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
get(Metadata & MD)19 ReplaceableMetadataImpl *ReplaceableMetadataImpl::get(Metadata &MD) {
20 if (auto *N = dyn_cast<MDNode>(&MD)) {
21 if (auto *U = dyn_cast<UniquableMDNode>(N))
22 return U->ReplaceableUses.get();
23 return cast<MDNodeFwdDecl>(N);
24 }
25 return dyn_cast<ValueAsMetadata>(&MD);
26 }
27
track(void * Ref,Metadata & MD,OwnerTy Owner)28 bool MetadataTracking::track(void *Ref, Metadata &MD, OwnerTy Owner) {
29 assert(Ref && "Expected live reference");
30 assert((Owner || *static_cast<Metadata **>(Ref) == &MD) &&
31 "Reference without owner must be direct");
32 if (auto *R = ReplaceableMetadataImpl::get(MD)) {
33 R->addRef(Ref, Owner);
34 return true;
35 }
36 return false;
37 }
38
untrack(void * Ref,Metadata & MD)39 void MetadataTracking::untrack(void *Ref, Metadata &MD) {
40 assert(Ref && "Expected live reference");
41 if (auto *R = ReplaceableMetadataImpl::get(MD))
42 R->dropRef(Ref);
43 }
44
retrack(void * Ref,Metadata & MD,void * New)45 bool MetadataTracking::retrack(void *Ref, Metadata &MD, void *New) {
46 assert(Ref && "Expected live reference");
47 assert(New && "Expected live reference");
48 assert(Ref != New && "Expected change");
49 if (auto *R = ReplaceableMetadataImpl::get(MD)) {
50 R->moveRef(Ref, New, MD);
51 return true;
52 }
53 return false;
54 }
55
isReplaceable(const Metadata & MD)56 bool MetadataTracking::isReplaceable(const Metadata &MD) {
57 return ReplaceableMetadataImpl::get(const_cast<Metadata &>(MD));
58 }
59