[turbofan] Output file for C1 visualizer.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index e8e1d66602b90606e3728f3590af7af3aecc9511..2874c168b74bdcc9e769b189e27020d3830f40ed 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -4,6 +4,8 @@
 
 #include <stdlib.h>
 
+#include <fstream>  // NOLINT(readability/streams)
+
 #include "src/v8.h"
 
 #include "src/ast.h"
@@ -1951,6 +1953,16 @@ bool Isolate::Init(Deserializer* des) {
 
   runtime_profiler_ = new RuntimeProfiler(this);
 
+  if (FLAG_trace_turbo) {
+    // Erase the file.
+    char buffer[512];
+    Vector<char> filename(buffer, sizeof(buffer));
+    GetTurboCfgFileName(filename);
+    std::ofstream turbo_cfg_stream(filename.start(),
+                                   std::fstream::out | std::fstream::trunc);
+  }
+
+
   // If we are deserializing, log non-function code objects and compiled
   // functions found in the snapshot.
   if (!create_heap_objects &&
@@ -2364,6 +2376,16 @@ BasicBlockProfiler* Isolate::GetOrCreateBasicBlockProfiler() {
 }
 
 
+void Isolate::GetTurboCfgFileName(Vector<char> filename) {
+  if (FLAG_trace_turbo_cfg_file == NULL) {
+    SNPrintF(filename, "turbo-%d-%d.cfg", base::OS::GetCurrentProcessId(),
+             id());
+  } else {
+    StrNCpy(filename, FLAG_trace_turbo_cfg_file, filename.length());
+  }
+}
+
+
 bool StackLimitCheck::JsHasOverflowed() const {
   StackGuard* stack_guard = isolate_->stack_guard();
 #ifdef USE_SIMULATOR