lldb/source/Target/MemoryTagMap.cpp

   1 //===-- MemoryTagMap.cpp --------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "lldb/Target/MemoryTagMap.h"
  10 #include <optional>
  11
  12 using namespace lldb_private;
  13
  14 MemoryTagMap::MemoryTagMap(const MemoryTagManager *manager)
  15     : m_manager(manager) {
  16   assert(m_manager && "valid tag manager required to construct a MemoryTagMap");
  17 }
  18
  19 void MemoryTagMap::InsertTags(lldb::addr_t addr,
  20                               const std::vector<lldb::addr_t> tags) {
  21   // We're assuming that addr has no non address bits and is granule aligned.
  22   size_t granule_size = m_manager->GetGranuleSize();
  23   for (auto tag : tags) {
  24     m_addr_to_tag[addr] = tag;
  25     addr += granule_size;
  26   }
  27 }
  28
  29 bool MemoryTagMap::Empty() const { return m_addr_to_tag.empty(); }
  30
  31 std::vector<std::optional<lldb::addr_t>>
  32 MemoryTagMap::GetTags(lldb::addr_t addr, size_t len) const {
  33   // Addr and len might be unaligned
  34   addr = m_manager->RemoveTagBits(addr);
  35   MemoryTagManager::TagRange range(addr, len);
  36   range = m_manager->ExpandToGranule(range);
  37
  38   std::vector<std::optional<lldb::addr_t>> tags;
  39   lldb::addr_t end_addr = range.GetRangeEnd();
  40   addr = range.GetRangeBase();
  41   bool got_valid_tags = false;
  42   size_t granule_size = m_manager->GetGranuleSize();
  43
  44   for (; addr < end_addr; addr += granule_size) {
  45     std::optional<lldb::addr_t> tag = GetTag(addr);
  46     tags.push_back(tag);
  47     if (tag)
  48       got_valid_tags = true;
  49   }
  50
  51   // To save the caller checking if every item is std::nullopt,
  52   // we return an empty vector if we got no tags at all.
  53   if (got_valid_tags)
  54     return tags;
  55   return {};
  56 }
  57
  58 std::optional<lldb::addr_t> MemoryTagMap::GetTag(lldb::addr_t addr) const {
  59   // Here we assume that addr is granule aligned, just like when the tags
  60   // were inserted.
  61   auto found = m_addr_to_tag.find(addr);
  62   if (found == m_addr_to_tag.end())
  63     return std::nullopt;
  64   return found->second;
  65 }