Commit Graph

4 Commits

Author SHA1 Message Date
John McCall 24fc0decfe Change the driver's logic about Objective-C runtimes: abstract out a
structure to hold inferred information, then propagate each invididual
bit down to -cc1.  Separate the bits of "supports weak" and "has a native
ARC runtime";  make the latter a CodeGenOption.

The tool chain is still driving this decision, because it's the place that
has the required deployment target information on Darwin, but at least it's
better-factored now.

llvm-svn: 134453
2011-07-06 00:26:06 +00:00
Douglas Gregor d7357a9b8e Objective-C++ ARC: eliminate the utterly unjustified loophole that
silently dropped ownership qualifiers that were being applied to
ownership-qualified, substituted type that was *not* a substituted
template type parameter. We now provide a diagnostic in such cases,
and recover by dropping the added qualifiers.

Document this behavior in the ARC specification.

llvm-svn: 133309
2011-06-17 23:16:24 +00:00
Douglas Gregor e46db90c9a Objective-ARC++: infer template type arguments of
ownership-unqualified retainable object type as __strong. This allows
us to write, e.g.,

  std::vector<id>

and we'll infer that the vector's element types have __strong
ownership semantics, which is far nicer than requiring:

  std::vector<__strong id>

Note that we allow one to override the ownership qualifier of a
substituted template type parameter, e.g., given

  template<typename T>
  struct X {
    typedef __weak T type;
  };

X<id> is treated the same as X<__strong id>. At instantiation type,
the __weak in "__weak T" overrides the (inferred or specified)
__strong on the template argument type, so that we can still provide
metaprogramming transformations.

This is part of <rdar://problem/9595486>.

llvm-svn: 133303
2011-06-17 22:11:49 +00:00
John McCall 31168b077c Automatic Reference Counting.
Language-design credit goes to a lot of people, but I particularly want
to single out Blaine Garst and Patrick Beard for their contributions.

Compiler implementation credit goes to Argyrios, Doug, Fariborz, and myself,
in no particular order.

llvm-svn: 133103
2011-06-15 23:02:42 +00:00