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, 42 insertions, 4 deletions

diff --git a/newlib/libc/stdio/fputs.c b/newlib/libc/stdio/fputs.c
index 7c1888f..75f65d9 100644
--- a/newlib/libc/stdio/fputs.c
+++ b/newlib/libc/stdio/fputs.c
@@ -17,38 +17,70 @@
 
 /*
 FUNCTION
-<<fputs>>---write a character string in a file or stream
+<<fputs>>, <<fputs_unlocked>>---write a character string in a file or stream
 
 INDEX
 	fputs
 INDEX
+	fputs_unlocked
+INDEX
 	_fputs_r
+INDEX
+	_fputs_unlocked_r
 
 ANSI_SYNOPSIS
 	#include <stdio.h>
 	int fputs(const char *restrict <[s]>, FILE *restrict <[fp]>);
 
+	#define _GNU_SOURCE
+	#include <stdio.h>
+	int fputs_unlocked(const char *restrict <[s]>, FILE *restrict <[fp]>);
+
 	#include <stdio.h>
 	int _fputs_r(struct _reent *<[ptr]>, const char *restrict <[s]>, FILE *restrict <[fp]>);
 
+	#include <stdio.h>
+	int _fputs_unlocked_r(struct _reent *<[ptr]>, const char *restrict <[s]>, FILE *restrict <[fp]>);
+
 TRAD_SYNOPSIS
 	#include <stdio.h>
 	int fputs(<[s]>, <[fp]>)
 	char *<[s]>;
 	FILE *<[fp]>;
 
+	#define _GNU_SOURCE
+	#include <stdio.h>
+	int fputs_unlocked(<[s]>, <[fp]>)
+	char *<[s]>;
+	FILE *<[fp]>;
+
 	#include <stdio.h>
 	int _fputs_r(<[ptr]>, <[s]>, <[fp]>)
 	struct _reent *<[ptr]>;
 	char *<[s]>;
 	FILE *<[fp]>;
 
+	#include <stdio.h>
+	int _fputs_unlocked_r(<[ptr]>, <[s]>, <[fp]>)
+	struct _reent *<[ptr]>;
+	char *<[s]>;
+	FILE *<[fp]>;
+
 DESCRIPTION
 <<fputs>> writes the string at <[s]> (but without the trailing null)
 to the file or stream identified by <[fp]>.
 
-<<_fputs_r>> is simply the reentrant version of <<fputs>> that takes
-an additional reentrant struct pointer argument: <[ptr]>.
+<<fputs_unlocked>> is a non-thread-safe version of <<fputs>>.
+<<fputs_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
+<<fputs_unlocked>> is equivalent to <<fputs>>.
+
+<<_fputs_r>> and <<_fputs_unlocked_r>> are simply reentrant versions of the
+above that take an additional reentrant struct pointer argument: <[ptr]>.
 
 RETURNS
 If successful, the result is <<0>>; otherwise, the result is <<EOF>>.
@@ -57,6 +89,8 @@ PORTABILITY
 ANSI C requires <<fputs>>, but does not specify that the result on
 success must be <<0>>; any non-negative value is permitted.
 
+<<fputs_unlocked>> is a GNU extension.
+
 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
 */
@@ -67,10 +101,14 @@ Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
 #include "fvwrite.h"
 #include "local.h"
 
+#ifdef __IMPL_UNLOCKED__
+#define _fputs_r _fputs_unlocked_r
+#define fputs fputs_unlocked
+#endif
+
 /*
  * Write the given string to the given file.
  */
-
 int
 _DEFUN(_fputs_r, (ptr, s, fp),
        struct _reent * ptr _AND