Re: [avr-gcc-list] Duplicated C++ constructor code

[Greg Tunnock]

Hi,

On Wed, 20 Nov 2002, Greg Tunnock wrote:

> Hi,
>
> I'm using avr-gcc-3.3.2002.10.01 on FreeBSD to compile C++ code. The listing
> file from avr-objdump show that the compile has duplicated the code for the
> class constructors.

<details removed>

> Is this a problem with avr-gcc? Or am I doing something silly? Or have I
> miss understood some aspect of C++?

I've found the answer to my own question. Is that like talking to yourself :-)

Duplicate identical C++ constructor generation is a feature/aspect of
gcc3.3. This aspect of gcc is document in the GCC Bugs web page under the
Non-bugs section <http://www.gnu.org/software/gcc/bugs.html#nonbugs>, which
says:

  G++ emits two copies of constructors and destructors.

      In general there are three types of constructors (and destructors).

         1. The complete object constructor/destructor.
         2. The base object constructor/destructor.
         3. The allocating destructor/deallocating destructor.

  The first two are different, when virtual base classes are involved. In some
  cases we can do better, and this is logged in GNATS.

Cheers,
Greg Tunnock

avr-gcc-list at http://avr1.org