-ifelse(m4_PACKAGE_VERSION, [2.62],, [
-
-# _AC_ARG_VAR_VALIDATE
-# --------------------
-# The code is the same as autoconf 2.59, but with a more lenient check
-# on precious variables that has been added in autoconf 2.62.
-m4_define([_AC_ARG_VAR_VALIDATE],
-[# Check that the precious variables saved in the cache have kept the same
-# value.
-ac_cache_corrupted=false
-for ac_var in `(set) 2>&1 |
- sed -n 's/^ac_env_\([[a-zA-Z_0-9]]*\)_set=.*/\1/p'`; do
- eval ac_old_set=\$ac_cv_env_${ac_var}_set
- eval ac_new_set=\$ac_env_${ac_var}_set
- eval ac_old_val="\$ac_cv_env_${ac_var}_value"
- eval ac_new_val="\$ac_env_${ac_var}_value"
- case $ac_old_set,$ac_new_set in
- set,)
- AS_MESSAGE([error: `$ac_var' was set to `$ac_old_val' in the previous run], 2)
- ac_cache_corrupted=: ;;
- ,set)
- AS_MESSAGE([error: `$ac_var' was not set in the previous run], 2)
- ac_cache_corrupted=: ;;
- ,);;
- *)
- if test "x$ac_old_val" != "x$ac_new_val"; then
- # differences in whitespace do not lead to failure.
- ac_old_val_w=`echo x $ac_old_val`
- ac_new_val_w=`echo x $ac_new_val`
- if test "$ac_old_val_w" != "$ac_new_val_w"; then
- AS_MESSAGE([error: `$ac_var' has changed since the previous run:], 2)
- ac_cache_corrupted=:
- else
- AS_MESSAGE([warning: ignoring whitespace changes in `$ac_var' since the previous run:], 2)
- eval $ac_var=\$ac_old_val
- fi
- AS_MESSAGE([ former value: `$ac_old_val'], 2)
- AS_MESSAGE([ current value: `$ac_new_val'], 2)
- fi;;
- esac
- # Pass precious variables to config.status.
- if test "$ac_new_set" = set; then
- case $ac_new_val in
-dnl If you change this globbing pattern, test it on an old shell --
-dnl it's sensitive. Putting any kind of quote in it causes syntax errors.
-[ *" "*|*" "*|*[\[\]\~\#\$\^\&\*\(\)\{\}\\\|\;\<\>\?\"\']*)]
- ac_arg=$ac_var=`echo "$ac_new_val" | sed "s/'/'\\\\\\\\''/g"` ;;
- *) ac_arg=$ac_var=$ac_new_val ;;
- esac
- case " $ac_configure_args " in
- *" '$ac_arg' "*) ;; # Avoid dups. Use of quotes ensures accuracy.
- *) ac_configure_args="$ac_configure_args '$ac_arg'" ;;
- esac
- fi
-done
-if $ac_cache_corrupted; then
- AS_MESSAGE([error: changes in the environment can compromise the build], 2)
- AS_ERROR([run `make distclean' and/or `rm $cache_file' and start over])
-fi
-])# _AC_ARG_VAR_VALIDATE
-])])
+
+dnl Ensure we do not use a buggy M4.
+m4_if(m4_index([..wi.d.], [.d.]), [-1],
+ [m4_fatal(m4_do([m4 with buggy strstr detected. Please install
+GNU M4 1.4.16 or newer and set the M4 environment variable]))])
+
+
+dnl Fix 2.64 cross compile detection for AVR and RTEMS
+dnl by not trying to compile fopen.
+m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.64],
+ [m4_foreach([_GCC_LANG], [C, C++, Fortran, Fortran 77],
+ [m4_define([_AC_LANG_IO_PROGRAM(]_GCC_LANG[)], m4_defn([AC_LANG_PROGRAM(]_GCC_LANG[)]))])])
+
+m4_version_prereq([2.66],, [
+dnl We need AC_CHECK_DECL which works for overloaded C++ functions.
+
+# _AC_CHECK_DECL_BODY
+# -------------------
+# Shell function body for AC_CHECK_DECL.
+m4_define([_AC_CHECK_DECL_BODY],
+[ AS_LINENO_PUSH([$[]1])
+ [as_decl_name=`echo $][2|sed 's/ *(.*//'`]
+ [as_decl_use=`echo $][2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`]
+ AC_CACHE_CHECK([whether $as_decl_name is declared], [$[]3],
+ [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$[]4],
+[@%:@ifndef $[]as_decl_name
+@%:@ifdef __cplusplus
+ (void) $[]as_decl_use;
+@%:@else
+ (void) $[]as_decl_name;
+@%:@endif
+@%:@endif
+])],
+ [AS_VAR_SET([$[]3], [yes])],
+ [AS_VAR_SET([$[]3], [no])])])
+ AS_LINENO_POP
+])# _AC_CHECK_DECL_BODY
+
+# _AC_CHECK_DECLS(SYMBOL, ACTION-IF_FOUND, ACTION-IF-NOT-FOUND,
+# INCLUDES)
+# -------------------------------------------------------------
+# Helper to AC_CHECK_DECLS, which generates the check for a single
+# SYMBOL with INCLUDES, performs the AC_DEFINE, then expands
+# ACTION-IF-FOUND or ACTION-IF-NOT-FOUND.
+m4_define([_AC_CHECK_DECLS],
+[AC_CHECK_DECL([$1], [ac_have_decl=1], [ac_have_decl=0], [$4])]dnl
+[AC_DEFINE_UNQUOTED(AS_TR_CPP(m4_bpatsubst(HAVE_DECL_[$1],[ *(.*])),
+ [$ac_have_decl],
+ [Define to 1 if you have the declaration of `$1',
+ and to 0 if you don't.])]dnl
+[m4_ifvaln([$2$3], [AS_IF([test $ac_have_decl = 1], [$2], [$3])])])
+
+])
+
+dnl If flex/lex are not found, the top level configure sets LEX to
+dnl "/path_to/missing flex". When AC_PROG_LEX tries to find the flex
+dnl output file, it calls $LEX to do so, but the current lightweight
+dnl "missing" won't create a file. This results in an error.
+dnl Avoid calling the bulk of AC_PROG_LEX when $LEX is "missing".
+AC_DEFUN_ONCE([AC_PROG_LEX],
+[AC_CHECK_PROGS(LEX, flex lex, :)
+case "$LEX" in
+ :|*"missing "*) ;;
+ *) _AC_PROG_LEX_YYTEXT_DECL ;;
+esac])
+
+])