libstdc++

libstdc++

[naga raj]

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....


Please help me in solving this issue..

Thanks in Advance,
Nagaraju

Re: libstdc++

[Andrew Haley]

On 08/24/2012 08:46 AM, 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....
> 
> 
> Please help me in solving this issue..

You're going to have to use custom I/O.  To start, link with
-Wl,-Map,mapfile to see what dependencies are being pulled in.

Andrew.

Re: libstdc++

[Jonathan Wakely]

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.

Re: libstdc++

[naga raj]

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@gmail.com> 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.

Re: libstdc++

[J.H.M. Dassen (Ray)]

Inferno <esheesle@bcpl.net> wrote:
>I have an Intel 486 running Solaris 2.5.1.  I am trying to install
>libstdc++(either 2.90.6 or 2.8.1.1) and neither works.

GNU libstdc++ (as well as libg++) is tightly coupled to the compiler
version; you can only compile it using the particular compiler version it is
supposed to work with.

>It used to work fine with GCC2.8.1 but now using GCC 2.95.1 it won't.

As of 2.95, the gcc sources include the libstdc++ source, so if you build
gcc 2.95.2 from source, you should get a working C++ compiler with matching
libstd++.

HTH,
-- 
Ray Dassen <jhm@cistron.nl>

libstdc++

[Inferno]

I have an Intel 486 running Solaris 2.5.1.  I am trying to install
libstdc++(either 2.90.6 or 2.8.1.1) and neither works.  2.8.1.1 gives
the following failures:
else true ; fi
c++ -c -g -O2 -fno-implicit-templates -I. -I./stl -I../libio
-I./../libio -nostdinc++  -DC `for N in REP MAIN TRAITS ADDSS ADDPS
ADDCS ADDSP ADDSC  EQSS EQPS EQSP NESS NEPS NESP LTSS LTPS LTSP GTSS
GTPS GTSP  LESS LEPS LESP GESS GEPS GESP; do echo " -D${N}"; done` \
  ./sinst.cc -o cstrmain.o
In file included from ../libio/iostream.h:31,
                 from stl/stl_alloc.h:45,
                 from stl/alloc.h:21,
                 from std/bastring.h:39,
                 from string:6,
                 from ./sinst.cc:36:
../libio/streambuf.h: In method `ios::~ios()':
../libio/streambuf.h:485: warning: `void *' is not a pointer-to-object
type
./sinst.cc: At top level:
./sinst.cc:47: explicit instantiation of `class
string_char_traits<char>' after
std/straits.h:132: explicit specialization here
*** Error code 1
make: Fatal error: Command failed for target `bigstmp-string'
Current working directory /root/libstdc++-2.8.1.1/libraries/libstdc++
*** Error code 1
make: Fatal error: Command failed for target `all-target-libstdc++'
#

It used to work fine with GCC2.8.1 but now using GCC 2.95.1 it won't.
Ideas?

Thanks,
Inferno

--
"Life is the whim of several billion cells to be you for a while."
                                            --Inferno

Re: libstdc++

[J.H.M. Dassen (Ray)]

Inferno <esheesle@bcpl.net> wrote:
>I have an Intel 486 running Solaris 2.5.1.  I am trying to install
>libstdc++(either 2.90.6 or 2.8.1.1) and neither works.

GNU libstdc++ (as well as libg++) is tightly coupled to the compiler
version; you can only compile it using the particular compiler version it is
supposed to work with.

>It used to work fine with GCC2.8.1 but now using GCC 2.95.1 it won't.

As of 2.95, the gcc sources include the libstdc++ source, so if you build
gcc 2.95.2 from source, you should get a working C++ compiler with matching
libstd++.

HTH,
-- 
Ray Dassen <jhm@cistron.nl>

libstdc++

[Inferno]

I have an Intel 486 running Solaris 2.5.1.  I am trying to install
libstdc++(either 2.90.6 or 2.8.1.1) and neither works.  2.8.1.1 gives
the following failures:
else true ; fi
c++ -c -g -O2 -fno-implicit-templates -I. -I./stl -I../libio
-I./../libio -nostdinc++  -DC `for N in REP MAIN TRAITS ADDSS ADDPS
ADDCS ADDSP ADDSC  EQSS EQPS EQSP NESS NEPS NESP LTSS LTPS LTSP GTSS
GTPS GTSP  LESS LEPS LESP GESS GEPS GESP; do echo " -D${N}"; done` \
  ./sinst.cc -o cstrmain.o
In file included from ../libio/iostream.h:31,
                 from stl/stl_alloc.h:45,
                 from stl/alloc.h:21,
                 from std/bastring.h:39,
                 from string:6,
                 from ./sinst.cc:36:
../libio/streambuf.h: In method `ios::~ios()':
../libio/streambuf.h:485: warning: `void *' is not a pointer-to-object
type
./sinst.cc: At top level:
./sinst.cc:47: explicit instantiation of `class
string_char_traits<char>' after
std/straits.h:132: explicit specialization here
*** Error code 1
make: Fatal error: Command failed for target `bigstmp-string'
Current working directory /root/libstdc++-2.8.1.1/libraries/libstdc++
*** Error code 1
make: Fatal error: Command failed for target `all-target-libstdc++'
#

It used to work fine with GCC2.8.1 but now using GCC 2.95.1 it won't.
Ideas?

Thanks,
Inferno

--
"Life is the whim of several billion cells to be you for a while."
                                            --Inferno

libstdc++

[Inferno]

I have gcc295 installed on my solaris 2.5.1 system.  I had gcc281 with
libstdc++ 2.8.1.1 installed.  I installed gcc295 over top of it.  I
tried to install libstdc++2.90.6 on my system and it gives several
errors during make about the src directory and not finding files.  I
checked the archive and it is fine.  I installed the libstdc++ on
another machine with no problem and one machine did have a problem(same
problem) other than my own machine.  What is going on.   I just used the
commands "configure, make, make install" in that order.  Ideas?

Thanks,
Inferno

--
What is reality?  Reality is what we believe.
What is the answer?  The answer is out there.
What drives us to do what we do?  The question.
We are the future.  We control reality, we
understand what reality really is.  The rest of the
world is blinded to the truth, but we know the truth.
What is the Matrix?  Reality, the universe in general.
Those who understand the matrix shape the matrix.
Because our eyes have been opened, we can
shape reality.
Who are we?  Infinity...
                         -Inferno
                         "The One"