Minutes, Oct 31, 2000
David Anderson acting for Michael Eager.
David Anderson, George Beshers, Ron Brender, Felix Burton,
Jim Dehnert, and David Weatherford attended (physically or
001018.1 Unspecified Type (void, void * and similar for other languages)
The proposal (which was discussed in the previous minutes)
was adopted. Ron Brender plans to put this as a section
between 5.1 and 5.2, causing renumbering of the rest of
chapter 5 (this editorial aspect is not part of the
proposal, it is simply the Editor's current plan for this topic).
001012.1 Factored Offset
Felix Burton asked "Why not use dwarf expressions
instead of new operators?" The suspicion is
that there is a meaningful difference in the space
required using expressions. Tabled till the next meeting
so the proposal champion (Anderson) can address this question
and get some real numbers together.
Weatherford pointed out yet a new name for these. "slipperies"
is a term often used at Sun (to add to the "thunks, trampolines,
and interludes" list).
The possibility of using DW_AT_artificial was raised as an
alternative to a new attribute.
But this was not felt to be direct or specific enough.
When used to describe adjusting a 'this' pointer
to point to a derived-type on entry, it was pointed out
that there could be 'adjust it back' code at the exit point,
which also fits the description.
The proposal was accepted with the stipulation that
the new attribute be named DW_AT_trampoline.
Additionally, it was stipulated that the FORM of the
DIE can be any of at least the following:
A string, an actual function name
This function name lookup is implementation-dependent
and could reference an ABI/implementation/object
specific table, such as an Elf symbol table.
An Address of a function that will be called.
A reference to a DIE, the function definition DIE
of the function that is being called.
A flag (when there is no way to know the
function address or name).
When it's just a flag the debugger must step (or equivalent)
to get to the target function.