1 files changed, 64 insertions, 0 deletions
diff --git a/lldb/source/Target/MemoryTagMap.cpp b/lldb/source/Target/MemoryTagMap.cpp
new file mode 100644
index 000000000000..846eef9209da
--- /dev/null
+++ b/lldb/source/Target/MemoryTagMap.cpp
@@ -0,0 +1,64 @@
+//===-- MemoryTagMap.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 "lldb/Target/MemoryTagMap.h"
+
+using namespace lldb_private;
+
+MemoryTagMap::MemoryTagMap(const MemoryTagManager *manager)
+    : m_manager(manager) {
+  assert(m_manager && "valid tag manager required to construct a MemoryTagMap");
+}
+
+void MemoryTagMap::InsertTags(lldb::addr_t addr,
+                              const std::vector<lldb::addr_t> tags) {
+  // We're assuming that addr has no non address bits and is granule aligned.
+  size_t granule_size = m_manager->GetGranuleSize();
+  for (auto tag : tags) {
+    m_addr_to_tag[addr] = tag;
+    addr += granule_size;
+  }
+}
+
+bool MemoryTagMap::Empty() const { return m_addr_to_tag.empty(); }
+
+std::vector<llvm::Optional<lldb::addr_t>>
+MemoryTagMap::GetTags(lldb::addr_t addr, size_t len) const {
+  // Addr and len might be unaligned
+  addr = m_manager->RemoveTagBits(addr);
+  MemoryTagManager::TagRange range(addr, len);
+  range = m_manager->ExpandToGranule(range);
+
+  std::vector<llvm::Optional<lldb::addr_t>> tags;
+  lldb::addr_t end_addr = range.GetRangeEnd();
+  addr = range.GetRangeBase();
+  bool got_valid_tags = false;
+  size_t granule_size = m_manager->GetGranuleSize();
+
+  for (; addr < end_addr; addr += granule_size) {
+    llvm::Optional<lldb::addr_t> tag = GetTag(addr);
+    tags.push_back(tag);
+    if (tag)
+      got_valid_tags = true;
+  }
+
+  // To save the caller checking if every item is llvm::None,
+  // we return an empty vector if we got no tags at all.
+  if (got_valid_tags)
+    return tags;
+  return {};
+}
+
+llvm::Optional<lldb::addr_t> MemoryTagMap::GetTag(lldb::addr_t addr) const {
+  // Here we assume that addr is granule aligned, just like when the tags
+  // were inserted.
+  auto found = m_addr_to_tag.find(addr);
+  if (found == m_addr_to_tag.end())
+    return llvm::None;
+  return found->second;
+}