Use RequiredProviders to validate rule prerequisites in RuleContext.

We now use a unified way to check provider requirements everywhere.

Reland of https://github.com/bazelbuild/bazel/commit/c32e1b1efcd703b3780de47fba62974123593d71.

RELNOTES: None.
PiperOrigin-RevId: 164038621

3 files changed, 100 insertions, 55 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/packages/RequiredProvidersTest.java b/src/test/java/com/google/devtools/build/lib/packages/RequiredProvidersTest.java
index e86cc41f16..489303fef3 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/RequiredProvidersTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/RequiredProvidersTest.java
@@ -16,7 +16,6 @@ package com.google.devtools.build.lib.packages;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import com.google.common.base.Predicates;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
@@ -31,6 +30,9 @@ import org.junit.runners.JUnit4;
  */
 @RunWith(JUnit4.class)
 public class RequiredProvidersTest {
+
+  private static final String NO_PROVIDERS_REQUIRED = "no providers required";
+
   private static final class P1 {}
   private static final class P2 {}
   private static final class P3 {}
@@ -59,10 +61,11 @@ public class RequiredProvidersTest {
       RequiredProviders requiredProviders) {
     boolean result = requiredProviders.isSatisfiedBy(providers);
 
-    assertThat(requiredProviders.isSatisfiedBy(
-        Predicates.in(providers.getNativeProviders()),
-        Predicates.in(providers.getSkylarkProviders())
-    )).isEqualTo(result);
+    assertThat(
+            requiredProviders.isSatisfiedBy(
+                providers.getNativeProviders()::contains,
+                providers.getSkylarkProviders()::contains))
+        .isEqualTo(result);
     return result;
   }
 
@@ -108,32 +111,31 @@ public class RequiredProvidersTest {
         .addNative(P1.class)
         .addNative(P2.class)
         .build();
-    assertThat(validateNative(providerSet, ImmutableSet.<Class<?>>of(P1.class, P2.class)))
+    assertThat(
+            validateNative(providerSet, NO_PROVIDERS_REQUIRED, ImmutableSet.of(P1.class, P2.class)))
         .isTrue();
   }
 
   @Test
   public void nativeProvidersBranchMatch() {
     assertThat(
-        validateNative(
-          AdvertisedProviderSet.builder()
-              .addNative(P1.class)
-              .build(),
-          ImmutableSet.<Class<?>>of(P1.class),
-          ImmutableSet.<Class<?>>of(P2.class)
-        )).isTrue();
+            validateNative(
+                AdvertisedProviderSet.builder().addNative(P1.class).build(),
+                NO_PROVIDERS_REQUIRED,
+                ImmutableSet.<Class<?>>of(P1.class),
+                ImmutableSet.<Class<?>>of(P2.class)))
+        .isTrue();
   }
 
   @Test
   public void nativeProvidersNoMatch() {
     assertThat(
-        validateNative(
-            AdvertisedProviderSet.builder()
-                .addNative(P3.class)
-                .build(),
-            ImmutableSet.<Class<?>>of(P1.class),
-            ImmutableSet.<Class<?>>of(P2.class)
-        )).isFalse();
+            validateNative(
+                AdvertisedProviderSet.builder().addNative(P3.class).build(),
+                "P1 or P2",
+                ImmutableSet.<Class<?>>of(P1.class),
+                ImmutableSet.<Class<?>>of(P2.class)))
+        .isFalse();
   }
 
   @Test
@@ -143,53 +145,75 @@ public class RequiredProvidersTest {
         .addSkylark(ID_NATIVE)
         .addSkylark(ID_SKYLARK)
         .build();
-    assertThat(validateSkylark(providerSet,
-        ImmutableSet.of(
-            ID_LEGACY, ID_SKYLARK, ID_NATIVE)))
+    assertThat(
+            validateSkylark(
+                providerSet,
+                NO_PROVIDERS_REQUIRED,
+                ImmutableSet.of(ID_LEGACY, ID_SKYLARK, ID_NATIVE)))
         .isTrue();
   }
 
   @Test
   public void skylarkProvidersBranchMatch() {
     assertThat(
-        validateSkylark(
-            AdvertisedProviderSet.builder()
-                .addSkylark(ID_LEGACY)
-                .build(),
-            ImmutableSet.of(ID_LEGACY),
-            ImmutableSet.of(ID_NATIVE)
-        )).isTrue();
+            validateSkylark(
+                AdvertisedProviderSet.builder().addSkylark(ID_LEGACY).build(),
+                NO_PROVIDERS_REQUIRED,
+                ImmutableSet.of(ID_LEGACY),
+                ImmutableSet.of(ID_NATIVE)))
+        .isTrue();
   }
 
   @Test
   public void skylarkProvidersNoMatch() {
     assertThat(
-        validateSkylark(
-            AdvertisedProviderSet.builder()
-                .addSkylark(ID_SKYLARK)
-                .build(),
-            ImmutableSet.of(ID_LEGACY),
-            ImmutableSet.of(ID_NATIVE)
-        )).isFalse();
+            validateSkylark(
+                AdvertisedProviderSet.builder().addSkylark(ID_SKYLARK).build(),
+                "'p_legacy' or 'p_native'",
+                ImmutableSet.of(ID_LEGACY),
+                ImmutableSet.of(ID_NATIVE)))
+        .isFalse();
+  }
+
+  @Test
+  public void checkDescriptions() {
+    assertThat(RequiredProviders.acceptAnyBuilder().build().getDescription())
+        .isEqualTo("no providers required");
+    assertThat(RequiredProviders.acceptNoneBuilder().build().getDescription())
+        .isEqualTo("no providers accepted");
+    assertThat(
+            RequiredProviders.acceptAnyBuilder()
+                .addSkylarkSet(ImmutableSet.of(ID_LEGACY, ID_SKYLARK))
+                .addSkylarkSet(ImmutableSet.of(ID_SKYLARK))
+                .addNativeSet(ImmutableSet.of(P1.class, P2.class))
+                .build()
+                .getDescription())
+        .isEqualTo("[P1, P2] or ['p_legacy', 'p_skylark'] or 'p_skylark'");
   }
 
   @SafeVarargs
-  private static boolean validateNative(AdvertisedProviderSet providerSet,
-      ImmutableSet<Class<?>>... sets) {
+  private static boolean validateNative(
+      AdvertisedProviderSet providerSet, String missing, ImmutableSet<Class<?>>... sets) {
     Builder anyBuilder = RequiredProviders.acceptAnyBuilder();
     Builder noneBuilder = RequiredProviders.acceptNoneBuilder();
     for (ImmutableSet<Class<?>> set : sets) {
       anyBuilder.addNativeSet(set);
       noneBuilder.addNativeSet(set);
     }
-    boolean result = satisfies(providerSet, anyBuilder.build());
-    assertThat(satisfies(providerSet, noneBuilder.build())).isEqualTo(result);
+    RequiredProviders rpStartingFromAny = anyBuilder.build();
+    boolean result = satisfies(providerSet, rpStartingFromAny);
+    assertThat(rpStartingFromAny.getMissing(providerSet).getDescription()).isEqualTo(missing);
+
+    RequiredProviders rpStaringFromNone = noneBuilder.build();
+    assertThat(satisfies(providerSet, rpStaringFromNone)).isEqualTo(result);
+    assertThat(rpStaringFromNone.getMissing(providerSet).getDescription()).isEqualTo(missing);
     return result;
   }
 
   @SafeVarargs
   private static boolean validateSkylark(
       AdvertisedProviderSet providerSet,
+      String missing,
       ImmutableSet<SkylarkProviderIdentifier>... sets) {
     Builder anyBuilder = RequiredProviders.acceptAnyBuilder();
     Builder noneBuilder = RequiredProviders.acceptNoneBuilder();
@@ -197,8 +221,14 @@ public class RequiredProvidersTest {
       anyBuilder.addSkylarkSet(set);
       noneBuilder.addSkylarkSet(set);
     }
-    boolean result = satisfies(providerSet, anyBuilder.build());
-    assertThat(satisfies(providerSet, noneBuilder.build())).isEqualTo(result);
+
+    RequiredProviders rpStartingFromAny = anyBuilder.build();
+    boolean result = satisfies(providerSet, rpStartingFromAny);
+    assertThat(rpStartingFromAny.getMissing(providerSet).getDescription()).isEqualTo(missing);
+
+    RequiredProviders rpStaringFromNone = noneBuilder.build();
+    assertThat(satisfies(providerSet, rpStaringFromNone)).isEqualTo(result);
+    assertThat(rpStaringFromNone.getMissing(providerSet).getDescription()).isEqualTo(missing);
     return result;
   }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
index b346a60513..71e084da10 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
@@ -711,7 +711,7 @@ public class SkylarkIntegrationTest extends BuildViewTestCase {
         "main_rule = rule(implementation = rule_impl, attrs = {",
         "    'deps': attr.label_list(providers = [",
         "        'files', 'data_runfiles', 'default_runfiles',",
-        "        'files_to_run', 'label', 'output_groups',",
+        "        'files_to_run', 'output_groups',",
         "    ])",
         "})");
     scratch.file(
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
index 5c32321734..c212605bc2 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleClassFunctionsTest.java
@@ -249,8 +249,18 @@ public class SkylarkRuleClassFunctionsTest extends SkylarkTestCase {
         buildAttribute("a1",
             "b = provider()",
             "attr.label_list(allow_files = True, providers = ['a', b])");
-    assertThat(attr.getMandatoryProvidersList())
-        .containsExactly(ImmutableSet.of(legacy("a"), declared("b")));
+    assertThat(attr.getRequiredProviders().isSatisfiedBy(set(legacy("a"), declared("b")))).isTrue();
+    assertThat(attr.getRequiredProviders().isSatisfiedBy(set(legacy("a")))).isFalse();
+  }
+
+  @Test
+  public void testAttrWithProvidersOneEmpty() throws Exception {
+    Attribute attr =
+        buildAttribute(
+            "a1",
+            "b = provider()",
+            "attr.label_list(allow_files = True, providers = [['a', b],[]])");
+    assertThat(attr.getRequiredProviders().acceptsAny()).isTrue();
   }
 
   @Test
@@ -259,9 +269,17 @@ public class SkylarkRuleClassFunctionsTest extends SkylarkTestCase {
         buildAttribute("a1",
             "b = provider()",
             "attr.label_list(allow_files = True, providers = [['a', b], ['c']])");
-    assertThat(attr.getMandatoryProvidersList()).containsExactly(
-        ImmutableSet.of(legacy("a"), declared("b")),
-        ImmutableSet.of(legacy("c")));
+    assertThat(attr.getRequiredProviders().isSatisfiedBy(set(legacy("a"), declared("b")))).isTrue();
+    assertThat(attr.getRequiredProviders().isSatisfiedBy(set(legacy("c")))).isTrue();
+    assertThat(attr.getRequiredProviders().isSatisfiedBy(set(legacy("a")))).isFalse();
+  }
+
+  private static AdvertisedProviderSet set(SkylarkProviderIdentifier... ids) {
+    AdvertisedProviderSet.Builder builder = AdvertisedProviderSet.builder();
+    for (SkylarkProviderIdentifier id : ids) {
+      builder.addSkylark(id);
+    }
+    return builder.build();
   }
 
   private void checkAttributeError(String expectedMessage, String... lines) throws Exception {
@@ -425,12 +443,9 @@ public class SkylarkRuleClassFunctionsTest extends SkylarkTestCase {
 
   private static final RuleClass.ConfiguredTargetFactory<Object, Object>
       DUMMY_CONFIGURED_TARGET_FACTORY =
-      new RuleClass.ConfiguredTargetFactory<Object, Object>() {
-        @Override
-        public Object create(Object ruleContext) throws InterruptedException {
-          throw new IllegalStateException();
-        }
-      };
+          ruleContext -> {
+            throw new IllegalStateException();
+          };
 
   private RuleClass ruleClass(String name) {
     return new RuleClass.Builder(name, RuleClassType.NORMAL, false)