Revert "filesystem.py: add `max_depth` argument to `find` (#41945)"

This reverts commit 38c8069ab42f44aa9f4779968937fc6842dc2109.

4 files changed, 77 insertions, 292 deletions

diff --git a/lib/spack/llnl/util/filesystem.py b/lib/spack/llnl/util/filesystem.py
index b63b6e94b3..00bb270151 100644
--- a/lib/spack/llnl/util/filesystem.py
+++ b/lib/spack/llnl/util/filesystem.py
@@ -1673,20 +1673,16 @@ def find_first(root: str, files: Union[Iterable[str], str], bfs_depth: int = 2)
     return FindFirstFile(root, *files, bfs_depth=bfs_depth).find()
 
 
-def find(root, files, recursive=True, max_depth: Optional[int] = None):
+def find(root, files, recursive=True):
     """Search for ``files`` starting from the ``root`` directory.
 
     Like GNU/BSD find but written entirely in Python.
 
-    Specifically this behaves like `find -type f`: it only returns
-    results that are files. When searching recursively, this behaves
-    as `find` with the `-L` option (follows symlinks).
-
     Examples:
 
     .. code-block:: console
 
-       $ find -L /usr -name python
+       $ find /usr -name python
 
     is equivalent to:
 
@@ -1716,8 +1712,6 @@ def find(root, files, recursive=True, max_depth: Optional[int] = None):
         files (str or collections.abc.Sequence): Library name(s) to search for
         recursive (bool): if False search only root folder,
             if True descends top-down from the root. Defaults to True.
-        max_depth (int): if set, don't search below this depth. Cannot be set
-            if recursive is False
 
     Returns:
         list: The files that have been found
@@ -1725,135 +1719,59 @@ def find(root, files, recursive=True, max_depth: Optional[int] = None):
     if isinstance(files, str):
         files = [files]
 
-    # If recursive is false, max_depth can only be None or 0
-    if max_depth and not recursive:
-        raise ValueError(f"max_depth ({max_depth}) cannot be set if recursive is False")
-
-    if not recursive:
-        max_depth = 0
-    elif max_depth is None:
-        max_depth = sys.maxsize
-
-    tty.debug(f"Find (max depth = {max_depth}): {root} {str(files)}")
-    result = find_max_depth(root, files, max_depth)
+    if recursive:
+        tty.debug(f"Find (recursive): {root} {str(files)}")
+        result = _find_recursive(root, files)
+    else:
+        tty.debug(f"Find (not recursive): {root} {str(files)}")
+        result = _find_non_recursive(root, files)
 
     tty.debug(f"Find complete: {root} {str(files)}")
     return result
 
 
-@system_path_filter(arg_slice=slice(1))
-def find_max_depth(root, globs, max_depth: Optional[int] = None):
-    """Given a set of non-recursive glob file patterns, finds all
-    files matching those patterns up to a maximum specified depth.
-
-    If a directory has a name which matches an input pattern, it will
-    not be included in the results.
-
-    If ``max_depth`` is specified, does not search below that depth.
+@system_path_filter
+def _find_recursive(root, search_files):
+    # The variable here is **on purpose** a defaultdict. The idea is that
+    # we want to poke the filesystem as little as possible, but still maintain
+    # stability in the order of the answer. Thus we are recording each library
+    # found in a key, and reconstructing the stable order later.
+    found_files = collections.defaultdict(list)
 
-    If ``globs`` is a list, files matching earlier entries are placed
-    in the return value before files matching later entries.
-    """
-    # If root doesn't exist, then we say we found nothing. If it
-    # exists but is not a dir, we assume the user would want to
-    # know; likewise if it exists but we do not have permission to
-    # access it.
-    try:
-        stat_root = os.stat(root)
-    except OSError as e:
-        if e.errno == errno.ENOENT:
-            return []
-        else:
-            raise
-    if not stat.S_ISDIR(stat_root.st_mode):
-        raise ValueError(f"{root} is not a directory")
+    # Make the path absolute to have os.walk also return an absolute path
+    root = os.path.abspath(root)
+    for path, _, list_files in os.walk(root):
+        for search_file in search_files:
+            matches = glob.glob(os.path.join(path, search_file))
+            matches = [os.path.join(path, x) for x in matches]
+            found_files[search_file].extend(matches)
 
-    if max_depth is None:
-        max_depth = sys.maxsize
+    answer = []
+    for search_file in search_files:
+        answer.extend(found_files[search_file])
 
-    if isinstance(globs, str):
-        globs = [globs]
-    # Apply normcase to regular expressions and to the filenames:
-    # this respects case-sensitivity semantics of different OSes
-    # (e.g. file search is typically case-insensitive on Windows)
-    regexes = [re.compile(fnmatch.translate(os.path.normcase(x))) for x in globs]
+    return answer
 
-    # Note later calls to os.scandir etc. return abspaths if the
-    # input is absolute, see https://docs.python.org/3/library/os.html#os.DirEntry.path
-    root = os.path.abspath(root)
 
+@system_path_filter
+def _find_non_recursive(root, search_files):
+    # The variable here is **on purpose** a defaultdict as os.list_dir
+    # can return files in any order (does not preserve stability)
     found_files = collections.defaultdict(list)
 
-    def _dir_id(stat_info):
-        # Note: on windows, st_ino is the file index and st_dev
-        # is the volume serial number. See
-        # https://github.com/python/cpython/blob/3.9/Python/fileutils.c
-        return (stat_info.st_ino, stat_info.st_dev)
-
-    def _log_file_access_issue(e):
-        errno_name = errno.errorcode.get(e.errno, "UNKNOWN")
-        tty.debug(f"find must skip {dir_entry.path}: {errno_name} {str(e)}")
-
-    visited_dirs = set([_dir_id(stat_root)])
-
-    # Each queue item stores the depth and path
-    # This achieves a consistent traversal order by iterating through
-    # each directory in alphabetical order.
-    # This also traverses in BFS order to ensure finding the shortest
-    # path to any file (or one of the shortest paths, if there are
-    # several - the one returned will be consistent given the prior
-    # point).
-    dir_queue = collections.deque([(0, root)])
-    while dir_queue:
-        depth, next_dir = dir_queue.pop()
-        try:
-            dir_iter = os.scandir(next_dir)
-        except OSError:
-            # Most commonly, this would be a permissions issue, for
-            # example if we are scanning an external directory like /usr
-            continue
-
-        with dir_iter:
-            ordered_entries = sorted(dir_iter, key=lambda x: x.name)
-            for dir_entry in ordered_entries:
-                try:
-                    it_is_a_dir = dir_entry.is_dir(follow_symlinks=True)
-                except OSError as e:
-                    # Possible permission issue, or a symlink that cannot
-                    # be resolved (ELOOP).
-                    _log_file_access_issue(e)
-                    continue
+    # Make the path absolute to have absolute path returned
+    root = os.path.abspath(root)
 
-                if it_is_a_dir and (depth < max_depth):
-                    try:
-                        # The stat should be performed in a try/except block.
-                        # We repeat that here vs. moving to the above block
-                        # because we only want to call `stat` if we haven't
-                        # exceeded our max_depth
-                        if sys.platform == "win32":
-                            # Note: st_ino/st_dev on DirEntry.stat are not set on
-                            # Windows, so we have to call os.stat
-                            stat_info = os.stat(dir_entry.path, follow_symlinks=True)
-                        else:
-                            stat_info = dir_entry.stat(follow_symlinks=True)
-                    except OSError as e:
-                        _log_file_access_issue(e)
-                        continue
-
-                    dir_id = _dir_id(stat_info)
-                    if dir_id not in visited_dirs:
-                        dir_queue.appendleft((depth + 1, dir_entry.path))
-                        visited_dirs.add(dir_id)
-                else:
-                    fname = os.path.basename(dir_entry.path)
-                    for pattern in regexes:
-                        if pattern.match(os.path.normcase(fname)):
-                            found_files[pattern].append(os.path.join(next_dir, fname))
+    for search_file in search_files:
+        matches = glob.glob(os.path.join(root, search_file))
+        matches = [os.path.join(root, x) for x in matches]
+        found_files[search_file].extend(matches)
 
-        # TODO: for fully-recursive searches, we can print a warning after
-        # after having searched everything up to some fixed depth
+    answer = []
+    for search_file in search_files:
+        answer.extend(found_files[search_file])
 
-    return list(itertools.chain(*[found_files[x] for x in regexes]))
+    return answer
 
 
 # Utilities for libraries and headers
@@ -2292,9 +2210,7 @@ def find_system_libraries(libraries, shared=True):
     return libraries_found
 
 
-def find_libraries(
-    libraries, root, shared=True, recursive=False, runtime=True, max_depth: Optional[int] = None
-):
+def find_libraries(libraries, root, shared=True, recursive=False, runtime=True):
     """Returns an iterable of full paths to libraries found in a root dir.
 
     Accepts any glob characters accepted by fnmatch:
@@ -2315,8 +2231,6 @@ def find_libraries(
             otherwise for static. Defaults to True.
         recursive (bool): if False search only root folder,
             if True descends top-down from the root. Defaults to False.
-        max_depth (int): if set, don't search below this depth. Cannot be set
-            if recursive is False
         runtime (bool): Windows only option, no-op elsewhere. If true,
             search for runtime shared libs (.DLL), otherwise, search
             for .Lib files. If shared is false, this has no meaning.
@@ -2325,7 +2239,6 @@ def find_libraries(
     Returns:
         LibraryList: The libraries that have been found
     """
-
     if isinstance(libraries, str):
         libraries = [libraries]
     elif not isinstance(libraries, collections.abc.Sequence):
@@ -2358,10 +2271,8 @@ def find_libraries(
     libraries = ["{0}.{1}".format(lib, suffix) for lib in libraries for suffix in suffixes]
 
     if not recursive:
-        if max_depth:
-            raise ValueError(f"max_depth ({max_depth}) cannot be set if recursive is False")
         # If not recursive, look for the libraries directly in root
-        return LibraryList(find(root, libraries, recursive=False))
+        return LibraryList(find(root, libraries, False))
 
     # To speedup the search for external packages configured e.g. in /usr,
     # perform first non-recursive search in root/lib then in root/lib64 and
@@ -2379,7 +2290,7 @@ def find_libraries(
         if found_libs:
             break
     else:
-        found_libs = find(root, libraries, recursive=True, max_depth=max_depth)
+        found_libs = find(root, libraries, True)
 
     return LibraryList(found_libs)
 
diff --git a/lib/spack/spack/test/llnl/util/file_list.py b/lib/spack/spack/test/llnl/util/file_list.py
index e2ff5a8210..75ba3ae89d 100644
--- a/lib/spack/spack/test/llnl/util/file_list.py
+++ b/lib/spack/spack/test/llnl/util/file_list.py
@@ -9,7 +9,7 @@ import sys
 
 import pytest
 
-from llnl.util.filesystem import HeaderList, LibraryList, find_headers, find_libraries
+from llnl.util.filesystem import HeaderList, LibraryList, find, find_headers, find_libraries
 
 import spack.paths
 
@@ -324,3 +324,33 @@ def test_searching_order(search_fn, search_list, root, kwargs):
 
     # List should be empty here
     assert len(rlist) == 0
+
+
+@pytest.mark.parametrize(
+    "root,search_list,kwargs,expected",
+    [
+        (
+            search_dir,
+            "*/*bar.tx?",
+            {"recursive": False},
+            [
+                os.path.join(search_dir, os.path.join("a", "foobar.txt")),
+                os.path.join(search_dir, os.path.join("b", "bar.txp")),
+                os.path.join(search_dir, os.path.join("c", "bar.txt")),
+            ],
+        ),
+        (
+            search_dir,
+            "*/*bar.tx?",
+            {"recursive": True},
+            [
+                os.path.join(search_dir, os.path.join("a", "foobar.txt")),
+                os.path.join(search_dir, os.path.join("b", "bar.txp")),
+                os.path.join(search_dir, os.path.join("c", "bar.txt")),
+            ],
+        ),
+    ],
+)
+def test_find_with_globbing(root, search_list, kwargs, expected):
+    matches = find(root, search_list, **kwargs)
+    assert sorted(matches) == sorted(expected)
diff --git a/lib/spack/spack/test/llnl/util/filesystem.py b/lib/spack/spack/test/llnl/util/filesystem.py
index 01379be94c..a0c9874769 100644
--- a/lib/spack/spack/test/llnl/util/filesystem.py
+++ b/lib/spack/spack/test/llnl/util/filesystem.py
@@ -6,7 +6,6 @@
 """Tests for ``llnl/util/filesystem.py``"""
 import filecmp
 import os
-import pathlib
 import shutil
 import stat
 import sys
@@ -15,8 +14,7 @@ from contextlib import contextmanager
 import pytest
 
 import llnl.util.filesystem as fs
-import llnl.util.symlink
-from llnl.util.symlink import _windows_can_symlink, islink, readlink, symlink
+from llnl.util.symlink import islink, readlink, symlink
 
 import spack.paths
 
@@ -1037,157 +1035,3 @@ def test_windows_sfn(tmpdir):
     assert "d\\LONGER~1" in fs.windows_sfn(d)
     assert "d\\LONGER~2" in fs.windows_sfn(e)
     shutil.rmtree(tmpdir.join("d"))
-
-
-@pytest.fixture
-def dir_structure_with_things_to_find(tmpdir):
-    """
-    <root>/
-        dir_one/
-            file_one
-        dir_two/
-        dir_three/
-            dir_four/
-                file_two
-            file_three
-        file_four
-    """
-    dir_one = tmpdir.join("dir_one").ensure(dir=True)
-    tmpdir.join("dir_two").ensure(dir=True)
-    dir_three = tmpdir.join("dir_three").ensure(dir=True)
-    dir_four = dir_three.join("dir_four").ensure(dir=True)
-
-    locations = {}
-    locations["file_one"] = str(dir_one.join("file_one").ensure())
-    locations["file_two"] = str(dir_four.join("file_two").ensure())
-    locations["file_three"] = str(dir_three.join("file_three").ensure())
-    locations["file_four"] = str(tmpdir.join("file_four").ensure())
-
-    return str(tmpdir), locations
-
-
-def test_find_max_depth(dir_structure_with_things_to_find):
-    root, locations = dir_structure_with_things_to_find
-
-    # Make sure the paths we use to verify are absolute
-    assert os.path.isabs(locations["file_one"])
-
-    assert set(fs.find_max_depth(root, "file_*", 0)) == {locations["file_four"]}
-    assert set(fs.find_max_depth(root, "file_*", 1)) == {
-        locations["file_one"],
-        locations["file_three"],
-        locations["file_four"],
-    }
-    assert set(fs.find_max_depth(root, "file_two", 2)) == {locations["file_two"]}
-    assert not set(fs.find_max_depth(root, "file_two", 1))
-    assert set(fs.find_max_depth(root, "file_two")) == {locations["file_two"]}
-    assert set(fs.find_max_depth(root, "file_*")) == set(locations.values())
-
-
-def test_find_max_depth_relative(dir_structure_with_things_to_find):
-    """find_max_depth should return absolute paths even if
-    the provided path is relative.
-    """
-    root, locations = dir_structure_with_things_to_find
-    with fs.working_dir(root):
-        assert set(fs.find_max_depth(".", "file_*", 0)) == {locations["file_four"]}
-        assert set(fs.find_max_depth(".", "file_two", 2)) == {locations["file_two"]}
-
-
-@pytest.mark.parametrize("recursive,max_depth", [(False, -1), (False, 1)])
-def test_max_depth_and_recursive_errors(tmpdir, recursive, max_depth):
-    root = str(tmpdir)
-    error_str = "cannot be set if recursive is False"
-    with pytest.raises(ValueError, match=error_str):
-        fs.find(root, ["some_file"], recursive=recursive, max_depth=max_depth)
-
-    with pytest.raises(ValueError, match=error_str):
-        fs.find_libraries(["some_lib"], root, recursive=recursive, max_depth=max_depth)
-
-
-def dir_structure_with_things_to_find_links(tmpdir, use_junctions=False):
-    """
-    "lx-dy" means "level x, directory y"
-    "lx-fy" means "level x, file y"
-    "lx-sy" means "level x, symlink y"
-
-    <root>/
-        l1-d1/
-            l2-d1/
-                l3-s1 -> l1-d2 # points to directory above l2-d1
-                l3-d2/
-                    l4-f1
-                l3-s3 -> l1-d1 # cyclic link
-                l3-d4/
-                    l4-f2
-        l1-d2/
-            l2-f1
-            l2-d2/
-                l3-f3
-            l2-s3 -> l2-d2
-        l1-s3 -> l3-d4 # a link that "skips" a directory level
-        l1-s4 -> l2-s3 # a link to a link to a dir
-    """
-    if sys.platform == "win32" and (not use_junctions) and (not _windows_can_symlink()):
-        pytest.skip("This Windows instance is not configured with symlink support")
-
-    l1_d1 = tmpdir.join("l1-d1").ensure(dir=True)
-    l2_d1 = l1_d1.join("l2-d1").ensure(dir=True)
-    l3_d2 = l2_d1.join("l3-d2").ensure(dir=True)
-    l3_d4 = l2_d1.join("l3-d4").ensure(dir=True)
-    l1_d2 = tmpdir.join("l1-d2").ensure(dir=True)
-    l2_d2 = l1_d2.join("l1-d2").ensure(dir=True)
-
-    if use_junctions:
-        link_fn = llnl.util.symlink._windows_create_junction
-    else:
-        link_fn = os.symlink
-
-    link_fn(l1_d2, pathlib.Path(l2_d1) / "l3-s1")
-    link_fn(l1_d1, pathlib.Path(l2_d1) / "l3-s3")
-    link_fn(l3_d4, pathlib.Path(tmpdir) / "l1-s3")
-    l2_s3 = pathlib.Path(l1_d2) / "l2-s3"
-    link_fn(l2_d2, l2_s3)
-    link_fn(l2_s3, pathlib.Path(tmpdir) / "l1-s4")
-
-    locations = {}
-    locations["l4-f1"] = str(l3_d2.join("l4-f1").ensure())
-    locations["l4-f2-full"] = str(l3_d4.join("l4-f2").ensure())
-    locations["l4-f2-link"] = str(pathlib.Path(tmpdir) / "l1-s3" / "l4-f2")
-    locations["l2-f1"] = str(l1_d2.join("l2-f1").ensure())
-    locations["l2-f1-link"] = str(pathlib.Path(tmpdir) / "l1-d1" / "l2-d1" / "l3-s1" / "l2-f1")
-    locations["l3-f3-full"] = str(l2_d2.join("l3-f3").ensure())
-    locations["l3-f3-link-l1"] = str(pathlib.Path(tmpdir) / "l1-s4" / "l3-f3")
-
-    return str(tmpdir), locations
-
-
-def _check_find_links(root, locations):
-    root = pathlib.Path(root)
-    assert set(fs.find_max_depth(root, "l4-f1")) == {locations["l4-f1"]}
-    assert set(fs.find_max_depth(root / "l1-s3", "l4-f2", 0)) == {locations["l4-f2-link"]}
-    assert set(fs.find_max_depth(root / "l1-d1", "l2-f1")) == {locations["l2-f1-link"]}
-    # File is accessible via symlink and subdir, the link path will be
-    # searched first, and the directory will not be searched again when
-    # it is encountered the second time (via not-link) in the traversal
-    assert set(fs.find_max_depth(root, "l4-f2")) == {locations["l4-f2-link"]}
-    # File is accessible only via the dir, so the full file path should
-    # be reported
-    assert set(fs.find_max_depth(root / "l1-d1", "l4-f2")) == {locations["l4-f2-full"]}
-    # Check following links to links
-    assert set(fs.find_max_depth(root, "l3-f3")) == {locations["l3-f3-link-l1"]}
-
-
-@pytest.mark.parametrize(
-    "use_junctions",
-    [
-        False,
-        pytest.param(
-            True,
-            marks=pytest.mark.skipif(sys.platform != "win32", reason="Only Windows has junctions"),
-        ),
-    ],
-)
-def test_find_max_depth_symlinks(tmpdir, use_junctions):
-    root, locations = dir_structure_with_things_to_find_links(tmpdir, use_junctions=use_junctions)
-    _check_find_links(root, locations)
diff --git a/var/spack/repos/builtin.mock/packages/attributes-foo/package.py b/var/spack/repos/builtin.mock/packages/attributes-foo/package.py
index b882fc9b65..31c88f4b08 100644
--- a/var/spack/repos/builtin.mock/packages/attributes-foo/package.py
+++ b/var/spack/repos/builtin.mock/packages/attributes-foo/package.py
@@ -44,7 +44,7 @@ class AttributesFoo(BundlePackage):
     # Header provided by the bar virutal package
     @property
     def bar_headers(self):
-        return find_headers("bar", root=self.home.include, recursive=True)
+        return find_headers("bar/bar", root=self.home.include, recursive=False)
 
     # Libary provided by the bar virtual package
     @property
@@ -59,7 +59,7 @@ class AttributesFoo(BundlePackage):
     # Header provided by the baz virtual package
     @property
     def baz_headers(self):
-        return find_headers("baz", root=self.baz_home.include, recursive=True)
+        return find_headers("baz/baz", root=self.baz_home.include, recursive=False)
 
     # Library provided by the baz virtual package
     @property