https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91602
--- Comment #7 from Serge Belyshev <belyshev at depni dot sinp.msu.ru> ---
(In reply to Jim Wilson from comment #5)
> When you build packages separately, each package after the first uses
> feature tests to configure itself appropriately to use the earlier packages.
> When you use a combined tree build, feature tests can't be used because
> earlier packages haven't been installed yet, so configure just makes
> guesses. We have the most commonly correct results hardwired in as guesses.
> This was fine when packages were smaller, and we had a smaller number of
> targets.
I believe that this particular problem was fixed since r100007 which made
configure-gcc depend on all-gas.
Which means that there is no need to treat in-tree case specially anymore, and
the proper fix is appears to be very simple:
--- a/gcc/acinclude.m4
+++ b/gcc/acinclude.m4
@@ -532,10 +532,8 @@ AC_DEFUN([gcc_GAS_CHECK_FEATURE],
[AC_REQUIRE([gcc_GAS_FLAGS])dnl
AC_CACHE_CHECK([assembler for $1], [$2],
[[$2]=no
- ifelse([$3],,,[dnl
- if test $in_tree_gas = yes; then
- gcc_GAS_VERSION_GTE_IFELSE($3, [[$2]=yes])
- el])if test x$gcc_cv_as != x; then
+ ifelse([$3],,,)
+ if test x$gcc_cv_as != x; then
AS_ECHO([ifelse(m4_substr([$5],0,1),[$], "[$5]", '[$5]')]) > conftest.s
if AC_TRY_COMMAND([$gcc_cv_as $gcc_cv_as_flags $4 -o conftest.o conftest.s
>&AS_MESSAGE_LOG_FD])
then
