deps: backport 010897c from V8 upstream

This is a reland of nodejs#3165. The patch abates
the truncation of script filenames in the perf-event output produced by V8.

V8 commits:
Original: v8/v8@03ef3cd
Reland: v8/v8@010897c

Original commit message:
  improve perf_basic_prof filename reporting

  The buffer used for appending filenames to the string printed to the
  perf_basic_prof log was unnecessarily too small. Bump it up to be at least
  kUtf8BufferSize.

  Truncation of filenames makes it really hard to work with profiles gathered on
  Node.js. Because of the way Node.js works, you can have node module dependencies
  in deeply nested directories. The last thing you want when investigating a
  performance problem is to have script names be truncated.

  This patch is a stop-gap. Ideally, I want no truncation of the filename at all
  and use a dynamically growing buffer. That would be a larger change, and I
  wanted to have a quick fix available that can be back-ported to Node.js LTS
  release.

  [email protected],[email protected]
  BUG=

  Review URL: https://codereview.chromium.org/1388543002

deps/v8/src/log.cc

@@ -125,17 +125,19 @@ class CodeEventLogger::NameBuffer {
   }
 
   void AppendInt(int n) {
-    Vector<char> buffer(utf8_buffer_ + utf8_pos_,
-                        kUtf8BufferSize - utf8_pos_);
+    int space = kUtf8BufferSize - utf8_pos_;
+    if (space <= 0) return;
+    Vector<char> buffer(utf8_buffer_ + utf8_pos_, space);
     int size = SNPrintF(buffer, "%d", n);
     if (size > 0 && utf8_pos_ + size <= kUtf8BufferSize) {
       utf8_pos_ += size;
     }
   }
 
   void AppendHex(uint32_t n) {
-    Vector<char> buffer(utf8_buffer_ + utf8_pos_,
-                        kUtf8BufferSize - utf8_pos_);
+    int space = kUtf8BufferSize - utf8_pos_;
+    if (space <= 0) return;
+    Vector<char> buffer(utf8_buffer_ + utf8_pos_, space);
     int size = SNPrintF(buffer, "%x", n);
     if (size > 0 && utf8_pos_ + size <= kUtf8BufferSize) {
       utf8_pos_ += size;
@@ -147,7 +149,7 @@ class CodeEventLogger::NameBuffer {
 
  private:
   static const int kUtf8BufferSize = 512;
-  static const int kUtf16BufferSize = 128;
+  static const int kUtf16BufferSize = kUtf8BufferSize;
 
   int utf8_pos_;
   char utf8_buffer_[kUtf8BufferSize];

deps/v8/test/cctest/test-log.cc

@@ -531,3 +531,58 @@ TEST(LogVersion) {
   }
   isolate->Dispose();
 }
+
+
+// https://crbug.com/539892
+// CodeCreateEvents with really large names should not crash.
+TEST(Issue539892) {
+  class : public i::CodeEventLogger {
+   public:
+    virtual void CodeMoveEvent(Address from, Address to) {}
+    virtual void CodeDeleteEvent(Address from) {}
+    virtual void CodeDisableOptEvent(i::Code* code,
+                                     i::SharedFunctionInfo* shared) {}
+
+   private:
+    virtual void LogRecordedBuffer(i::Code* code, i::SharedFunctionInfo* shared,
+                                   const char* name, int length) {}
+  } code_event_logger;
+  SETUP_FLAGS();
+  v8::Isolate::CreateParams create_params;
+  create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
+  v8::Isolate* isolate = v8::Isolate::New(create_params);
+
+  {
+    ScopedLoggerInitializer initialize_logger(saved_log, saved_prof, isolate);
+    Logger* logger = initialize_logger.logger();
+    logger->addCodeEventListener(&code_event_logger);
+
+    // Function with a really large name.
+    const char* source_text =
+        "(function "
+        "baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac"
+        "(){})();";
+
+    CompileRun(source_text);
+
+    // Must not crash.
+    logger->LogCompiledFunctions();
+  }
+  isolate->Dispose();
+}