[Bug ada/21276] New: Cross building gnats misses newlib headers

["corsepiu at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

One-tree style bootstrapping a newlib-based cross GCC with ada enabled breaks
with this breakdown:

make[3]: Entering directory
`/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/build/gcc/ada/rts'../../xgcc
-B../../ -c -DCROSS_COMPILE -DIN_GCC   `echo -g -O2  -fexceptions -DIN_RTS |sed
-e 's/-pedantic//g' -e 's/-Wtraditional//g'`      -I. -I.. -I../..
-I/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada
-I/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada/../config
-I/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada/../../include
-I/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada/..
-I./../.. adaint.c \
  -o adaint.o
In file included from adaint.c:59:
/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada/../tsystem.h:90:19:
error: stdio.h: No such file or directory
/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada/../tsystem.h:93:23:
error: sys/types.h: No such file or directory
/users/columbo/src/rpms/BUILD/rtems-4.7-sparc-rtems4.7-gcc-newlib-gcc4.0.0newlib1.13.0/gcc-4.0.0/gcc/ada/../tsystem.h:96:19:
error: errno.h: No such file or directory

IMO, this indicates a bug inside of the GNAT configury, probably it is not aware
about newlib and therefore misses to acknowledge newlib's include directories
(Missing -I...)
 
Work around to this problem is to have a cross-gcc for the same target
previously installed, whose header sufficently match with the headers being used
by the build. In this case, bootstrapping seems to be using the already
installed headers instead of the headers of the GCC being build.

[I.e. 1. build and install gcc+newlib w/o gnat, then rebuild gcc w/ gnat].

-- 
           Summary: Cross building gnats misses newlib headers
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: build
          Severity: normal
          Priority: P2
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: corsepiu at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org,joel at oarcorp dot
                    com,laurent at guerby dot net,neroden at gcc dot gnu dot
                    org
  GCC host triplet: any
GCC target triplet: !=host


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21276