* Eric Blake wrote on Mon, Feb 28, 2011 at 07:06:50PM CET: > On 02/26/2011 07:50 AM, Ralf Wildenhues wrote: > >> Autoconf's m4/m4.m4 needs a similar test. > > > > Thanks. Like this? > > Close, but I'm still thinking about it. > > There's two separate strstr issues:
Thanks for the detailed explanations. That's going to be painful though, as basically only (little-tested) 1.4.16 is the only viable alternative, as there have been security issues fixed after 1.4.10. > > I should note that it won't exclude a buggy m4 that the user has > > explicitly set by setting the M4 environment variable. > > Agreed. It's also possible to detect a broken strstr at runtime as part > of m4_init, although I'm not sure whether to do that yet. It's even > technically feasible to replace a broken m4_index() with m4_regex() (by > escaping the search string and doing the search via regular expressions > instead), but certainly inefficient, and I'm not sure it's worth the > hassle to try that. It would be sad to see further runtime slowdown due to bugs in tools, IMVHO. Updated patch below. OK? Thanks, Ralf 2011-03-05 Ralf Wildenhues <[email protected]> Eric Blake <[email protected]> Exclude M4 with buggy strstr when configuring Autoconf. * m4/m4.m4 (AC_PROG_GNU_M4): When searching PATH, do not accept an m4 that has either the gnulib strstr bug, or the glibc/gnulib strstr bug. diff --git a/m4/m4.m4 b/m4/m4.m4 index a11fe0d..e37ff4e 100644 --- a/m4/m4.m4 +++ b/m4/m4.m4 @@ -1,4 +1,4 @@ -# m4.m4 serial 11 +# m4.m4 serial 12 # Copyright (C) 2000, 2006-2011 Free Software Foundation, Inc. @@ -25,15 +25,24 @@ AS_UNSET([POSIXLY_CORRECT]) AC_PATH_PROGS_FEATURE_CHECK([M4], [m4 gm4 gnum4], [dnl Creative quoting here to avoid raw dnl and ifdef in configure. # Root out GNU M4 1.4.5, as well as non-GNU m4 that ignore -t, -F. + # Root out GNU M4 1.4.13 and 1.4.14 with buggy replacement strstr. + # Root out Glibc 2.9 - 2.12 and GNU M4 1.4.11 - 1.4.15 with buggy + # strstr. ac_snippet=change'quote(<,>)in''dir(<if''def>,mac,bug)' ac_snippet=${ac_snippet}pat'subst(a,\(b\)\|\(a\),\1)d'nl + ac_snippet=${ac_snippet}${as_nl}if'else(in''dex(..wi.d.,.d.),-1,strstr-bug)' + ac_snippet=${ac_snippet}${as_nl}if'else(in''dex(dnl +;:11-:12-:12-:12-:12-:12-:12-:12-:12.:12.:12.:12.:12.:12.:12.:12.:12-,dnl +:12-:12-:12-:12-:12-:12-:12-:12-),-1,,strstr-bug2)' test -z "`$ac_path_M4 -F conftest.m4f </dev/null 2>&1`" \ && test -z "`AS_ECHO([$ac_snippet]) | $ac_path_M4 --trace=mac 2>&1`" \ && test -f conftest.m4f \ && ac_cv_path_M4=$ac_path_M4 ac_path_M4_found=: rm -f conftest.m4f], [AC_MSG_ERROR([no acceptable m4 could be found in \$PATH. -GNU M4 1.4.6 or later is required; 1.4.14 is recommended])])]) +GNU M4 1.4.6 or later is required; 1.4.16 or newer is recommended. +GNU M4 1.4.14 and 1.4.15 use a buggy replacement strstr on some systems. +Glibc 2.9 - 2.12 and GNU M4 1.4.11 - 1.4.15 have another strstr bug])])]) M4=$ac_cv_path_M4 AC_CACHE_CHECK([whether $ac_cv_path_M4 accepts --gnu], [ac_cv_prog_gnu_m4_gnu],
