posix.cfg: Added support for ttyname_r().

cfg/posix.cfg

@@ -3477,6 +3477,27 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <warn severity="portability">Non reentrant function 'ttyname' called. For threadsafe applications it is recommended to use the reentrant replacement function 'ttyname_r'.</warn>
   </function>
+  <!-- int ttyname_r(int fd, char *buf, size_t buflen); -->
+  <function name="ttyname">
+    <use-retval/>
+    <returnValue type="int"/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="1" direction="in">
+      <valid>0:</valid>
+      <not-uninit/>
+      <not-bool/>
+    </arg>
+    <arg nr="2" direction="inout">
+      <not-null/>
+      <not-uninit/>
+      <minsize type="argvalue" arg="3"/>
+    </arg>
+    <arg nr="3" direction="in">
+      <not-uninit/>
+      <valid>0:</valid>
+    </arg>
+  </function>
   <!-- struct spwd *getspnam(const char *name); -->
   <function name="getspnam">
     <use-retval/>