diff options
| author | Douglas Gregor <dgregor@apple.com> | 2013-11-08 02:04:24 +0000 |
|---|---|---|
| committer | Douglas Gregor <dgregor@apple.com> | 2013-11-08 02:04:24 +0000 |
| commit | 3940e3b9c7cc89284117112e07ad1c925dcd0ab4 (patch) | |
| tree | 1a839cc4fe9e59e230bbf276bdee7322fad09c96 /lib/Sema/SemaTemplateDeduction.cpp | |
| parent | 80aecf578fa0b24e1f4280820a1b6f1bf34862e0 (diff) | |
Objective-C++ ARC: Improve the conversion to a const __unsafe_unretained reference.
Under ARC++, a reference to a const Objective-C pointer is implicitly
treated as __unsafe_unretained, and can be initialized with (e.g.) a
__strong lvalue. Make sure this behavior does not break template
argument deduction and (related) that partial ordering still prefers a
'T* const&' template over a 'T const&' template when this case kicks
in. Fixes <rdar://problem/14467941>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194239 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Sema/SemaTemplateDeduction.cpp')
| -rw-r--r-- | lib/Sema/SemaTemplateDeduction.cpp | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp index 6e510c2dbc..b401db21a8 100644 --- a/lib/Sema/SemaTemplateDeduction.cpp +++ b/lib/Sema/SemaTemplateDeduction.cpp @@ -2687,13 +2687,16 @@ CheckOriginalCallArgDeduction(Sema &S, Sema::OriginalCallArg OriginalArg, Qualifiers AQuals = A.getQualifiers(); Qualifiers DeducedAQuals = DeducedA.getQualifiers(); - // Under Objective-C++ ARC, the deduced type may have implicitly been - // given strong lifetime. If so, update the original qualifiers to - // include this strong lifetime. + // Under Objective-C++ ARC, the deduced type may have implicitly + // been given strong or (when dealing with a const reference) + // unsafe_unretained lifetime. If so, update the original + // qualifiers to include this lifetime. if (S.getLangOpts().ObjCAutoRefCount && - DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_Strong && - AQuals.getObjCLifetime() == Qualifiers::OCL_None) { - AQuals.setObjCLifetime(Qualifiers::OCL_Strong); + ((DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_Strong && + AQuals.getObjCLifetime() == Qualifiers::OCL_None) || + (DeducedAQuals.hasConst() && + DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone))) { + AQuals.setObjCLifetime(DeducedAQuals.getObjCLifetime()); } if (AQuals == DeducedAQuals) { @@ -2714,7 +2717,7 @@ CheckOriginalCallArgDeduction(Sema &S, Sema::OriginalCallArg OriginalArg, // // Also allow conversions which merely strip [[noreturn]] from function types // (recursively) as an extension. - // FIXME: Currently, this doesn't place nicely with qualfication conversions. + // FIXME: Currently, this doesn't play nicely with qualification conversions. bool ObjCLifetimeConversion = false; QualType ResultTy; if ((A->isAnyPointerType() || A->isMemberPointerType()) && |