new warnings in mktime.c

[Jim Meyering]

With gcc-4.0 -O -Wall, I get these new warnings:

  mktime.c: In function 'ranged_convert':
  mktime.c:244: warning: 'tm.tm_zone' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_gmtoff' may be used uninitialized in this 
function
  mktime.c:244: warning: 'tm.tm_isdst' may be used uninitialized in this 
function
  mktime.c:244: warning: 'tm.tm_yday' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_wday' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_year' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_mon' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_mday' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_hour' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_min' may be used uninitialized in this function
  mktime.c:244: warning: 'tm.tm_sec' may be used uninitialized in this function
  make[1]: *** [mktime.o] Error 1

There is no real problem, but it's best to provide a way
to suppress such warnings.  So here's one approach,
but I'm hoping there's a better way...

2005-06-22  Jim Meyering  <address@hidden>

        * mktime.c (IF_LINT) [lint]: Define.
        (ranged_convert) [lint]: Define `tm', to avoid `may be used
        uninitialized' warnings from gcc -O -Wall.

Index: lib/mktime.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/mktime.c,v
retrieving revision 1.51
diff -u -p -r1.51 mktime.c
--- lib/mktime.c        14 May 2005 06:03:58 -0000      1.51
+++ lib/mktime.c        22 Jun 2005 09:43:50 -0000
@@ -46,6 +46,12 @@
 # define mktime my_mktime
 #endif /* DEBUG */
 
+#ifdef lint
+# define IF_LINT(Code) Code
+#else
+# define IF_LINT(Code) /* empty */
+#endif
+
 /* Shift A right by B bits portably, by dividing A by 2**B and
    truncating towards minus infinity.  A and B should be free of side
    effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
@@ -234,7 +240,8 @@ ranged_convert (struct tm *(*convert) (c
     {
       time_t bad = *t;
       time_t ok = 0;
-      struct tm tm;
+      IF_LINT (static struct tm z);
+      struct tm tm IF_LINT (= z);
 
       /* BAD is a known unconvertible time_t, and OK is a known good one.
         Use binary search to narrow the range between BAD and OK until