[Tools] Update linux_perf_report to split out GC.

tools/ignition/linux_perf_report.py

 #! /usr/bin/python2
 #
 # Copyright 2016 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 import argparse
 import collections
 import re
@@ skipping 36 matching lines @@
   $ tools/run-perf.sh out/x64.release/d8 \\
         --ignition --noturbo --nocrankshaft octane/run.js
   $ tools/ignition/linux_perf_report.py
 """
 
 
 COMPILER_SYMBOLS_RE = re.compile(
   r"v8::internal::(?:\(anonymous namespace\)::)?Compile|v8::internal::Parser")
 JIT_CODE_SYMBOLS_RE = re.compile(
   r"(LazyCompile|Compile|Eval|Script):(\*|~)")
+GC_SYMBOLS_RE = re.compile(
+  r"v8::internal::Heap::CollectGarbage")
 
 
 def strip_function_parameters(symbol):
   if symbol[-1] != ')': return symbol
   pos = 1
   parenthesis_count = 0
   for c in reversed(symbol):
     if c == ')':
       parenthesis_count += 1
     elif c == '(':
       parenthesis_count -= 1
     if parenthesis_count == 0:
       break
     else:
       pos += 1
   return symbol[:-pos]
 
 
 def collapsed_callchains_generator(perf_stream, hide_other=False,
                                    hide_compiler=False, hide_jit=False,
-                                   show_full_signatures=False):
+                                   hide_gc=False, show_full_signatures=False):
   current_chain = []
   skip_until_end_of_chain = False
   compiler_symbol_in_chain = False
 
   for line in perf_stream:
     # Lines starting with a "#" are comments, skip them.
     if line[0] == "#":
       continue
 
     line = line.strip()
@@ skipping 27 matching lines @@
 
     if symbol.startswith("BytecodeHandler:"):
       current_chain.append("[interpreter]")
       yield current_chain
       skip_until_end_of_chain = True
     elif JIT_CODE_SYMBOLS_RE.match(symbol):
       if not hide_jit:
         current_chain.append("[jit]")
         yield current_chain
         skip_until_end_of_chain = True
+    elif GC_SYMBOLS_RE.match(symbol):
+      if not hide_gc:
+        current_chain.append("[gc]")
+        yield current_chain
+        skip_until_end_of_chain = True
     elif symbol == "Stub:CEntryStub" and compiler_symbol_in_chain:
       if not hide_compiler:
         current_chain.append("[compiler]")
         yield current_chain
       skip_until_end_of_chain = True
     elif COMPILER_SYMBOLS_RE.match(symbol):
       compiler_symbol_in_chain = True
     elif symbol == "Builtin:InterpreterEntryTrampoline":
       if len(current_chain) == 1:
         yield ["[entry trampoline]"]
@@ skipping 70 matching lines @@
     "--hide-compiler",
     help="Hide samples during compilation",
     action="store_true"
   )
   command_line_parser.add_argument(
     "--hide-jit",
     help="Hide samples from JIT code execution",
     action="store_true"
   )
   command_line_parser.add_argument(
+    "--hide-gc",
+    help="Hide samples from garbage collection",
+    action="store_true"
+  )
+  command_line_parser.add_argument(
     "--show-full-signatures", "-s",
     help="show full signatures instead of function names",
     action="store_true"
   )
   command_line_parser.add_argument(
     "--output", "-o",
     help="output file name (stdout if omitted)",
     type=argparse.FileType('wt'),
     default=sys.stdout,
     metavar="<output filename>",
     dest="output_stream"
   )
 
   return command_line_parser.parse_args()
 
 
 def main():
   program_options = parse_command_line()
 
   perf = subprocess.Popen(["perf", "script", "--fields", "ip,sym",
                            "-i", program_options.perf_filename],
                           stdout=subprocess.PIPE)
 
   callchains = collapsed_callchains_generator(
     perf.stdout, program_options.hide_other, program_options.hide_compiler,
-    program_options.hide_jit, program_options.show_full_signatures)
+    program_options.hide_jit, program_options.hide_gc,
+    program_options.show_full_signatures)
 
   if program_options.output_flamegraph:
     write_flamegraph_input_file(program_options.output_stream, callchains)
   else:
     write_handlers_report(program_options.output_stream, callchains)
 
 
 if __name__ == "__main__":
   main()