Use is/is not to check for None in python code.
While reviewing a patch sent to the mailing list, I noticed there are few
places where python code checks if a variable is 'None' or not by using the
comparison operators '==' and '!='. PEP8[1], which is used as coding standard
in GDBÂ coding standards, recommends using 'is' / 'is not' when comparing to a
singleton such as 'None'.
This patch proposes to change the instances of '== None' by 'is None' and
'!= None' by 'is not None'.
[1] https://www.python.org/dev/peps/pep-0008/
gdb/doc/ChangeLog:
* python.texi (Writing a Pretty-Printer): Use 'is None' instead of
'== None'.
gdb/ChangeLog:
* python/lib/gdb/FrameDecorator.py (FrameDecorator): Use 'is None' instead of
'== None'.
(FrameVars): Use 'is not None' instead of '!= None'.
* python/lib/gdb/command/frame_filters.py (SetFrameFilterPriority): Use 'is None'
instead of '== None' and 'is not None' instead of '!= None'.
gdb/testsuite/ChangeLog:
* gdb.base/premature-dummy-frame-removal.py (TestUnwinder): Use
'is None' instead of '== None' and 'is not None' instead of
'!= None'.
* gdb.python/py-frame-args.py (lookup_function): Same.
* gdb.python/py-framefilter-invalidarg.py (Reverse_Function): Same.
* gdb.python/py-framefilter.py (Reverse_Function): Same.
* gdb.python/py-nested-maps.py (lookup_function): Same.
* gdb.python/py-objfile-script-gdb.py (lookup_function): Same.
* gdb.python/py-prettyprint.py (lookup_function): Same.
* gdb.python/py-section-script.py (lookup_function): Same.
* gdb.python/py-unwind-inline.py (dummy_unwinder): Same.
* gdb.python/python.exp: Same.
* gdb.rust/pp.py (lookup_function): Same.
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 05c307b..36cb4c9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2021-06-08 Lancelot Six <lsix@lancelotsix.com>
+
+ * python/lib/gdb/FrameDecorator.py (FrameDecorator): Use 'is None'
+ instead of '== None'.
+ (FrameVars): Use 'is not None' instead of '!= None'.
+ * python/lib/gdb/command/frame_filters.py (SetFrameFilterPriority):
+ Use 'is None' instead of '== None' and 'is not None' instead of '!=
+ None'.
+
2021-06-08 Simon Marchi <simon.marchi@polymtl.ca>
* inferior.h (class inferior) <in_initial_library_scan>: New.
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 61d40b9..80b9f44 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2021-06-08 Lancelot Six <lsix@lancelotsix.com>
+
+ * python.texi (Writing a Pretty-Printer): Use 'is None' instead of
+ '== None'.
+
2021-06-05 Shahab Vahedi <shahab@synopsys.com>
* gdb.texinfo (Source and Machine Code): Document 'set
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 7b7f069..ab934a8 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -1661,7 +1661,7 @@
@smallexample
def str_lookup_function(val):
lookup_tag = val.type.tag
- if lookup_tag == None:
+ if lookup_tag is None:
return None
regex = re.compile("^std::basic_string<char,.*>$")
if regex.match(lookup_tag):
diff --git a/gdb/python/lib/gdb/FrameDecorator.py b/gdb/python/lib/gdb/FrameDecorator.py
index 1f4b2ca..69a0a9a 100644
--- a/gdb/python/lib/gdb/FrameDecorator.py
+++ b/gdb/python/lib/gdb/FrameDecorator.py
@@ -117,7 +117,7 @@
# address. If GDB detects an integer value from this function
# it will attempt to find the function name from minimal
# symbols via its own internal functions.
- if func == None:
+ if func is None:
pc = frame.pc()
return pc
@@ -270,7 +270,7 @@
except RuntimeError:
block = None
- while block != None:
+ while block is not None:
if block.is_global or block.is_static:
break
for sym in block:
@@ -295,12 +295,12 @@
except RuntimeError:
block = None
- while block != None:
- if block.function != None:
+ while block is not None:
+ if block.function is not None:
break
block = block.superblock
- if block != None:
+ if block is not None:
for sym in block:
if not sym.is_argument:
continue
diff --git a/gdb/python/lib/gdb/command/frame_filters.py b/gdb/python/lib/gdb/command/frame_filters.py
index 91e8ca2..97488ca 100644
--- a/gdb/python/lib/gdb/command/frame_filters.py
+++ b/gdb/python/lib/gdb/command/frame_filters.py
@@ -372,7 +372,7 @@
def invoke(self, arg, from_tty):
command_tuple = self._parse_pri_arg(arg)
- if command_tuple != None:
+ if command_tuple is not None:
self._set_filter_priority(command_tuple)
@@ -453,7 +453,7 @@
def invoke(self, arg, from_tty):
command_tuple = self._parse_pri_arg(arg)
- if command_tuple == None:
+ if command_tuple is None:
return
filter_name = command_tuple[1]
list_name = command_tuple[0]
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 51abd0e..92894d6 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,19 @@
+2021-06-08 Lancelot Six <lsix@lancelotsix.com>
+
+ * gdb.base/premature-dummy-frame-removal.py (TestUnwinder): Use
+ 'is None' instead of '== None' and 'is not None' instead of
+ '!= None'.
+ * gdb.python/py-frame-args.py (lookup_function): Same.
+ * gdb.python/py-framefilter-invalidarg.py (Reverse_Function): Same.
+ * gdb.python/py-framefilter.py (Reverse_Function): Same.
+ * gdb.python/py-nested-maps.py (lookup_function): Same.
+ * gdb.python/py-objfile-script-gdb.py (lookup_function): Same.
+ * gdb.python/py-prettyprint.py (lookup_function): Same.
+ * gdb.python/py-section-script.py (lookup_function): Same.
+ * gdb.python/py-unwind-inline.py (dummy_unwinder): Same.
+ * gdb.python/python.exp: Same.
+ * gdb.rust/pp.py (lookup_function): Same.
+
2021-06-08 Tom de Vries <tdevries@suse.de>
* lib/gdb.exp (multi_line): Require more than one argument.
diff --git a/gdb/testsuite/gdb.base/premature-dummy-frame-removal.py b/gdb/testsuite/gdb.base/premature-dummy-frame-removal.py
index 3193665..fbad6d4 100644
--- a/gdb/testsuite/gdb.base/premature-dummy-frame-removal.py
+++ b/gdb/testsuite/gdb.base/premature-dummy-frame-removal.py
@@ -46,10 +46,10 @@
sp = pending_frame.read_register(sp_desc)
block = gdb.block_for_pc(int(pc))
- if block == None:
+ if block is None:
return None
func = block.function
- if func == None:
+ if func is None:
return None
if str(func) != "break_bt_here":
return None
diff --git a/gdb/testsuite/gdb.python/py-frame-args.py b/gdb/testsuite/gdb.python/py-frame-args.py
index 32d7204..59dd14d 100644
--- a/gdb/testsuite/gdb.python/py-frame-args.py
+++ b/gdb/testsuite/gdb.python/py-frame-args.py
@@ -53,7 +53,7 @@
# Get the type name.
typename = type.tag
- if typename == None:
+ if typename is None:
return None
# Iterate over local dictionary of types to determine
diff --git a/gdb/testsuite/gdb.python/py-framefilter-invalidarg.py b/gdb/testsuite/gdb.python/py-framefilter-invalidarg.py
index 609ff80..20af516 100644
--- a/gdb/testsuite/gdb.python/py-framefilter-invalidarg.py
+++ b/gdb/testsuite/gdb.python/py-framefilter-invalidarg.py
@@ -28,7 +28,7 @@
def function(self):
fname = str(self.fobj.function())
- if fname == None or fname == "":
+ if not fname:
return None
if fname == "end_func":
extra = self.fobj.inferior_frame().read_var("str").string()
diff --git a/gdb/testsuite/gdb.python/py-framefilter.py b/gdb/testsuite/gdb.python/py-framefilter.py
index ce5a35d..8058f61 100644
--- a/gdb/testsuite/gdb.python/py-framefilter.py
+++ b/gdb/testsuite/gdb.python/py-framefilter.py
@@ -28,7 +28,7 @@
def function(self):
fname = str(self.fobj.function())
- if fname == None or fname == "":
+ if not fname:
return None
if fname == "end_func":
extra = self.fobj.inferior_frame().read_var("str").string()
diff --git a/gdb/testsuite/gdb.python/py-nested-maps.py b/gdb/testsuite/gdb.python/py-nested-maps.py
index 163fc86..2848347 100644
--- a/gdb/testsuite/gdb.python/py-nested-maps.py
+++ b/gdb/testsuite/gdb.python/py-nested-maps.py
@@ -88,7 +88,7 @@
# Get the type name.
typename = type.tag
- if typename == None:
+ if typename is None:
return None
# Iterate over local dictionary of types to determine
@@ -109,7 +109,7 @@
# Get the type.
type = val.type
- if type == None or type.name == None or type.code != gdb.TYPE_CODE_TYPEDEF:
+ if type is None or type.name is None or type.code != gdb.TYPE_CODE_TYPEDEF:
return None
# Iterate over local dictionary of typedef types to determine if a
diff --git a/gdb/testsuite/gdb.python/py-objfile-script-gdb.py b/gdb/testsuite/gdb.python/py-objfile-script-gdb.py
index 88372e4..45d036c 100644
--- a/gdb/testsuite/gdb.python/py-objfile-script-gdb.py
+++ b/gdb/testsuite/gdb.python/py-objfile-script-gdb.py
@@ -42,7 +42,7 @@
# Get the type name.
typename = type.tag
- if typename == None:
+ if typename is None:
return None
# Iterate over local dictionary of types to determine
diff --git a/gdb/testsuite/gdb.python/py-prettyprint.py b/gdb/testsuite/gdb.python/py-prettyprint.py
index 84dbc3b..89ffc0f 100644
--- a/gdb/testsuite/gdb.python/py-prettyprint.py
+++ b/gdb/testsuite/gdb.python/py-prettyprint.py
@@ -314,7 +314,7 @@
# Get the type name.
typename = type.tag
- if typename == None:
+ if typename is None:
return None
# Iterate over local dictionary of types to determine
@@ -344,7 +344,7 @@
# Get the type.
type = val.type
- if type == None or type.name == None or type.code != gdb.TYPE_CODE_TYPEDEF:
+ if type is None or type.name is None or type.code != gdb.TYPE_CODE_TYPEDEF:
return None
# Iterate over local dictionary of typedef types to determine if a
diff --git a/gdb/testsuite/gdb.python/py-section-script.py b/gdb/testsuite/gdb.python/py-section-script.py
index aac70a0..8562e52 100644
--- a/gdb/testsuite/gdb.python/py-section-script.py
+++ b/gdb/testsuite/gdb.python/py-section-script.py
@@ -42,7 +42,7 @@
# Get the type name.
typename = type.tag
- if typename == None:
+ if typename is None:
return None
# Iterate over local dictionary of types to determine
diff --git a/gdb/testsuite/gdb.python/py-unwind-inline.py b/gdb/testsuite/gdb.python/py-unwind-inline.py
index 3042472..2892f41 100644
--- a/gdb/testsuite/gdb.python/py-unwind-inline.py
+++ b/gdb/testsuite/gdb.python/py-unwind-inline.py
@@ -45,7 +45,7 @@
def get_regs(self, pending_frame):
"""Return a list of register names that should be read. Only
gathers the list once, then caches the result."""
- if self.regs != None:
+ if self.regs is not None:
return self.regs
# Collect the names of all registers to read.
diff --git a/gdb/testsuite/gdb.python/python.exp b/gdb/testsuite/gdb.python/python.exp
index c7d879e..d9fd60f 100644
--- a/gdb/testsuite/gdb.python/python.exp
+++ b/gdb/testsuite/gdb.python/python.exp
@@ -192,7 +192,7 @@
# Test PR 12212, using InfThread.selected_thread() when no inferior is
# loaded.
gdb_py_test_silent_cmd "python nothread = gdb.selected_thread()" "Attempt to aquire thread with no inferior" 1
-gdb_test "python print (nothread == None)" "True" "ensure that no threads are returned"
+gdb_test "python print (nothread is None)" "True" "ensure that no threads are returned"
gdb_test_multiline "register atexit function" \
"python" "" \
diff --git a/gdb/testsuite/gdb.rust/pp.py b/gdb/testsuite/gdb.rust/pp.py
index 57c8cc3..a78e300 100644
--- a/gdb/testsuite/gdb.rust/pp.py
+++ b/gdb/testsuite/gdb.rust/pp.py
@@ -38,7 +38,7 @@
# Get the type name.
typename = type.tag
- if typename == None:
+ if typename is None:
return None
if typename == "pp::Inner":
