Make `off_t` handling simpler; #4872 #4939

The newer `clang` warns implicit float conversions.

mrbgems/mruby-io/src/file.c

@@ -458,7 +458,7 @@ mrb_file_size(mrb_state *mrb, mrb_value self)
 }
 
 static int
-mrb_ftruncate(int fd, int64_t length)
+mrb_ftruncate(int fd, mrb_int length)
 {
 #ifndef _WIN32
   return ftruncate(fd, (off_t)length);
@@ -491,32 +491,12 @@ static mrb_value
 mrb_file_truncate(mrb_state *mrb, mrb_value self)
 {
   int fd;
-  int64_t length;
+  mrb_int length;
   mrb_value lenv;
 
   fd = mrb_io_fileno(mrb, self);
   mrb_get_args(mrb, "o", &lenv);
-  switch (mrb_type(lenv)) {
-#ifndef MRB_WITHOUT_FLOAT
-    case MRB_TT_FLOAT:
-      {
-        mrb_float lenf = mrb_float(lenv);
-        if (lenf > INT64_MAX) {
-          mrb_raise(mrb, E_ARGUMENT_ERROR, "length too large");
-        }
-        length = (int64_t)lenf;
-      }
-      break;
-#endif
-    case MRB_TT_FIXNUM:
-    default:
-      {
-        mrb_int leni = mrb_int(mrb, lenv);
-        length = (int64_t)leni;
-      }
-      break;
-  }
-
+  length = mrb_int(mrb, lenv);
   if (mrb_ftruncate(fd, length) != 0) {
     mrb_raise(mrb, E_IO_ERROR, "ftruncate failed");
   }

mrbgems/mruby-io/src/io.c

@@ -1404,22 +1404,7 @@ mrb_io_sync(mrb_state *mrb, mrb_value self)
 static off_t
 value2off(mrb_state *mrb, mrb_value offv)
 {
-  switch (mrb_type(offv)) {
-#ifndef MRB_WITHOUT_FLOAT
-    case MRB_TT_FLOAT:
-      {
-        mrb_float tmp = mrb_float(offv);
-        if (tmp < INT64_MIN || tmp > INT64_MAX) {
-          /* fall through to use convert by `mrb_int()` (and raise error if out of range) */
-        } else {
-          return (off_t)tmp;
-        }
-      }
-      /* fall through */
-#endif /* MRB_WITHOUT_FLOAT */
-    default:
-      return (off_t)mrb_int(mrb, offv);
-  }
+  return (off_t)mrb_int(mrb, offv);
 }
 
 /*