Remove references to trace_child_process.py by generating it on the fly instead.

This removes any dependency from trace_inputs.py on any other script. This also
fixes the fact that 'trace_child_process.py' was a confusing script in itself.

Fix trace_inputs_smoke_tests.py on Windows.

R=csharp@chromium.org
NOTRY=true
BUG=


Review URL: https://chromiumcodereview.appspot.com/10914144

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@155437 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 34 insertions, 59 deletions

diff --git a/tools/isolate/README.py b/tools/isolate/README.py
index 863e0fe..2cd4cca 100755
--- a/tools/isolate/README.py
+++ b/tools/isolate/README.py
@@ -33,7 +33,7 @@ import sys
 
 def main():
   for i in sorted(os.listdir(os.path.dirname(os.path.abspath(__file__)))):
-    if not i.endswith('.py') or i in ('PRESUBMIT.py', 'trace_child_process.py'):
+    if not i.endswith('.py') or i == 'PRESUBMIT.py':
       continue
     module = __import__(i[:-3])
     if hasattr(module, '__doc__'):
diff --git a/tools/isolate/tests/trace_inputs_smoke_test.py b/tools/isolate/tests/trace_inputs_smoke_test.py
index db46036..da56971 100755
--- a/tools/isolate/tests/trace_inputs_smoke_test.py
+++ b/tools/isolate/tests/trace_inputs_smoke_test.py
@@ -140,7 +140,7 @@ class TraceInputs(TraceInputsBase):
       '  tests/trace_inputs/child2.py'.replace('/', os.path.sep),
       '  tests/trace_inputs/files1/'.replace('/', os.path.sep),
       '  tests/trace_inputs/test_file.txt'.replace('/', os.path.sep),
-      '  tests/%s' % FILENAME,
+      ('  tests/%s' % FILENAME).replace('/', os.path.sep),
       '  trace_inputs.py',
     )) + '\n'
     trace_expected = '\n'.join((
@@ -414,7 +414,7 @@ class TraceInputsImport(TraceInputsBase):
       u'tests/trace_inputs/child2.py'.replace('/', os.path.sep),
       u'tests/trace_inputs/files1/'.replace('/', os.path.sep),
       u'tests/trace_inputs/test_file.txt'.replace('/', os.path.sep),
-      u'tests/trace_inputs_smoke_test.py',
+      u'tests/trace_inputs_smoke_test.py'.replace('/', os.path.sep),
       u'trace_inputs.py',
     ]
     def blacklist(f):
diff --git a/tools/isolate/trace_child_process.py b/tools/isolate/trace_child_process.py
deleted file mode 100755
index d3071be..0000000
--- a/tools/isolate/trace_child_process.py
+++ /dev/null
@@ -1,40 +0,0 @@
-#!/usr/bin/env python
-# Copyright (c) 2012 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-"""Executes with the command to be run.
-
-Not meant to be used directly, only meant to be used by trace_inputs.py.
-
-This script is used by the tracer as a signal for the log parser that the child
-process is the process we care about. It is especially important on kernel based
-tracer because we want it to trace the relevant process tree.
-"""
-
-import subprocess
-import sys
-
-
-def fix_python_path(cmd):
-  """Returns the fixed command line to call the right python executable."""
-  out = cmd[:]
-  if out[0] == 'python':
-    out[0] = sys.executable
-  elif out[0].endswith('.py'):
-    out.insert(0, sys.executable)
-  return out
-
-
-def main():
-  cmd = fix_python_path(sys.argv[2:])
-
-  # The reason os.execve() is not used is that we don't want the modules
-  # imported here to influence the executable being traced, so we need a fresh
-  # pid and need to fork.
-  # TODO(maruel): Use CreateProcess() on Windows and fork manually on OSX.
-  return subprocess.call(cmd)
-
-
-if __name__ == '__main__':
-  sys.exit(main())
diff --git a/tools/isolate/trace_inputs.py b/tools/isolate/trace_inputs.py
index 92da755..c315d10 100755
--- a/tools/isolate/trace_inputs.py
+++ b/tools/isolate/trace_inputs.py
@@ -429,6 +429,19 @@ def fix_python_path(cmd):
   return out
 
 
+def create_thunk():
+  handle, name = tempfile.mkstemp(prefix='trace_inputs_thunk', suffix='.py')
+  os.write(
+      handle,
+      (
+        'import subprocess\n'
+        'import sys\n'
+        'sys.exit(subprocess.call(sys.argv[2:]))\n'
+      ))
+  os.close(handle)
+  return name
+
+
 def strace_process_quoted_arguments(text):
   """Extracts quoted arguments on a string and return the arguments as a list.
 
@@ -1526,7 +1539,7 @@ class Dtrace(ApiBase):
       logging.info(
           '%s(%d, %s)' % (self.__class__.__name__, tracer_pid, initial_cwd))
       super(Dtrace.Context, self).__init__(blacklist)
-      # Process ID of the trace_child_process.py wrapper script instance.
+      # Process ID of the temporary script created by create_thunk().
       self._tracer_pid = tracer_pid
       self._initial_cwd = initial_cwd
       self._line_number = 0
@@ -1784,8 +1797,8 @@ class Dtrace(ApiBase):
     # 0 is for untracked processes and is the default value for items not
     #   in the associative array.
     # 1 is for tracked processes.
-    # 2 is for trace_child_process.py only. It is not tracked itself but
-    #   all its decendants are.
+    # 2 is for the script created by create_thunk() only. It is not tracked
+    #   itself but all its decendants are.
     #
     # The script will kill itself only once waiting_to_die == 1 and
     # current_processes == 0, so that both getlogin() was called and that
@@ -2078,7 +2091,7 @@ class Dtrace(ApiBase):
       this needs to wait for dtrace to be "warmed up".
       """
       super(Dtrace.Tracer, self).__init__(logname)
-      self._script = os.path.join(BASE_DIR, 'trace_child_process.py')
+      self._script = create_thunk()
       # This unique dummy temp file is used to signal the dtrace script that it
       # should stop as soon as all the child processes are done. A bit hackish
       # but works fine enough.
@@ -2119,8 +2132,8 @@ class Dtrace(ApiBase):
 
       Injects the cookie in the script so it knows when to stop.
 
-      The script will detect any trace_child_process.py instance and will start
-      tracing it.
+      The script will detect any instance of the script created with
+      create_thunk() and will start tracing it.
       """
       return (
           'inline int PID = %d;\n'
@@ -2138,8 +2151,7 @@ class Dtrace(ApiBase):
 
       This dtruss is broken when it starts the process itself or when tracing
       child processes, this code starts a wrapper process
-      trace_child_process.py, which waits for dtrace to start, then
-      trace_child_process.py starts the executable to trace.
+      generated with create_thunk() which starts the executable to trace.
       """
       logging.info('trace(%s, %s, %s, %s)' % (cmd, cwd, tracename, output))
       assert os.path.isabs(cmd[0]), cmd[0]
@@ -2167,7 +2179,7 @@ class Dtrace(ApiBase):
       # that needs to be traced.
       # Yummy.
       child = subprocess.Popen(
-          child_cmd + cmd,
+          child_cmd + fix_python_path(cmd),
           stdin=subprocess.PIPE,
           stdout=stdout,
           stderr=stderr,
@@ -2222,6 +2234,7 @@ class Dtrace(ApiBase):
       finally:
         os.close(self._dummy_file_id)
         os.remove(self._dummy_file_name)
+        os.remove(self._script)
 
     def post_process_log(self):
       """Sorts the log back in order when each call occured.
@@ -2627,7 +2640,7 @@ class LogmanTrace(ApiBase):
       "logman query providers | findstr /i file"
       """
       super(LogmanTrace.Tracer, self).__init__(logname)
-      self._script = os.path.join(BASE_DIR, 'trace_child_process.py')
+      self._script = create_thunk()
       cmd_start = [
         'logman.exe',
         'start',
@@ -2679,18 +2692,19 @@ class LogmanTrace(ApiBase):
 
       # Run the child process.
       logging.debug('Running: %s' % cmd)
-      # Use trace_child_process.py so we have a clear pid owner. Since
-      # trace_inputs.py can be used as a library and could trace mulitple
-      # processes simultaneously, it makes it more complex if the executable to
-      # be traced is executed directly here. It also solves issues related to
-      # logman.exe that needs to be executed to control the kernel trace.
+      # Use the temporary script generated with create_thunk() so we have a
+      # clear pid owner. Since trace_inputs.py can be used as a library and
+      # could trace multiple processes simultaneously, it makes it more complex
+      # if the executable to be traced is executed directly here. It also solves
+      # issues related to logman.exe that needs to be executed to control the
+      # kernel trace.
       child_cmd = [
         sys.executable,
         self._script,
         tracename,
       ]
       child = subprocess.Popen(
-          child_cmd + cmd,
+          child_cmd + fix_python_path(cmd),
           cwd=cwd,
           stdin=subprocess.PIPE,
           stdout=stdout,
@@ -2721,6 +2735,7 @@ class LogmanTrace(ApiBase):
           raise TracingFailure(
               'Called Tracer.close() on an unitialized object',
               None, None, None)
+        os.remove(self._script)
         # Save metadata, add 'format' key..
         data = {
           'format': 'csv',