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>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133303 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index b8caad8..fa2182a 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -2357,8 +2357,20 @@
return true;
// Add the converted template type argument.
- Converted.push_back(
- TemplateArgument(Context.getCanonicalType(Arg.getAsType())));
+ QualType ArgType = Context.getCanonicalType(Arg.getAsType());
+
+ // Objective-C ARC:
+ // If an explicitly-specified template argument type is a lifetime type
+ // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
+ if (getLangOptions().ObjCAutoRefCount &&
+ ArgType->isObjCLifetimeType() &&
+ !ArgType.getObjCLifetime()) {
+ Qualifiers Qs;
+ Qs.setObjCLifetime(Qualifiers::OCL_Strong);
+ ArgType = Context.getQualifiedType(ArgType, Qs);
+ }
+
+ Converted.push_back(TemplateArgument(ArgType));
return false;
}