// Copyright 2015 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.devtools.build.lib.actions;
import com.google.common.base.Optional;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.util.Fingerprint;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.vfs.RootedPath;
import java.util.Set;
/**
* Parameters of a filesystem traversal requested by a Fileset rule.
*
* <p>This object stores the details of the traversal request, e.g. whether it's a direct or nested
* traversal (see {@link #getDirectTraversal()} and {@link #getNestedTraversal()}) or who the owner
* of the traversal is.
*/
public interface FilesetTraversalParams {
/** Desired behavior if the traversal hits a directory with a BUILD file, i.e. a subpackage. */
public enum PackageBoundaryMode {
/** The traversal should recurse into the directory, optionally reporting a warning. */
CROSS,
// TODO(bazel-team): deprecate CROSS and REPORT_ERROR in favor of DONT_CROSS. Clean up the depot
// and lock down the semantics of FilesetEntry.srcdir to only accept other Filesets or BUILD
// files of a package, in which case also require an explicit list of files.
/** The traversal should not recurse into the directory but silently skip it. */
DONT_CROSS,
/** The traversal should not recurse into the directory and report an error. */
REPORT_ERROR;
public static PackageBoundaryMode forStrictFilesetFlag(boolean flagEnabled) {
return flagEnabled ? REPORT_ERROR : CROSS;
}
public void fingerprint(Fingerprint fp) {
fp.addInt(ordinal());
}
}
/**
* Abstraction of the root directory of a {@link DirectTraversal}.
*
* <ul>
* <li>The root of package traversals is the package directory, i.e. the parent of the BUILD file.
* <li>The root of "recursive" directory traversals is the directory's path.
* <li>The root of "file" traversals is the path of the file (or directory, or symlink) itself.
* </ul>
*
* <p>For the meaning of "recursive" and "file" traversals see {@link DirectTraversal}.
*/
interface DirectTraversalRoot {
/**
* Returns the root part of the full path.
*
* <p>This is typically the workspace root or some output tree's root (e.g. genfiles, binfiles).
*/
Path getRootPart();
/**
* Returns the {@link #getRootPart() root}-relative part of the path.
*
* <p>This is typically the source directory under the workspace or the output file under an
* output directory.
*/
PathFragment getRelativePart();
/** Returns a {@link RootedPath} composed of the root and relative parts. */
RootedPath asRootedPath();
}
/**
* Describes a request for a direct filesystem traversal.
*
* <p>"Direct" means this corresponds to an actual filesystem traversal as opposed to traversing
* another Fileset rule, which is called a "nested" traversal.
*
* <p>Direct traversals can further be divided into two categories, "file" traversals and
* "recursive" traversals.
*
* <p>File traversal requests are created when the FilesetEntry.files attribute is defined; one
* file traversal request is created for each entry.
*
* <p>Recursive traversal requests are created when the FilesetEntry.files attribute is
* unspecified; one recursive traversal request is created for the FilesetEntry.srcdir.
*
* <p>See {@link DirectTraversal#getRoot()} for more details.
*/
interface DirectTraversal {
/** Returns the root of the traversal; see {@link DirectTraversalRoot}. */
DirectTraversalRoot getRoot();
/**
* Returns true if this traversal refers to a whole package.
*
* <p>In that case the root (see {@link #getRoot()}) refers to the path of the package.
*
* <p>Package traversals are always recursive (see {@link #isRecursive()}) and are never
* generated (see {@link #isGenerated()}).
*/
boolean isPackage();
/**
* Returns true if this is a "recursive traversal", i.e. created from FilesetEntry.srcdir.
*
* <p>This type of traversal is created when the FilesetEntry doesn't define a "files" list.
* When it does, the traversal is referred to as a "file traversal". When it doesn't, but the
* srcdir points to another Fileset, it is called a "nested" traversal.
*
* <p>Recursive traversals got their name from recursively traversing a directory structure.
* These are usually whole-package traversals, i.e. when FilesetEntry.srcdir refers to a BUILD
* file (see {@link #isPackage()}), but sometimes the srcdir references a input or output
* directory (the latter being generated by a local genrule) or a symlink (which must point to a
* directory; enforced during action execution).
*
* <p>The files in the results of a recursive traversal are all under the {@link #getRoot()
* root}. The root's path is stripped from the results.
*
* <p>N.B.: "file traversals" can also be recursive if the entry in FilesetEntry.files, for
* which the traversal parameters were created, turned out to be a directory. The difference
* lies in how the output paths are computed (with recursive traversals, the directory's name
* is stripped; with file traversals it is not, modulo usage of strip_prefix and the excludes
* attributes), and how directory symlinks are handled (in "recursive traversals" they are
* expanded just like normal directories, subsequent directory symlinks under them are *not*
* expanded though; they are not expanded at all in "file traversals").
*/
boolean isRecursive();
/** Returns true if the root points to a generated file, symlink or directory. */
boolean isGenerated();
/** Returns true if input symlinks should be dereferenced; false if copied. */
boolean isFollowingSymlinks();
/** Returns the desired behavior when the traversal hits a subpackage. */
PackageBoundaryMode getPackageBoundaryMode();
}
/** Label of the Fileset rule that owns this traversal. */
Label getOwnerLabelForErrorMessages();
/** Returns the directory under the output path where the files will be mapped. May be empty. */
PathFragment getDestPath();
/** Returns a list of file basenames to be excluded from the output. May be empty. */
Set<String> getExcludedFiles();
/**
* Returns the parameters of the direct traversal request, if any.
*
* <p>A direct traversal is anything that's not a nested traversal, e.g. traversal of a package or
* directory (when FilesetEntry.srcdir is specified) or traversal of a single file (when
* FilesetEntry.files is specified). See {@link DirectTraversal} for more detail.
*
* <p>The value is present if and only if {@link #getNestedTraversal} is absent.
*/
Optional<DirectTraversal> getDirectTraversal();
/**
* Returns the parameters of the nested traversal request, if any.
*
* <p>A nested traversal is the traversal of another Fileset referenced by FilesetEntry.srcdir.
*
* <p>The value is present if and only if {@link #getDirectTraversal} is absent.
*/
Optional<FilesetTraversalParams> getNestedTraversal();
/** Adds the fingerprint of this traversal object. */
void fingerprint(Fingerprint fp);
}