src/main/java/com/google/devtools/build/lib/packages/RuleVisibility.java - bazel - Git at Google

 // Copyright 2014 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.packages;

 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.SerializationConstant;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.List;
 import javax.annotation.Nullable;
 import net.starlark.java.eval.EvalException;
 import net.starlark.java.eval.Starlark;

 /**
  * A RuleVisibility specifies which other rules can depend on a specified rule. Note that the actual
  * method that performs this check is declared in RuleConfiguredTargetVisibility.
  *
  * <p>The conversion to ConfiguredTargetVisibility is handled in an ugly if-ladder, because I want
  * to avoid this package depending on build.lib.view.
  *
  * <p>All implementations of this interface are immutable.
  */
 public interface RuleVisibility {

   /**
    * Returns the list of all labels comprising this visibility.
    *
    * <p>This includes labels that are not loadable, such as //visibility:public and //foo:__pkg__.
    */
   List<Label> getDeclaredLabels();

   /**
    * Same as {@link #getDeclaredLabels}, but excludes labels that cannot be loaded.
    *
    * <p>I.e., this returns the labels of the top-level {@code package_group}s that must be loaded in
    * order to determine the complete set of packages represented by this visibility. (Additional
    * {@code package_group}s may need to be loaded due to their {@code includes} attribute.)
    */
   List<Label> getDependencyLabels();

   @SerializationConstant Label PUBLIC_LABEL = Label.parseCanonicalUnchecked("//visibility:public");

   @SerializationConstant
   Label PRIVATE_LABEL = Label.parseCanonicalUnchecked("//visibility:private");

   // Constant for memory efficiency; see b/370873477.
   @SerializationConstant
   ImmutableList<Label> PUBLIC_DECLARED_LABELS = ImmutableList.of(PUBLIC_LABEL);

   // Constant for memory efficiency; see b/370873477.
   @SerializationConstant
   ImmutableList<Label> PRIVATE_DECLARED_LABELS = ImmutableList.of(PRIVATE_LABEL);

   @SerializationConstant
   RuleVisibility PUBLIC =
       new RuleVisibility() {
         @Override
         public ImmutableList<Label> getDeclaredLabels() {
           return PUBLIC_DECLARED_LABELS;
         }

         @Override
         public ImmutableList<Label> getDependencyLabels() {
           return ImmutableList.of();
         }

         @Override
         public String toString() {
           return PUBLIC_LABEL.toString();
         }
       };

   @SerializationConstant
   RuleVisibility PRIVATE =
       new RuleVisibility() {
         @Override
         public ImmutableList<Label> getDeclaredLabels() {
           return PRIVATE_DECLARED_LABELS;
         }

         @Override
         public ImmutableList<Label> getDependencyLabels() {
           return ImmutableList.of();
         }

         @Override
         public String toString() {
           return PRIVATE_LABEL.toString();
         }
       };

   /** Validates and parses the given labels into a {@link RuleVisibility}. */
   static RuleVisibility parse(List<Label> labels) throws EvalException {
     return parseUnchecked(validateAndSimplify(labels));
   }

   /**
    * Same as {@link #parse} except does not perform validation checks or public/private
    * simplification.
    *
    * <p>Use only after the given labels have been {@linkplain #validateAndSimplify validated and
    * simplified}.
    */
   static RuleVisibility parseUnchecked(List<Label> labels) {
     RuleVisibility result = parseIfConstant(labels);
     if (result != null) {
       return result;
     }
     return PackageGroupsRuleVisibility.create(labels);
   }

   /**
    * If the given list of labels represents a constant {@link RuleVisibility} ({@link #PUBLIC} or
    * {@link #PRIVATE}), returns that visibility instance, otherwise returns {@code null}.
    *
    * <p>Use only after the given labels have been {@linkplain #validateAndSimplify validated and
    * simplified}.
    */
   @Nullable
   static RuleVisibility parseIfConstant(List<Label> labels) {
     if (labels.size() != 1) {
       return null;
     }
     Label label = labels.getFirst();
     if (label.equals(PUBLIC_LABEL)) {
       return PUBLIC;
     }
     if (label.equals(PRIVATE_LABEL)) {
       return PRIVATE;
     }
     return null;
   }

   @CanIgnoreReturnValue
   private static Label validate(Label label) throws EvalException {
     if (label.getPackageIdentifier().equals(PUBLIC_LABEL.getPackageIdentifier())
         && PackageSpecification.fromLabel(label) == null) {
       // In other words, if the label is in //visibility and is not //visibility:public,
       // //visibility:private, or (for the unusual case where //visibility exists as a package)
       // //visibility:__pkg__ or //visibility:__subpackages__
       throw Starlark.errorf(
           "Invalid visibility label '%s'; did you mean //visibility:public or"
               + " //visibility:private?",
           label);
     }
     return label;
   }

   /**
    * Validates visibility labels, simplifies a list containing "//visibility:public" to
    * ["//visibility:public"], drops "//visibility:private" if it occurs with other labels, and
    * canonicalizes an empty list to ["//visibility:private"].
    *
    * @param labels list of visibility labels; not modified even if mutable.
    * @return either {@code labels} unmodified if it does not require simplification, or a new
    *     simplified list of visibility labels.
    */
   // TODO(arostovtsev): we ought to uniquify the labels, matching the behavior of {@link
   // #concatWithElement}; note that this would be an incompatible change (affects query output).
   static List<Label> validateAndSimplify(List<Label> labels) throws EvalException {
     boolean hasPublicLabel = false;
     int numPrivateLabels = 0;
     for (Label label : labels) {
       if (label.equals(PUBLIC_LABEL)) {
         // Do not short-circuit here; we want to validate all the labels.
         hasPublicLabel = true;
       } else if (label.equals(PRIVATE_LABEL)) {
         numPrivateLabels++;
       } else {
         validate(label);
       }
     }
     if (hasPublicLabel) {
       return PUBLIC_DECLARED_LABELS;
     }
     if (numPrivateLabels == labels.size()) {
       return PRIVATE_DECLARED_LABELS;
     }
     if (numPrivateLabels == 0) {
       return labels;
     }
     ImmutableList.Builder<Label> withoutPrivateLabels =
         ImmutableList.builderWithExpectedSize(labels.size() - numPrivateLabels);
     for (Label label : labels) {
       if (!label.equals(PRIVATE_LABEL)) {
         withoutPrivateLabels.add(label);
       }
     }
     return withoutPrivateLabels.build();
   }

   /**
    * Returns a {@code RuleVisibility} representing the logical result of concatenating the given
    * {@code visibility} with the additional {@code element}.
    *
    * <p>If {@code element} or {@code visibility} is public, the result is public. If {@code element}
    * or {@code visibility} is private, the result is {@code visibility} or a visibility consisting
    * solely of {@code element}, respectively.
    *
    * <p>If {@code element} is already present in {@code visibility}, the result is just {@code
    * visibility}.
    *
    * @throws EvalException if there's a problem parsing {@code element} into a visibility
    */
   static RuleVisibility concatWithElement(RuleVisibility visibility, Label element)
       throws EvalException {
     if (visibility.equals(RuleVisibility.PRIVATE)) {
       // Left-side private is dropped.
       return parse(ImmutableList.of(element));
     } else if (element.equals(PRIVATE_LABEL)) {
       // Right-side private is dropped.
       return visibility;
     } else if (visibility.equals(RuleVisibility.PUBLIC) || element.equals(PUBLIC_LABEL)) {
       // Public is idempotent.
       return RuleVisibility.PUBLIC;
     } else {
       List<Label> items = visibility.getDeclaredLabels();
       if (items.contains(element)) {
         return visibility;
       } else {
         ImmutableList.Builder<Label> newItems = new ImmutableList.Builder<>();
         newItems.addAll(items);
         newItems.add(validate(element));
         return parseUnchecked(newItems.build());
       }
     }
   }

   /**
    * Convenience wrapper for {@link #concatWithElement} where the added element is the given
    * package.
    *
    * <p>Unlike that method, this does not throw EvalException.
    */
   static RuleVisibility concatWithPackage(
       RuleVisibility visibility, PackageIdentifier packageIdentifier) {
     Label pkgItem = Label.createUnvalidated(packageIdentifier, "__pkg__");
     try {
       return concatWithElement(visibility, pkgItem);
     } catch (EvalException ex) {
       throw new AssertionError(
           String.format("Unreachable; couldn't parse %s as visibility", pkgItem), ex);
     }
   }
 }
	// Copyright 2014 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.packages;

	import com.google.common.collect.ImmutableList;
	import com.google.devtools.build.lib.cmdline.Label;
	import com.google.devtools.build.lib.cmdline.PackageIdentifier;
	import com.google.devtools.build.lib.skyframe.serialization.autocodec.SerializationConstant;
	import com.google.errorprone.annotations.CanIgnoreReturnValue;
	import java.util.List;
	import javax.annotation.Nullable;
	import net.starlark.java.eval.EvalException;
	import net.starlark.java.eval.Starlark;

	/**
	* A RuleVisibility specifies which other rules can depend on a specified rule. Note that the actual
	* method that performs this check is declared in RuleConfiguredTargetVisibility.
	*
	* <p>The conversion to ConfiguredTargetVisibility is handled in an ugly if-ladder, because I want
	* to avoid this package depending on build.lib.view.
	*
	* <p>All implementations of this interface are immutable.
	*/
	public interface RuleVisibility {

	/**
	* Returns the list of all labels comprising this visibility.
	*
	* <p>This includes labels that are not loadable, such as //visibility:public and //foo:__pkg__.
	*/
	List<Label> getDeclaredLabels();

	/**
	* Same as {@link #getDeclaredLabels}, but excludes labels that cannot be loaded.
	*
	* <p>I.e., this returns the labels of the top-level {@code package_group}s that must be loaded in
	* order to determine the complete set of packages represented by this visibility. (Additional
	* {@code package_group}s may need to be loaded due to their {@code includes} attribute.)
	*/
	List<Label> getDependencyLabels();

	@SerializationConstant Label PUBLIC_LABEL = Label.parseCanonicalUnchecked("//visibility:public");

	@SerializationConstant
	Label PRIVATE_LABEL = Label.parseCanonicalUnchecked("//visibility:private");

	// Constant for memory efficiency; see b/370873477.
	@SerializationConstant
	ImmutableList<Label> PUBLIC_DECLARED_LABELS = ImmutableList.of(PUBLIC_LABEL);

	// Constant for memory efficiency; see b/370873477.
	@SerializationConstant
	ImmutableList<Label> PRIVATE_DECLARED_LABELS = ImmutableList.of(PRIVATE_LABEL);

	@SerializationConstant
	RuleVisibility PUBLIC =
	new RuleVisibility() {
	@Override
	public ImmutableList<Label> getDeclaredLabels() {
	return PUBLIC_DECLARED_LABELS;
	}

	@Override
	public ImmutableList<Label> getDependencyLabels() {
	return ImmutableList.of();
	}

	@Override
	public String toString() {
	return PUBLIC_LABEL.toString();
	}
	};

	@SerializationConstant
	RuleVisibility PRIVATE =
	new RuleVisibility() {
	@Override
	public ImmutableList<Label> getDeclaredLabels() {
	return PRIVATE_DECLARED_LABELS;
	}

	@Override
	public ImmutableList<Label> getDependencyLabels() {
	return ImmutableList.of();
	}

	@Override
	public String toString() {
	return PRIVATE_LABEL.toString();
	}
	};

	/** Validates and parses the given labels into a {@link RuleVisibility}. */
	static RuleVisibility parse(List<Label> labels) throws EvalException {
	return parseUnchecked(validateAndSimplify(labels));
	}

	/**
	* Same as {@link #parse} except does not perform validation checks or public/private
	* simplification.
	*
	* <p>Use only after the given labels have been {@linkplain #validateAndSimplify validated and
	* simplified}.
	*/
	static RuleVisibility parseUnchecked(List<Label> labels) {
	RuleVisibility result = parseIfConstant(labels);
	if (result != null) {
	return result;
	}
	return PackageGroupsRuleVisibility.create(labels);
	}

	/**
	* If the given list of labels represents a constant {@link RuleVisibility} ({@link #PUBLIC} or
	* {@link #PRIVATE}), returns that visibility instance, otherwise returns {@code null}.
	*
	* <p>Use only after the given labels have been {@linkplain #validateAndSimplify validated and
	* simplified}.
	*/
	@Nullable
	static RuleVisibility parseIfConstant(List<Label> labels) {
	if (labels.size() != 1) {
	return null;
	}
	Label label = labels.getFirst();
	if (label.equals(PUBLIC_LABEL)) {
	return PUBLIC;
	}
	if (label.equals(PRIVATE_LABEL)) {
	return PRIVATE;
	}
	return null;
	}

	@CanIgnoreReturnValue
	private static Label validate(Label label) throws EvalException {
	if (label.getPackageIdentifier().equals(PUBLIC_LABEL.getPackageIdentifier())
	&& PackageSpecification.fromLabel(label) == null) {
	// In other words, if the label is in //visibility and is not //visibility:public,
	// //visibility:private, or (for the unusual case where //visibility exists as a package)
	// //visibility:__pkg__ or //visibility:__subpackages__
	throw Starlark.errorf(
	"Invalid visibility label '%s'; did you mean //visibility:public or"
	+ " //visibility:private?",
	label);
	}
	return label;
	}

	/**
	* Validates visibility labels, simplifies a list containing "//visibility:public" to
	* ["//visibility:public"], drops "//visibility:private" if it occurs with other labels, and
	* canonicalizes an empty list to ["//visibility:private"].
	*
	* @param labels list of visibility labels; not modified even if mutable.
	* @return either {@code labels} unmodified if it does not require simplification, or a new
	* simplified list of visibility labels.
	*/
	// TODO(arostovtsev): we ought to uniquify the labels, matching the behavior of {@link
	// #concatWithElement}; note that this would be an incompatible change (affects query output).
	static List<Label> validateAndSimplify(List<Label> labels) throws EvalException {
	boolean hasPublicLabel = false;
	int numPrivateLabels = 0;
	for (Label label : labels) {
	if (label.equals(PUBLIC_LABEL)) {
	// Do not short-circuit here; we want to validate all the labels.
	hasPublicLabel = true;
	} else if (label.equals(PRIVATE_LABEL)) {
	numPrivateLabels++;
	} else {
	validate(label);
	}
	}
	if (hasPublicLabel) {
	return PUBLIC_DECLARED_LABELS;
	}
	if (numPrivateLabels == labels.size()) {
	return PRIVATE_DECLARED_LABELS;
	}
	if (numPrivateLabels == 0) {
	return labels;
	}
	ImmutableList.Builder<Label> withoutPrivateLabels =
	ImmutableList.builderWithExpectedSize(labels.size() - numPrivateLabels);
	for (Label label : labels) {
	if (!label.equals(PRIVATE_LABEL)) {
	withoutPrivateLabels.add(label);
	}
	}
	return withoutPrivateLabels.build();
	}

	/**
	* Returns a {@code RuleVisibility} representing the logical result of concatenating the given
	* {@code visibility} with the additional {@code element}.
	*
	* <p>If {@code element} or {@code visibility} is public, the result is public. If {@code element}
	* or {@code visibility} is private, the result is {@code visibility} or a visibility consisting
	* solely of {@code element}, respectively.
	*
	* <p>If {@code element} is already present in {@code visibility}, the result is just {@code
	* visibility}.
	*
	* @throws EvalException if there's a problem parsing {@code element} into a visibility
	*/
	static RuleVisibility concatWithElement(RuleVisibility visibility, Label element)
	throws EvalException {
	if (visibility.equals(RuleVisibility.PRIVATE)) {
	// Left-side private is dropped.
	return parse(ImmutableList.of(element));
	} else if (element.equals(PRIVATE_LABEL)) {
	// Right-side private is dropped.
	return visibility;
	} else if (visibility.equals(RuleVisibility.PUBLIC) \|\| element.equals(PUBLIC_LABEL)) {
	// Public is idempotent.
	return RuleVisibility.PUBLIC;
	} else {
	List<Label> items = visibility.getDeclaredLabels();
	if (items.contains(element)) {
	return visibility;
	} else {
	ImmutableList.Builder<Label> newItems = new ImmutableList.Builder<>();
	newItems.addAll(items);
	newItems.add(validate(element));
	return parseUnchecked(newItems.build());
	}
	}
	}

	/**
	* Convenience wrapper for {@link #concatWithElement} where the added element is the given
	* package.
	*
	* <p>Unlike that method, this does not throw EvalException.
	*/
	static RuleVisibility concatWithPackage(
	RuleVisibility visibility, PackageIdentifier packageIdentifier) {
	Label pkgItem = Label.createUnvalidated(packageIdentifier, "__pkg__");
	try {
	return concatWithElement(visibility, pkgItem);
	} catch (EvalException ex) {
	throw new AssertionError(
	String.format("Unreachable; couldn't parse %s as visibility", pkgItem), ex);
	}
	}
	}