[Bug ada/86211] New: GCC 8 ada cannot build GCC 7 ada

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86211

            Bug ID: 86211
           Summary: GCC 8 ada cannot build GCC 7 ada
           Product: gcc
           Version: 8.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

Not sure whether this can be worked around for GCC 7 or GCC 8 but it's
unfortunate
that the GCC 8 ada compiler cannot be used to bootstrap GCC 7 with ada enabled.

Yes, I know this isn't really supported but it's unfortunate because it makes
me unable to bootstrap/test patches with ada on the GCC 6 and 7 branches on
the systems that have the system compiler updated to GCC 8.

The specific error I am getting is

[  154s] gcc -c -g -O2  -gnatp -gnatws -nostdinc -I- -I. -Iada/generated -Iada
-I../../gcc/ada -I../../gcc/ada/gcc-interface \
[  154s]     ada/b_gnat1.adb -o ada/b_gnat1.o
[  154s] b_gnat1.adb:174:79: "SS_Stack" not declared in "Secondary_Stack"
[  154s] b_gnat1.adb:174:89: incorrect constraint for this kind of type
[  154s] b_gnat1.adb:268:56: "Runtime_Default_Sec_Stack_Size" not declared in
"Parameters"
[  154s] make[3]: *** [../../gcc/ada/gcc-interface/Make-lang.in:949:
ada/b_gnat1.o] Error 1

maybe there's a workaround available?

Using system GCC 7 was fine for bootstrapping and testing patches on the GCC 6
branch.