Hi Jonathan/Andrew
Thank you very much for your responses.
I think I have to select a subset of the C++ standard libraries and
implement a smaller library.
Thanks,
Nagaraju
On Fri, Aug 24, 2012 at 3:09 PM, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote:
> On 24 August 2012 08:46, naga raj wrote:
>> Hi,
>>
>> I have ported Gcc-4.6.2 to an embedded target. My C++ compiler is
>> generating huge code size.
>>
>> #include <iostream>
>> using namespace std;
>> int main()
>> {
>> return 0;
>> }
>>
>> If we execute the above program then all the function in the
>> iostream library are included in the elf as a result size of elf is
>> increased....
>
> Including <iostream> causes global objects to be constructed, so even
> though you're not explicitly using std::cout or std::cin, those
> streams are initialized and code is run (before main) just because
> <iostream> is included. If you don't need to use it then don't
> include it. If you do need to use it then obviously the code size is
> larger if you use I/O features than if you don't use them.
>
> That said, libstdc++ isn't really optimised for embedded systems.
> Some configure-time options such as building libstdc++ without
> exceptions can help reduce code size, if you don't need to use
> exceptions.
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43852 would also help
> avoid dependency on the I/O facilities.
