Within one C file, current gcc can optimize the global static variables
according to the C code, but it will skip assembly code -- it will pass
them to gas directly.
if the static variable is used between C code and assembly code in one C
file (e.g. is_dyn_brkp in kgdb.c), it needs '__used' to let gcc know it
should be still used, or gcc may remove it for optimization.
The related error in this case:
LD init/built-in.o
arch/cris/arch-v10/kernel/built-in.o: In function `kgdb_handle_breakpoint':
(.text+0x2aca): undefined reference to `is_dyn_brkp'
arch/cris/arch-v10/kernel/built-in.o: In function `is_static':
kgdb.c:(.text+0x2ada): undefined reference to `is_dyn_brkp'
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
c33fe44443