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Re: RFC: attribute "unpadded"



That statement seems plausible, but your examples are not very convincing,
IMHO.
All I can tell you is what our customers tell us...

For example, Ada people have talked about laying
out objects in a C++-compatible way so that objects could be passed back
and forth between the languages.
I don't see how extending the C front-end to support attribute "unpadded"
would achieve that goal.  Presumably Ada objects are layed out by GNAT,
not C... if the issue is Ada/C++ compatibility, I don't see where C
comes into it.
This was meant as an example of an object-oriented language that might
like to be binary-compatible with C++.

People who generate C from their
object-oriented language compilers and want C++ interoperability also
would like to make use of this feature.
Wouldn't those people be better off just retargetting their compilers
to generate C++ rather than C?
There are things that can make that difficult; C++ has some pretty complex
rules that you can dodge for C.  And, a lot of these compilers already
exist.

As you say, the primary motivation was testing.  We're trying to provide
a tool that will make it easier for G++ to make sure its ABI-compliant.
This would make it easier for us to build the tool.  Let's leave it at
that.

--
Mark Mitchell                mark@codesourcery.com
CodeSourcery, LLC            http://www.codesourcery.com


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