-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Ralf Wildenhues on 6/15/2009 2:46 PM: > This rewrite causes new autoconf on gcc/gcc/configure.ac to hang. > gcc/config/acx.m4 contains > > AC_DEFUN([AC_PROG_CPP_WERROR], > [AC_REQUIRE([AC_PROG_CPP])dnl > m4_define([AC_CHECK_HEADER],m4_defn([_AC_CHECK_HEADER_OLD])) > ac_c_preproc_warn_flag=yes])# AC_PROG_CPP_WERROR
Ouch. The AU_DEFUN'd version is now in terms of AC_CHECK_HEADER, yet the gcc AC_CHECK_HEADER is in terms of _AC_CHECK_HEADER_OLD. Hence the infinite expansion loop, because gcc is changing AC_CHECK_HEADER behind autoconf's back. It feels like gcc would be the better place to fix this; how about doing the following in gcc instead of the current code: m4_copy([AC_CHECK_HEADER], [gcc_CHECK_HEADER_1]) m4_define([gcc_CHECK_HEADER_2], [m4_if([$4], [], ]m4_dquote(m4_defn([_AC_CHECK_HEADER_OLD]))[, [gcc_CHECK_HEADER_1($@)])]) AC_DEFUN([AC_PROG_CPP_WERROR], [AC_REQUIRE([AC_PROG_CPP])dnl m4_define([AC_CHECK_HEADER], m4_defn([gcc_CHECK_HEADER_2])) ac_c_preproc_warn_flag=yes])# AC_PROG_CPP_WERROR Or is this usage of _AC_CHECK_HEADER_OLD so pervasive in the wild that we should make the AU_DEFUN forward to _AC_CHECK_HEADER_PREPROC instead of the public AC_CHECK_HEADER, the way I originally proposed? - -- Don't work too hard, make some time for fun as well! Eric Blake [email protected] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAko2/L0ACgkQ84KuGfSFAYDAnACgmKAOgo1YX/L34MHlsqQVb5/b RhEAoIL1pNCJZI9JJ+jwfDV7dzDD1NBJ =M0Mz -----END PGP SIGNATURE-----
