build: hide extensions, skip branch sysmon on 3.12/3.13

Author: nedbat

igor.py

@@ -52,52 +52,50 @@ def do_show_env():
         print(f"  {env} = {os.environ[env]!r}")
 
 
-def do_remove_extension(*args):
+def remove_extension(core):
     """Remove the compiled C extension, no matter what its name."""
 
+    if core == "ctrace":
+        return
+
     so_patterns = """
         tracer.so
         tracer.*.so
         tracer.pyd
         tracer.*.pyd
         """.split()
 
-    if "--from-install" in args:
-        # Get the install location using a subprocess to avoid
-        # locking the file we are about to delete
-        root = os.path.dirname(
-            subprocess.check_output(
-                [
-                    sys.executable,
-                    "-Xutf8",
-                    "-c",
-                    "import coverage; print(coverage.__file__)",
-                ],
-                encoding="utf-8",
-            ).strip(),
-        )
-        roots = [root]
-    else:
-        roots = [
-            "coverage",
-            "build/*/coverage",
-            ".tox/*/[Ll]ib/*/site-packages/coverage",
-            ".tox/*/[Ll]ib/site-packages/coverage",
-        ]
+    roots = [
+        "coverage",
+        "build/*/coverage",
+        ".tox/*/[Ll]ib/*/site-packages/coverage",
+        ".tox/*/[Ll]ib/site-packages/coverage",
+    ]
 
+    # On windows at least, we can't delete a loaded .pyd file. So move them
+    # out of the way into the tmp/ directory.
+    os.makedirs("tmp", exist_ok=True)
     for root, pattern in itertools.product(roots, so_patterns):
         pattern = os.path.join(root, pattern)
         if VERBOSITY > 1:
             print(f"Searching for {pattern} from {os.getcwd()}")
         for filename in glob.glob(pattern):
             if os.path.exists(filename):
+                hidden = f"tmp/{os.path.basename(filename)}"
                 if VERBOSITY > 1:
-                    print(f"Removing {os.path.abspath(filename)}")
+                    print(f"Moving {filename} to {hidden}")
                 try:
-                    os.remove(filename)
+                    if os.path.exists(hidden):
+                        os.remove(hidden)
                 except OSError as exc:
                     if VERBOSITY > 1:
-                        print(f"Couldn't remove {os.path.abspath(filename)}: {exc}")
+                        print(f"Couldn't remove {hidden}: {exc}")
+                else:
+                    try:
+                        os.rename(filename, hidden)
+                    except OSError as exc:
+                        if VERBOSITY > 1:
+                            print(f"Couldn't rename: {exc}")
 
 
 def label_for_core(core):
@@ -112,14 +110,17 @@ def label_for_core(core):
         raise ValueError(f"Bad core: {core!r}")
 
 
-def should_skip(core):
+def should_skip(core, metacov):
     """Is there a reason to skip these tests?
 
     Return empty string to run tests, or a message about why we are skipping
     the tests.
     """
     skipper = ""
 
+    if metacov and core == "sysmon" and ((3, 12) <= sys.version_info < (3, 14)):
+        skipper = "sysmon can't measure branches in Python 3.12-3.13"
+
     # $set_env.py: COVERAGE_TEST_CORES - List of cores to run: ctrace, pytrace, sysmon
     test_cores = os.getenv("COVERAGE_TEST_CORES")
     if test_cores:
@@ -140,7 +141,8 @@ def should_skip(core):
                     skipper = f"No C core for {platform.python_implementation()}"
 
     if skipper:
-        return f"Skipping tests {label_for_core(core)}: {skipper}"
+        what = "metacov" if metacov else "tests"
+        return f"Skipping {what} {label_for_core(core)}: {skipper}"
     else:
         return ""
 
@@ -157,10 +159,10 @@ def make_env_id(core):
 
 def run_tests(core, *runner_args):
     """The actual running of tests."""
+    remove_extension(core)
     if "COVERAGE_TESTING" not in os.environ:
         os.environ["COVERAGE_TESTING"] = "True"
     print_banner(label_for_core(core))
-
     return pytest.main(list(runner_args))
 
 
@@ -209,6 +211,8 @@ def run_tests_with_coverage(core, *runner_args):
                 if getattr(mod, "__file__", "??").startswith(covdir):
                     covmods[name] = mod
                     del sys.modules[name]
+        remove_extension(core)
+
         import coverage  # pylint: disable=reimported
 
         sys.modules.update(covmods)
@@ -246,15 +250,17 @@ def do_combine_html():
 
 def do_test_with_core(core, *runner_args):
     """Run tests with a particular core."""
+    metacov = os.getenv("COVERAGE_COVERAGE", "no") == "yes"
+
     # If we should skip these tests, skip them.
-    skip_msg = should_skip(core)
+    skip_msg = should_skip(core, metacov)
     if skip_msg:
         if VERBOSITY > 0:
             print(skip_msg)
         return None
 
     os.environ["COVERAGE_CORE"] = core
-    if os.getenv("COVERAGE_COVERAGE", "no") == "yes":
+    if metacov:
         return run_tests_with_coverage(core, *runner_args)
     else:
         return run_tests(core, *runner_args)

tests/test_cmdline.py

@@ -1372,7 +1372,7 @@ def test_version(self) -> None:
         self.command_line("--version")
         out = self.stdout()
         assert "ersion " in out
-        if testenv.C_TRACER or testenv.SYS_MON:
+        if testenv.C_TRACER:
             assert "with C extension" in out
         else:
             assert "without C extension" in out

tests/test_concurrency.py

@@ -251,10 +251,16 @@ def try_some_code(
             lines = line_count(code)
             assert line_counts(data)["try_it.py"] == lines
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_THREADS, reason="Can't measure threads with this core."
+    )
     def test_threads(self) -> None:
         code = (THREAD + SUM_RANGE_Q + PRINT_SUM_RANGE).format(QLIMIT=self.QLIMIT)
         self.try_some_code(code, "thread", threading)
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_THREADS, reason="Can't measure threads with this core."
+    )
     def test_threads_simple_code(self) -> None:
         code = SIMPLE.format(QLIMIT=self.QLIMIT)
         self.try_some_code(code, "thread", threading)
@@ -318,6 +324,9 @@ def do():
         self.try_some_code(BUG_330, "eventlet", eventlet, "0\n")
 
     # Sometimes a test fails due to inherent randomness. Try more times.
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_THREADS, reason="Can't measure threads with this core."
+    )
     @pytest.mark.flaky(max_runs=3)
     def test_threads_with_gevent(self) -> None:
         self.make_file(
@@ -554,6 +563,9 @@ def test_multiprocessing_and_gevent(self, start_method: str) -> None:
             start_method=start_method,
         )
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_BRANCHES, reason="Can't measure branches with this core"
+    )
     def test_multiprocessing_with_branching(self, start_method: str) -> None:
         nprocs = 3
         upto = 30

tests/test_debug.py

@@ -231,7 +231,7 @@ def test_debug_sys(self) -> None:
     def test_debug_sys_ctracer(self) -> None:
         out_text = self.f1_debug_output(["sys"])
         tracer_line = re_line(r"CTracer:", out_text).strip()
-        if testenv.C_TRACER or testenv.SYS_MON:
+        if testenv.C_TRACER:
             assert tracer_line.startswith("CTracer: available from ")
         else:
             assert tracer_line == "CTracer: unavailable"

tests/test_process.py

@@ -1516,6 +1516,9 @@ def test_subprocess_in_directories(self) -> None:
         assert line_counts(data)["main.py"] == 6
         assert line_counts(data)["subproc.py"] == 2
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_BRANCHES, reason="Can't measure branches with this core"
+    )
     def test_subprocess_gets_nonfile_config(self) -> None:
         # https://github.com/nedbat/coveragepy/issues/2021
         self.make_file(

tests/testenv.py

@@ -7,6 +7,8 @@
 
 import os
 
+from coverage import env
+
 REQUESTED_CORE = os.getenv("COVERAGE_CORE", "ctrace")
 
 REQUESTED_TRACER_CLASS = {
@@ -32,3 +34,9 @@
 
 # Are dynamic contexts supported during these tests?
 DYN_CONTEXTS = C_TRACER or PY_TRACER
+
+# Can we measure threads?
+CAN_MEASURE_THREADS = not SYS_MON
+
+# Can we measure branches?
+CAN_MEASURE_BRANCHES = env.PYBEHAVIOR.branch_right_left

tox.ini

@@ -42,17 +42,15 @@ commands =
     # Create tests/zipmods.zip
     python igor.py zip_mods
 
-    # Remove the C extension so that we can test the PyTracer
-    python igor.py remove_extension
-
-    # Test with the PyTracer
-    python igor.py test_with_core pytrace {posargs}
-
     # Build the C extension and test with the CTracer
     python setup.py --quiet build_ext --inplace
     python -m pip install {env:COVERAGE_PIP_ARGS} -q -e .
     python igor.py test_with_core ctrace {posargs}
 
+    # Test with the PyTracer
+    python igor.py test_with_core pytrace {posargs}
+
+    # Test with sys.monitoring
     py3{12-15}{,t},anypy: python igor.py test_with_core sysmon {posargs}
 
 [testenv:anypy]