[CI] Add vulture, a deadcode checker for python. NFC (#25382)

Adding this actually turned up a bug in test code where we were skipping
more variants of a test than we needed to because a tautological `if`
condition.

Author: sbc100

.circleci/config.yml

@@ -507,6 +507,12 @@ jobs:
       - run: ruff check
       # TODO (cclauss): When ruff supports rules these errors without --preview, remove following line
       - run: ruff check --preview --select=E20,E30,E221,E225,E226
+  vulture:
+    executor: focal
+    steps:
+      - checkout
+      - pip-install
+      - run: vulture . --min-confidence 100
   mypy:
     executor: focal
     steps:
@@ -1213,6 +1219,7 @@ workflows:
     jobs:
       - ruff
       - mypy
+      - vulture
       - eslint
       - build-docs
       - build-linux

pyproject.toml

@@ -111,3 +111,6 @@ ignore_missing_imports = true
 
 [tool.deadcode]
 exclude = ["out", "cache", "third_party", "test/third_party", "node_modules", "site/source/_themes", "site/source/conf.py"]
+
+[tool.vulture]
+exclude = ["out", "cache", "third_party", "test/third_party", "node_modules", "site/source/_themes", "site/source/conf.py"]

requirements-dev.txt

@@ -11,6 +11,7 @@ ruff==0.11.7
 types-requests==2.32.0.20241016
 unittest-xml-reporting==3.2.0
 deadcode==2.3.1
+vulture==2.14
 
 # This version is mentioned in `site/source/docs/site/about.rst`.
 # Please keep them in sync.

test/test_benchmark.py

@@ -160,7 +160,7 @@ def __init__(self, name, cc, cxx, args=None):
     self.cxx = cxx
     self.args = args or [OPTIMIZATIONS]
 
-  def build(self, parent, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder, has_output_parser):
+  def build(self, parent, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder):
     native_args = native_args or []
     shared_args = shared_args or []
     self.parent = parent
@@ -213,7 +213,7 @@ def __init__(self, name, engine, extra_args=None, env=None, binaryen_opts=None):
       self.env.update(env)
     self.binaryen_opts = binaryen_opts or []
 
-  def build(self, parent, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder, has_output_parser):
+  def build(self, parent, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder):
     emcc_args = emcc_args or []
     self.filename = filename
     llvm_root = self.env.get('LLVM') or config.LLVM_ROOT
@@ -294,7 +294,7 @@ def __init__(self, name, engine, args=None, binaryen_opts=None):
     self.args = args or [OPTIMIZATIONS]
     self.binaryen_opts = binaryen_opts or []
 
-  def build(self, parent, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder, has_output_parser):
+  def build(self, parent, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder):
     cheerp_args = [
       '-fno-math-errno',
     ]
@@ -459,7 +459,7 @@ def do_benchmark(self, name, src, expected_output='FAIL', args=None,
         reps = 0
       baseline = b
       print('Running benchmarker: %s: %s' % (b.__class__.__name__, b.name))
-      b.build(self, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder, has_output_parser=output_parser is not None)
+      b.build(self, filename, args, shared_args, emcc_args, native_args, native_exec, lib_builder)
       b.bench(args, output_parser, reps, expected_output)
       recorded_stats = b.display(baseline)
       if recorded_stats:

test/test_core.py

@@ -7486,7 +7486,7 @@ def test2():
     'no_dynamic': (['--bind', '-sDYNAMIC_EXECUTION=0', '-sLEGACY_VM_SUPPORT'],),
   })
   def test_embind_val_basics(self, args):
-    if '-sLEGACY_VM_SUPPORT':
+    if '-sLEGACY_VM_SUPPORT' in args:
       if self.get_setting('MODULARIZE') == 'instance' or self.get_setting('WASM_ESM_INTEGRATION'):
         self.skipTest('LEGACY_VM_SUPPORT is not compatible with EXPORT_ES6')
       if self.is_wasm64():

tools/filelock.py

@@ -128,7 +128,7 @@ def __init__(self, lock):
     def __enter__(self):
         return self.lock
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(self, _exc_type, _exc_value, _traceback):
         self.lock.release()
         return None
 
@@ -330,7 +330,7 @@ def __enter__(self):
         self.acquire()
         return self
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(self, _exc_type, _exc_value, _traceback):
         self.release()
         return None
 

tools/gen_struct_info.py

@@ -123,7 +123,7 @@ def __enter__(self):
     self.code.append('puts("{");')
     return self
 
-  def __exit__(self, exc_type, exc_val, exc_tb):
+  def __exit__(self, _exc_type, _exc_val, _exc_tb):
     if self.has_data:
       self.code.append('puts("");')
     self.code.append('printf("}");')