Major fixes and new features

venv/lib/python3.12/site-packages/coverage/patch.py

@@ -0,0 +1,165 @@
+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
+
+"""Invasive patches for coverage.py."""
+
+from __future__ import annotations
+
+import atexit
+import contextlib
+import os
+import site
+from pathlib import Path
+from typing import TYPE_CHECKING, Any, NoReturn
+
+from coverage import env
+from coverage.debug import NoDebugging, DevNullDebug
+from coverage.exceptions import ConfigError, CoverageException
+
+if TYPE_CHECKING:
+    from coverage import Coverage
+    from coverage.config import CoverageConfig
+    from coverage.types import TDebugCtl
+
+
+def apply_patches(
+    cov: Coverage,
+    config: CoverageConfig,
+    debug: TDebugCtl,
+    *,
+    make_pth_file: bool = True,
+) -> None:
+    """Apply invasive patches requested by `[run] patch=`."""
+    debug = debug if debug.should("patch") else DevNullDebug()
+    for patch in sorted(set(config.patch)):
+        if patch == "_exit":
+            _patch__exit(cov, debug)
+
+        elif patch == "execv":
+            _patch_execv(cov, config, debug)
+
+        elif patch == "fork":
+            _patch_fork(debug)
+
+        elif patch == "subprocess":
+            _patch_subprocess(config, debug, make_pth_file)
+
+        else:
+            raise ConfigError(f"Unknown patch {patch!r}")
+
+
+def _patch__exit(cov: Coverage, debug: TDebugCtl) -> None:
+    """Patch os._exit."""
+    debug.write("Patching _exit")
+
+    old_exit = os._exit
+
+    def coverage_os_exit_patch(status: int) -> NoReturn:
+        with contextlib.suppress(Exception):
+            debug.write(f"Using _exit patch with {cov = }")
+        with contextlib.suppress(Exception):
+            cov.save()
+        old_exit(status)
+
+    os._exit = coverage_os_exit_patch
+
+
+def _patch_execv(cov: Coverage, config: CoverageConfig, debug: TDebugCtl) -> None:
+    """Patch the execv family of functions."""
+    if env.WINDOWS:
+        raise CoverageException("patch=execv isn't supported yet on Windows.")
+
+    debug.write("Patching execv")
+
+    def make_execv_patch(fname: str, old_execv: Any) -> Any:
+        def coverage_execv_patch(*args: Any, **kwargs: Any) -> Any:
+            with contextlib.suppress(Exception):
+                debug.write(f"Using execv patch for {fname} with {cov = }")
+            with contextlib.suppress(Exception):
+                cov.save()
+
+            if fname.endswith("e"):
+                # Assume the `env` argument is passed positionally.
+                new_env = args[-1]
+                # Pass our configuration in the new environment.
+                new_env["COVERAGE_PROCESS_CONFIG"] = config.serialize()
+                if env.TESTING:
+                    # The subprocesses need to use the same core as the main process.
+                    new_env["COVERAGE_CORE"] = os.getenv("COVERAGE_CORE")
+
+                    # When testing locally, we need to honor the pyc file location
+                    # or they get written to the .tox directories and pollute the
+                    # next run with a different core.
+                    if (cache_prefix := os.getenv("PYTHONPYCACHEPREFIX")) is not None:
+                        new_env["PYTHONPYCACHEPREFIX"] = cache_prefix
+
+                    # Without this, it fails on PyPy and Ubuntu.
+                    new_env["PATH"] = os.getenv("PATH")
+            old_execv(*args, **kwargs)
+
+        return coverage_execv_patch
+
+    # All the exec* and spawn* functions eventually call execv or execve.
+    os.execv = make_execv_patch("execv", os.execv)
+    os.execve = make_execv_patch("execve", os.execve)
+
+
+def _patch_fork(debug: TDebugCtl) -> None:
+    """Ensure Coverage is properly reset after a fork."""
+    from coverage.control import _after_fork_in_child
+
+    if env.WINDOWS:
+        raise CoverageException("patch=fork isn't supported yet on Windows.")
+
+    debug.write("Patching fork")
+    os.register_at_fork(after_in_child=_after_fork_in_child)
+
+
+def _patch_subprocess(config: CoverageConfig, debug: TDebugCtl, make_pth_file: bool) -> None:
+    """Write .pth files and set environment vars to measure subprocesses."""
+    debug.write("Patching subprocess")
+
+    if make_pth_file:
+        pth_files = create_pth_files(debug)
+
+        def delete_pth_files() -> None:
+            for p in pth_files:
+                debug.write(f"Deleting subprocess .pth file: {str(p)!r}")
+                p.unlink(missing_ok=True)
+
+        atexit.register(delete_pth_files)
+    assert config.config_file is not None
+    os.environ["COVERAGE_PROCESS_CONFIG"] = config.serialize()
+
+
+# Writing .pth files is not obvious. On Windows, getsitepackages() returns two
+# directories.  A .pth file in the first will be run, but coverage isn't
+# importable yet.  We write into all the places we can, but with defensive
+# import code.
+
+PTH_CODE = """\
+try:
+    import coverage
+except:
+    pass
+else:
+    coverage.process_startup()
+"""
+
+PTH_TEXT = f"import sys; exec({PTH_CODE!r})\n"
+
+
+def create_pth_files(debug: TDebugCtl = NoDebugging()) -> list[Path]:
+    """Create .pth files for measuring subprocesses."""
+    pth_files = []
+    for pth_dir in site.getsitepackages():
+        pth_file = Path(pth_dir) / f"subcover_{os.getpid()}.pth"
+        try:
+            if debug.should("patch"):
+                debug.write(f"Writing subprocess .pth file: {str(pth_file)!r}")
+            pth_file.write_text(PTH_TEXT, encoding="utf-8")
+        except OSError:  # pragma: cant happen
+            continue
+        else:
+            pth_files.append(pth_file)
+    return pth_files