1 files changed, 73 insertions, 0 deletions
diff --git a/contrib/llvm-project/lldb/source/Plugins/Process/Utility/HistoryUnwind.cpp b/contrib/llvm-project/lldb/source/Plugins/Process/Utility/HistoryUnwind.cpp
new file mode 100644
index 000000000000..7749dc6f5d51
--- /dev/null
+++ b/contrib/llvm-project/lldb/source/Plugins/Process/Utility/HistoryUnwind.cpp
@@ -0,0 +1,73 @@
+//===-- HistoryUnwind.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/lldb-private.h"
+
+#include "Plugins/Process/Utility/HistoryUnwind.h"
+#include "Plugins/Process/Utility/RegisterContextHistory.h"
+
+#include "lldb/Target/Process.h"
+#include "lldb/Target/StackFrame.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/Thread.h"
+
+#include <memory>
+
+using namespace lldb;
+using namespace lldb_private;
+
+// Constructor
+
+HistoryUnwind::HistoryUnwind(Thread &thread, std::vector<lldb::addr_t> pcs,
+                             bool pcs_are_call_addresses)
+    : Unwind(thread), m_pcs(pcs),
+      m_pcs_are_call_addresses(pcs_are_call_addresses) {}
+
+// Destructor
+
+HistoryUnwind::~HistoryUnwind() = default;
+
+void HistoryUnwind::DoClear() {
+  std::lock_guard<std::recursive_mutex> guard(m_unwind_mutex);
+  m_pcs.clear();
+}
+
+lldb::RegisterContextSP
+HistoryUnwind::DoCreateRegisterContextForFrame(StackFrame *frame) {
+  RegisterContextSP rctx;
+  if (frame) {
+    addr_t pc = frame->GetFrameCodeAddress().GetLoadAddress(
+        &frame->GetThread()->GetProcess()->GetTarget());
+    if (pc != LLDB_INVALID_ADDRESS) {
+      rctx = std::make_shared<RegisterContextHistory>(
+          *frame->GetThread().get(), frame->GetConcreteFrameIndex(),
+          frame->GetThread()->GetProcess()->GetAddressByteSize(), pc);
+    }
+  }
+  return rctx;
+}
+
+bool HistoryUnwind::DoGetFrameInfoAtIndex(uint32_t frame_idx, lldb::addr_t &cfa,
+                                          lldb::addr_t &pc,
+                                          bool &behaves_like_zeroth_frame) {
+  // FIXME do not throw away the lock after we acquire it..
+  std::unique_lock<std::recursive_mutex> guard(m_unwind_mutex);
+  guard.unlock();
+  if (frame_idx < m_pcs.size()) {
+    cfa = frame_idx;
+    pc = m_pcs[frame_idx];
+    if (m_pcs_are_call_addresses)
+      behaves_like_zeroth_frame = true;
+    else
+      behaves_like_zeroth_frame = (frame_idx == 0);
+    return true;
+  }
+  return false;
+}
+
+uint32_t HistoryUnwind::DoGetFrameCount() { return m_pcs.size(); }