Support statistics dump summary only mode

Summary:
Added a new --summary option to statistics dump command so that it is much light weight than the full version.
With this change, statistics dump --summary can now be included in lldb command line telemetry without slowing down lldb exiting.

Author: kusmour

lldb/include/lldb/API/SBTarget.h

@@ -86,9 +86,13 @@ class LLDB_API SBTarget {
 
   /// Returns a dump of the collected statistics.
   ///
+  /// \param[in] summary_only
+  ///   If true, only report high level summary statistics without
+  ///   targets/modules/breakpoints etc.. details.
+  ///
   /// \return
   ///     A SBStructuredData with the statistics collected.
-  lldb::SBStructuredData GetStatistics();
+  lldb::SBStructuredData GetStatistics(bool summary_only = false);
 
   /// Return the platform object associated with the target.
   ///
@@ -326,7 +330,7 @@ class LLDB_API SBTarget {
   uint32_t GetAddressByteSize();
 
   const char *GetTriple();
-  
+
   const char *GetABIName();
 
   const char *GetLabel() const;

lldb/include/lldb/Target/Statistics.h

@@ -133,7 +133,7 @@ struct ConstStringStats {
 /// A class that represents statistics for a since lldb_private::Target.
 class TargetStats {
 public:
-  llvm::json::Value ToJSON(Target &target);
+  llvm::json::Value ToJSON(Target &target, bool summary_only = false);
 
   void SetLaunchOrAttachTime();
   void SetFirstPrivateStopTime();
@@ -171,9 +171,14 @@ class DebuggerStats {
   ///   The single target to emit statistics for if non NULL, otherwise dump
   ///   statistics only for the specified target.
   ///
+  /// \param summary_only
+  ///   If true, only report high level summary statistics without
+  ///   targets/modules/breakpoints etc.. details.
+  ///
   /// \return
   ///     Returns a JSON value that contains all target metrics.
-  static llvm::json::Value ReportStatistics(Debugger &debugger, Target *target);
+  static llvm::json::Value ReportStatistics(Debugger &debugger, Target *target,
+                                            bool summary_only = false);
 
 protected:
   // Collecting stats can be set to true to collect stats that are expensive

lldb/include/lldb/Target/Target.h

@@ -1599,7 +1599,7 @@ class Target : public std::enable_shared_from_this<Target>,
   ///
   /// \return
   ///     Returns a JSON value that contains all target metrics.
-  llvm::json::Value ReportStatistics();
+  llvm::json::Value ReportStatistics(bool summary_only = false);
 
   TargetStats &GetStatistics() { return m_stats; }
 

lldb/source/API/SBTarget.cpp

@@ -197,17 +197,18 @@ SBDebugger SBTarget::GetDebugger() const {
   return debugger;
 }
 
-SBStructuredData SBTarget::GetStatistics() {
+SBStructuredData SBTarget::GetStatistics(bool summary_only) {
   LLDB_INSTRUMENT_VA(this);
 
   SBStructuredData data;
   TargetSP target_sp(GetSP());
   if (!target_sp)
     return data;
   std::string json_str =
-      llvm::formatv("{0:2}",
-          DebuggerStats::ReportStatistics(target_sp->GetDebugger(),
-                                          target_sp.get())).str();
+      llvm::formatv(
+          "{0:2}", DebuggerStats::ReportStatistics(
+                       target_sp->GetDebugger(), target_sp.get(), summary_only))
+          .str();
   data.m_impl_up->SetObjectSP(StructuredData::ParseJSON(json_str));
   return data;
 }

lldb/source/Commands/CommandObjectStats.cpp

@@ -75,6 +75,9 @@ class CommandObjectStatsDump : public CommandObjectParsed {
       case 'a':
         m_all_targets = true;
         break;
+      case 's':
+        m_summary_only = true;
+        break;
       default:
         llvm_unreachable("Unimplemented option");
       }
@@ -83,13 +86,15 @@ class CommandObjectStatsDump : public CommandObjectParsed {
 
     void OptionParsingStarting(ExecutionContext *execution_context) override {
       m_all_targets = false;
+      m_summary_only = false;
     }
 
     llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
       return llvm::ArrayRef(g_statistics_dump_options);
     }
 
     bool m_all_targets = false;
+    bool m_summary_only = false;
   };
 
 public:
@@ -109,7 +114,8 @@ class CommandObjectStatsDump : public CommandObjectParsed {
       target = m_exe_ctx.GetTargetPtr();
 
     result.AppendMessageWithFormatv(
-        "{0:2}", DebuggerStats::ReportStatistics(GetDebugger(), target));
+        "{0:2}", DebuggerStats::ReportStatistics(GetDebugger(), target,
+                                                 m_options.m_summary_only));
     result.SetStatus(eReturnStatusSuccessFinishResult);
   }
 

lldb/source/Commands/Options.td

@@ -1412,4 +1412,7 @@ let Command = "trace schema" in {
 let Command = "statistics dump" in {
   def statistics_dump_all: Option<"all-targets", "a">, Group<1>,
     Desc<"Include statistics for all targets.">;
+  def statistics_dump_summary: Option<"summary", "s">, Group<1>,
+    Desc<"Dump only high level summary statistics."
+         "Exclude targets, modules, breakpoints etc.. details.">;
 }