Use CallbackVH in AliasSetTracker to avoid getting stuck with

dangling Value*s.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77623 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-07-30 20:21:41 +00:00
parent d8c95b5ac2
commit b5b56ba9d4
2 changed files with 36 additions and 6 deletions

View File

@ -18,6 +18,7 @@
#define LLVM_ANALYSIS_ALIASSETTRACKER_H
#include "llvm/Support/CallSite.h"
#include "llvm/Support/ValueHandle.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/ilist.h"
@ -251,11 +252,24 @@ inline std::ostream& operator<<(std::ostream &OS, const AliasSet &AS) {
class AliasSetTracker {
/// CallbackVH - A CallbackVH to arrange for AliasSetTracker to be
/// notified whenever a Value is deleted.
class ASTCallbackVH : public CallbackVH {
AliasSetTracker *AST;
virtual void deleted();
public:
ASTCallbackVH(Value *V, AliasSetTracker *AST = 0);
};
AliasAnalysis &AA;
ilist<AliasSet> AliasSets;
typedef DenseMap<ASTCallbackVH, AliasSet::PointerRec*, DenseMapInfo<Value*> >
PointerMapType;
// Map from pointers to their node
DenseMap<Value*, AliasSet::PointerRec*> PointerMap;
PointerMapType PointerMap;
public:
/// AliasSetTracker ctor - Create an empty collection of AliasSets, and use
/// the specified alias analysis object to disambiguate load and store
@ -364,7 +378,7 @@ private:
// getEntryFor - Just like operator[] on the map, except that it creates an
// entry for the pointer if it doesn't already exist.
AliasSet::PointerRec &getEntryFor(Value *V) {
AliasSet::PointerRec *&Entry = PointerMap[V];
AliasSet::PointerRec *&Entry = PointerMap[ASTCallbackVH(V, this)];
if (Entry == 0)
Entry = new AliasSet::PointerRec(V);
return *Entry;

View File

@ -187,8 +187,8 @@ bool AliasSet::aliasesCallSite(CallSite CS, AliasAnalysis &AA) const {
void AliasSetTracker::clear() {
// Delete all the PointerRec entries.
for (DenseMap<Value*, AliasSet::PointerRec*>::iterator I = PointerMap.begin(),
E = PointerMap.end(); I != E; ++I)
for (PointerMapType::iterator I = PointerMap.begin(), E = PointerMap.end();
I != E; ++I)
I->second->eraseFromList();
PointerMap.clear();
@ -485,7 +485,7 @@ void AliasSetTracker::deleteValue(Value *PtrVal) {
AS->removeCallSite(CS);
// First, look up the PointerRec for this pointer.
DenseMap<Value*, AliasSet::PointerRec*>::iterator I = PointerMap.find(PtrVal);
PointerMapType::iterator I = PointerMap.find(PtrVal);
if (I == PointerMap.end()) return; // Noop
// If we found one, remove the pointer from the alias set it is in.
@ -511,7 +511,7 @@ void AliasSetTracker::copyValue(Value *From, Value *To) {
AA.copyValue(From, To);
// First, look up the PointerRec for this pointer.
DenseMap<Value*, AliasSet::PointerRec*>::iterator I = PointerMap.find(From);
PointerMapType::iterator I = PointerMap.find(From);
if (I == PointerMap.end())
return; // Noop
assert(I->second->hasAliasSet() && "Dead entry?");
@ -575,6 +575,22 @@ void AliasSetTracker::print(std::ostream &OS) const {
void AliasSet::dump() const { print (cerr); }
void AliasSetTracker::dump() const { print(cerr); }
//===----------------------------------------------------------------------===//
// ASTCallbackVH Class Implementation
//===----------------------------------------------------------------------===//
void AliasSetTracker::ASTCallbackVH::deleted() {
assert(AST && "ASTCallbackVH called with a null AliasSetTracker!");
AST->deleteValue(getValPtr());
// this now dangles!
}
AliasSetTracker::ASTCallbackVH::ASTCallbackVH(Value *V, AliasSetTracker *ast)
: CallbackVH(V == DenseMapInfo<Value *>::getEmptyKey() ? 0 :
V == DenseMapInfo<Value *>::getTombstoneKey() ? 0 :
V),
AST(ast) {}
//===----------------------------------------------------------------------===//
// AliasSetPrinter Pass
//===----------------------------------------------------------------------===//