binutils-gdb

mirror of https://github.com/espressif/binutils-gdb.git synced 2025-12-19 01:19:41 +08:00

Files

Tom de Vries 9197e8eebe [gdb/python] Reimplement F405 fix

At commit 34b0776fd73^, flake8 reports the following F405 warnings:
...
$ pre-commit run flake8 --file gdb/python/lib/gdb/__init__.py
flake8...................................................................Failed
- hook id: flake8
- exit code: 1

F405 'flush' may be undefined, or defined from star imports: _gdb
F405 'write' may be undefined, or defined from star imports: _gdb
F405 'STDOUT' may be undefined, or defined from star imports: _gdb
F405 'STDERR' may be undefined, or defined from star imports: _gdb
  ...
F405 'selected_inferior' may be undefined, or defined from star imports: _gdb
F405 'execute' may be undefined, or defined from star imports: _gdb
F405 'parameter' may be undefined, or defined from star imports: _gdb
...

The F405s are addressed by commit 34b0776fd7 ('Suppress some "undefined"
warnings from flake8').

The problem indicated by the first F405 is that the use of flush here:
...
class _GdbFile(object):
     ...
    def flush(self):
        flush(stream=self.stream)
...
cannot be verified by flake8.  It concludes that either, flush is undefined,
or it is defined by this "star import":
...
from _gdb import *  # noqa: F401,F403
...

In this particular case, indeed flush is defined by the star import.

This can be addressed by simply adding:
...
        flush(stream=self.stream)  # noqa: F405
...
but that has only effect for flake8, so other analyzers may report the same
problem.

The commit 34b0776fd7 addresses it instead by adding an "import _gdb" and
adding a "_gdb." prefix:
...
        _gdb.flush(stream=self.stream)
...

This introduces a second way to specify _gdb names, but the first one still
remains, and occasionally someone will use the first one, which then requires
fixing once flake8 is run [1].

While this works to silence the warnings, there is a problem: if a developer
makes a typo:
...
        _gdb.flash(stream=self.stream)
...
this is not detected by flake8.

This matters because although the python import already complains:
...
$ gdb -q -batch -ex "python import gdb"
Exception ignored in: <gdb._GdbFile object at 0x7f6186d4d7f0>
Traceback (most recent call last):
  File "__init__.py", line 63, in flush
    _gdb.flash(stream=self.stream)
AttributeError: module '_gdb' has no attribute 'flash'
...
that doesn't trigger if the code is hidden behind some control flow:
...
	if _var_mostly_false:
	    flash(stream=self.stream)
...

Instead, fix the F405s by reverting commit 34b0776fd7 and adding a second
import of _gdb alongside the star import which lists the names used locally:
...
 from _gdb import *  # noqa: F401,F403
+from _gdb import (
+    STDERR,
+    STDOUT,
+    Command,
+    execute,
+    flush,
+    parameter,
+    selected_inferior,
+    write,
+)
...

This gives the following warnings for the flash typo:
...
31:1: F401 '_gdb.flush' imported but unused
70:5: F811 redefinition of unused 'flush' from line 31
71:9: F405 'flash' may be undefined, or defined from star imports: _gdb
...

The benefits of this approach compared to the previous one are that:
- the typo is noticed, and
- when using a new name, the F405 fix needs to be done once (by adding it to
  the explicit import list), while previously the fix had to be applied to
  each use (by adding the "_gdb." prefix).

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>

[1] Commit 475799b692 ("Fix some pre-commit nits in gdb/__init__.py")

2025-06-02 06:44:59 +02:00