[lit] Compare to None using identity, not equality

Summary:
In Python, `None` is a singleton, so checking whether a variable is
`None` may be done with `is` or `is not`. This has a slight advantage
over equiality comparisons `== None` and `!= None`, since `__eq__` may
be overridden in Python to produce sometimes unexpected results.

Using `is None` and `is not None` is also recommended practice in
https://www.python.org/dev/peps/pep-0008:

> Comparisons to singletons like `None` should always be done with `is` or
> `is not`, never the equality operators.

Patch by Brian Gesiak!

Reviewers: ddunbar, echristo, beanz

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D25168

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283088 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/utils/lit/lit/TestRunner.py b/utils/lit/lit/TestRunner.py
index 24d687280c43f5e98f049680ebca8d2bc85da414..7c5683036a08c3fe46ad0028cce47595540ed13a 100644 (file)
--- a/utils/lit/lit/TestRunner.py
+++ b/utils/lit/lit/TestRunner.py
@@ -406,7 +406,7 @@ def _executeShCmd(cmd, shenv, results, timeoutHelper):
                             data = f.read()
                     except:
                         data = None
-                    if data != None:
+                    if data is not None:
                         output_files.append((name, path, data))
             
         results.append(ShellCommandResult(
@@ -786,7 +786,7 @@ def _runShTest(test, litConfig, useExternalSh, script, tmpBase):
     if exitCode == 0:
         status = Test.PASS
     else:
-        if timeoutInfo == None:
+        if timeoutInfo is None:
             status = Test.FAIL
         else:
             status = Test.TIMEOUT
@@ -795,7 +795,7 @@ def _runShTest(test, litConfig, useExternalSh, script, tmpBase):
     output = """Script:\n--\n%s\n--\nExit Code: %d\n""" % (
         '\n'.join(script), exitCode)
 
-    if timeoutInfo != None:
+    if timeoutInfo is not None:
         output += """Timeout: %s\n""" % (timeoutInfo,)
     output += "\n"
 

diff --git a/utils/lit/lit/main.py b/utils/lit/lit/main.py
index 53f026dde18fd3b33991410ad67b3c6b3c2e957e..82c863c8e9f8fe49ce6b6165334b405a32b762ca 100755 (executable)
--- a/utils/lit/lit/main.py
+++ b/utils/lit/lit/main.py
@@ -309,7 +309,7 @@ def main_with_tmp(builtinParameters):
         userParams[name] = val
 
     # Decide what the requested maximum indvidual test time should be
-    if opts.maxIndividualTestTime != None:
+    if opts.maxIndividualTestTime is not None:
         maxIndividualTestTime = opts.maxIndividualTestTime
     else:
         # Default is zero
@@ -340,7 +340,7 @@ def main_with_tmp(builtinParameters):
     # After test discovery the configuration might have changed
     # the maxIndividualTestTime. If we explicitly set this on the
     # command line then override what was set in the test configuration
-    if opts.maxIndividualTestTime != None:
+    if opts.maxIndividualTestTime is not None:
         if opts.maxIndividualTestTime != litConfig.maxIndividualTestTime:
             litConfig.note(('The test suite configuration requested an individual'
                 ' test timeout of {0} seconds but a timeout of {1} seconds was'