[turbofan] Fix --trace-turbo handle dereferences.

Whenever tracing is activated we disable concurrent compilation. Hence
all tracing functions can safely dereference all handles. This fixes the
tracing functionality by annotating tracing functions with proper scopes.

R=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/1976123002
Cr-Commit-Position: refs/heads/master@{#36241}

src/compiler/pipeline.cc

@@ -403,6 +403,7 @@ struct TurboCfgFile : public std::ofstream {
 
 void TraceSchedule(CompilationInfo* info, Schedule* schedule) {
   if (FLAG_trace_turbo) {
+    AllowHandleDereference allow_deref;
     FILE* json_file = OpenVisualizerLogFile(info, nullptr, "json", "a+");
     if (json_file != nullptr) {
       OFStream json_of(json_file);
@@ -417,9 +418,11 @@ void TraceSchedule(CompilationInfo* info, Schedule* schedule) {
       fclose(json_file);
     }
   }
-  if (!FLAG_trace_turbo_graph && !FLAG_trace_turbo_scheduler) return;
-  OFStream os(stdout);
-  os << "-- Schedule --------------------------------------\n" << *schedule;
+  if (FLAG_trace_turbo_graph || FLAG_trace_turbo_scheduler) {
+    AllowHandleDereference allow_deref;
+    OFStream os(stdout);
+    os << "-- Schedule --------------------------------------\n" << *schedule;
+  }
 }
 
 
@@ -1305,6 +1308,7 @@ struct PrintGraphPhase {
     Graph* graph = data->graph();
 
     {  // Print JSON.
+      AllowHandleDereference allow_deref;
       FILE* json_file = OpenVisualizerLogFile(info, nullptr, "json", "a+");
       if (json_file == nullptr) return;
       OFStream json_of(json_file);
@@ -1314,6 +1318,7 @@ struct PrintGraphPhase {
     }
 
     if (FLAG_trace_turbo_graph) {  // Simple textual RPO.
+      AllowHandleDereference allow_deref;
       OFStream os(stdout);
       os << "-- Graph after " << phase << " -- " << std::endl;
       os << AsRPO(*graph);
@@ -1620,6 +1625,7 @@ bool PipelineImpl::ScheduleAndSelectInstructions(Linkage* linkage) {
   Run<InstructionSelectionPhase>(linkage);
 
   if (FLAG_trace_turbo && !data->MayHaveUnverifiableGraph()) {
+    AllowHandleDereference allow_deref;
     TurboCfgFile tcf(isolate());
     tcf << AsC1V("CodeGen", data->schedule(), data->source_positions(),
                  data->sequence());
@@ -1751,10 +1757,10 @@ void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
   Run<ResolvePhisPhase>();
   Run<BuildLiveRangesPhase>();
   if (FLAG_trace_turbo_graph) {
+    AllowHandleDereference allow_deref;
     OFStream os(stdout);
-    PrintableInstructionSequence printable = {config, data->sequence()};
     os << "----- Instruction sequence before register allocation -----\n"
-       << printable;
+       << PrintableInstructionSequence({config, data->sequence()});
   }
   if (verifier != nullptr) {
     CHECK(!data->register_allocation_data()->ExistsUseWithoutDefinition());
@@ -1791,10 +1797,10 @@ void PipelineImpl::AllocateRegisters(const RegisterConfiguration* config,
   Run<LocateSpillSlotsPhase>();
 
   if (FLAG_trace_turbo_graph) {
+    AllowHandleDereference allow_deref;
     OFStream os(stdout);
-    PrintableInstructionSequence printable = {config, data->sequence()};
     os << "----- Instruction sequence after register allocation -----\n"
-       << printable;
+       << PrintableInstructionSequence({config, data->sequence()});
   }
 
   if (verifier != nullptr) {