InstructionDeleter ctor moves callbacks to fix iterator invalidation

The InstructionDeleter needs to move the callbacks during construction
to prevent the client code from using the old callbacks.

Fixes iterator invalidation bugs.

Author: atrick

lib/SILOptimizer/Mandatory/OSLogOptimization.cpp

@@ -1250,7 +1250,7 @@ static bool tryEliminateOSLogMessage(SingleValueInstruction *oslogMessage) {
         }
         (void)deletedInstructions.insert(deadInst);
       });
-  InstructionDeleter deleter(callbacks);
+  InstructionDeleter deleter(std::move(callbacks));
 
   unsigned startIndex = 0;
   while (startIndex < worklist.size()) {

lib/SILOptimizer/Transforms/AccessEnforcementOpts.cpp

@@ -1028,7 +1028,7 @@ static bool extendOwnership(BeginAccessInst *parentInst,
 static bool
 mergeAccesses(SILFunction *F, PostDominanceInfo *postDomTree,
               const AccessConflictAndMergeAnalysis::MergeablePairs &mergePairs,
-              InstModCallbacks &callbacks, DeadEndBlocks &deBlocks) {
+              DeadEndBlocks &deBlocks) {
 
   if (mergePairs.empty()) {
     LLVM_DEBUG(llvm::dbgs() << "Skipping SCC Analysis...\n");
@@ -1064,7 +1064,7 @@ mergeAccesses(SILFunction *F, PostDominanceInfo *postDomTree,
   // begin_access instruction. We store (begin_access %2 -> begin_access %1)
   // to re-map a merged begin_access to it's replaced instruction.
   llvm::DenseMap<BeginAccessInst *, BeginAccessInst *> oldToNewMap;
-  InstructionDeleter deleter(callbacks);
+  InstructionDeleter deleter;
 
   while (!workPairs.empty()) {
     auto curr = workPairs.pop_back_val();
@@ -1162,8 +1162,7 @@ struct AccessEnforcementOpts : public SILFunctionTransform {
         getAnalysis<PostDominanceAnalysis>();
     PostDominanceInfo *postDomTree = postDomAnalysis->get(F);
     DeadEndBlocks *deBlocks = deBlocksAnalysis->get(F);
-    InstModCallbacks callbacks;
-    if (mergeAccesses(F, postDomTree, result.mergePairs, callbacks, *deBlocks))
+    if (mergeAccesses(F, postDomTree, result.mergePairs, *deBlocks))
       invalidateAnalysis(SILAnalysis::InvalidationKind::Instructions);
   }
 };

lib/SILOptimizer/Utils/ConstantFolding.cpp

@@ -1654,6 +1654,7 @@ ConstantFolder::processWorkList() {
         InvalidateInstructions = true;
         instToDelete->eraseFromParent();
       });
+  InstructionDeleter deleter(std::move(callbacks));
 
   // An out parameter array that we use to return new simplified results from
   // constantFoldInstruction.
@@ -1677,7 +1678,7 @@ ConstantFolder::processWorkList() {
           // Schedule users for constant folding.
           WorkList.insert(AssertConfInt);
           // Delete the call.
-          eliminateDeadInstruction(BI, callbacks);
+          eliminateDeadInstruction(BI, deleter.getCallbacks());
           continue;
         }
 
@@ -1686,7 +1687,7 @@ ConstantFolder::processWorkList() {
         if (isApplyOfBuiltin(*BI, BuiltinValueKind::CondUnreachable)) {
           assert(BI->use_empty() && "use of conditionallyUnreachable?!");
           recursivelyDeleteTriviallyDeadInstructions(BI, /*force*/ true,
-                                                     callbacks);
+                                                     deleter.getCallbacks());
           InvalidateInstructions = true;
           continue;
         }
@@ -1698,7 +1699,7 @@ ConstantFolder::processWorkList() {
         SILBuilderWithScope B(I);
         auto tru = B.createIntegerLiteral(apply->getLoc(), apply->getType(), 1);
         apply->replaceAllUsesWith(tru);
-        eliminateDeadInstruction(I, callbacks);
+        eliminateDeadInstruction(I, deleter.getCallbacks());
         WorkList.insert(tru);
         InvalidateInstructions = true;
       }
@@ -1747,7 +1748,7 @@ ConstantFolder::processWorkList() {
       if (constantFoldGlobalStringTablePointerBuiltin(cast<BuiltinInst>(I),
                                                       EnableDiagnostics)) {
         // Here, the builtin instruction got folded, so clean it up.
-        eliminateDeadInstruction(I, callbacks);
+        eliminateDeadInstruction(I, deleter.getCallbacks());
       }
       continue;
     }
@@ -1763,7 +1764,7 @@ ConstantFolder::processWorkList() {
                                              sli->getValue());
           WorkList.insert(cfi);
           recursivelyDeleteTriviallyDeadInstructions(I, /*force*/ true,
-                                                     callbacks);
+                                                     deleter.getCallbacks());
         }
       }
       continue;
@@ -1773,7 +1774,7 @@ ConstantFolder::processWorkList() {
       if (constantFoldIsConcrete(cast<BuiltinInst>(I))) {
         // Here, the builtin instruction got folded, so clean it up.
         recursivelyDeleteTriviallyDeadInstructions(I, /*force*/ true,
-                                                   callbacks);
+                                                   deleter.getCallbacks());
       }
       continue;
     }
@@ -1796,7 +1797,7 @@ ConstantFolder::processWorkList() {
             SILType::getBuiltinIntegerType(1, builder.getASTContext()), val);
         BI->replaceAllUsesWith(inst);
 
-        eliminateDeadInstruction(I, callbacks);
+        eliminateDeadInstruction(I, deleter.getCallbacks());
         continue;
       }
     }
@@ -1817,7 +1818,6 @@ ConstantFolder::processWorkList() {
     }
 
     // Go through all users of the constant and try to fold them.
-    InstructionDeleter deleter(callbacks);
     for (auto Result : I->getResults()) {
       for (auto *Use : Result->getUses()) {
         SILInstruction *User = Use->getUser();

lib/SILOptimizer/Utils/OwnershipOptUtils.cpp

@@ -555,7 +555,10 @@ extendOverBorrowScopeAndConsume(SILValue ownedValue) {
   // Populate the reborrowedPhis vector.
   analyzeExtendedScope();
 
-  InstructionDeleter deleter(callbacks);
+  // Warning: don't use the original callbacks in this function after creating a
+  // deleter.
+  InstModCallbacks tempCallbacks = callbacks;
+  InstructionDeleter deleter(std::move(tempCallbacks));
 
   // Generate and map the phis with undef operands first, in case of recursion.
   auto undef = SILUndef::get(ownedValue->getType(), *ownedValue->getFunction());