Implement BSD/GNU unlocked stdio extensions.

* libc/include/stdio.h (clearerr_unlocked, feof_unlocked,
ferror_unlocked, fflush_unlocked, fgetc_unlocked, fgets_unlocked,
fileno_unlocked, fputc_unlocked, fputs_unlocked, fread_unlocked,
fwrite_unlocked): Declare.
* libc/include/wchar.h (fgetwc_unlocked, fgetws_unlocked,
fputwc_unlocked, fputws_unlocked, getwc_unlocked, getwchar_unlocked,
putwc_unlocked, putwchar_unlocked): Declare.
* libc/stdio/Makefile.am (ELIX_4_SOURCES): Add clearerr_u.c,
feof_u.c, ferror_u.c, fflush_u.c, fgetc_u.c, fgets_u.c, fgetwc_u.c,
fgetws_u.c, fileno_u.c, fputc_u.c, fputs_u.c, fputwc_u.c, fputws_u.c,
fread_u.c, fwrite_u.c, getwc_u.c, getwchar_u.c, putwc_u.c, putwchar_u.c.
Add necessary dependencies.
* libc/stdio/Makefile.in: Regenerate.
* libc/stdio/clearerr.c: Document unlocked variant.
* libc/stdio/clearerr_u.c: New file.
* libc/stdio/feof.c: Document unlocked variant.
* libc/stdio/feof_u.c: New file.
* libc/stdio/ferror.c: Document unlocked variant.
* libc/stdio/ferror_u.c: New file.
* libc/stdio/fflush.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fflush_u.c: New file.
* libc/stdio/fgetc.c: Document unlocked variants.
* libc/stdio/fgetc_u.c: New file.
* libc/stdio/fgets.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fgets_u.c: New file.
* libc/stdio/fgetwc.c: Document unlocked variants.
(__fgetwc): Make non-static.
* libc/stdio/fgetwc_u.c: New file.
* libc/stdio/fgetws.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fgetws_u.c: New file.
* libc/stdio/fileno.c: Document unlocked variant.
* libc/stdio/fileno_u.c: New file.
* libc/stdio/fputc.c: Document unlocked variants.
* libc/stdio/fputc_u.c: New file.
* libc/stdio/fputs.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fputs_u.c: New file.
* libc/stdio/fputwc.c: Document unlocked variants.
(__fputwc): Make non-static.
* libc/stdio/fputwc_u.c: New file.
* libc/stdio/fputws.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fputws_u.c: New file.
* libc/stdio/fread.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fread_u.c: New file.
* libc/stdio/fwrite.c: Add __IMPL_UNLOCKED__ overrides.
Document unlocked variants.
* libc/stdio/fwrite_u.c: New file.
* libc/stdio/getwc_u.c: New file.
* libc/stdio/getwchar.c: Document unlocked variants.
* libc/stdio/getwchar_u.c: New file.
* libc/stdio/local.h: Define locking macros as empty ifdef
__IMPL_UNLOCKED__.
(__fgetwc, __fputwc): Declare.
* libc/stdio/putwc_u.c: New file.
* libc/stdio/putwchar.c: Document unlocked variants.
* libc/stdio/putwchar_u.c: New file.

1 files changed, 70 insertions, 9 deletions

diff --git a/newlib/libc/stdio/fgetwc.c b/newlib/libc/stdio/fgetwc.c
index 14c554786..e89404be8 100644
--- a/newlib/libc/stdio/fgetwc.c
+++ b/newlib/libc/stdio/fgetwc.c
@@ -26,40 +26,72 @@
 
 /*
 FUNCTION
-<<fgetwc>>, <<getwc>>---get a wide character from a file or stream
+<<fgetwc>>, <<getwc>>, <<fgetwc_unlocked>>, <<getwc_unlocked>>---get a wide character from a file or stream
 
 INDEX
 	fgetwc
 INDEX
+	fgetwc_unlocked
+INDEX
 	_fgetwc_r
 INDEX
+	_fgetwc_unlocked_r
+INDEX
 	getwc
 INDEX
+	getwc_unlocked
+INDEX
 	_getwc_r
+INDEX
+	_getwc_unlocked_r
 
 ANSI_SYNOPSIS
 	#include <stdio.h>
 	#include <wchar.h>
 	wint_t fgetwc(FILE *<[fp]>);
 
+	#define _GNU_SOURCE
+	#include <stdio.h>
+	#include <wchar.h>
+	wint_t fgetwc_unlocked(FILE *<[fp]>);
+
 	#include <stdio.h>
 	#include <wchar.h>
 	wint_t _fgetwc_r(struct _reent *<[ptr]>, FILE *<[fp]>);
 
 	#include <stdio.h>
 	#include <wchar.h>
+	wint_t _fgetwc_unlocked_r(struct _reent *<[ptr]>, FILE *<[fp]>);
+
+	#include <stdio.h>
+	#include <wchar.h>
 	wint_t getwc(FILE *<[fp]>);
 
+	#define _GNU_SOURCE
+	#include <stdio.h>
+	#include <wchar.h>
+	wint_t getwc_unlocked(FILE *<[fp]>);
+
 	#include <stdio.h>
 	#include <wchar.h>
 	wint_t _getwc_r(struct _reent *<[ptr]>, FILE *<[fp]>);
 
+	#include <stdio.h>
+	#include <wchar.h>
+	wint_t _getwc_unlocked_r(struct _reent *<[ptr]>, FILE *<[fp]>);
+
 TRAD_SYNOPSIS
 	#include <stdio.h>
 	#include <wchar.h>
 	wint_t fgetwc(<[fp]>)
 	FILE *<[fp]>;
 
+	#define _GNU_SOURCE
+	#include <stdio.h>
+	#include <wchar.h>
+	wint_t fgetwc_unlocked(<[fp]>)
+	FILE *<[fp]>;
+
 	#include <stdio.h>
 	#include <wchar.h>
 	wint_t _fgetwc_r(<[ptr]>, <[fp]>)
@@ -68,27 +100,54 @@ TRAD_SYNOPSIS
 
 	#include <stdio.h>
 	#include <wchar.h>
+	wint_t _fgetwc_unlocked_r(<[ptr]>, <[fp]>)
+	struct _reent *<[ptr]>;
+	FILE *<[fp]>;
+
+	#include <stdio.h>
+	#include <wchar.h>
 	wint_t getwc(<[fp]>)
 	FILE *<[fp]>;
 
+	#define _GNU_SOURCE
+	#include <stdio.h>
+	#include <wchar.h>
+	wint_t getwc_unlocked(<[fp]>)
+	FILE *<[fp]>;
+
 	#include <stdio.h>
 	#include <wchar.h>
 	wint_t _getwc_r(<[ptr]>, <[fp]>)
 	struct _reent *<[ptr]>;
 	FILE *<[fp]>;
 
+	#include <stdio.h>
+	#include <wchar.h>
+	wint_t _getwc_unlocked_r(<[ptr]>, <[fp]>)
+	struct _reent *<[ptr]>;
+	FILE *<[fp]>;
+
 DESCRIPTION
 Use <<fgetwc>> to get the next wide character from the file or stream
 identified by <[fp]>.  As a side effect, <<fgetwc>> advances the file's
 current position indicator.
 
-The  <<getwc>>  function  or macro functions identically to <<fgetwc>>.  It
-may be implemented as a macro, and may evaluate its argument more  than
-once. There is no reason ever to use it.
+<<fgetwc_unlocked>> is a non-thread-safe version of <<fgetwc>>.
+<<fgetwc_unlocked>> may only safely be used within a scope
+protected by flockfile() (or ftrylockfile()) and funlockfile().  This
+function may safely be used in a multi-threaded program if and only
+if they are called while the invoking thread owns the (FILE *)
+object, as is the case after a successful call to the flockfile() or
+ftrylockfile() functions.  If threads are disabled, then
+<<fgetwc_unlocked>> is equivalent to <<fgetwc>>.
+
+The <<getwc>> and <<getwc_unlocked>> functions or macros functions identically
+to <<fgetwc>> and <<fgetwc_unlocked>>.  It may be implemented as a macro, and
+may evaluate its argument more than once. There is no reason ever to use it.
 
-<<_fgetwc_r>> and <<_getwc_r>> are simply reentrant versions of
-<<fgetwc>> and <<getwc>> that are passed the additional reentrant
-structure pointer argument: <[ptr]>.
+<<_fgetwc_r>>, <<_getwc_r>>, <<_fgetwc_unlocked_r>>, and <<_getwc_unlocked_r>>
+are simply reentrant versions of the above functions that are passed the
+additional reentrant structure pointer argument: <[ptr]>.
 
 RETURNS
 The next wide character cast to <<wint_t>>), unless there is no more data,
@@ -99,7 +158,9 @@ You can distinguish the two situations that cause an <<EOF>> result by
 using the <<ferror>> and <<feof>> functions.
 
 PORTABILITY
-C99, POSIX.1-2001
+<<fgetwc>> and <<getwc>> are required by C99 and POSIX.1-2001.
+
+<<fgetwc_unlocked>> and <<getwc_unlocked>> are GNU extensions.
 */
 
 #include <_ansi.h>
@@ -110,7 +171,7 @@ C99, POSIX.1-2001
 #include <wchar.h>
 #include "local.h"
 
-static wint_t
+wint_t
 _DEFUN(__fgetwc, (ptr, fp),
 	struct _reent *ptr _AND
 	register FILE *fp)