[CallSite removal] Migrate all Alias Analysis APIs to use the newly

minted `CallBase` class instead of the `CallSite` wrapper.

This moves the largest interwoven collection of APIs that traffic in
`CallSite`s. While a handful of these could have been migrated with
a minorly more shallow migration by converting from a `CallSite` to
a `CallBase`, it hardly seemed worth it. Most of the APIs needed to
migrate together because of the complex interplay of AA APIs and the
fact that converting from a `CallBase` to a `CallSite` isn't free in its
current implementation.

Out of tree users of these APIs can fairly reliably migrate with some
combination of `.getInstruction()` on the `CallSite` instance and
casting the resulting pointer. The most generic form will look like `CS`
-> `cast_or_null<CallBase>(CS.getInstruction())` but in most cases there
is a more elegant migration. Hopefully, this migrates enough APIs for
users to fully move from `CallSite` to the base class. All of the
in-tree users were easily migrated in that fashion.

Thanks for the review from Saleem!

Differential Revision: https://reviews.llvm.org/D55641

llvm-svn: 350503

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/ObjCARC/DependencyAnalysis.cpp b/llvm/lib/Transforms/ObjCARC/DependencyAnalysis.cpp
index 52a5e8c96ab..4bd5fd1acd4 100644
--- a/llvm/lib/Transforms/ObjCARC/DependencyAnalysis.cpp
+++ b/llvm/lib/Transforms/ObjCARC/DependencyAnalysis.cpp
@@ -45,18 +45,15 @@ bool llvm::objcarc::CanAlterRefCount(const Instruction *Inst, const Value *Ptr,
   default: break;
   }
 
-  ImmutableCallSite CS(Inst);
-  assert(CS && "Only calls can alter reference counts!");
+  const auto *Call = cast<CallBase>(Inst);
 
   // See if AliasAnalysis can help us with the call.
-  FunctionModRefBehavior MRB = PA.getAA()->getModRefBehavior(CS);
+  FunctionModRefBehavior MRB = PA.getAA()->getModRefBehavior(Call);
   if (AliasAnalysis::onlyReadsMemory(MRB))
     return false;
   if (AliasAnalysis::onlyAccessesArgPointees(MRB)) {
     const DataLayout &DL = Inst->getModule()->getDataLayout();
-    for (ImmutableCallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
-         I != E; ++I) {
-      const Value *Op = *I;
+    for (const Value *Op : Call->args()) {
       if (IsPotentialRetainableObjPtr(Op, *PA.getAA()) &&
           PA.related(Ptr, Op, DL))
         return true;