Add print-to-file for turbofan tracing.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index fa0ff173b25703d3994b2d428160c953ee14c269..28801804ecd9fed6f000f5890f99cbe1451657b0 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -22,6 +22,7 @@
 #include "src/compiler/verifier.h"
 #include "src/hydrogen.h"
 #include "src/ostreams.h"
+#include "src/utils.h"
 
 namespace v8 {
 namespace internal {
@@ -73,9 +74,22 @@ class PhaseStats {
 
 void Pipeline::VerifyAndPrintGraph(Graph* graph, const char* phase) {
   if (FLAG_trace_turbo) {
+    Vector<char> str = Vector<char>::New(256);

[Michael Starzinger, 2014/08/11 18:31:23]

nit: s/str/filename/

[sigurds, 2014/08/12 09:24:49]

Done.

+    SmartArrayPointer<char> name =
+        info_->shared_info()->DebugName()->ToCString();
+    if (strlen(name.get()) > 0) {
+      SNPrintF(str, "%s-%s.dot", name.get(), phase);

[Michael Starzinger, 2014/08/11 18:31:23]

Can we get a common prefix for all of the files? That way they are nicely
grouped in any file browser and can also be easily added to the GIT ignore file.
I vote for "turbo-%s-%s.dot" as a file name.

[sigurds, 2014/08/12 09:24:49]

Done.

+    } else {
+      SNPrintF(str, "%p-%s.dot", static_cast<void*>(info_), phase);
+    }
+    std::replace(str.start(), str.start() + str.length(), ' ', '_');
+    FILE* file = fopen(str.start(), "w+");

[Michael Starzinger, 2014/08/11 18:31:23]

I think we will need to use base::OS::FOpen to make all platforms happy here.

[sigurds, 2014/08/12 09:24:49]

Done.

+    OFStream of(file);
+    of << AsDOT(*graph);
+    fclose(file);
+
     OFStream os(stdout);
-    os << "-- " << phase << " graph -----------------------------------\n"
-       << AsDOT(*graph);
+    os << "-- " << phase << " graph printed to file " << str.start() << "\n";
   }
   if (VerifyGraphs()) Verifier::Run(graph);
 }