On a SPARC Classic:

all ===> gnu/usr.bin/gdb
cc -O  -Werror   -I/usr/src/gnu/usr.bin/gdb/obj -I/usr/src/gnu/usr.bin/gdb -I/usr/src/gnu/usr.bin/gdb/../../dist/gdb -I/usr/src/gnu/usr.bin/gdb/../../dist/gdb/config -I/usr/src/gnu/usr.bin/gdb/../../dist/readline -I/usr/src/gnu/lib/bfd/obj -I/usr/src/gnu/usr.bin/gdb/../../dist/bfd -I/usr/src/gnu/usr.bin/gdb/../../dist/include -DNO_MMALLOC -c /usr/src/gnu/usr.bin/gdb/../../dist/gdb/valops.c
cc1: warnings being treated as errors
/usr/src/gnu/usr.bin/gdb/../../dist/gdb/valops.c: In function `search_struct_field':
/usr/src/gnu/usr.bin/gdb/../../dist/gdb/valops.c:1583: warning: cast from pointer to integer of different size
/usr/src/gnu/usr.bin/gdb/../../dist/gdb/valops.c: In function `value_struct_elt_for_reference':
/usr/src/gnu/usr.bin/gdb/../../dist/gdb/valops.c:2026: warning: cast from pointer to integer of different size
*** Error code 1

Stop.