[PATCH] fix #19443 - build failures with -DDEBUG

[Martin Sebor <msebor at gmail dot com>]

A number of glibc source files contain debugging code guarded
by the "#if DEBUG" preprocessor conditional.  The DEBUG macro
isn't documented but as Carlos notes in his comment on the bug,
it can be useful to enable various debugging aspects of glibc,
for example in the resolver library.

The attached patch makes it possible to build glibc with the macro
defined.  In one instance (time/mktime.c) the macro is being used
in a way that's incompatible with the other uses. In that case I
renamed to avoid this problem.

In case that raises questions, in resolv/res_send.c, I chose
to replace the undeclared abort with __builtin_abort to avoid
(mostly) unnecessarily including <stdlib.h>.  I checked for
uses of other GCC builtins and found a bunch, though not any
of __builtin_abort.  Either approach works for me.

Tested by building and using the library on powerpc64le and
x86_64 with the macro defined.

Martin

2016-01-12  Martin Sebor  <msebor@redhat.com>

	[BZ #19443]
	* crypt/crypt_util.c [DEBUG] (_ufc_prbits): Correct format string.
	[DEBUG] (_ufc_set_bits): Declare used.
	* iconv/gconv_dl.c [DEBUG]: Add a missing include directive.
	[DEBUG] (print_all): Declare used.
	* resolv/res_send.c [DEBUG] (__libc_res_nsend): Explicitly convert
	operands of the ternary ?: expression to target type.
	* stdlib/rshift.c [DEBUG] (mpn_rshift): Call __builtin_abort()  
	instead of the undeclared abort.
	* time/mktime.c [DEBUG] (DEBUG): Rename to DEBUG_MKTIME.

diff --git a/crypt/crypt_util.c b/crypt/crypt_util.c
index 4b6490e..1f42f59 100644
--- a/crypt/crypt_util.c
+++ b/crypt/crypt_util.c
@@ -271,12 +271,12 @@ _ufc_prbits (ufc_long *a, int n)
       t=8*i+j;
       tmp|=(a[t/24] & BITMASK[t % 24])?bytemask[j]:0;
     }
-    (void)printf("%02x ",tmp);
+    (void)printf("%02lx ", tmp);
   }
   printf(" ");
 }
 
-static void
+static void __attribute__ ((unused))
 _ufc_set_bits (ufc_long v, ufc_long *b)
 {
   ufc_long i;
diff --git a/iconv/gconv_dl.c b/iconv/gconv_dl.c
index 86559d3..4e9dfea 100644
--- a/iconv/gconv_dl.c
+++ b/iconv/gconv_dl.c
@@ -219,6 +219,9 @@ libc_freeres_fn (free_mem)
 
 
 #ifdef DEBUG
+
+#include <stdio.h>
+
 static void
 do_print (const void *nodep, VISIT value, int level)
 {
@@ -231,7 +234,7 @@ do_print (const void *nodep, VISIT value, int level)
 	  obj->name, obj->counter);
 }
 
-static void
+static void __attribute__ ((used))
 print_all (void)
 {
   __twalk (loaded, do_print);
diff --git a/resolv/res_send.c b/resolv/res_send.c
index 3550740..776dcb5 100644
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -499,8 +499,8 @@ __libc_res_nsend(res_state statp, const u_char *buf, int buflen,
 		       (stdout, ";; Querying server (# %d) address = %s\n",
 			ns + 1, inet_ntop(nsap->sa_family,
 					  (nsap->sa_family == AF_INET6
-					   ? &((struct sockaddr_in6 *) nsap)->sin6_addr
-					   : &((struct sockaddr_in *) nsap)->sin_addr),
+					   ? (char *)&((struct sockaddr_in6 *) nsap)->sin6_addr
+					   : (char *)&((struct sockaddr_in *) nsap)->sin_addr),
 					  tmpbuf, sizeof (tmpbuf))));
 
 		if (__glibc_unlikely (v_circuit))       {
diff --git a/stdlib/rshift.c b/stdlib/rshift.c
index 4cf345c..71f8736 100644
--- a/stdlib/rshift.c
+++ b/stdlib/rshift.c
@@ -42,7 +42,7 @@ mpn_rshift (register mp_ptr wp,
 
 #ifdef DEBUG
   if (usize == 0 || cnt == 0)
-    abort ();
+    __builtin_abort ();
 #endif
 
   sh_1 = cnt;
diff --git a/time/mktime.c b/time/mktime.c
index 7d06314..bc7ed56 100644
--- a/time/mktime.c
+++ b/time/mktime.c
@@ -19,7 +19,7 @@
 
 /* Define this to have a standalone program to test this implementation of
    mktime.  */
-/* #define DEBUG 1 */
+/* #define DEBUG_MKTIME 1 */
 
 #ifndef _LIBC
 # include <config.h>
@@ -38,13 +38,13 @@
 
 #include <string.h>		/* For the real memcpy prototype.  */
 
-#if defined DEBUG && DEBUG
+#if defined DEBUG_MKTIME && DEBUG_MKTIME
 # include <stdio.h>
 # include <stdlib.h>
 /* Make it work even if the system's libc has its own mktime routine.  */
 # undef mktime
 # define mktime my_mktime
-#endif /* DEBUG */
+#endif /* DEBUG_MKTIME */
 
 /* Some of the code in this file assumes that signed integer overflow
    silently wraps around.  This assumption can't easily be programmed
@@ -600,7 +600,7 @@ libc_hidden_def (mktime)
 libc_hidden_weak (timelocal)
 #endif
 
-#if defined DEBUG && DEBUG
+#if defined DEBUG_MKTIME && DEBUG_MKTIME
 
 static int
 not_equal_tm (const struct tm *a, const struct tm *b)
@@ -732,10 +732,10 @@ main (int argc, char **argv)
   return status;
 }
 
-#endif /* DEBUG */
+#endif /* DEBUG_MKTIME */
 
 /*
 Local Variables:
-compile-command: "gcc -DDEBUG -I. -Wall -W -O2 -g mktime.c -o mktime"
+compile-command: "gcc -DDEBUG_MKTIME -I. -Wall -W -O2 -g mktime.c -o mktime"
 End:
 */