[cxx1z-constexpr-lambda] Make conversion function constexpr, and teach the expression-evaluator to evaluate the static-invoker.

This patch has been sitting in review hell since july 2016 and our lack of constexpr lambda support is getting embarrassing (given that I've had a branch that implements the feature (modulo *this capture) for over a year.  While in Issaquah I was enjoying shamelessly trying to convince folks of the lie that this was Richard's fault ;) I won't be able to do so in Kona since I won't be attending - so I'm going to aim to have this feature be implemented by then.

I'm quite confident of the approach in this patch, which simply maps the static-invoker 'thunk' back to the corresponding call-operator (specialization).

Thanks!

llvm-svn: 291397

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 1680d8a6960..a0d574915eb 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -1274,7 +1274,7 @@ static void addFunctionPointerConversion(Sema &S,
                                 ConvTy, 
                                 ConvTSI,
                                 /*isInline=*/true, /*isExplicit=*/false,
-                                /*isConstexpr=*/false, 
+                                /*isConstexpr=*/S.getLangOpts().CPlusPlus1z, 
                                 CallOperator->getBody()->getLocEnd());
   Conversion->setAccess(AS_public);
   Conversion->setImplicit(true);