On 14 Feb 2011, at 13:45, Jeppe Johansen wrote:
I did a little change to the patch though. I changed the syntax to
be "weakexternal ['library'] [name 'name'] [default
'initialvalue'];" since I figured default made more sense than set,
in the given context. I still think using weakexternal makes
sense(over adding a new "weak" keyword), since the meaning and
functionality still is the same
It's not the same.
"weak" (without external) would be a definition, which means that it
would be used in a situation like this:
procedure Test; weak;
begin
writeln('test');
end;
And the compiler would then generate something like this:
.weak Test
Test:
<code for test>
This would however be invalid code:
procedure Test; weak; external; // or "weakexternal" instead of
"weak; external;"
begin
end;
And this would be an incomplete declaration (missing function body):
procedure Test; weak;
That's why it was not a good idea (from me) to introduce
"weakexternal", since "weak" combined with "external" would be the
same (even if "weak" by itself weren't supported immediately).
Furthermore, the whole "default 'initialvalue'" stuff is actually
superfluous, since it basically is already part of the weak(external)
declaration:
procedure Test; weakexternal name 'aliasedTest';
could be defined to generate this:
.weak Test
.set Test,aliasedTest
After all, the above states that references to "Test" should be
treated as weak references to a symbol called "aliasedTest". It would
also be equivalent to what C does. I also don't think it would break
much, if any, existing code that uses "weakexternal" if the semantics
were to be redefined in this way.
Jonas
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