1 files changed, 110 insertions, 0 deletions
diff --git a/python/mach/mach/util.py b/python/mach/mach/util.py
new file mode 100644
index 0000000000..4ed303cf3b
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+++ b/python/mach/mach/util.py
@@ -0,0 +1,110 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import hashlib
+import os
+import sys
+from pathlib import Path, PurePosixPath
+from typing import Optional, Union
+
+
+class UserError(Exception):
+    """Represents an error caused by something the user did wrong rather than
+    an internal `mach` failure. Exceptions that are subclasses of this class
+    will not be reported as failures to Sentry.
+    """
+
+
+def setenv(key, value):
+    """Compatibility shim to ensure the proper string type is used with
+    os.environ for the version of Python being used.
+    """
+    from six import text_type
+
+    encoding = "mbcs" if sys.platform == "win32" else "utf-8"
+
+    if sys.version_info[0] == 2:
+        if isinstance(key, text_type):
+            key = key.encode(encoding)
+        if isinstance(value, text_type):
+            value = value.encode(encoding)
+    else:
+        if isinstance(key, bytes):
+            key = key.decode(encoding)
+        if isinstance(value, bytes):
+            value = value.decode(encoding)
+
+    os.environ[key] = value
+
+
+def get_state_dir(
+    specific_to_topsrcdir=False, topsrcdir: Optional[Union[str, Path]] = None
+):
+    """Obtain path to a directory to hold state.
+
+    Args:
+        specific_to_topsrcdir (bool): If True, return a state dir specific to the current
+            srcdir instead of the global state dir (default: False)
+
+    Returns:
+        A path to the state dir (str)
+    """
+    state_dir = Path(os.environ.get("MOZBUILD_STATE_PATH", Path.home() / ".mozbuild"))
+    if not specific_to_topsrcdir:
+        return str(state_dir)
+
+    if not topsrcdir:
+        # Only import MozbuildObject if topsrcdir isn't provided. This is to cover
+        # the Mach initialization stage, where "mozbuild" isn't in the import scope.
+        from mozbuild.base import MozbuildObject
+
+        topsrcdir = Path(
+            MozbuildObject.from_environment(cwd=str(Path(__file__).parent)).topsrcdir
+        )
+
+    # Ensure that the topsrcdir is a consistent string before hashing it.
+    topsrcdir = Path(topsrcdir).resolve()
+
+    # Shortening to 12 characters makes these directories a bit more manageable
+    # in a terminal and is more than good enough for this purpose.
+    srcdir_hash = hashlib.sha256(str(topsrcdir).encode("utf-8")).hexdigest()[:12]
+
+    state_dir = state_dir / "srcdirs" / f"{topsrcdir.name}-{srcdir_hash}"
+
+    if not state_dir.is_dir():
+        # We create the srcdir here rather than 'mach_initialize.py' so direct
+        # consumers of this function don't create the directory inconsistently.
+        print(f"Creating local state directory: {state_dir}")
+        state_dir.mkdir(mode=0o770, parents=True)
+        # Save the topsrcdir that this state dir corresponds to so we can clean
+        # it up in the event its srcdir was deleted.
+        with (state_dir / "topsrcdir.txt").open(mode="w") as fh:
+            fh.write(str(topsrcdir))
+
+    return str(state_dir)
+
+
+def win_to_msys_path(path: Path):
+    """Convert a windows-style path to msys-style."""
+    drive, path = os.path.splitdrive(path)
+    path = "/".join(path.split("\\"))
+    if drive:
+        if path[0] == "/":
+            path = path[1:]
+        path = f"/{drive[:-1]}/{path}"
+    return PurePosixPath(path)
+
+
+def to_optional_path(path: Optional[Path]):
+    if path:
+        return Path(path)
+    else:
+        return None
+
+
+def to_optional_str(path: Optional[Path]):
+    if path:
+        return str(path)
+    else:
+        return None