Re: ordering of constructors

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Joe Buck <Joe.Buck@synopsys.com> writes:

| On Fri, Apr 09, 2004 at 10:52:00AM -0400, Daniel Jacobowitz wrote:
| > On Fri, Apr 09, 2004 at 03:33:20PM +0200, Gabriel Dos Reis wrote:
| > >   It is implementation-defined whether or not the dynamic
| > >   initialization (8.5, 9.4, 12.1, 12.6.1) of an object of namespace
| > >   scope is done before the first statement of main. If the
| > >   initialization is deferred to some point in time after the first
| > >   statement of main, *it shall occur before the first use of any
| > >   function or object defined in the same translation unit as the
| > >   object to be initialized*. 
| > 
| > Does that answer the question?  I don't believe that it does.  In this
| > case, the initialization is _not_ deferred until after the first
| > statement of main.  Instead, we're before main executing global
| > constructors.
| > 
| > To honor your interpretation of that paragraph, we would have to check
| > at the beginning of every external function in every translation unit
| > containing static variables whether they had been initialized yet,
| > which would be prohibitively expensive - and I'm pretty sure we don't
| > do that.
| 
| It's worse than that; an attempt to provide the guarantee before main
| is called fails in cases where constructors in file A.cpp depend on
| the construction of objects in B.cpp and vice versa: an attempt to
| provide the guarantee would cause a deadlock.

I don't see why that is different from what happens when the dynamic
initialization is delayed until main() as described by 3.6.2/3.

-- Gaby