src/main/java/com/google/devtools/build/lib/analysis/platform/PlatformInfo.java - bazel - Git at Google

 // Copyright 2017 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.analysis.platform;

 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.platform.ConstraintCollection.DuplicateConstraintException;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.packages.BuiltinProvider;
 import com.google.devtools.build.lib.packages.NativeInfo;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
 import com.google.devtools.build.lib.skylarkbuildapi.platform.PlatformInfoApi;
 import com.google.devtools.build.lib.syntax.Dict;
 import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.syntax.Printer;
 import com.google.devtools.build.lib.syntax.Sequence;
 import com.google.devtools.build.lib.syntax.Starlark;
 import com.google.devtools.build.lib.syntax.StarlarkThread;
 import com.google.devtools.build.lib.util.Fingerprint;
 import com.google.devtools.build.lib.util.StringUtilities;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 import javax.annotation.Nullable;

 /** Provider for a platform, which is a group of constraints and values. */
 @Immutable
 @AutoCodec
 public class PlatformInfo extends NativeInfo
     implements PlatformInfoApi<ConstraintSettingInfo, ConstraintValueInfo> {

   /**
    * The literal key that will be used to copy the {@link #remoteExecutionProperties} from the
    * parent {@link PlatformInfo} into a new {@link PlatformInfo}'s {@link
    * #remoteExecutionProperties}.
    */
   public static final String PARENT_REMOTE_EXECUTION_KEY = "{PARENT_REMOTE_EXECUTION_PROPERTIES}";

   /** Name used in Skylark for accessing this provider. */
   public static final String SKYLARK_NAME = "PlatformInfo";

   /** Provider singleton constant. */
   public static final BuiltinProvider<PlatformInfo> PROVIDER = new Provider();

   /** Provider for {@link ToolchainInfo} objects. */
   private static class Provider extends BuiltinProvider<PlatformInfo>
       implements PlatformInfoApi.Provider<
           ConstraintSettingInfo, ConstraintValueInfo, PlatformInfo> {
     private Provider() {
       super(SKYLARK_NAME, PlatformInfo.class);
     }

     @Override
     public PlatformInfo platformInfo(
         Label label,
         Object parentUnchecked,
         Sequence<?> constraintValuesUnchecked,
         Object execPropertiesUnchecked,
         StarlarkThread thread)
         throws EvalException {
       PlatformInfo.Builder builder = PlatformInfo.builder();
       builder.setLabel(label);
       if (parentUnchecked != Starlark.NONE) {
         builder.setParent((PlatformInfo) parentUnchecked);
       }
       if (!constraintValuesUnchecked.isEmpty()) {
         builder.addConstraints(
             constraintValuesUnchecked.getContents(ConstraintValueInfo.class, "constraint_values"));
       }
       if (execPropertiesUnchecked != null) {
         Map<String, String> execProperties =
             Dict.castSkylarkDictOrNoneToDict(
                 execPropertiesUnchecked, String.class, String.class, "exec_properties");
         builder.setExecProperties(ImmutableMap.copyOf(execProperties));
       }
       builder.setLocation(thread.getCallerLocation());

       try {
         return builder.build();
       } catch (DuplicateConstraintException | ExecPropertiesException e) {
         throw new EvalException(null, e);
       }
     }
   }

   private final Label label;
   private final ConstraintCollection constraints;
   private final String remoteExecutionProperties;
   /** execProperties will deprecate and replace remoteExecutionProperties */
   private final ImmutableMap<String, String> execProperties;

   @AutoCodec.Instantiator
   @VisibleForSerialization
   PlatformInfo(
       Label label,
       ConstraintCollection constraints,
       String remoteExecutionProperties,
       ImmutableMap<String, String> execProperties,
       Location location) {
     super(PROVIDER, location);

     this.label = label;
     this.constraints = constraints;
     this.remoteExecutionProperties = Strings.nullToEmpty(remoteExecutionProperties);
     this.execProperties = execProperties;
   }

   @Override
   public Label label() {
     return label;
   }

   @Override
   public ConstraintCollection constraints() {
     return constraints;
   }

   @Override
   public String remoteExecutionProperties() {
     return remoteExecutionProperties;
   }

   @Override
   public ImmutableMap<String, String> execProperties() {
     return execProperties;
   }

   @Override
   public void repr(Printer printer) {
     printer.format("PlatformInfo(%s, constraints=%s)", label.toString(), constraints.toString());
   }

   /** Returns a new {@link Builder} for creating a fresh {@link PlatformInfo} instance. */
   public static Builder builder() {
     return new Builder();
   }

   /** Add this platform to the given fingerprint. */
   public void addTo(Fingerprint fp) {
     fp.addString(label.toString());
     fp.addNullableString(remoteExecutionProperties);
     fp.addStringMap(execProperties);
     constraints.addToFingerprint(fp);
   }

   /** Builder class to facilitate creating valid {@link PlatformInfo} instances. */
   public static class Builder {

     @Nullable private PlatformInfo parent = null;
     private Label label;
     private final ConstraintCollection.Builder constraints = ConstraintCollection.builder();
     private String remoteExecutionProperties = null;
     @Nullable private ImmutableMap<String, String> execProperties;
     private Location location = Location.BUILTIN;

     /**
      * Sets the parent {@link PlatformInfo} that this platform inherits from. Constraint values set
      * directly on this instance will be kept, but any other constraint settings will be found from
      * the parent, if set.
      *
      * @param parent the platform that is the parent of this platform
      * @return the {@link Builder} instance for method chaining
      */
     public Builder setParent(@Nullable PlatformInfo parent) {
       this.parent = parent;
       if (parent == null) {
         this.constraints.parent(null);
       } else {
         this.constraints.parent(parent.constraints);
       }
       return this;
     }

     /**
      * Sets the {@link Label} for this {@link PlatformInfo}.
      *
      * @param label the label identifying this platform
      * @return the {@link Builder} instance for method chaining
      */
     public Builder setLabel(Label label) {
       this.label = label;
       return this;
     }

     /**
      * Adds the given constraint value to the constraints that define this {@link PlatformInfo}.
      *
      * @param constraint the constraint to add
      * @return the {@link Builder} instance for method chaining
      */
     public Builder addConstraint(ConstraintValueInfo constraint) {
       this.constraints.addConstraints(constraint);
       return this;
     }

     /**
      * Adds the given constraint values to the constraints that define this {@link PlatformInfo}.
      *
      * @param constraints the constraints to add
      * @return the {@link Builder} instance for method chaining
      */
     public Builder addConstraints(Iterable<ConstraintValueInfo> constraints) {
       this.constraints.addConstraints(constraints);
       return this;
     }

     /** Returns the remote execution properties. */
     @Nullable
     public String getRemoteExecutionProperties() {
       return remoteExecutionProperties;
     }

     /** Returns the exec properties. */
     @Nullable
     public ImmutableMap<String, String> getExecProperties() {
       return execProperties;
     }

     /**
      * Sets the data being sent to a potential remote executor. If there is a parent {@link
      * PlatformInfo} set, the literal string "{PARENT_REMOTE_EXECUTION_PROPERTIES}" will be replaced
      * by the {@link #remoteExecutionProperties} from that parent. Also if the parent is set, and
      * this instance's {@link #remoteExecutionProperties} is blank or unset, the parent's will be
      * used directly.
      *
      * <p>Specific examples:
      *
      * <ul>
      *   <li>parent.remoteExecutionProperties is unset: use the child's value
      *   <li>parent.remoteExecutionProperties is set, child.remoteExecutionProperties is unset: use
      *       the parent's value
      *   <li>parent.remoteExecutionProperties is set, child.remoteExecutionProperties is set, and
      *       does not contain {PARENT_REMOTE_EXECUTION_PROPERTIES}: use the child's value
      *   <li>parent.remoteExecutionProperties is set, child.remoteExecutionProperties is set, and
      *       does contain {PARENT_REMOTE_EXECUTION_PROPERTIES}: use the child's value, but
      *       substitute the parent's value for {PARENT_REMOTE_EXECUTION_PROPERTIES}
      * </ul>
      *
      * @param properties the properties to be added
      * @return the {@link Builder} instance for method chaining
      */
     public Builder setRemoteExecutionProperties(String properties) {
       this.remoteExecutionProperties = properties;
       return this;
     }

     /**
      * Sets the execution properties.
      *
      * <p>If there is a parent {@link PlatformInfo} set, then all parent's properties will be
      * inherited. Any properties included in both will use the child's value. Use the value of empty
      * string to unset a property.
      */
     public Builder setExecProperties(@Nullable ImmutableMap<String, String> properties) {
       this.execProperties = properties;
       return this;
     }

     /**
      * Sets the {@link Location} where this {@link PlatformInfo} was created.
      *
      * @param location the location where the instance was created
      * @return the {@link Builder} instance for method chaining
      */
     public Builder setLocation(Location location) {
       this.location = location;
       return this;
     }

     private void checkRemoteExecutionProperties() throws ExecPropertiesException {
       if (execProperties != null && !Strings.isNullOrEmpty(remoteExecutionProperties)) {
         throw new ExecPropertiesException(
             "Platform contains both remote_execution_properties and exec_properties. Prefer"
                 + " exec_properties over the deprecated remote_execution_properties.");
       }
       if (execProperties != null
           && parent != null
           && !Strings.isNullOrEmpty(parent.remoteExecutionProperties())) {
         throw new ExecPropertiesException(
             "Platform specifies exec_properties but its parent "
                 + parent.label()
                 + " specifies remote_execution_properties. Prefer exec_properties over the"
                 + " deprecated remote_execution_properties.");
       }
       if (!Strings.isNullOrEmpty(remoteExecutionProperties)
           && parent != null
           && !parent.execProperties().isEmpty()) {
         throw new ExecPropertiesException(
             "Platform specifies remote_execution_properties but its parent specifies"
                 + " exec_properties. Prefer exec_properties over the deprecated"
                 + " remote_execution_properties.");
       }
     }

     /**
      * Returns the new {@link PlatformInfo} instance.
      *
      * @throws DuplicateConstraintException if more than one constraint value exists for the same
      *     constraint setting
      */
     public PlatformInfo build() throws DuplicateConstraintException, ExecPropertiesException {
       checkRemoteExecutionProperties();

       // Merge the remote execution properties.
       String remoteExecutionProperties =
           mergeRemoteExecutionProperties(parent, this.remoteExecutionProperties);

       ImmutableMap<String, String> execProperties =
           mergeExecProperties(parent, this.execProperties);
       if (execProperties == null) {
         execProperties = ImmutableMap.of();
       }

       return new PlatformInfo(
           label, constraints.build(), remoteExecutionProperties, execProperties, location);
     }

     private static String mergeRemoteExecutionProperties(
         PlatformInfo parent, String remoteExecutionProperties) {
       String parentRemoteExecutionProperties = "";
       if (parent != null) {
         parentRemoteExecutionProperties = parent.remoteExecutionProperties();
       }

       if (remoteExecutionProperties == null) {
         return parentRemoteExecutionProperties;
       }

       return StringUtilities.replaceAllLiteral(
           remoteExecutionProperties, PARENT_REMOTE_EXECUTION_KEY, parentRemoteExecutionProperties);
     }

     @Nullable
     private static ImmutableMap<String, String> mergeExecProperties(
         PlatformInfo parent, Map<String, String> execProperties) {
       if ((parent == null || parent.execProperties() == null) && execProperties == null) {
         return null;
       }

       HashMap<String, String> result = new HashMap<>();
       if (parent != null && parent.execProperties() != null) {
         result.putAll(parent.execProperties());
       }

       if (execProperties != null) {
         for (Map.Entry<String, String> entry : execProperties.entrySet()) {
           if (Strings.isNullOrEmpty(entry.getValue())) {
             result.remove(entry.getKey());
           } else {
             result.put(entry.getKey(), entry.getValue());
           }
         }
       }

       return ImmutableMap.copyOf(result);
     }
   }

   @Override
   public boolean equals(Object o) {
     if (!(o instanceof PlatformInfo)) {
       return false;
     }
     PlatformInfo that = (PlatformInfo) o;
     return Objects.equals(label, that.label)
         && Objects.equals(constraints, that.constraints)
         && Objects.equals(remoteExecutionProperties, that.remoteExecutionProperties)
         && Objects.equals(execProperties, that.execProperties);
   }

   @Override
   public int hashCode() {
     return Objects.hash(label, constraints, remoteExecutionProperties);
   }

   /** Exception that indicates something is wrong in exec_properties configuration. */
   public static class ExecPropertiesException extends Exception {
     ExecPropertiesException(String message) {
       super(message);
     }
   }
 }
	// Copyright 2017 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.analysis.platform;

	import com.google.common.base.Strings;
	import com.google.common.collect.ImmutableMap;
	import com.google.devtools.build.lib.analysis.platform.ConstraintCollection.DuplicateConstraintException;
	import com.google.devtools.build.lib.cmdline.Label;
	import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
	import com.google.devtools.build.lib.events.Location;
	import com.google.devtools.build.lib.packages.BuiltinProvider;
	import com.google.devtools.build.lib.packages.NativeInfo;
	import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
	import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
	import com.google.devtools.build.lib.skylarkbuildapi.platform.PlatformInfoApi;
	import com.google.devtools.build.lib.syntax.Dict;
	import com.google.devtools.build.lib.syntax.EvalException;
	import com.google.devtools.build.lib.syntax.Printer;
	import com.google.devtools.build.lib.syntax.Sequence;
	import com.google.devtools.build.lib.syntax.Starlark;
	import com.google.devtools.build.lib.syntax.StarlarkThread;
	import com.google.devtools.build.lib.util.Fingerprint;
	import com.google.devtools.build.lib.util.StringUtilities;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Objects;
	import javax.annotation.Nullable;

	/** Provider for a platform, which is a group of constraints and values. */
	@Immutable
	@AutoCodec
	public class PlatformInfo extends NativeInfo
	implements PlatformInfoApi<ConstraintSettingInfo, ConstraintValueInfo> {

	/**
	* The literal key that will be used to copy the {@link #remoteExecutionProperties} from the
	* parent {@link PlatformInfo} into a new {@link PlatformInfo}'s {@link
	* #remoteExecutionProperties}.
	*/
	public static final String PARENT_REMOTE_EXECUTION_KEY = "{PARENT_REMOTE_EXECUTION_PROPERTIES}";

	/** Name used in Skylark for accessing this provider. */
	public static final String SKYLARK_NAME = "PlatformInfo";

	/** Provider singleton constant. */
	public static final BuiltinProvider<PlatformInfo> PROVIDER = new Provider();

	/** Provider for {@link ToolchainInfo} objects. */
	private static class Provider extends BuiltinProvider<PlatformInfo>
	implements PlatformInfoApi.Provider<
	ConstraintSettingInfo, ConstraintValueInfo, PlatformInfo> {
	private Provider() {
	super(SKYLARK_NAME, PlatformInfo.class);
	}

	@Override
	public PlatformInfo platformInfo(
	Label label,
	Object parentUnchecked,
	Sequence<?> constraintValuesUnchecked,
	Object execPropertiesUnchecked,
	StarlarkThread thread)
	throws EvalException {
	PlatformInfo.Builder builder = PlatformInfo.builder();
	builder.setLabel(label);
	if (parentUnchecked != Starlark.NONE) {
	builder.setParent((PlatformInfo) parentUnchecked);
	}
	if (!constraintValuesUnchecked.isEmpty()) {
	builder.addConstraints(
	constraintValuesUnchecked.getContents(ConstraintValueInfo.class, "constraint_values"));
	}
	if (execPropertiesUnchecked != null) {
	Map<String, String> execProperties =
	Dict.castSkylarkDictOrNoneToDict(
	execPropertiesUnchecked, String.class, String.class, "exec_properties");
	builder.setExecProperties(ImmutableMap.copyOf(execProperties));
	}
	builder.setLocation(thread.getCallerLocation());

	try {
	return builder.build();
	} catch (DuplicateConstraintException \| ExecPropertiesException e) {
	throw new EvalException(null, e);
	}
	}
	}

	private final Label label;
	private final ConstraintCollection constraints;
	private final String remoteExecutionProperties;
	/** execProperties will deprecate and replace remoteExecutionProperties */
	private final ImmutableMap<String, String> execProperties;

	@AutoCodec.Instantiator
	@VisibleForSerialization
	PlatformInfo(
	Label label,
	ConstraintCollection constraints,
	String remoteExecutionProperties,
	ImmutableMap<String, String> execProperties,
	Location location) {
	super(PROVIDER, location);

	this.label = label;
	this.constraints = constraints;
	this.remoteExecutionProperties = Strings.nullToEmpty(remoteExecutionProperties);
	this.execProperties = execProperties;
	}

	@Override
	public Label label() {
	return label;
	}

	@Override
	public ConstraintCollection constraints() {
	return constraints;
	}

	@Override
	public String remoteExecutionProperties() {
	return remoteExecutionProperties;
	}

	@Override
	public ImmutableMap<String, String> execProperties() {
	return execProperties;
	}

	@Override
	public void repr(Printer printer) {
	printer.format("PlatformInfo(%s, constraints=%s)", label.toString(), constraints.toString());
	}

	/** Returns a new {@link Builder} for creating a fresh {@link PlatformInfo} instance. */
	public static Builder builder() {
	return new Builder();
	}

	/** Add this platform to the given fingerprint. */
	public void addTo(Fingerprint fp) {
	fp.addString(label.toString());
	fp.addNullableString(remoteExecutionProperties);
	fp.addStringMap(execProperties);
	constraints.addToFingerprint(fp);
	}

	/** Builder class to facilitate creating valid {@link PlatformInfo} instances. */
	public static class Builder {

	@Nullable private PlatformInfo parent = null;
	private Label label;
	private final ConstraintCollection.Builder constraints = ConstraintCollection.builder();
	private String remoteExecutionProperties = null;
	@Nullable private ImmutableMap<String, String> execProperties;
	private Location location = Location.BUILTIN;

	/**
	* Sets the parent {@link PlatformInfo} that this platform inherits from. Constraint values set
	* directly on this instance will be kept, but any other constraint settings will be found from
	* the parent, if set.
	*
	* @param parent the platform that is the parent of this platform
	* @return the {@link Builder} instance for method chaining
	*/
	public Builder setParent(@Nullable PlatformInfo parent) {
	this.parent = parent;
	if (parent == null) {
	this.constraints.parent(null);
	} else {
	this.constraints.parent(parent.constraints);
	}
	return this;
	}

	/**
	* Sets the {@link Label} for this {@link PlatformInfo}.
	*
	* @param label the label identifying this platform
	* @return the {@link Builder} instance for method chaining
	*/
	public Builder setLabel(Label label) {
	this.label = label;
	return this;
	}

	/**
	* Adds the given constraint value to the constraints that define this {@link PlatformInfo}.
	*
	* @param constraint the constraint to add
	* @return the {@link Builder} instance for method chaining
	*/
	public Builder addConstraint(ConstraintValueInfo constraint) {
	this.constraints.addConstraints(constraint);
	return this;
	}

	/**
	* Adds the given constraint values to the constraints that define this {@link PlatformInfo}.
	*
	* @param constraints the constraints to add
	* @return the {@link Builder} instance for method chaining
	*/
	public Builder addConstraints(Iterable<ConstraintValueInfo> constraints) {
	this.constraints.addConstraints(constraints);
	return this;
	}

	/** Returns the remote execution properties. */
	@Nullable
	public String getRemoteExecutionProperties() {
	return remoteExecutionProperties;
	}

	/** Returns the exec properties. */
	@Nullable
	public ImmutableMap<String, String> getExecProperties() {
	return execProperties;
	}

	/**
	* Sets the data being sent to a potential remote executor. If there is a parent {@link
	* PlatformInfo} set, the literal string "{PARENT_REMOTE_EXECUTION_PROPERTIES}" will be replaced
	* by the {@link #remoteExecutionProperties} from that parent. Also if the parent is set, and
	* this instance's {@link #remoteExecutionProperties} is blank or unset, the parent's will be
	* used directly.
	*
	* <p>Specific examples:
	*
	* <ul>
	* <li>parent.remoteExecutionProperties is unset: use the child's value
	* <li>parent.remoteExecutionProperties is set, child.remoteExecutionProperties is unset: use
	* the parent's value
	* <li>parent.remoteExecutionProperties is set, child.remoteExecutionProperties is set, and
	* does not contain {PARENT_REMOTE_EXECUTION_PROPERTIES}: use the child's value
	* <li>parent.remoteExecutionProperties is set, child.remoteExecutionProperties is set, and
	* does contain {PARENT_REMOTE_EXECUTION_PROPERTIES}: use the child's value, but
	* substitute the parent's value for {PARENT_REMOTE_EXECUTION_PROPERTIES}
	* </ul>
	*
	* @param properties the properties to be added
	* @return the {@link Builder} instance for method chaining
	*/
	public Builder setRemoteExecutionProperties(String properties) {
	this.remoteExecutionProperties = properties;
	return this;
	}

	/**
	* Sets the execution properties.
	*
	* <p>If there is a parent {@link PlatformInfo} set, then all parent's properties will be
	* inherited. Any properties included in both will use the child's value. Use the value of empty
	* string to unset a property.
	*/
	public Builder setExecProperties(@Nullable ImmutableMap<String, String> properties) {
	this.execProperties = properties;
	return this;
	}

	/**
	* Sets the {@link Location} where this {@link PlatformInfo} was created.
	*
	* @param location the location where the instance was created
	* @return the {@link Builder} instance for method chaining
	*/
	public Builder setLocation(Location location) {
	this.location = location;
	return this;
	}

	private void checkRemoteExecutionProperties() throws ExecPropertiesException {
	if (execProperties != null && !Strings.isNullOrEmpty(remoteExecutionProperties)) {
	throw new ExecPropertiesException(
	"Platform contains both remote_execution_properties and exec_properties. Prefer"
	+ " exec_properties over the deprecated remote_execution_properties.");
	}
	if (execProperties != null
	&& parent != null
	&& !Strings.isNullOrEmpty(parent.remoteExecutionProperties())) {
	throw new ExecPropertiesException(
	"Platform specifies exec_properties but its parent "
	+ parent.label()
	+ " specifies remote_execution_properties. Prefer exec_properties over the"
	+ " deprecated remote_execution_properties.");
	}
	if (!Strings.isNullOrEmpty(remoteExecutionProperties)
	&& parent != null
	&& !parent.execProperties().isEmpty()) {
	throw new ExecPropertiesException(
	"Platform specifies remote_execution_properties but its parent specifies"
	+ " exec_properties. Prefer exec_properties over the deprecated"
	+ " remote_execution_properties.");
	}
	}

	/**
	* Returns the new {@link PlatformInfo} instance.
	*
	* @throws DuplicateConstraintException if more than one constraint value exists for the same
	* constraint setting
	*/
	public PlatformInfo build() throws DuplicateConstraintException, ExecPropertiesException {
	checkRemoteExecutionProperties();

	// Merge the remote execution properties.
	String remoteExecutionProperties =
	mergeRemoteExecutionProperties(parent, this.remoteExecutionProperties);

	ImmutableMap<String, String> execProperties =
	mergeExecProperties(parent, this.execProperties);
	if (execProperties == null) {
	execProperties = ImmutableMap.of();
	}

	return new PlatformInfo(
	label, constraints.build(), remoteExecutionProperties, execProperties, location);
	}

	private static String mergeRemoteExecutionProperties(
	PlatformInfo parent, String remoteExecutionProperties) {
	String parentRemoteExecutionProperties = "";
	if (parent != null) {
	parentRemoteExecutionProperties = parent.remoteExecutionProperties();
	}

	if (remoteExecutionProperties == null) {
	return parentRemoteExecutionProperties;
	}

	return StringUtilities.replaceAllLiteral(
	remoteExecutionProperties, PARENT_REMOTE_EXECUTION_KEY, parentRemoteExecutionProperties);
	}

	@Nullable
	private static ImmutableMap<String, String> mergeExecProperties(
	PlatformInfo parent, Map<String, String> execProperties) {
	if ((parent == null \|\| parent.execProperties() == null) && execProperties == null) {
	return null;
	}

	HashMap<String, String> result = new HashMap<>();
	if (parent != null && parent.execProperties() != null) {
	result.putAll(parent.execProperties());
	}

	if (execProperties != null) {
	for (Map.Entry<String, String> entry : execProperties.entrySet()) {
	if (Strings.isNullOrEmpty(entry.getValue())) {
	result.remove(entry.getKey());
	} else {
	result.put(entry.getKey(), entry.getValue());
	}
	}
	}

	return ImmutableMap.copyOf(result);
	}
	}

	@Override
	public boolean equals(Object o) {
	if (!(o instanceof PlatformInfo)) {
	return false;
	}
	PlatformInfo that = (PlatformInfo) o;
	return Objects.equals(label, that.label)
	&& Objects.equals(constraints, that.constraints)
	&& Objects.equals(remoteExecutionProperties, that.remoteExecutionProperties)
	&& Objects.equals(execProperties, that.execProperties);
	}

	@Override
	public int hashCode() {
	return Objects.hash(label, constraints, remoteExecutionProperties);
	}

	/** Exception that indicates something is wrong in exec_properties configuration. */
	public static class ExecPropertiesException extends Exception {
	ExecPropertiesException(String message) {
	super(message);
	}
	}
	}