Add FIXMEs for calls to liveness that fail to check pointer escapes.

Author: atrick

lib/SILOptimizer/Mandatory/MoveOnlyAddressCheckerUtils.cpp

@@ -3827,6 +3827,8 @@ bool MoveOnlyAddressCheckerPImpl::performSingleCheck(
 
     CopiedLoadBorrowEliminationState state(markedAddress->getFunction());
     CopiedLoadBorrowEliminationVisitor copiedLoadBorrowEliminator(state);
+    // FIXME: should check AddressUseKind::NonEscaping != walk() to handle
+    // PointerEscape.
     if (AddressUseKind::Unknown ==
         std::move(copiedLoadBorrowEliminator).walk(markedAddress)) {
       LLVM_DEBUG(llvm::dbgs() << "Failed copied load borrow eliminator visit: "
@@ -3869,6 +3871,8 @@ bool MoveOnlyAddressCheckerPImpl::performSingleCheck(
     RAIILLVMDebug l("main use gathering visitor");
 
     visitor.reset(markedAddress);
+    // FIXME: should check walkResult != AddressUseKind::NonEscaping to handle
+    // PointerEscape.
     if (AddressUseKind::Unknown == std::move(visitor).walk(markedAddress)) {
       LLVM_DEBUG(llvm::dbgs()
                  << "Failed access path visit: " << *markedAddress);

lib/SILOptimizer/Mandatory/MoveOnlyUtils.cpp

@@ -583,6 +583,7 @@ bool siloptimizer::eliminateTemporaryAllocationsFromLet(
   };
   FindCopyAddrWalker walker(copiesToVisit);
   std::move(walker).walk(markedInst);
+  // FIXME: should check walk() == AddressUseKind::NonEscaping.
 
   bool madeChange = false;
 
@@ -612,6 +613,8 @@ bool siloptimizer::eliminateTemporaryAllocationsFromLet(
       nextCAI = nullptr;
       SimpleTemporaryAllocStackElimVisitor visitor(state, cai, nextCAI);
 
+      // FIXME: should check AddressUseKind::NonEscaping != walk() to handle
+      // PointerEscape.
       if (AddressUseKind::Unknown == std::move(visitor).walk(cai->getDest()))
         return false;
 

lib/SILOptimizer/Utils/SILIsolationInfo.cpp

@@ -211,6 +211,8 @@ inferIsolationInfoForTempAllocStack(AllocStackInst *asi) {
   AddressWalker walker(state);
 
   // If we fail to walk, emit an unknown patten error.
+  //
+  // FIXME: check AddressUseKind::NonEscaping != walk().
   if (AddressUseKind::Unknown == std::move(walker).walk(asi)) {
     return SILIsolationInfo();
   }