Add constraint_setting and constraint_value rules, to enable defining

platform-related constraints and values.

Part of ongoing work on #2219.

--
Change-Id: Ice370ee26469f4992faf72c0c95a1a3e51a9f9e7
Reviewed-on: https://cr.bazel.build/9091
PiperOrigin-RevId: 148758190
MOS_MIGRATED_REVID=148758190

7 files changed, 313 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/BUILD b/src/main/java/com/google/devtools/build/lib/rules/platform/BUILD
new file mode 100644
index 0000000000..d8c6ca9b79
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/BUILD
@@ -0,0 +1,25 @@
+# Description:
+#   Rules to define Platforms and related Constraints.
+
+package(
+    default_visibility = ["//src:__subpackages__"],
+)
+
+java_library(
+    name = "platform",
+    srcs = glob([
+        "*.java",
+    ]),
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib:build-base",
+        "//src/main/java/com/google/devtools/build/lib:packages",
+        "//third_party:auto_value",
+        "//third_party:guava",
+    ],
+)
+
+filegroup(
+    name = "srcs",
+    testonly = 0,  # All srcs should be not test only, overwrite package default.
+    srcs = glob(["**"]),
+)
diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSetting.java b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSetting.java
new file mode 100644
index 0000000000..03e924f1db
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSetting.java
@@ -0,0 +1,45 @@
+// 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.rules.platform;
+
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.FileProvider;
+import com.google.devtools.build.lib.analysis.FilesToRunProvider;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.RunfilesProvider;
+import com.google.devtools.build.lib.packages.RuleClass.ConfiguredTargetFactory.RuleErrorException;
+import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
+
+/**
+ * Defines a category of constraint that can be fulfilled by a constraint_value rule in a platform
+ * definition.
+ */
+public class ConstraintSetting implements RuleConfiguredTargetFactory {
+
+  @Override
+  public ConfiguredTarget create(RuleContext ruleContext)
+      throws InterruptedException, RuleErrorException {
+
+    return new RuleConfiguredTargetBuilder(ruleContext)
+        .addProvider(RunfilesProvider.class, RunfilesProvider.EMPTY)
+        .addProvider(FileProvider.class, FileProvider.EMPTY)
+        .addProvider(FilesToRunProvider.class, FilesToRunProvider.EMPTY)
+        .addProvider(
+            ConstraintSettingProvider.class,
+            ConstraintSettingProvider.create(ruleContext.getLabel()))
+        .build();
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSettingProvider.java b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSettingProvider.java
new file mode 100644
index 0000000000..9459a07e91
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSettingProvider.java
@@ -0,0 +1,31 @@
+// 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.rules.platform;
+
+import com.google.auto.value.AutoValue;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+
+/** Provider for a platform constraint setting that is available to be fulfilled. */
+@AutoValue
+@Immutable
+public abstract class ConstraintSettingProvider implements TransitiveInfoProvider {
+  public abstract Label constraintSetting();
+
+  public static ConstraintSettingProvider create(Label constraintSetting) {
+    return new AutoValue_ConstraintSettingProvider(constraintSetting);
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSettingRule.java b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSettingRule.java
new file mode 100644
index 0000000000..6b239834ac
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintSettingRule.java
@@ -0,0 +1,57 @@
+// 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.rules.platform;
+
+import static com.google.devtools.build.lib.packages.Attribute.attr;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.BaseRuleClasses;
+import com.google.devtools.build.lib.analysis.RuleDefinition;
+import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
+import com.google.devtools.build.lib.packages.RuleClass;
+import com.google.devtools.build.lib.syntax.Type;
+
+/** Rule definition for {@link ConstraintSetting}. */
+public class ConstraintSettingRule implements RuleDefinition {
+  public static final String RULE_NAME = "constraint_setting";
+
+  @Override
+  public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
+    return builder
+        .override(
+            attr("tags", Type.STRING_LIST)
+                // No need to show up in ":all", etc. target patterns.
+                .value(ImmutableList.of("manual"))
+                .nonconfigurable("low-level attribute, used in platform configuration"))
+        .removeAttribute("deps")
+        .removeAttribute("data")
+        .exemptFromConstraintChecking("this rule *defines* a constraint")
+        .build();
+  }
+
+  @Override
+  public RuleDefinition.Metadata getMetadata() {
+    return RuleDefinition.Metadata.builder()
+        .name(RULE_NAME)
+        .ancestors(BaseRuleClasses.RuleBase.class)
+        .factoryClass(ConstraintSetting.class)
+        .build();
+  }
+}
+/*<!-- #BLAZE_RULE (NAME = constraint_setting, TYPE = OTHER, FAMILY = Platform)[GENERIC_RULE] -->
+
+<p>This rule defines a type of constraint that can be used to define an execution platform.</p>
+
+<!-- #END_BLAZE_RULE -->*/
diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValue.java b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValue.java
new file mode 100644
index 0000000000..c232c92212
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValue.java
@@ -0,0 +1,48 @@
+// 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.rules.platform;
+
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.FileProvider;
+import com.google.devtools.build.lib.analysis.FilesToRunProvider;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.RunfilesProvider;
+import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
+
+/** Defines a potential value of a constraint. */
+public class ConstraintValue implements RuleConfiguredTargetFactory {
+
+  @Override
+  public ConfiguredTarget create(RuleContext ruleContext)
+      throws InterruptedException, RuleErrorException {
+
+    ConstraintSettingProvider constraint =
+        ruleContext.getPrerequisite(
+            ConstraintValueRule.CONSTRAINT_SETTING_ATTR,
+            Mode.DONT_CHECK,
+            ConstraintSettingProvider.class);
+
+    return new RuleConfiguredTargetBuilder(ruleContext)
+        .addProvider(RunfilesProvider.class, RunfilesProvider.EMPTY)
+        .addProvider(FileProvider.class, FileProvider.EMPTY)
+        .addProvider(FilesToRunProvider.class, FilesToRunProvider.EMPTY)
+        .addProvider(
+            ConstraintValueProvider.class,
+            ConstraintValueProvider.create(constraint, ruleContext.getLabel()))
+        .build();
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValueProvider.java b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValueProvider.java
new file mode 100644
index 0000000000..1ade6ddded
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValueProvider.java
@@ -0,0 +1,33 @@
+// 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.rules.platform;
+
+import com.google.auto.value.AutoValue;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+
+/** Provider for a platform constraint value that fulfills a {@link ConstraintSettingProvider}. */
+@AutoValue
+@Immutable
+public abstract class ConstraintValueProvider implements TransitiveInfoProvider {
+  public abstract ConstraintSettingProvider constraint();
+
+  public abstract Label value();
+
+  public static ConstraintValueProvider create(ConstraintSettingProvider constraint, Label value) {
+    return new AutoValue_ConstraintValueProvider(constraint, value);
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValueRule.java b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValueRule.java
new file mode 100644
index 0000000000..55e85b1048
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/ConstraintValueRule.java
@@ -0,0 +1,74 @@
+// 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.rules.platform;
+
+import static com.google.devtools.build.lib.packages.Attribute.attr;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.BaseRuleClasses;
+import com.google.devtools.build.lib.analysis.RuleDefinition;
+import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.packages.BuildType;
+import com.google.devtools.build.lib.packages.RuleClass;
+import com.google.devtools.build.lib.syntax.Type;
+import com.google.devtools.build.lib.util.FileTypeSet;
+
+/** Rule definition for {@link ConstraintValue}. */
+public class ConstraintValueRule implements RuleDefinition {
+  public static final String RULE_NAME = "constraint_value";
+  public static final String CONSTRAINT_SETTING_ATTR = "constraint_setting";
+
+  @Override
+  public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
+    return builder
+        .override(
+            attr("tags", Type.STRING_LIST)
+                // No need to show up in ":all", etc. target patterns.
+                .value(ImmutableList.of("manual"))
+                .nonconfigurable("low-level attribute, used in platform configuration"))
+
+        /* <!-- #BLAZE_RULE(constraint_value).ATTRIBUTE(constraint) -->
+        The constraint_setting rule this value is applied to.
+        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+        .add(
+            attr(CONSTRAINT_SETTING_ATTR, BuildType.LABEL)
+                .mandatory()
+                .allowedRuleClasses(ConstraintSettingRule.RULE_NAME)
+                .allowedFileTypes(FileTypeSet.NO_FILE)
+                .mandatoryNativeProviders(
+                    ImmutableList.<Class<? extends TransitiveInfoProvider>>of(
+                        ConstraintSettingProvider.class)))
+        .removeAttribute("deps")
+        .removeAttribute("data")
+        .exemptFromConstraintChecking("this rule *defines* a constraint")
+        .build();
+  }
+
+  @Override
+  public Metadata getMetadata() {
+    return Metadata.builder()
+        .name(RULE_NAME)
+        .ancestors(BaseRuleClasses.RuleBase.class)
+        .factoryClass(ConstraintValue.class)
+        .build();
+  }
+}
+/*<!-- #BLAZE_RULE (NAME = constraint_value, TYPE = OTHER, FAMILY = Platform)[GENERIC_RULE] -->
+
+<p>This rule defines a specific value of a constraint, which can be used to define execution
+platforms.
+
+<!-- #END_BLAZE_RULE -->*/