vfscanf_internal (f, format, args, 0);

> +  return __vfscanf_internal (f, format, args, SCANF_ISOC99_A);

>  }

>  libc_hidden_def (__isoc99_vsscanf)

> diff --git a/stdio-common/vfscanf-internal.c b/stdio-common/vfscanf-internal.c

> index 13a7a300b7..f0072d8682 100644

> --- a/stdio-common/vfscanf-internal.c

> +++ b/stdio-common/vfscanf-internal.c

> @@ -335,8 +335,6 @@ __vfscanf_internal (FILE *s, const char *format, va_list argptr,

>    /* Temporarily honor the environmental mode bits.  */

>    if (__ldbl_is_dbl)

>      mode_flags |= SCANF_LDBL_IS_DBL;

> -  if (s->_flags2 & _IO_FLAGS2_SCANF_STD)

> -    mode_flags |= SCANF_ISOC99_A;

>  

>  #ifdef __va_copy

>    __va_copy (arg, argptr);

> diff --git a/wcsmbs/isoc99_fwscanf.c b/wcsmbs/isoc99_fwscanf.c

> index 00b07dd48e..5829607916 100644

> --- a/wcsmbs/isoc99_fwscanf.c

> +++ b/wcsmbs/isoc99_fwscanf.c

> @@ -21,20 +21,15 @@

>  #include <wchar.h>

>  

>  /* Read formatted input from STREAM according to the format string FORMAT.  */

> -/* VARARGS2 */

>  int

>  __isoc99_fwscanf (FILE *stream, const wchar_t *format, ...)

>  {

>    va_list arg;

>    int done;

>  

> -  _IO_acquire_lock_clear_flags2 (stream);

> -  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -

>    va_start (arg, format);

> -  done = __vfwscanf_internal (stream, format, arg, 0);

> +  done = __vfwscanf_internal (stream, format, arg, SCANF_ISOC99_A);

>    va_end (arg);

>  

> -  _IO_release_lock (stream);

>    return done;

>  }

> diff --git a/wcsmbs/isoc99_swscanf.c b/wcsmbs/isoc99_swscanf.c

> index 40401d0aa1..f90e56d97f 100644

> --- a/wcsmbs/isoc99_swscanf.c

> +++ b/wcsmbs/isoc99_swscanf.c

> @@ -28,10 +28,9 @@ __isoc99_swscanf (const wchar_t *s, const wchar_t *format, ...)

>    _IO_strfile sf;

>    struct _IO_wide_data wd;

>    FILE *f = _IO_strfile_readw (&sf, &wd, s);

> -  f->_flags2 |= _IO_FLAGS2_SCANF_STD;

>  

>    va_start (arg, format);

> -  done = __vfwscanf_internal (f, format, arg, 0);

> +  done = __vfwscanf_internal (f, format, arg, SCANF_ISOC99_A);

>    va_end (arg);

>  

>    return done;

> diff --git a/wcsmbs/isoc99_vfwscanf.c b/wcsmbs/isoc99_vfwscanf.c

> index f70c6b596d..715d354b5a 100644

> --- a/wcsmbs/isoc99_vfwscanf.c

> +++ b/wcsmbs/isoc99_vfwscanf.c

> @@ -20,16 +20,9 @@

>  #include <wchar.h>

>  

>  /* Read formatted input from STREAM according to the format string FORMAT.  */

> -/* VARARGS2 */

>  int

>  __isoc99_vfwscanf (FILE *stream, const wchar_t *format, va_list args)

>  {

> -  int done;

> -

> -  _IO_acquire_lock_clear_flags2 (stream);

> -  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -  done = __vfwscanf_internal (stream, format, args, 0);

> -  _IO_release_lock (stream);

> -  return done;

> +  return __vfwscanf_internal (stream, format, args, SCANF_ISOC99_A);

>  }

>  libc_hidden_def (__isoc99_vfwscanf)

> diff --git a/wcsmbs/isoc99_vswscanf.c b/wcsmbs/isoc99_vswscanf.c

> index b91eb651a3..0d8ef7611a 100644

> --- a/wcsmbs/isoc99_vswscanf.c

> +++ b/wcsmbs/isoc99_vswscanf.c

> @@ -33,7 +33,6 @@ __isoc99_vswscanf (const wchar_t *string, const wchar_t *format, va_list args)

>    _IO_strfile sf;

>    struct _IO_wide_data wd;

>    FILE *f = _IO_strfile_readw (&sf, &wd, string);

> -  f->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -  return __vfwscanf_internal (f, format, args, 0);

> +  return __vfwscanf_internal (f, format, args, SCANF_ISOC99_A);

>  }

>  libc_hidden_def (__isoc99_vswscanf)

> diff --git a/wcsmbs/isoc99_vwscanf.c b/wcsmbs/isoc99_vwscanf.c

> index eb22c8acae..3ac3182608 100644

> --- a/wcsmbs/isoc99_vwscanf.c

> +++ b/wcsmbs/isoc99_vwscanf.c

> @@ -20,15 +20,8 @@

>  #include <wchar.h>

>  

>  /* Read formatted input from STDIN according to the format string FORMAT.  */

> -/* VARARGS2 */

>  int

>  __isoc99_vwscanf (const wchar_t *format, va_list args)

>  {

> -  int done;

> -

> -  _IO_acquire_lock_clear_flags2 (stdin);

> -  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -  done = __vfwscanf_internal (stdin, format, args, 0);

> -  _IO_release_lock (stdin);

> -  return done;

> +  return __vfwscanf_internal (stdin, format, args, SCANF_ISOC99_A);

>  }

> diff --git a/wcsmbs/isoc99_wscanf.c b/wcsmbs/isoc99_wscanf.c

> index 59f80d78fb..b9418f7912 100644

> --- a/wcsmbs/isoc99_wscanf.c

> +++ b/wcsmbs/isoc99_wscanf.c

> @@ -22,20 +22,15 @@

>  

>  

>  /* Read formatted input from stdin according to the format string FORMAT.  */

> -/* VARARGS1 */

>  int

>  __isoc99_wscanf (const wchar_t *format, ...)

>  {

>    va_list arg;

>    int done;

>  

> -  _IO_acquire_lock_clear_flags2 (stdin);

> -  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;

> -

>    va_start (arg, format);

> -  done = __vfwscanf_internal (stdin, format, arg, 0);

> +  done = __vfwscanf_internal (stdin, format, arg, SCANF_ISOC99_A);

>    va_end (arg);

>  

> -  _IO_release_lock (stdin);

>    return done;

>  }

>

Patch

diff --git a/libio/libio.h b/libio/libio.h
index d4eba2df54..30cb7d784f 100644
--- a/libio/libio.h
+++ b/libio/libio.h
@@ -92,7 +92,6 @@  typedef union
 #define _IO_FLAGS2_NOTCANCEL 2
 #define _IO_FLAGS2_FORTIFY 4
 #define _IO_FLAGS2_USER_WBUF 8
-#define _IO_FLAGS2_SCANF_STD 16
 #define _IO_FLAGS2_NOCLOSE 32
 #define _IO_FLAGS2_CLOEXEC 64
 #define _IO_FLAGS2_NEED_LOCK 128
diff --git a/libio/libioP.h b/libio/libioP.h
index 525dce19ee..9e971cb96b 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -786,7 +786,7 @@  __attribute__ ((__always_inline__))
 _IO_acquire_lock_clear_flags2_fct (FILE **p)
 {
   FILE *fp = *p;
-  fp->_flags2 &= ~(_IO_FLAGS2_FORTIFY | _IO_FLAGS2_SCANF_STD);
+  fp->_flags2 &= ~(_IO_FLAGS2_FORTIFY);
   if ((fp->_flags & _IO_USER_LOCK) == 0)
     _IO_funlockfile (fp);
 }
@@ -800,8 +800,7 @@  _IO_acquire_lock_clear_flags2_fct (FILE **p)
     FILE *_IO_acquire_lock_file = (_fp)
 # define _IO_release_lock(_fp)						      \
     if (_IO_acquire_lock_file != NULL)					      \
-      _IO_acquire_lock_file->_flags2 &= ~(_IO_FLAGS2_FORTIFY		      \
-                                          | _IO_FLAGS2_SCANF_STD);	      \
+      _IO_acquire_lock_file->_flags2 &= ~(_IO_FLAGS2_FORTIFY);		      \
   } while (0)
 #endif
 
diff --git a/stdio-common/isoc99_fscanf.c b/stdio-common/isoc99_fscanf.c
index 4210d11f2b..d7b5993f3e 100644
--- a/stdio-common/isoc99_fscanf.c
+++ b/stdio-common/isoc99_fscanf.c
@@ -20,20 +20,15 @@ 
 #include <stdio.h>
 
 /* Read formatted input from STREAM according to the format string FORMAT.  */
-/* VARARGS2 */
 int
 __isoc99_fscanf (FILE *stream, const char *format, ...)
 {
   va_list arg;
   int done;
 
-  _IO_acquire_lock_clear_flags2 (stream);
-  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;
-
   va_start (arg, format);
-  done = __vfscanf_internal (stream, format, arg, 0);
+  done = __vfscanf_internal (stream, format, arg, SCANF_ISOC99_A);
   va_end (arg);
 
-  _IO_release_lock (stream);
   return done;
 }
diff --git a/stdio-common/isoc99_scanf.c b/stdio-common/isoc99_scanf.c
index 64c873eed9..3998322ea1 100644
--- a/stdio-common/isoc99_scanf.c
+++ b/stdio-common/isoc99_scanf.c
@@ -19,26 +19,16 @@ 
 #include <stdio.h>
 #include <libioP.h>
 
-
 /* Read formatted input from stdin according to the format string FORMAT.  */
-/* VARARGS1 */
 int
 __isoc99_scanf (const char *format, ...)
 {
   va_list arg;
   int done;
 
-#ifdef _IO_MTSAFE_IO
-  _IO_acquire_lock_clear_flags2 (stdin);
-#endif
-  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;
-
   va_start (arg, format);
-  done = __vfscanf_internal (stdin, format, arg, 0);
+  done = __vfscanf_internal (stdin, format, arg, SCANF_ISOC99_A);
   va_end (arg);
 
-#ifdef _IO_MTSAFE_IO
-  _IO_release_lock (stdin);
-#endif
   return done;
 }
diff --git a/stdio-common/isoc99_sscanf.c b/stdio-common/isoc99_sscanf.c
index 2c89a03fe9..c9e5103b81 100644
--- a/stdio-common/isoc99_sscanf.c
+++ b/stdio-common/isoc99_sscanf.c
@@ -26,10 +26,9 @@  __isoc99_sscanf (const char *s, const char *format, ...)
   int done;
   _IO_strfile sf;
   FILE *f = _IO_strfile_read (&sf, s);
-  f->_flags2 |= _IO_FLAGS2_SCANF_STD;
 
   va_start (arg, format);
-  done = __vfscanf_internal (f, format, arg, 0);
+  done = __vfscanf_internal (f, format, arg, SCANF_ISOC99_A);
   va_end (arg);
 
   return done;
diff --git a/stdio-common/isoc99_vfscanf.c b/stdio-common/isoc99_vfscanf.c
index c96ca831ae..3c59c60b3e 100644
--- a/stdio-common/isoc99_vfscanf.c
+++ b/stdio-common/isoc99_vfscanf.c
@@ -19,16 +19,9 @@ 
 #include <stdio.h>
 
 /* Read formatted input from STREAM according to the format string FORMAT.  */
-/* VARARGS2 */
 int
 __isoc99_vfscanf (FILE *stream, const char *format, va_list args)
 {
-  int done;
-
-  _IO_acquire_lock_clear_flags2 (stream);
-  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;
-  done = __vfscanf_internal (stream, format, args, 0);
-  _IO_release_lock (stream);
-  return done;
+  return __vfscanf_internal (stream, format, args, SCANF_ISOC99_A);
 }
 libc_hidden_def (__isoc99_vfscanf)
diff --git a/stdio-common/isoc99_vscanf.c b/stdio-common/isoc99_vscanf.c
index 72ae72ddee..fc5d609ae7 100644
--- a/stdio-common/isoc99_vscanf.c
+++ b/stdio-common/isoc99_vscanf.c
@@ -19,15 +19,8 @@ 
 #include <stdio.h>
 
 /* Read formatted input from STDIN according to the format string FORMAT.  */
-/* VARARGS2 */
 int
 __isoc99_vscanf (const char *format, va_list args)
 {
-  int done;
-
-  _IO_acquire_lock_clear_flags2 (stdin);
-  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;
-  done = __vfscanf_internal (stdin, format, args, 0);
-  _IO_release_lock (stdin);
-  return done;
+  return __vfscanf_internal (stdin, format, args, SCANF_ISOC99_A);
 }
diff --git a/stdio-common/isoc99_vsscanf.c b/stdio-common/isoc99_vsscanf.c
index 02bc0f50e6..dfc394bb51 100644
--- a/stdio-common/isoc99_vsscanf.c
+++ b/stdio-common/isoc99_vsscanf.c
@@ -31,7 +31,6 @@  __isoc99_vsscanf (const char *string, const char *format, va_list args)
 {
   _IO_strfile sf;
   FILE *f = _IO_strfile_read (&sf, string);
-  f->_flags2 |= _IO_FLAGS2_SCANF_STD;
-  return __vfscanf_internal (f, format, args, 0);
+  return __vfscanf_internal (f, format, args, SCANF_ISOC99_A);
 }
 libc_hidden_def (__isoc99_vsscanf)
diff --git a/stdio-common/vfscanf-internal.c b/stdio-common/vfscanf-internal.c
index 13a7a300b7..f0072d8682 100644
--- a/stdio-common/vfscanf-internal.c
+++ b/stdio-common/vfscanf-internal.c
@@ -335,8 +335,6 @@  __vfscanf_internal (FILE *s, const char *format, va_list argptr,
   /* Temporarily honor the environmental mode bits.  */
   if (__ldbl_is_dbl)
     mode_flags |= SCANF_LDBL_IS_DBL;
-  if (s->_flags2 & _IO_FLAGS2_SCANF_STD)
-    mode_flags |= SCANF_ISOC99_A;
 
 #ifdef __va_copy
   __va_copy (arg, argptr);
diff --git a/wcsmbs/isoc99_fwscanf.c b/wcsmbs/isoc99_fwscanf.c
index 00b07dd48e..5829607916 100644
--- a/wcsmbs/isoc99_fwscanf.c
+++ b/wcsmbs/isoc99_fwscanf.c
@@ -21,20 +21,15 @@ 
 #include <wchar.h>
 
 /* Read formatted input from STREAM according to the format string FORMAT.  */
-/* VARARGS2 */
 int
 __isoc99_fwscanf (FILE *stream, const wchar_t *format, ...)
 {
   va_list arg;
   int done;
 
-  _IO_acquire_lock_clear_flags2 (stream);
-  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;
-
   va_start (arg, format);
-  done = __vfwscanf_internal (stream, format, arg, 0);
+  done = __vfwscanf_internal (stream, format, arg, SCANF_ISOC99_A);
   va_end (arg);
 
-  _IO_release_lock (stream);
   return done;
 }
diff --git a/wcsmbs/isoc99_swscanf.c b/wcsmbs/isoc99_swscanf.c
index 40401d0aa1..f90e56d97f 100644
--- a/wcsmbs/isoc99_swscanf.c
+++ b/wcsmbs/isoc99_swscanf.c
@@ -28,10 +28,9 @@  __isoc99_swscanf (const wchar_t *s, const wchar_t *format, ...)
   _IO_strfile sf;
   struct _IO_wide_data wd;
   FILE *f = _IO_strfile_readw (&sf, &wd, s);
-  f->_flags2 |= _IO_FLAGS2_SCANF_STD;
 
   va_start (arg, format);
-  done = __vfwscanf_internal (f, format, arg, 0);
+  done = __vfwscanf_internal (f, format, arg, SCANF_ISOC99_A);
   va_end (arg);
 
   return done;
diff --git a/wcsmbs/isoc99_vfwscanf.c b/wcsmbs/isoc99_vfwscanf.c
index f70c6b596d..715d354b5a 100644
--- a/wcsmbs/isoc99_vfwscanf.c
+++ b/wcsmbs/isoc99_vfwscanf.c
@@ -20,16 +20,9 @@ 
 #include <wchar.h>
 
 /* Read formatted input from STREAM according to the format string FORMAT.  */
-/* VARARGS2 */
 int
 __isoc99_vfwscanf (FILE *stream, const wchar_t *format, va_list args)
 {
-  int done;
-
-  _IO_acquire_lock_clear_flags2 (stream);
-  stream->_flags2 |= _IO_FLAGS2_SCANF_STD;
-  done = __vfwscanf_internal (stream, format, args, 0);
-  _IO_release_lock (stream);
-  return done;
+  return __vfwscanf_internal (stream, format, args, SCANF_ISOC99_A);
 }
 libc_hidden_def (__isoc99_vfwscanf)
diff --git a/wcsmbs/isoc99_vswscanf.c b/wcsmbs/isoc99_vswscanf.c
index b91eb651a3..0d8ef7611a 100644
--- a/wcsmbs/isoc99_vswscanf.c
+++ b/wcsmbs/isoc99_vswscanf.c
@@ -33,7 +33,6 @@  __isoc99_vswscanf (const wchar_t *string, const wchar_t *format, va_list args)
   _IO_strfile sf;
   struct _IO_wide_data wd;
   FILE *f = _IO_strfile_readw (&sf, &wd, string);
-  f->_flags2 |= _IO_FLAGS2_SCANF_STD;
-  return __vfwscanf_internal (f, format, args, 0);
+  return __vfwscanf_internal (f, format, args, SCANF_ISOC99_A);
 }
 libc_hidden_def (__isoc99_vswscanf)
diff --git a/wcsmbs/isoc99_vwscanf.c b/wcsmbs/isoc99_vwscanf.c
index eb22c8acae..3ac3182608 100644
--- a/wcsmbs/isoc99_vwscanf.c
+++ b/wcsmbs/isoc99_vwscanf.c
@@ -20,15 +20,8 @@ 
 #include <wchar.h>
 
 /* Read formatted input from STDIN according to the format string FORMAT.  */
-/* VARARGS2 */
 int
 __isoc99_vwscanf (const wchar_t *format, va_list args)
 {
-  int done;
-
-  _IO_acquire_lock_clear_flags2 (stdin);
-  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;
-  done = __vfwscanf_internal (stdin, format, args, 0);
-  _IO_release_lock (stdin);
-  return done;
+  return __vfwscanf_internal (stdin, format, args, SCANF_ISOC99_A);
 }
diff --git a/wcsmbs/isoc99_wscanf.c b/wcsmbs/isoc99_wscanf.c
index 59f80d78fb..b9418f7912 100644
--- a/wcsmbs/isoc99_wscanf.c
+++ b/wcsmbs/isoc99_wscanf.c
@@ -22,20 +22,15 @@ 
 
 
 /* Read formatted input from stdin according to the format string FORMAT.  */
-/* VARARGS1 */
 int
 __isoc99_wscanf (const wchar_t *format, ...)
 {
   va_list arg;
   int done;
 
-  _IO_acquire_lock_clear_flags2 (stdin);
-  stdin->_flags2 |= _IO_FLAGS2_SCANF_STD;
-
   va_start (arg, format);
-  done = __vfwscanf_internal (stdin, format, arg, 0);
+  done = __vfwscanf_internal (stdin, format, arg, SCANF_ISOC99_A);
   va_end (arg);
 
-  _IO_release_lock (stdin);
   return done;
 }