[CallSite] Make construction from Value* (or Instruction*) explicit.

CallSite roughly behaves as a common base CallInst and InvokeInst. Bring
the behavior closer to that model by making upcasts explicit. Downcasts
remain implicit and work as before.

Following dyn_cast as a mental model checking whether a Value *V isa
CallSite now looks like this: 
  if (auto CS = CallSite(V)) // think dyn_cast
instead of:
  if (CallSite CS = V)

This is an extra token but I think it is slightly clearer. Making the
ctor explicit has the advantage of not accidentally creating nullptr
CallSites, e.g. when you pass a Value * to a function taking a CallSite
argument.

llvm-svn: 234601

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/MemDepPrinter.cpp b/llvm/lib/Analysis/MemDepPrinter.cpp
index e1b7b4b8509..da3b829b6d3 100644
--- a/llvm/lib/Analysis/MemDepPrinter.cpp
+++ b/llvm/lib/Analysis/MemDepPrinter.cpp
@@ -106,7 +106,7 @@ bool MemDepPrinter::runOnFunction(Function &F) {
     if (!Res.isNonLocal()) {
       Deps[Inst].insert(std::make_pair(getInstTypePair(Res),
                                        static_cast<BasicBlock *>(nullptr)));
-    } else if (CallSite CS = cast<Value>(Inst)) {
+    } else if (auto CS = CallSite(Inst)) {
       const MemoryDependenceAnalysis::NonLocalDepInfo &NLDI =
         MDA.getNonLocalCallDependency(CS);