Migrating from gcc-3.3 to gcc-4.2

["Sivaprasad.pv" <sivaprasad.pv@xxxxxxxxxxxxxxxxxx>]

Hi All,

I want to upgrade our gcc cross compiler from gcc-3.3 to gcc-4.2.
I have made direct attempt but I got following error messages .

error: attempt to use poisoned "TARGET_SWITCHES"
error: attempt to use poisoned "DEFAULT_SHORT_ENUMS"
error: attempt to use poisoned "SMALL_STACK"
error: attempt to use poisoned "FUNCTION_ARG_PASS_BY_REFERENCE"
error: attempt to use poisoned "MUST_PASS_IN_STACK"
error: attempt to use poisoned "FUNCTION_ARG_PARTIAL_NREGS"
error: attempt to use poisoned "EXPAND_BUILTIN_VA_ARG"
error: attempt to use poisoned "TARGET_MEM_FUNCTIONS"
error: attempt to use poisoned "CONST_COSTS"
error: attempt to use poisoned "RTX_COSTS"
error: attempt to use poisoned "ADDRESS_COST"
error: attempt to use poisoned "PROMOTE_PROTOTYPES"
error: attempt to use poisoned "INIT_TARGET_OPTABS"

I think all these macro's are deprecated in gcc-4.2.
Can any body suggest me how to find an  equivalent macro's in gcc.4.2.
Is there any specific documents available to upgrade from gcc-3.3 to 
gcc-4.2 ?

Thanks,
Siva