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Re: breakpoints in constructors


>>>>> "Daniel" == Daniel Jacobowitz <drow at mvista dot com> writes:

 Daniel> On Fri, Apr 18, 2003 at 01:04:46PM -0700, David Carlton
 Daniel> wrote:
 >> I might have some time over the next few weeks (/months) to work
 >> on the "breakpoints in constructors" issue.  Daniel: clearly
 >> you've thought about this already, so if you happen to have time
 >> to do a bit of a brain dump on the issue at some point, I'd
 >> appreciate it.

 Daniel> Sure.  First of all, a rough overview of the problem; might
 Daniel> as well keep everything in one place.

 Daniel> With the new GCC 3.x multi-vendor C++ ABI, constructors are
 Daniel> implemented as multiple functions: C1, the complete object
 Daniel> constructor [in-charge] C2, the base object constructor
 Daniel> [not-in-charge] C3, the allocating constructor [not currently
 Daniel> used]

 Daniel> Similarly for destructors - most of the rest of this message
 Daniel> applies to destructors too.  The base constructor is
 Daniel> generally called for the base objects of a derived class,
 Daniel> esp. with virtual inheritance; it's been a while since I
 Daniel> looked at exactly when.

 Daniel> GCC has chosen to implement this by duplicating the function,
 Daniel> including any user-provided code and any compiler-added code.
 Daniel> A better implementation would have one copy and labels for
 Daniel> multiple entry points, on systems where that is supported;
 Daniel> that's temporarily tabled pending a better description of the
 Daniel> GCC tree structure to describe multiple entry points.

Maybe this is off base, but Fortran has always had multiple entry
points, and GCC supports Fortran (g77), so presumably there is a way
to represent this in the tree structure already.

   paul


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