- now counting instances only when requested via --debug=count

9 files changed, 36 insertions, 21 deletions

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index 50a27dcc8..b0d2d3c06 100644
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -30,6 +30,8 @@ RELEASE 2.3.1.alpha.yyyymmdd - NEW DATE WILL BE INSERTED HERE
   From Dirk Baechle:
     - Update bootstrap.py so it can be used from any dir, to run
       SCons from a source (non-installed) dir.
+    - Count statistics of instances are now collected only when
+      the --debug=count command-line option is used (#2922).
 
   From Gary Oberbrunner:
     - Test harness: fail_test() can now print a message to help debugging.
diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py
index c1eef756b..82b8fb955 100644
--- a/src/engine/SCons/Action.py
+++ b/src/engine/SCons/Action.py
@@ -109,6 +109,7 @@ import re
 import sys
 import subprocess
 
+import SCons.Debug
 from SCons.Debug import logInstanceCreation
 import SCons.Errors
 import SCons.Executor
@@ -698,7 +699,7 @@ class CommandAction(_ActionAction):
         # factory above does).  cmd will be passed to
         # Environment.subst_list() for substituting environment
         # variables.
-        if __debug__: logInstanceCreation(self, 'Action.CommandAction')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.CommandAction')
 
         _ActionAction.__init__(self, **kw)
         if is_List(cmd):
@@ -855,7 +856,7 @@ class CommandAction(_ActionAction):
 class CommandGeneratorAction(ActionBase):
     """Class for command-generator actions."""
     def __init__(self, generator, kw):
-        if __debug__: logInstanceCreation(self, 'Action.CommandGeneratorAction')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.CommandGeneratorAction')
         self.generator = generator
         self.gen_kw = kw
         self.varlist = kw.get('varlist', ())
@@ -944,7 +945,7 @@ class CommandGeneratorAction(ActionBase):
 class LazyAction(CommandGeneratorAction, CommandAction):
 
     def __init__(self, var, kw):
-        if __debug__: logInstanceCreation(self, 'Action.LazyAction')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.LazyAction')
         #FUTURE CommandAction.__init__(self, '${'+var+'}', **kw)
         CommandAction.__init__(self, '${'+var+'}', **kw)
         self.var = SCons.Util.to_String(var)
@@ -986,7 +987,7 @@ class FunctionAction(_ActionAction):
     """Class for Python function actions."""
 
     def __init__(self, execfunction, kw):
-        if __debug__: logInstanceCreation(self, 'Action.FunctionAction')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.FunctionAction')
 
         self.execfunction = execfunction
         try:
@@ -1108,7 +1109,7 @@ class FunctionAction(_ActionAction):
 class ListAction(ActionBase):
     """Class for lists of other actions."""
     def __init__(self, actionlist):
-        if __debug__: logInstanceCreation(self, 'Action.ListAction')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.ListAction')
         def list_of_actions(x):
             if isinstance(x, ActionBase):
                 return x
diff --git a/src/engine/SCons/Builder.py b/src/engine/SCons/Builder.py
index 6dc9e17e0..ed7650a8b 100644
--- a/src/engine/SCons/Builder.py
+++ b/src/engine/SCons/Builder.py
@@ -102,6 +102,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 import collections
 
 import SCons.Action
+import SCons.Debug
 from SCons.Debug import logInstanceCreation
 from SCons.Errors import InternalError, UserError
 import SCons.Executor
@@ -225,7 +226,7 @@ class OverrideWarner(collections.UserDict):
     """
     def __init__(self, dict):
         collections.UserDict.__init__(self, dict)
-        if __debug__: logInstanceCreation(self, 'Builder.OverrideWarner')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Builder.OverrideWarner')
         self.already_warned = None
     def warn(self):
         if self.already_warned:
@@ -376,7 +377,7 @@ class BuilderBase(object):
                         src_builder = None,
                         ensure_suffix = False,
                         **overrides):
-        if __debug__: logInstanceCreation(self, 'Builder.BuilderBase')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Builder.BuilderBase')
         self._memo = {}
         self.action = action
         self.multi = multi
@@ -847,7 +848,7 @@ class CompositeBuilder(SCons.Util.Proxy):
     """
 
     def __init__(self, builder, cmdgen):
-        if __debug__: logInstanceCreation(self, 'Builder.CompositeBuilder')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Builder.CompositeBuilder')
         SCons.Util.Proxy.__init__(self, builder)
 
         # cmdgen should always be an instance of DictCmdGenerator.
diff --git a/src/engine/SCons/Debug.py b/src/engine/SCons/Debug.py
index 1c0c63854..997403983 100644
--- a/src/engine/SCons/Debug.py
+++ b/src/engine/SCons/Debug.py
@@ -35,6 +35,10 @@ import sys
 import time
 import weakref
 
+# Global variable that gets set to 'True' by the Main script,
+# when the creation of class instances should get tracked.
+track_instances = False
+# List of currently tracked classes
 tracked_classes = {}
 
 def logInstanceCreation(instance, name=None):
diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index 55a82065d..ca5df588e 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -43,6 +43,7 @@ from collections import UserDict
 
 import SCons.Action
 import SCons.Builder
+import SCons.Debug
 from SCons.Debug import logInstanceCreation
 import SCons.Defaults
 import SCons.Errors
@@ -370,7 +371,7 @@ class SubstitutionEnvironment(object):
     def __init__(self, **kw):
         """Initialization of an underlying SubstitutionEnvironment class.
         """
-        if __debug__: logInstanceCreation(self, 'Environment.SubstitutionEnvironment')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Environment.SubstitutionEnvironment')
         self.fs = SCons.Node.FS.get_default_fs()
         self.ans = SCons.Node.Alias.default_ans
         self.lookup_list = SCons.Node.arg2nodes_lookups
@@ -931,7 +932,7 @@ class Base(SubstitutionEnvironment):
         initialize things in a very specific order that doesn't work
         with the much simpler base class initialization.
         """
-        if __debug__: logInstanceCreation(self, 'Environment.Base')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Environment.Base')
         self._memo = {}
         self.fs = SCons.Node.FS.get_default_fs()
         self.ans = SCons.Node.Alias.default_ans
@@ -1414,7 +1415,7 @@ class Base(SubstitutionEnvironment):
         # Finally, apply any flags to be merged in
         if parse_flags: clone.MergeFlags(parse_flags)
 
-        if __debug__: logInstanceCreation(self, 'Environment.EnvironmentClone')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Environment.EnvironmentClone')
         return clone
 
     def Copy(self, *args, **kw):
@@ -2270,7 +2271,7 @@ class OverrideEnvironment(Base):
     """
 
     def __init__(self, subject, overrides={}):
-        if __debug__: logInstanceCreation(self, 'Environment.OverrideEnvironment')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Environment.OverrideEnvironment')
         self.__dict__['__subject'] = subject
         self.__dict__['overrides'] = overrides
 
diff --git a/src/engine/SCons/Executor.py b/src/engine/SCons/Executor.py
index 6f2489b3d..7875537a4 100644
--- a/src/engine/SCons/Executor.py
+++ b/src/engine/SCons/Executor.py
@@ -31,6 +31,7 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 import collections
 
+import SCons.Debug
 from SCons.Debug import logInstanceCreation
 import SCons.Errors
 import SCons.Memoize
@@ -123,7 +124,7 @@ class Executor(object):
 
     def __init__(self, action, env=None, overridelist=[{}],
                  targets=[], sources=[], builder_kw={}):
-        if __debug__: logInstanceCreation(self, 'Executor.Executor')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Executor.Executor')
         self.set_action_list(action)
         self.pre_actions = []
         self.post_actions = []
@@ -575,7 +576,7 @@ class Null(object):
     going to worry about unit tests for this--at least for now.
     """
     def __init__(self, *args, **kw):
-        if __debug__: logInstanceCreation(self, 'Executor.Null')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Executor.Null')
         self.batches = [Batch(kw['targets'][:], [])]
     def get_build_env(self):
         return get_NullEnvironment()
diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index 438169743..18400e845 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -44,6 +44,7 @@ import time
 import codecs
 
 import SCons.Action
+import SCons.Debug
 from SCons.Debug import logInstanceCreation
 import SCons.Errors
 import SCons.Memoize
@@ -581,7 +582,7 @@ class Base(SCons.Node.Node):
         our relative and absolute paths, identify our parent
         directory, and indicate that this node should use
         signatures."""
-        if __debug__: logInstanceCreation(self, 'Node.FS.Base')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.Base')
         SCons.Node.Node.__init__(self)
 
         # Filenames and paths are probably reused and are intern'ed to
@@ -1111,7 +1112,7 @@ class FS(LocalFS):
 
         The path argument must be a valid absolute path.
         """
-        if __debug__: logInstanceCreation(self, 'Node.FS')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS')
 
         self._memo = {}
 
@@ -1445,7 +1446,7 @@ class Dir(Base):
     BuildInfo = DirBuildInfo
 
     def __init__(self, name, directory, fs):
-        if __debug__: logInstanceCreation(self, 'Node.FS.Dir')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.Dir')
         Base.__init__(self, name, directory, fs)
         self._morph()
 
@@ -2113,7 +2114,7 @@ class RootDir(Dir):
     this directory.
     """
     def __init__(self, drive, fs):
-        if __debug__: logInstanceCreation(self, 'Node.FS.RootDir')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.RootDir')
         # We're going to be our own parent directory (".." entry and .dir
         # attribute) so we have to set up some values so Base.__init__()
         # won't gag won't it calls some of our methods.
@@ -2361,7 +2362,7 @@ class File(Base):
                         "Directory %s found where file expected.")
 
     def __init__(self, name, directory, fs):
-        if __debug__: logInstanceCreation(self, 'Node.FS.File')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.File')
         Base.__init__(self, name, directory, fs)
         self._morph()
 
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index 992284dca..c11428122 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -47,6 +47,7 @@ import collections
 import copy
 from itertools import chain
 
+import SCons.Debug
 from SCons.Debug import logInstanceCreation
 import SCons.Executor
 import SCons.Memoize
@@ -183,7 +184,7 @@ class Node(object):
         pass
 
     def __init__(self):
-        if __debug__: logInstanceCreation(self, 'Node.Node')
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.Node')
         # Note that we no longer explicitly initialize a self.builder
         # attribute to None here.  That's because the self.builder
         # attribute may be created on-the-fly later by a subclass (the
diff --git a/src/engine/SCons/Script/Main.py b/src/engine/SCons/Script/Main.py
index 837c1039d..9083b8ee3 100644
--- a/src/engine/SCons/Script/Main.py
+++ b/src/engine/SCons/Script/Main.py
@@ -622,7 +622,7 @@ def _set_debug_values(options):
     debug_values = options.debug
 
     if "count" in debug_values:
-        # All of the object counts are within "if __debug__:" blocks,
+        # All of the object counts are within "if track_instances:" blocks,
         # which get stripped when running optimized (with python -O or
         # from compiled *.pyo files).  Provide a warning if __debug__ is
         # stripped, so it doesn't just look like --debug=count is broken.
@@ -630,6 +630,7 @@ def _set_debug_values(options):
         if __debug__: enable_count = True
         if enable_count:
             count_stats.enable(sys.stdout)
+            SCons.Debug.track_instances = True
         else:
             msg = "--debug=count is not supported when running SCons\n" + \
                   "\twith the python -O option or optimized (.pyo) modules."
@@ -644,6 +645,8 @@ def _set_debug_values(options):
     if "memory" in debug_values:
         memory_stats.enable(sys.stdout)
     print_objects = ("objects" in debug_values)
+    if print_objects:
+        SCons.Debug.track_instances = True
     if "presub" in debug_values:
         SCons.Action.print_actions_presub = 1
     if "stacktrace" in debug_values: