From c4e7831db10382862dff0afd337178cf8199d561 Mon Sep 17 00:00:00 2001
From: AFellmett <17900799+AFellmett@users.noreply.github.com>
Date: Fri, 25 May 2018 23:24:52 +0200
Subject: [PATCH] fix(newlib): Fixed invalid function descriptions

Merges https://github.com/espressif/ESP8266_RTOS_SDK/pull/196
---
 components/newlib/newlib/port/syscall.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/components/newlib/newlib/port/syscall.c b/components/newlib/newlib/port/syscall.c
index f88d39f7..cf949856 100644
--- a/components/newlib/newlib/port/syscall.c
+++ b/components/newlib/newlib/port/syscall.c
@@ -40,12 +40,12 @@ int _open_r(struct _reent *r, const char *filename, int flags, int mode)
     return 0;
 }
 
-int _read_r(struct _reent *r, int fd, void *buf, int len)
+_ssize_t _read_r(struct _reent *r, int fd, void *buf, size_t len)
 {
     return 0;
 }
 
-int _write_r(struct _reent *r, int fd, void *buf, int len)
+_ssize_t _write_r(struct _reent *r, int fd, void *buf, size_t len)
 {
     int i;
     const char *cbuf = buf;
@@ -83,9 +83,9 @@ int _fstat_r(struct _reent *r, int fd, struct stat *s)
     return 0;
 }
 
-void _sbrk_r(void *ptr, int incr)
+void *_sbrk_r(struct _reent *r, ptrdiff_t incr)
 {
-    return ;
+    return NULL;
 }
 
 void *_malloc_r(struct _reent *r, size_t n)