Initial implementation of SB APIs for Tracing support.

Summary:
This patch introduces new SB APIs for tracing support
inside LLDB. The idea is to gather trace data from
LLDB and provide it through this APIs to external
tools integrating with LLDB. These tools will be
responsible for interpreting and presenting the
trace data to their users.

The patch implements the following new SB APIs ->
-> StartTrace - starts tracing with given parameters
-> StopTrace - stops tracing.
-> GetTraceData - read the trace data .
-> GetMetaData - read the meta data assosciated with the trace.
-> GetTraceConfig - read the trace configuration

Tracing is associated with a user_id that is returned
by the StartTrace API and this id needs to be used
for accessing the trace data and also Stopping
the trace. The user_id itself may map to tracing
the complete process or just an individual thread.
The APIs require an additional thread parameter
when the user of these APIs wishes to perform
thread specific manipulations on the tracing instances.
The patch also includes the corresponding
python wrappers for the C++ based APIs.

Reviewers: k8stone, lldb-commits, clayborg

Reviewed By: clayborg

Subscribers: jingham, mgorny

Differential Revision: https://reviews.llvm.org/D29581

llvm-svn: 301389

1 files changed, 109 insertions, 0 deletions

diff --git a/lldb/source/API/SBTrace.cpp b/lldb/source/API/SBTrace.cpp
new file mode 100644
index 00000000000..18f7d36e775
--- /dev/null
+++ b/lldb/source/API/SBTrace.cpp
@@ -0,0 +1,109 @@
+//===-- SBTrace.cpp ---------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/Log.h"
+#include "lldb/Target/Process.h"
+
+#include "lldb/API/SBTrace.h"
+#include "lldb/API/SBTraceOptions.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+class TraceImpl {
+public:
+  lldb::user_id_t uid;
+};
+
+lldb::ProcessSP SBTrace::GetSP() const { return m_opaque_wp.lock(); }
+
+size_t SBTrace::GetTraceData(SBError &error, void *buf, size_t size,
+                             size_t offset, lldb::tid_t thread_id) {
+  size_t bytes_read = 0;
+  ProcessSP process_sp(GetSP());
+  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
+  error.Clear();
+
+  if (!process_sp) {
+    error.SetErrorString("invalid process");
+  } else {
+    bytes_read = process_sp->GetData(GetTraceUID(), thread_id, error.ref(), buf,
+                                     size, offset);
+    LLDB_LOG(log, "SBTrace::bytes_read - %" PRIx64, bytes_read);
+  }
+  return bytes_read;
+}
+
+size_t SBTrace::GetMetaData(SBError &error, void *buf, size_t size,
+                            size_t offset, lldb::tid_t thread_id) {
+  size_t bytes_read = 0;
+  ProcessSP process_sp(GetSP());
+  Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
+  error.Clear();
+
+  if (!process_sp) {
+    error.SetErrorString("invalid process");
+  } else {
+
+    bytes_read = process_sp->GetMetaData(GetTraceUID(), thread_id, error.ref(),
+                                         buf, size, offset);
+    LLDB_LOG(log, "SBTrace::bytes_read - %" PRIx64, bytes_read);
+  }
+  return bytes_read;
+}
+
+void SBTrace::StopTrace(SBError &error, lldb::tid_t thread_id) {
+  ProcessSP process_sp(GetSP());
+  error.Clear();
+
+  if (!process_sp) {
+    error.SetErrorString("invalid process");
+    return;
+  }
+  process_sp->StopTrace(GetTraceUID(), thread_id, error.ref());
+}
+
+void SBTrace::GetTraceConfig(SBTraceOptions &options, SBError &error) {
+  ProcessSP process_sp(GetSP());
+  error.Clear();
+
+  if (!process_sp) {
+    error.SetErrorString("invalid process");
+  } else {
+    process_sp->GetTraceConfig(GetTraceUID(), error.ref(),
+                               options.m_traceoptions_sp);
+  }
+}
+
+lldb::user_id_t SBTrace::GetTraceUID() {
+  if (m_trace_impl_sp)
+    return m_trace_impl_sp->uid;
+  return LLDB_INVALID_UID;
+}
+
+void SBTrace::SetTraceUID(lldb::user_id_t uid) {
+  if (m_trace_impl_sp)
+    m_trace_impl_sp->uid = uid;
+}
+
+SBTrace::SBTrace() {
+  m_trace_impl_sp.reset(new TraceImpl);
+  if (m_trace_impl_sp)
+    m_trace_impl_sp->uid = LLDB_INVALID_UID;
+}
+
+void SBTrace::SetSP(const ProcessSP &process_sp) { m_opaque_wp = process_sp; }
+
+bool SBTrace::IsValid() {
+  if (!m_trace_impl_sp)
+    return false;
+  if (!GetSP())
+    return false;
+  return true;
+}