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, 37 insertions, 4 deletions

diff --git a/newlib/libc/stdio/putwchar.c b/newlib/libc/stdio/putwchar.c
index fcb0a7dba..cdd254217 100644
--- a/newlib/libc/stdio/putwchar.c
+++ b/newlib/libc/stdio/putwchar.c
@@ -26,34 +26,65 @@
 
 /*
 FUNCTION
-<<putwchar>>---write a wide character to standard output
+<<putwchar>>, <<putwchar_unlocked>>---write a wide character to standard output
 
 INDEX
 	putwchar
 INDEX
+	putwchar_unlocked
+INDEX
 	_putwchar_r
+INDEX
+	_putwchar_unlocked_r
 
 ANSI_SYNOPSIS
 	#include <wchar.h>
 	wint_t putwchar(wchar_t <[wc]>);
 
+	#include <wchar.h>
+	wint_t putwchar_unlocked(wchar_t <[wc]>);
+
+	#include <wchar.h>
 	wint_t _putwchar_r(struct _reent *<[reent]>, wchar_t <[wc]>);
 
+	#include <wchar.h>
+	wint_t _putwchar_unlocked_r(struct _reent *<[reent]>, wchar_t <[wc]>);
+
 TRAD_SYNOPSIS
 	#include <wchar.h>
 	wint_t putwchar(<[wc]>)
 	wchar_t <[wc]>;
 
+	#include <wchar.h>
+	wint_t putwchar_unlocked(<[wc]>)
+	wchar_t <[wc]>;
+
+	#include <wchar.h>
 	wint_t _putwchar_r(<[reent]>, <[wc]>)
 	struct _reent *<[reent]>;
 	wchar_t <[wc]>;
 
+	#include <wchar.h>
+	wint_t _putwchar_unlocked_r(<[reent]>, <[wc]>)
+	struct _reent *<[reent]>;
+	wchar_t <[wc]>;
+
 DESCRIPTION
 The <<putwchar>> function or macro is the wide-character equivalent of
 the <<putchar>> function. It writes the wide character wc to stdout.
 
-The alternate function <<_putwchar_r>> is a reentrant version.  The
-extra argument <[reent]> is a pointer to a reentrancy structure.
+<<putwchar_unlocked>> is a non-thread-safe version of <<putwchar>>.
+<<putwchar_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
+<<putwchar_unlocked>> is equivalent to <<putwchar>>.
+
+The alternate functions <<_putwchar_r>> and <<_putwchar_unlocked_r>> are
+reentrant versions of the above.  The extra argument <[reent]> is a pointer
+to a reentrancy structure.
 
 RETURNS
 If successful, <<putwchar>> returns its argument <[wc]>.  If an error
@@ -61,7 +92,9 @@ intervenes, the result is <<EOF>>.  You can use `<<ferror(stdin)>>' to
 query for errors.
 
 PORTABILITY
-C99
+<<putwchar>> is required by C99.
+
+<<putwchar_unlocked>> is a GNU extension.
 */
 
 #include <_ansi.h>