PATCH RFA: Build stages 2 and 3 with C++

[David Edelsohn]

On Wed, Jul 20, 2011 at 4:53 PM, Mike Stump <mikestump@comcast.net> wrote:
> On Jul 20, 2011, at 1:25 PM, Ian Lance Taylor wrote:
>> Interesting.  I don't know why this doesn't happen on GNU/Linux.
>
> It doesn't happen as the symbols in question are local on linux.  collect2 runs nm on public symbols looking for symbols of a particular form, it then builds two lists, one for constructors of global objects (simplistic view) and one for destructors.  a.out systems liked doing this sort of things as well.  On more modern OSes, the constructors and destructors hook into crt code that can run per translation unit initializations, for example on elf, one might use .init to achieve this.  When one uses one of these more advanced features to hook into the OS, then the symbols no longer need to be public and the port is changed to make them non-public.

This is not the global constructor/destructor issue with names
generated by collect2.  But ELF or SVR4 is able to provide a unique
name without resorting to random numbers.

- David