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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133309 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/AutomaticReferenceCounting.html b/docs/AutomaticReferenceCounting.html
index b5b17b7..d094d74 100644
--- a/docs/AutomaticReferenceCounting.html
+++ b/docs/AutomaticReferenceCounting.html
@@ -598,12 +598,15 @@
element type is a retainable object owner type.</p>
<p>An <span class="term">ownership qualifier</span> is a type
-qualifier which applies only to retainable object owner types. A
-program is ill-formed if it attempts to apply an ownership qualifier
+qualifier which applies only to retainable object owner types. An array type is
+ownership-qualified according to its element type, and adding an ownership
+qualifier to an array type so qualifies its element type.</p>
+
+<p>A program is ill-formed if it attempts to apply an ownership qualifier
to a type which is already ownership-qualified, even if it is the same
-qualifier. An array type is ownership-qualified according to its
-element type, and adding an ownership qualifier to an array type so
-qualifies its element type.</p>
+qualifier. There is a single exception to this rule: an ownership qualifier
+may be applied to a substituted template type parameter, which overrides the
+ownership qualifier provided by the template argument.</p>
<p>Except as described under
the <a href="#ownership.inference">inference rules</a>, a program is
@@ -612,7 +615,7 @@
<div class="rationale"><p>Rationale: these rules, together with the
inference rules, ensure that all objects and lvalues of retainable
-object pointer type have an ownership qualifier.</p></div>
+object pointer type have an ownership qualifier. The ability to override an ownership qualifier during template substitution is required to counteract the <a href="#ownership.inference.template_arguments">inference of <tt>__strong</tt> for template type arguments</a>. </p></div>
<p>There are four ownership qualifiers:</p>