[llvm] [SandboxIR] IR Tracker (PR #99238)

[Arthur Eubanks via llvm-commits]

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@@ -0,0 +1,84 @@
+//===- SandboxIRTracker.cpp -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/SandboxIR/SandboxIRTracker.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/SandboxIR/SandboxIR.h"
+#include <sstream>
+
+using namespace llvm::sandboxir;
+
+IRChangeBase::IRChangeBase(TrackID ID, SandboxIRTracker &Parent)
+    : ID(ID), Parent(Parent) {
+#ifndef NDEBUG
+  Idx = Parent.size();
+
+  assert(!Parent.InMiddleOfCreatingChange &&
+         "We are in the middle of creating another change!");
+  if (Parent.tracking())
+    Parent.InMiddleOfCreatingChange = true;
+#endif // NDEBUG
+}
+
+#ifndef NDEBUG
+void UseSet::dump() const {
+  dump(dbgs());
+  dbgs() << "\n";
+}
+#endif // NDEBUG
+
+SandboxIRTracker::~SandboxIRTracker() {
+  assert(Changes.empty() && "You must accept or revert changes!");
+}
+
+void SandboxIRTracker::track(std::unique_ptr<IRChangeBase> &&Change) {
+#ifndef NDEBUG
+  assert(State != TrackerState::Revert &&
+         "No changes should be tracked during revert()!");
+#endif // NDEBUG
+  Changes.push_back(std::move(Change));
+
+#ifndef NDEBUG
+  InMiddleOfCreatingChange = false;
+#endif
+}
+
+void SandboxIRTracker::save() { State = TrackerState::Record; }
+
+void SandboxIRTracker::revert() {
+  auto SavedState = State;
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aeubanks wrote:

 does the state need to be `Record` here? or we allow calling this even when not tracking?

https://github.com/llvm/llvm-project/pull/99238