maint: port --enable-gcc-warnings to clang

* configure.ac: If clang, add -Wno-format-extra-args and
-Wno-tautological-constant-out-of-range-compare.
* gl/lib/rand-isaac.c (ind):
* gl/lib/randread.c (readisaac):
* src/ls.c (dev_ino_push, dev_ino_pop):
* src/sort.c (buffer_linelim):
* src/system.h (is_nul):
* src/tail.c (tail_forever_inotify):
Rewrite to avoid casts that clang dislikes.
It's good to avoid casts anyway.
* src/expr.c (integer_overflow): Declare only if it exists.
(die): Remove; unused.
* src/ls.c (dev_ino_push): New function, replacing ...
(DEV_INO_PUSH): ... this removed macro.  All uses changed.
(decode_switches): Rewrite "str"+i to &str[i].

1 files changed, 3 insertions, 11 deletions

diff --git a/src/expr.c b/src/expr.c
index b4fa808a0..9d21ca87f 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -44,8 +44,6 @@
    int, the widest unsigned type that GMP supports.  */
 verify (SIZE_MAX <= ULONG_MAX);
 
-static void integer_overflow (char) ATTRIBUTE_NORETURN;
-
 #ifndef HAVE_GMP
 # define HAVE_GMP 0
 #endif
@@ -53,6 +51,7 @@ static void integer_overflow (char) ATTRIBUTE_NORETURN;
 #if HAVE_GMP
 # include <gmp.h>
 #else
+static void integer_overflow (char) ATTRIBUTE_NORETURN;
 /* Approximate gmp.h well enough for expr.c's purposes.  */
 typedef intmax_t mpz_t[1];
 static void mpz_clear (mpz_t z) { (void) z; }
@@ -278,6 +277,7 @@ syntax_error (void)
   error (EXPR_INVALID, 0, _("syntax error"));
 }
 
+#if ! HAVE_GMP
 /* Report an integer overflow for operation OP and exit.  */
 static void
 integer_overflow (char op)
@@ -285,15 +285,7 @@ integer_overflow (char op)
   error (EXPR_FAILURE, ERANGE, "%c", op);
   abort (); /* notreached */
 }
-
-static void die (int errno_val, char const *msg)
-  ATTRIBUTE_NORETURN;
-static void
-die (int errno_val, char const *msg)
-{
-  error (EXPR_FAILURE, errno_val, "%s", msg);
-  abort (); /* notreached */
-}
+#endif
 
 int
 main (int argc, char **argv)