1 //===- MetadataTracking.cpp - Implement metadata tracking -----------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements Metadata tracking. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/IR/MetadataTracking.h" 15 #include "llvm/IR/Metadata.h" 16 17 using namespace llvm; 18 19 ReplaceableMetadataImpl *ReplaceableMetadataImpl::get(Metadata &MD) { 20 if (auto *N = dyn_cast<MDNode>(&MD)) 21 return N->Context.getReplaceableUses(); 22 return dyn_cast<ValueAsMetadata>(&MD); 23 } 24 25 bool MetadataTracking::track(void *Ref, Metadata &MD, OwnerTy Owner) { 26 assert(Ref && "Expected live reference"); 27 assert((Owner || *static_cast<Metadata **>(Ref) == &MD) && 28 "Reference without owner must be direct"); 29 if (auto *R = ReplaceableMetadataImpl::get(MD)) { 30 R->addRef(Ref, Owner); 31 return true; 32 } 33 return false; 34 } 35 36 void MetadataTracking::untrack(void *Ref, Metadata &MD) { 37 assert(Ref && "Expected live reference"); 38 if (auto *R = ReplaceableMetadataImpl::get(MD)) 39 R->dropRef(Ref); 40 } 41 42 bool MetadataTracking::retrack(void *Ref, Metadata &MD, void *New) { 43 assert(Ref && "Expected live reference"); 44 assert(New && "Expected live reference"); 45 assert(Ref != New && "Expected change"); 46 if (auto *R = ReplaceableMetadataImpl::get(MD)) { 47 R->moveRef(Ref, New, MD); 48 return true; 49 } 50 return false; 51 } 52 53 bool MetadataTracking::isReplaceable(const Metadata &MD) { 54 return ReplaceableMetadataImpl::get(const_cast<Metadata &>(MD)); 55 } 56
