Hi all, In "config/acx.m4", there are still some "tail +16c" which are invalid on POSIX systems. In my opinion, all "tail +16c" should be changed to "tail -c +16" directly, as most systems has accept the latter. And, to skip first 16 bytes, we should use "tail -c +17" instead of "tail -c +16".
* config/acx.m4:Change "tail +16c" to "tail -c +17". * configure: Regenerate. --- gcc-6.2.0/config/acx.m4 2011-12-18 17:58:37.000000000 +0800 +++ gcc-6.2.0-bak/config/acx.m4 2016-11-23 10:56:21.065817691 +0800 @@ -404,7 +404,7 @@ AC_DEFUN([ACX_PROG_CMP_IGNORE_INITIAL], [AC_CACHE_CHECK([how to compare bootstrapped objects], gcc_cv_prog_cmp_skip, [ echo abfoo >t1 echo cdfoo >t2 - gcc_cv_prog_cmp_skip='tail +16c $$f1 > tmp-foo1; tail +16c $$f2 > tmp-foo2; cmp tmp-foo1 tmp-foo2' + gcc_cv_prog_cmp_skip='tail -c +17 $$f1 > tmp-foo1; tail -c +17 $$f2 > tmp-foo2; cmp tmp-foo1 tmp-foo2' if cmp t1 t2 2 2 > /dev/null 2>&1; then if cmp t1 t2 1 1 > /dev/null 2>&1; then :