1 files changed, 44 insertions, 1 deletions
diff --git a/lldb/source/Plugins/Trace/intel-pt/PerfContextSwitchDecoder.cpp b/lldb/source/Plugins/Trace/intel-pt/PerfContextSwitchDecoder.cpp
index 6b4251a0fcd9..0c468cf7852f 100644
--- a/lldb/source/Plugins/Trace/intel-pt/PerfContextSwitchDecoder.cpp
+++ b/lldb/source/Plugins/Trace/intel-pt/PerfContextSwitchDecoder.cpp
@@ -16,8 +16,13 @@ using namespace llvm;
 /// non-linux platforms.
 /// \{
 #define PERF_RECORD_MISC_SWITCH_OUT (1 << 13)
-#define PERF_RECORD_MAX 19
+
+#define PERF_RECORD_LOST 2
+#define PERF_RECORD_THROTTLE 5
+#define PERF_RECORD_UNTHROTTLE 6
+#define PERF_RECORD_LOST_SAMPLES 13
 #define PERF_RECORD_SWITCH_CPU_WIDE 15
+#define PERF_RECORD_MAX 19
 
 struct perf_event_header {
   uint32_t type;
@@ -54,6 +59,11 @@ struct perf_event_header {
   bool IsContextSwitchRecord() const {
     return type == PERF_RECORD_SWITCH_CPU_WIDE;
   }
+
+  bool IsErrorRecord() const {
+    return type == PERF_RECORD_LOST || type == PERF_RECORD_THROTTLE ||
+           type == PERF_RECORD_UNTHROTTLE || type == PERF_RECORD_LOST_SAMPLES;
+  }
 };
 /// \}
 
@@ -286,3 +296,36 @@ lldb_private::trace_intel_pt::DecodePerfContextSwitchTrace(
 
   return executions;
 }
+
+Expected<std::vector<uint8_t>>
+lldb_private::trace_intel_pt::FilterProcessesFromContextSwitchTrace(
+    llvm::ArrayRef<uint8_t> data, const std::set<lldb::pid_t> &pids) {
+  size_t offset = 0;
+  std::vector<uint8_t> out_data;
+
+  while (offset < data.size()) {
+    const perf_event_header &perf_record =
+        *reinterpret_cast<const perf_event_header *>(data.data() + offset);
+    if (Error err = perf_record.SanityCheck())
+      return std::move(err);
+    bool should_copy = false;
+    if (perf_record.IsContextSwitchRecord()) {
+      const PerfContextSwitchRecord &context_switch_record =
+          *reinterpret_cast<const PerfContextSwitchRecord *>(data.data() +
+                                                             offset);
+      if (pids.count(context_switch_record.pid))
+        should_copy = true;
+    } else if (perf_record.IsErrorRecord()) {
+      should_copy = true;
+    }
+
+    if (should_copy) {
+      for (size_t i = 0; i < perf_record.size; i++) {
+        out_data.push_back(data[offset + i]);
+      }
+    }
+
+    offset += perf_record.size;
+  }
+  return out_data;
+}