com.facebook.buck.core.rules.attr

Interface SupportsDependencyFileRuleKey

All Superinterfaces:

AllowsNonAnnotatedFields, BuildEngineAction, BuildRule, Comparable<BuildRule>, HasNameAndType

All Known Implementing Classes:

AndroidLibrary, AndroidPrebuiltAar, CalculateSourceAbi, CxxPreprocessAndCompile, DefaultJavaLibrary

public interface SupportsDependencyFileRuleKey
extends BuildRule

Used to tag a rule that supports dependency-file input-based rule keys.

Method Summary

Modifier and Type	Method and Description
java.util.function.Predicate<SourcePath>	getCoveredByDepFilePredicate(SourcePathResolverAdapter pathResolver) Returns a predicate that can tell whether a given path is covered by dep-file or not.
java.util.function.Predicate<SourcePath>	getExistenceOfInterestPredicate(SourcePathResolverAdapter pathResolver) Returns a predicate that can tell whether the existence of a given path may be of interest to compiler.
com.google.common.collect.ImmutableList<SourcePath>	getInputsAfterBuildingLocally(BuildContext context, CellPathResolver cellPathResolver) Returns a list of source paths that were actually used for the rule.
boolean	useDependencyFileRuleKeys()

Methods inherited from interface com.facebook.buck.core.rules.BuildRule

compareTo, getBuildDeps, getBuildSteps, getBuildTarget, getFullyQualifiedName, getProjectFilesystem, getSourcePathToOutput, hasBuildSteps, isCacheable, outputFileCanBeCopied, shouldRespectInputSizeLimitForRemoteExecution, toString, updateBuildRuleResolver

Methods inherited from interface com.facebook.buck.core.build.action.BuildEngineAction

getDependencies, getSourcePathOutputs

Methods inherited from interface com.facebook.buck.core.rules.HasNameAndType

getType

Method Detail

useDependencyFileRuleKeys

boolean useDependencyFileRuleKeys()

getCoveredByDepFilePredicate

java.util.function.Predicate<SourcePath> getCoveredByDepFilePredicate(SourcePathResolverAdapter pathResolver)

Returns a predicate that can tell whether a given path is covered by dep-file or not. Note that being covered by dep-file doesn't necessarily mean being present in the dep-file. A covered path will only be present if actually used and that's the core idea of dep-file keys.

I.e. this predicate should return true only for source paths that *may* be returned from getInputsAfterBuildingLocally(BuildContext, CellPathResolver). This information is used by the rule key builder to infer that inputs *not* in this list should be included unconditionally in the rule key. Inputs that *are* in this list should be included in the rule key if and only if they are actually being used for the rule. I.e. if they are present in the dep-file listed by getInputsAfterBuildingLocally(BuildContext, CellPathResolver).

getExistenceOfInterestPredicate

java.util.function.Predicate<SourcePath> getExistenceOfInterestPredicate(SourcePathResolverAdapter pathResolver)

Returns a predicate that can tell whether the existence of a given path may be of interest to compiler. If this predicate returns true, the path should be included in the rule key. Note that we only care about the existence here. The actual content of the file is not relevant.

The main purpose of this predicate is to support scenarios where compiler decides whether to use a file or not solely based on its path. Of course, if compiler decides to use the file, it should list it in the dep-file in which case both the path and the content will be included in the rule key. However, relying only on presence in the dep-file for such paths is not sufficient. The problem occurs when a new such file just gets added, in which case it won't be present in the dep-file produced in the previous build, and yet if we run a local build now the compiler may decide to use it. For that reason rule key needs to reflect existence of all such files and change when a such a file gets added or removed.

getInputsAfterBuildingLocally

com.google.common.collect.ImmutableList<SourcePath> getInputsAfterBuildingLocally(BuildContext context,
                                                                                  CellPathResolver cellPathResolver)
                                                                           throws IOException

Returns a list of source paths that were actually used for the rule. This list comes from the dep-file produced by compiler.

Throws:

IOException