maint: avoid -Werror=strict-overflow warnings with GCC 5

All warnings were of the form: "assuming signed overflow does not occur
when simplifying conditional to constant [-Werror=strict-overflow]"

* src/dd.c (cache_round): Use an appropriately sized unsigned type,
to avoid possibility of undefined signed overflow.
* src/mknod.c (main): Likewise.
* src/pr.c (pad_down): Likewise.
* src/wc.c (main): Likewise.
* src/tail.c (main): Assert that argc >= 0 thus allowing the
compiler to assume without implication that argc - optind
is positive.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/wc.c b/src/wc.c
index 91f4a3145..fe73d2ce1 100644
--- a/src/wc.c
+++ b/src/wc.c
@@ -558,7 +558,7 @@ wc_file (char const *file, struct fstatus *fstatus)
    that happens when we don't know how long the list of file names will be.  */
 
 static struct fstatus *
-get_input_fstatus (int nfiles, char *const *file)
+get_input_fstatus (size_t nfiles, char *const *file)
 {
   struct fstatus *fstatus = xnmalloc (nfiles ? nfiles : 1, sizeof *fstatus);
 
@@ -570,7 +570,7 @@ get_input_fstatus (int nfiles, char *const *file)
     fstatus[0].failed = 1;
   else
     {
-      int i;
+      size_t i;
 
       for (i = 0; i < nfiles; i++)
         fstatus[i].failed = (! file[i] || STREQ (file[i], "-")
@@ -586,7 +586,7 @@ get_input_fstatus (int nfiles, char *const *file)
    get_input_fstatus optimizes.  */
 
 static int _GL_ATTRIBUTE_PURE
-compute_number_width (int nfiles, struct fstatus const *fstatus)
+compute_number_width (size_t nfiles, struct fstatus const *fstatus)
 {
   int width = 1;
 
@@ -594,7 +594,7 @@ compute_number_width (int nfiles, struct fstatus const *fstatus)
     {
       int minimum_width = 1;
       uintmax_t regular_total = 0;
-      int i;
+      size_t i;
 
       for (i = 0; i < nfiles; i++)
         if (! fstatus[i].failed)
@@ -620,7 +620,7 @@ main (int argc, char **argv)
 {
   bool ok;
   int optc;
-  int nfiles;
+  size_t nfiles;
   char **files;
   char *files_from = NULL;
   struct fstatus *fstatus;