+dnl Check if the system has struct stat::st_mtim.
+AC_CACHE_CHECK([for struct stat::st_mtim.],
+[gold_cv_stat_st_mtim],
+[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/stat.h>
+long bar() { struct stat s; return (long)(s.st_mtim.tv_sec + s.st_mtim.tv_sec);}
+]])], [gold_cv_stat_st_mtim=yes], [gold_cv_stat_st_mtim=no])])
+if test "$gold_cv_stat_st_mtim" = "yes"; then
+ AC_DEFINE(HAVE_STAT_ST_MTIM, 1,
+ [Define if struct stat has a field st_mtim with timespec for mtime])
+fi
+
+dnl Check if gcc supports the -gpubnames option.
+dnl Use -Werror in case of compilers that make unknown -g options warnings.
+dnl They would pass the test here, but fail in actual use when $WARN_CFLAGS
+dnl gets set later by default Autoconf magic to include -Werror. (We are
+dnl assuming here that there is no compiler that groks -gpubnames
+dnl but does not grok -Werror.)
+save_CXXFLAGS="$CXXFLAGS"
+CXXFLAGS="$CXXFLAGS -Werror -gpubnames"
+AC_COMPILE_IFELSE([int i;], [have_pubnames=yes], [have_pubnames=no])
+CXXFLAGS="$save_CXXFLAGS"
+AM_CONDITIONAL(HAVE_PUBNAMES, test "$have_pubnames" = "yes")
+