drivers/syslog: syslog internal functions should not set the errno variable: ...

drivers/syslog:  syslog internal functions should not set the errno variable:  ramlog_putc(), syslog_dev_putc(), syslog_dev_write(), syslog_force().

drivers/syslog/ramlog.c

 /****************************************************************************
  * drivers/syslog/ramlog.c
  *
- *   Copyright (C) 2012, 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2012, 2016-2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -802,7 +802,7 @@ int ramlog_putc(int ch)
         {
           /* The buffer is full and nothing was saved. */
 
-          goto errout;
+          return ret;
         }
     }
 #endif
@@ -810,20 +810,16 @@ int ramlog_putc(int ch)
   /* Add the character to the RAMLOG */
 
   ret = ramlog_addchar(priv, ch);
-  if (ret >= 0)
+  if (ret < 0)
     {
-      /* Return the character added on success */
+      /* ramlog_addchar() failed */
 
-      return ch;
+      return ret;
     }
 
-  /* On a failure, we need to return EOF and set the errno so that
-   * work like all other putc-like functions.
-   */
+  /* Return the character added on success */
 
-errout:
-  set_errno(-ret);
-  return EOF;
+  return ch;
 }
 #endif
 

drivers/syslog/syslog.h

 /****************************************************************************
  * drivers/syslog/syslog.h
  *
- *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2016-2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -303,8 +303,8 @@ ssize_t syslog_default_write(FAR const char *buffer, size_t buflen);
  *   ch - The character to add to the SYSLOG (must be positive).
  *
  * Returned Value:
- *   On success, the character is echoed back to the caller.  A negated
- *   errno value is returned on any failure.
+ *   On success, the character is echoed back to the caller. A negated errno
+ *   value is returned on any failure.
  *
  ****************************************************************************/
 
@@ -322,8 +322,8 @@ int syslog_force(int ch);
  *   buflen - The number of bytes in the buffer
  *
  * Returned Value:
- *   On success, the character is echoed back to the caller.  Minus one
- *   is returned on any failure with the errno set correctly.
+ *   On success, the character is echoed back to the caller. A negated errno
+ *   value is returned on any failure.
  *
  ****************************************************************************/
 

drivers/syslog/syslog_device.c

@@ -474,8 +474,8 @@ int syslog_dev_uninitialize(void)
  *   buflen - The number of bytes in the buffer
  *
  * Returned Value:
- *   On success, the character is echoed back to the caller.  Minus one
- *   is returned on any failure with the errno set correctly.
+ *   On success, the character is echoed back to the caller. A negated errno
+ *   value is returned on any failure.
  *
  ****************************************************************************/
 
@@ -485,7 +485,6 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
   ssize_t nwritten;
   size_t writelen;
   size_t remaining;
-  int errcode;
   int ret;
 
   /* Check if the system is ready to do output operations */
@@ -493,8 +492,7 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
   ret = syslog_dev_outputready();
   if (ret < 0)
     {
-      errcode = -ret;
-      goto errout_with_errcode;
+      return ret;
     }
 
   /* The syslog device is ready for writing */
@@ -508,8 +506,7 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
        * way, we are outta here.
        */
 
-      errcode = -ret;
-      goto errout_with_errcode;
+      return ret;
     }
 
   /* Loop until we have output all characters */
@@ -548,7 +545,7 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
                   nwritten = file_write(&g_syslog_dev.sl_file, buffer, writelen);
                   if (nwritten < 0)
                     {
-                      errcode = -nwritten;
+                      ret = (int)nwritten;
                       goto errout_with_sem;
                     }
                 }
@@ -562,7 +559,7 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
                   nwritten = file_write(&g_syslog_dev.sl_file, g_syscrlf, 2);
                   if (nwritten < 0)
                     {
-                      errcode = -nwritten;
+                      ret = (int)nwritten;
                       goto errout_with_sem;
                     }
                 }
@@ -587,7 +584,7 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
       nwritten = file_write(&g_syslog_dev.sl_file, buffer, writelen);
       if (nwritten < 0)
         {
-          errcode = -nwritten;
+          ret = (int)nwritten;
           goto errout_with_sem;
         }
     }
@@ -597,9 +594,7 @@ ssize_t syslog_dev_write(FAR const char *buffer, size_t buflen)
 
 errout_with_sem:
   syslog_dev_givesem();
-errout_with_errcode:
-  set_errno(errcode);
-  return -1;
+  return ret;
 }
 
 /****************************************************************************
@@ -622,7 +617,6 @@ int syslog_dev_putc(int ch)
 {
   ssize_t nbytes;
   uint8_t uch;
-  int errcode;
   int ret;
 
   /* Check if the system is ready to do output operations */
@@ -630,8 +624,7 @@ int syslog_dev_putc(int ch)
   ret = syslog_dev_outputready();
   if (ret < 0)
     {
-      errcode = -ret;
-      goto errout_with_errcode;
+      return ret;
     }
 
   /* Ignore carriage returns */
@@ -654,8 +647,7 @@ int syslog_dev_putc(int ch)
        * way, we are outta here.
        */
 
-      errcode = -ret;
-      goto errout_with_errcode;
+      return ret;
     }
 
   /* Pre-pend a newline with a carriage return. */
@@ -693,15 +685,10 @@ int syslog_dev_putc(int ch)
 
   if (nbytes < 0)
     {
-      errcode = -ret;
-      goto errout_with_errcode;
+      return (int)nbytes;
     }
 
   return ch;
-
-errout_with_errcode:
-  set_errno(errcode);
-  return EOF;
 }
 
 /****************************************************************************

drivers/syslog/syslog_force.c

 /****************************************************************************
  * drivers/syslog/syslog_force.c
  *
- *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2016-2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -63,8 +63,8 @@
  *   ch - The character to add to the SYSLOG (must be positive).
  *
  * Returned Value:
- *   On success, the character is echoed back to the caller.  A negated
- *   errno value is returned on any failure.
+ *   On success, the character is echoed back to the caller. A negated errno
+ *   value is returned on any failure.
  *
  ****************************************************************************/