Silence some false positive warnings for gcc 4.7

ChangeLog

@@ -1,3 +1,9 @@
+2016-01-20  Chris Metcalf  <cmetcalf@ezchip.com>
+
+	* nis/nis_table.c (__follow_path): Disable diagnostic for
+	uninitialized variable that is a false positive for gcc 4.7.
+	* stdio-common/vfscanf.c (_IO_vfwscanf): Likewise.
+
 2016-01-20  Roland McGrath  <roland@hack.frob.com>
 
 	* sysdeps/nacl/lowlevellock-futex.h

nis/nis_table.c

@@ -19,6 +19,7 @@
 #include <assert.h>
 #include <string.h>
 #include <rpcsvc/nis.h>
+#include <libc-internal.h>
 
 #include "nis_xdr.h"
 #include "nis_intern.h"
@@ -175,13 +176,21 @@ __follow_path (char **tablepath, char **tableptr, struct ib_request *ibreq,
 
       *tableptr = *tablepath;
     }
+
+  /* Since tableptr is only set here, and it's set when tablepath is NULL,
+     which it is initially defined as, we know it will always be set here.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
+
   if (*tableptr == NULL)
     return NIS_NOTFOUND;
 
   char *newname = strsep (tableptr, ":");
   if (newname[0] == '\0')
     return NIS_NOTFOUND;
 
+  DIAG_POP_NEEDS_COMMENT;
+
   newname = strdup (newname);
   if (newname == NULL)
     return NIS_NOMEMORY;

stdio-common/vfscanf.c

@@ -27,6 +27,7 @@
 #include <string.h>
 #include <wchar.h>
 #include <wctype.h>
+#include <libc-internal.h>
 #include <libc-lock.h>
 #include <locale/localeinfo.h>
 #include <scratch_buffer.h>
@@ -1535,13 +1536,22 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr,
 		    {
 		      /* Get the string for the digits with value N.  */
 #ifdef COMPILE_WSCANF
+
+		      /* wcdigits_extended[] is fully set in the loop
+			 above, but the test for "map != NULL" is done
+			 inside the loop here and outside the loop there.  */
+		      DIAG_PUSH_NEEDS_COMMENT;
+		      DIAG_IGNORE_NEEDS_COMMENT (4.7, "-Wmaybe-uninitialized");
+
 		      if (__glibc_unlikely (map != NULL))
 			wcdigits[n] = wcdigits_extended[n];
 		      else
 			wcdigits[n] = (const wchar_t *)
 			  _NL_CURRENT (LC_CTYPE, _NL_CTYPE_INDIGITS0_WC + n);
 		      wcdigits[n] += from_level;
 
+		      DIAG_POP_NEEDS_COMMENT;
+
 		      if (c == (wint_t) *wcdigits[n])
 			{
 			  to_level = from_level;