about gcc version

lwb422 · 04-08-2010, 10:58 PM

As a newbie for linux , i am really confused about gcc version.
Aren't the new ones compatible the old ones? But online there is always someone says ,he should install a old suitalbe one for his IDE. I am really confused. If it needs a long words to express the reason clearly, a link or some books you recommend is a good answer. Thanks.

grail · 04-09-2010, 12:34 AM

I am not a whole lot sure about the IDE reference (maybe someone else can confirm) but it has been
my experience that certain applications (generally old ones) will require older versions of a compiler.
I believe the reason is that to make the necessary changes to the old applications code is such a large
task that it far out weighs simply using the older compiler.
And the reason the changes are required is generally as deprecated options/functions have been replaced.

knudfl · 04-09-2010, 05:22 AM

The older compilers were much more tolerant with sloppy code.
But you can of course find code written in 1999, that will
compile nice with gcc-4.4.1 !

Porting the code ... to gcc 4.3
http://gcc.gnu.org/gcc-4.3/porting_to.html
and to gcc 4.4
http://gcc.gnu.org/gcc-4.4/porting_to.html

Porting 2,000 files for an application : you probably wouldn't.
But then again, you can have as many compilers as you want,
installed at the same time. Four times gcc / g++ is not unusual.
# yum install compat-gcc-34-c++ gcc-c++ gcc44-c++
.. will provide versions 3.4.6 , 4.1.2 , 4.4.0 for EL 5.
.....