2 files changed, 13 insertions, 4 deletions
diff --git a/newlib/libc/include/sys/config.h b/newlib/libc/include/sys/config.h
index c726e14c9..0de3ffb88 100644
--- a/newlib/libc/include/sys/config.h
+++ b/newlib/libc/include/sys/config.h
@@ -250,6 +250,12 @@
 #ifndef _READ_WRITE_RETURN_TYPE
 #define _READ_WRITE_RETURN_TYPE int
 #endif
+/* Define `count' parameter of read/write routines.  In POSIX, the `count'
+   parameter is "size_t" but legacy newlib code has been using "int" for some
+   time.  If not specified, "int" is defaulted.  */
+#ifndef _READ_WRITE_BUFSIZE_TYPE
+#define _READ_WRITE_BUFSIZE_TYPE int
+#endif
 
 #ifndef __WCHAR_MAX__
 #if __INT_MAX__ == 32767 || defined (_WIN32)
diff --git a/newlib/libc/include/sys/reent.h b/newlib/libc/include/sys/reent.h
index c8ef6302f..ce5b3eda7 100644
--- a/newlib/libc/include/sys/reent.h
+++ b/newlib/libc/include/sys/reent.h
@@ -11,6 +11,7 @@ extern "C" {
 #define _SYS_REENT_H_
 
 #include <_ansi.h>
+#include <stddef.h>
 #include <sys/_types.h>
 
 #define _NULL 0
@@ -192,9 +193,10 @@ struct __sFILE {
   _PTR	_cookie;	/* cookie passed to io functions */
 
   _READ_WRITE_RETURN_TYPE _EXFNPTR(_read, (struct _reent *, _PTR,
-					   char *, int));
+					   char *, _READ_WRITE_BUFSIZE_TYPE));
   _READ_WRITE_RETURN_TYPE _EXFNPTR(_write, (struct _reent *, _PTR,
-					    const char *, int));
+					    const char *,
+					    _READ_WRITE_BUFSIZE_TYPE));
   _fpos_t _EXFNPTR(_seek, (struct _reent *, _PTR, _fpos_t, int));
   int _EXFNPTR(_close, (struct _reent *, _PTR));
 
@@ -247,9 +249,10 @@ struct __sFILE64 {
   _PTR	_cookie;	/* cookie passed to io functions */
 
   _READ_WRITE_RETURN_TYPE _EXFNPTR(_read, (struct _reent *, _PTR,
-					   char *, int));
+					   char *, _READ_WRITE_BUFSIZE_TYPE));
   _READ_WRITE_RETURN_TYPE _EXFNPTR(_write, (struct _reent *, _PTR,
-					    const char *, int));
+					    const char *,
+					    _READ_WRITE_BUFSIZE_TYPE));
   _fpos_t _EXFNPTR(_seek, (struct _reent *, _PTR, _fpos_t, int));
   int _EXFNPTR(_close, (struct _reent *, _PTR));