com.facebook.buck.core.starlark.rule.attr

Class Attribute<CoercedType>

java.lang.Object

com.facebook.buck.core.starlark.rule.attr.Attribute<CoercedType>

All Implemented Interfaces:

AttributeHolder, com.google.devtools.build.lib.skylarkinterface.SkylarkPrintable, com.google.devtools.build.lib.skylarkinterface.SkylarkValue

Direct Known Subclasses:

BoolAttribute, DepAttribute, DepListAttribute, IntAttribute, IntListAttribute, OutputAttribute, OutputListAttribute, SourceAttribute, SourceListAttribute, SourceSortedSetAttribute, StringAttribute, StringListAttribute, StringSortedSetAttribute, UnconfiguredDepListAttribute, UnconfiguredOptionalDepAttribute

public abstract class Attribute<CoercedType>
extends Object
implements AttributeHolder

Representation of a parameter of a user defined rule

Constructor Summary

Constructors

Constructor and Description
Attribute()

Method Summary

Modifier and Type	Method and Description
Attribute<?>	getAttribute() Get the actual attribute object
abstract String	getDoc() The docstring to use for this attribute
Type	getGenericType() Get the generic type of CoercedType.
abstract boolean	getMandatory() Whether this attribute is mandatory or not
PostCoercionTransform<RuleAnalysisContext,?>	getPostCoercionTransform()
abstract Object	getPreCoercionDefaultValue() The default value to use if no value is provided.
abstract TypeCoercer<?,CoercedType>	getTypeCoercer() The type coercer to use to convert raw values from the parser into something usable internally.
CoercedType	getValue(CellNameResolver cellNameResolver, ProjectFilesystem projectFilesystem, ForwardRelativePath pathRelativeToProjectRoot, TargetConfiguration targetConfiguration, TargetConfiguration hostConfiguration, Object value) Get the coerced value for this attribute.
protected void	validateCoercedValue(CoercedType value) Validates values post-coercion to ensure other properties besides 'type' are valid
protected static void	validateProvidersPresent(List<Provider<?>> expectedProviders, BuildTarget target, ProviderInfoCollection providerInfos) Ensures that all of the Providers in expectedProviders are present in providerInfos
protected void	validateValueInList(List<CoercedType> values, CoercedType value) Helper method to validate that a value is in a list and throw a reasonable error if not

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.google.devtools.build.lib.skylarkinterface.SkylarkValue

isHashable, isImmutable

Methods inherited from interface com.google.devtools.build.lib.skylarkinterface.SkylarkPrintable

debugPrint, repr, str

Constructor Detail

Attribute

public Attribute()

Method Detail

getAttribute

public Attribute<?> getAttribute()

Description copied from interface: AttributeHolder

Get the actual attribute object

Specified by:

getAttribute in interface AttributeHolder

getGenericType

@Value.Lazy
public Type getGenericType()

Get the generic type of CoercedType.

getPreCoercionDefaultValue

public abstract Object getPreCoercionDefaultValue()

The default value to use if no value is provided.

This will be validated against getTypeCoercer(), so may return a value whose type does not match CoercedType (e.g. a list of strings, rather than a list of SourcePath)

getDoc

public abstract String getDoc()

The docstring to use for this attribute

getMandatory

public abstract boolean getMandatory()

Whether this attribute is mandatory or not

getTypeCoercer

public abstract TypeCoercer<?,CoercedType> getTypeCoercer()

The type coercer to use to convert raw values from the parser into something usable internally. This coercer also performs validation

validateCoercedValue

protected void validateCoercedValue(CoercedType value)
                             throws CoerceFailedException

Validates values post-coercion to ensure other properties besides 'type' are valid

Parameters:

value - The value to check

Throws:

CoerceFailedException - if the value is invalid (e.g. not in a list of pre-approved values)

getPostCoercionTransform

public PostCoercionTransform<RuleAnalysisContext,?> getPostCoercionTransform()

Returns:

a method that transforms a coerced value into something more useful to users, taking into account the rule's dependencies

getValue

public CoercedType getValue(CellNameResolver cellNameResolver,
                            ProjectFilesystem projectFilesystem,
                            ForwardRelativePath pathRelativeToProjectRoot,
                            TargetConfiguration targetConfiguration,
                            TargetConfiguration hostConfiguration,
                            Object value)
                     throws CoerceFailedException

Get the coerced value for this attribute.

Parameters:

cellNameResolver - The cell roots

projectFilesystem - The project file system

pathRelativeToProjectRoot - The path relative to the project root

targetConfiguration - The configuration for this target

hostConfiguration -

value - The object that is to be coerced. This generally comes directly from the parser.

Throws:

CoerceFailedException - if the value could not be coerced

validateValueInList

protected void validateValueInList(List<CoercedType> values,
                                   CoercedType value)
                            throws CoerceFailedException

Helper method to validate that a value is in a list and throw a reasonable error if not

Throws:

CoerceFailedException

validateProvidersPresent

protected static void validateProvidersPresent(List<Provider<?>> expectedProviders,
                                               BuildTarget target,
                                               ProviderInfoCollection providerInfos)

Ensures that all of the Providers in expectedProviders are present in providerInfos

Note that it is enforced that all build rules return at least DefaultInfo, so that is not required to be specified

Parameters:

expectedProviders - The providers that ALL MUST be present. If empty, no providers are required, and all providerInfos will be considered valid.

target - the target that providerInfos is associated with. Used in errors.

providerInfos - The ProviderInfos for a given dependency

Throws:

com.google.common.base.VerifyException - if a provider is missing in providerInfos