Add incompatible flag to guard top-level aspects dependencies

This CL introduces `incompatible_top_level_aspects_dependency` flag to enable aspect-on-aspect and requiring aspects for command line aspects. This can be needed because the new behavior can break builds where a relation between top-level aspects existed (based on required_aspect_providers and provides) but it was never actually applied as it was not supported.

One example of these cases:
blaze build //:main --aspects=/tools:my_def.bzl%a1,/tools:my_def.bzl%a2

If aspect a1 provides a1p provider, aspect a2 requires a1p provider and the rule of target `main` also provides a1p. Once top-level aspect-on-aspect is enabled this build will fail because a1p will be provided twice to a2 (from a1 applied on `main` and from `main` target rule). Previously the relation between a1 and a2 was not detected and a2 used to get only the value of a1p from `main`'s rule.

PiperOrigin-RevId: 390587290

src/main/java/com/google/devtools/build/lib/analysis/AnalysisOptions.java

@@ -166,19 +166,4 @@ public class AnalysisOptions extends OptionsBase {
               + " be used. Example value: \"HOST_CPUS*0.5\".",
       converter = CpuResourceConverter.class)
   public int oomSensitiveSkyFunctionsSemaphoreSize;
-
-  @Option(
-      name = "incompatible_ignore_duplicate_top_level_aspects",
-      defaultValue = "true",
-      documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
-      metadataTags = {
-        OptionMetadataTag.INCOMPATIBLE_CHANGE,
-        OptionMetadataTag.TRIGGERED_BY_ALL_INCOMPATIBLE_CHANGES
-      },
-      effectTags = {OptionEffectTag.LOADING_AND_ANALYSIS},
-      help =
-          "If true, remove duplicates from --aspects list by keeping only the first occurrence of"
-              + " every aspect. Otherwise, throw validation error if duplicate aspects are"
-              + " encountered.")
-  public boolean ignoreDuplicateTopLevelAspects;
 }

src/main/java/com/google/devtools/build/lib/analysis/BuildView.java

@@ -275,10 +275,6 @@ public AnalysisResult update(
             .collect(Collectors.toList());
 
     ImmutableList.Builder<AspectClass> aspectClassesBuilder = ImmutableList.builder();
-    if (viewOptions.ignoreDuplicateTopLevelAspects) {
-      // remove duplicates from aspects list
-      aspects = ImmutableSet.copyOf(aspects).asList();
-    }
     for (String aspect : aspects) {
       // Syntax: label%aspect
       int delimiterPosition = aspect.indexOf('%');

src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java

@@ -306,17 +306,18 @@ public class BuildRequestOptions extends OptionsBase {
       allowMultiple = true,
       help =
           "Comma-separated list of aspects to be applied to top-level targets. All aspects are"
-              + " applied to all top-level targets. If aspect <code>some_aspect</code> specifies"
-              + " required aspect providers via <code>required_aspect_providers</code>,"
-              + " <code>some_aspect</code> will run after every aspect that was mentioned before it"
-              + " in the aspects list and whose advertised providers satisfy"
-              + " <code>some_aspect</code> required aspect providers. <code>some_aspect</code> will"
-              + " then have access to the values of those aspects' providers. Aspects that do not"
-              + " have such dependency will run independently on the top-level targets."
-              + ""
-              + " Aspects are specified in the form <bzl-file-label>%<aspect_name>, for example"
-              + " '//tools:my_def.bzl%my_aspect', where 'my_aspect' is a top-level value from a"
-              + " file tools/my_def.bzl")
+              + " applied independently to all top-level targets except if"
+              + " <code>incompatible_top_level_aspects_dependency</code> is used. In this case, if"
+              + " aspect <code>some_aspect</code> specifies required aspect providers via"
+              + " <code>required_aspect_providers</code>, <code>some_aspect</code> will run after"
+              + " every aspect that was mentioned before it in the aspects list whose advertised"
+              + " providers satisfy <code>some_aspect</code> required aspect providers. Moreover,"
+              + " <code>some_aspect</code> will run after all its required aspects specified by"
+              + " <code>requires</code> attribute which otherwise will be ignored."
+              + " <code>some_aspect</code> will then have access to the values of those aspects'"
+              + " providers."
+              + " <bzl-file-label>%<aspect_name>, for example '//tools:my_def.bzl%my_aspect', where"
+              + " 'my_aspect' is a top-level value from a file tools/my_def.bzl")
   public List<String> aspects;
 
   public BuildRequestOptions() throws OptionsParsingException {}

src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java

@@ -619,6 +619,22 @@ public class BuildLanguageOptions extends OptionsBase implements Serializable {
               + " providers of the aspect.")
   public boolean incompatibleTopLevelAspectsRequireProviders;
 
+  @Option(
+      name = "incompatible_top_level_aspects_dependency",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.STARLARK_SEMANTICS,
+      metadataTags = {
+        OptionMetadataTag.INCOMPATIBLE_CHANGE,
+        OptionMetadataTag.TRIGGERED_BY_ALL_INCOMPATIBLE_CHANGES
+      },
+      effectTags = {OptionEffectTag.LOADING_AND_ANALYSIS},
+      help =
+          "If set to true, a dependency between the top level aspects will be built based on their"
+              + " required aspect providers, advertised providers and required aspects. Otherwise,"
+              + " each aspect in the list will run independently and its required aspects will be"
+              + " ignored.")
+  public boolean incompatibleTopLevelAspectsDependOnAspects;
+
   @Option(
       name = "experimental_required_aspects",
       defaultValue = "false",
@@ -698,6 +714,9 @@ public StarlarkSemantics toStarlarkSemantics() {
             .setBool(
                 INCOMPATIBLE_TOP_LEVEL_ASPECTS_REQUIRE_PROVIDERS,
                 incompatibleTopLevelAspectsRequireProviders)
+            .setBool(
+                INCOMPATIBLE_TOP_LEVEL_ASPECTS_DEPENDENCY,
+                incompatibleTopLevelAspectsDependOnAspects)
             .setBool(EXPERIMENTAL_REQUIRED_ASPECTS, experimentalRequiredAspects)
             .build();
     return INTERNER.intern(semantics);
@@ -770,6 +789,8 @@ public StarlarkSemantics toStarlarkSemantics() {
       "-incompatible_visibility_private_attributes_at_definition";
   public static final String INCOMPATIBLE_TOP_LEVEL_ASPECTS_REQUIRE_PROVIDERS =
       "-incompatible_top_level_aspects_require_providers";
+  public static final String INCOMPATIBLE_TOP_LEVEL_ASPECTS_DEPENDENCY =
+      "-incompatible_top_level_aspects_dependency";
   public static final String EXPERIMENTAL_REQUIRED_ASPECTS = "-experimental_required_aspects";
 
   // non-booleans

src/main/java/com/google/devtools/build/lib/skyframe/BuildTopLevelAspectsDetailsFunction.java

@@ -16,6 +16,7 @@
 
 import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Interner;
 import com.google.devtools.build.lib.analysis.AspectCollection;
 import com.google.devtools.build.lib.analysis.AspectCollection.AspectCycleOnPathException;
@@ -28,6 +29,7 @@
 import com.google.devtools.build.lib.packages.NativeAspectClass;
 import com.google.devtools.build.lib.packages.StarlarkAspect;
 import com.google.devtools.build.lib.packages.StarlarkAspectClass;
+import com.google.devtools.build.lib.packages.semantics.BuildLanguageOptions;
 import com.google.devtools.build.lib.server.FailureDetails.Analysis;
 import com.google.devtools.build.lib.server.FailureDetails.Analysis.Code;
 import com.google.devtools.build.lib.server.FailureDetails.FailureDetail;
@@ -46,6 +48,7 @@
 import java.util.Map;
 import javax.annotation.Nullable;
 import net.starlark.java.eval.EvalException;
+import net.starlark.java.eval.StarlarkSemantics;
 
 /**
  * SkyFunction to load top level aspects, build the dependency relation between them based on the
@@ -68,11 +71,33 @@ public class BuildTopLevelAspectsDetailsFunction implements SkyFunction {
   @Override
   public SkyValue compute(SkyKey skyKey, Environment env)
       throws BuildTopLevelAspectsDetailsFunctionException, InterruptedException {
+
     BuildTopLevelAspectsDetailsKey topLevelAspectsDetailsKey =
         (BuildTopLevelAspectsDetailsKey) skyKey.argument();
+    ImmutableList<AspectClass> topLevelAspectsClasses =
+        topLevelAspectsDetailsKey.getTopLevelAspectsClasses();
+
+    StarlarkSemantics starlarkSemantics = PrecomputedValue.STARLARK_SEMANTICS.get(env);
+    if (starlarkSemantics == null) {
+      return null;
+    }
+    boolean buildTopLevelAspectsDependency =
+        starlarkSemantics.getBool(BuildLanguageOptions.INCOMPATIBLE_TOP_LEVEL_ASPECTS_DEPENDENCY);
+    if (!buildTopLevelAspectsDependency) {
+      // If building a relation between top-level aspects is not required, then we can remove
+      // duplicate aspects by keeping the first occurrence of each aspect.
+      topLevelAspectsClasses = ImmutableSet.copyOf(topLevelAspectsClasses).asList();
+
+      // Then return a list of indenpendent aspects to be applied on the top-level targets
+      ImmutableList<AspectDetails> aspectsDetailsList =
+          getIndependentTopLevelAspects(env, topLevelAspectsClasses);
+      if (aspectsDetailsList == null) {
+        return null; // some aspects are not loaded
+      }
+      return new BuildTopLevelAspectsDetailsValue(aspectsDetailsList);
+    }
 
-    ImmutableList<Aspect> topLevelAspects =
-        getTopLevelAspects(env, topLevelAspectsDetailsKey.getTopLevelAspectsClasses());
+    ImmutableList<Aspect> topLevelAspects = getTopLevelAspects(env, topLevelAspectsClasses);
 
     if (topLevelAspects == null) {
       return null; // some aspects are not loaded
@@ -98,11 +123,9 @@ public String extractTag(SkyKey skyKey) {
   }
 
   @Nullable
-  private static ImmutableList<Aspect> getTopLevelAspects(
+  private static Map<SkyKey, SkyValue> loadAspects(
       Environment env, ImmutableList<AspectClass> topLevelAspectsClasses)
-      throws InterruptedException, BuildTopLevelAspectsDetailsFunctionException {
-    AspectsListBuilder aspectsList = new AspectsListBuilder();
-
+      throws InterruptedException {
     ImmutableList.Builder<StarlarkAspectLoadingKey> aspectLoadingKeys = ImmutableList.builder();
     for (AspectClass aspectClass : topLevelAspectsClasses) {
       if (aspectClass instanceof StarlarkAspectClass) {
@@ -116,6 +139,47 @@ private static ImmutableList<Aspect> getTopLevelAspects(
     if (env.valuesMissing()) {
       return null;
     }
+    return loadedAspects;
+  }
+
+  @Nullable
+  private static ImmutableList<AspectDetails> getIndependentTopLevelAspects(
+      Environment env, ImmutableList<AspectClass> topLevelAspectsClasses)
+      throws InterruptedException {
+    Map<SkyKey, SkyValue> loadedAspects = loadAspects(env, topLevelAspectsClasses);
+    if (loadedAspects == null) {
+      return null;
+    }
+    ImmutableList.Builder<AspectDetails> aspectDetailsList = ImmutableList.builder();
+
+    for (AspectClass aspectClass : topLevelAspectsClasses) {
+      if (aspectClass instanceof StarlarkAspectClass) {
+        StarlarkAspectLoadingValue aspectLoadingValue =
+            (StarlarkAspectLoadingValue)
+                loadedAspects.get(
+                    LoadStarlarkAspectFunction.createStarlarkAspectLoadingKey(
+                        (StarlarkAspectClass) aspectClass));
+        StarlarkAspect starlarkAspect = aspectLoadingValue.getAspect();
+        aspectDetailsList.add(
+            new AspectDetails(
+                ImmutableList.of(), new AspectDescriptor(starlarkAspect.getAspectClass())));
+      } else {
+        aspectDetailsList.add(
+            new AspectDetails(ImmutableList.of(), new AspectDescriptor(aspectClass)));
+      }
+    }
+    return aspectDetailsList.build();
+  }
+
+  @Nullable
+  private static ImmutableList<Aspect> getTopLevelAspects(
+      Environment env, ImmutableList<AspectClass> topLevelAspectsClasses)
+      throws InterruptedException, BuildTopLevelAspectsDetailsFunctionException {
+    AspectsListBuilder aspectsList = new AspectsListBuilder();
+    Map<SkyKey, SkyValue> loadedAspects = loadAspects(env, topLevelAspectsClasses);
+    if (loadedAspects == null) {
+      return null;
+    }
 
     for (AspectClass aspectClass : topLevelAspectsClasses) {
       if (aspectClass instanceof StarlarkAspectClass) {

src/test/java/com/google/devtools/build/lib/analysis/AspectTest.java

@@ -904,7 +904,7 @@ public void duplicateTopLevelAspects_duplicateAspectsNotAllowed() throws Excepti
     AspectApplyingToFiles aspectApplyingToFiles = new AspectApplyingToFiles();
     setRulesAndAspectsAvailableInTests(ImmutableList.of(aspectApplyingToFiles), ImmutableList.of());
     pkg("a", "java_binary(name = 'x', main_class = 'x.FooBar', srcs = ['x.java'])");
-    useConfiguration("--incompatible_ignore_duplicate_top_level_aspects=false");
+    useConfiguration("--incompatible_top_level_aspects_dependency");
     reporter.removeHandler(failFastHandler);
 
     assertThrows(