Fix strict module map propagation for j2objc.

J2Objc needs special consideration to implement strict Swift-ObjC deps. The module maps for the generated Objective-C code are associated with their originating java_library targets (via the J2Objc aspect), which a swift_library cannot directly depend on. So those deeper down module maps need to be propagated transitively *until* a j2objc_library is reached; at that point, the j2objc_library should propagate all of its Java deps module maps, but *not* any of its j2objc_library deps (because that would be non-strict).

PiperOrigin-RevId: 191754811

3 files changed, 84 insertions, 24 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java
index c12faf2e1c..73a3557164 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcAspect.java
@@ -809,10 +809,13 @@ public class J2ObjcAspect extends NativeAspectClass implements ConfiguredAspectF
     for (Attribute dependentAttribute : dependentAttributes) {
       if (ruleContext.attributes().has(dependentAttribute.getName(), BuildType.LABEL_LIST)
           || ruleContext.attributes().has(dependentAttribute.getName(), BuildType.LABEL)) {
-        builder.addDepObjcProviders(ruleContext.getPrerequisites(
-            dependentAttribute.getName(),
-            dependentAttribute.getAccessMode(),
-            ObjcProvider.SKYLARK_CONSTRUCTOR));
+        Iterable<ObjcProvider> depObjcProviders =
+            ruleContext.getPrerequisites(
+                dependentAttribute.getName(),
+                dependentAttribute.getAccessMode(),
+                ObjcProvider.SKYLARK_CONSTRUCTOR);
+        builder.addDepObjcProviders(depObjcProviders);
+        builder.addRepropagatedModuleMapObjcProviders(depObjcProviders);
       }
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java
index b761f53fdc..317fbbb221 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/J2ObjcLibrary.java
@@ -15,8 +15,6 @@
 package com.google.devtools.build.lib.rules.objc;
 
 import static com.google.devtools.build.lib.collect.nestedset.Order.STABLE_ORDER;
-import static com.google.devtools.build.lib.rules.objc.ObjcProvider.JRE_LIBRARY;
-import static com.google.devtools.build.lib.rules.objc.ObjcProvider.LIBRARY;
 
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.actions.Artifact;
@@ -29,6 +27,7 @@ import com.google.devtools.build.lib.analysis.RunfilesProvider;
 import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget.Mode;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.packages.BuildType;
+import com.google.devtools.build.lib.skyframe.ConfiguredTargetAndData;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import java.util.List;
@@ -48,13 +47,51 @@ public class J2ObjcLibrary implements RuleConfiguredTargetFactory {
       ImmutableList.of("java_import", "java_library", "proto_library");
 
   private ObjcCommon common(RuleContext ruleContext) throws InterruptedException {
+    List<ConfiguredTargetAndData> deps =
+        ruleContext.getPrerequisiteConfiguredTargetAndTargets("deps", Mode.TARGET);
+    List<ConfiguredTargetAndData> jreDeps =
+        ruleContext.getPrerequisiteConfiguredTargetAndTargets("jre_deps", Mode.TARGET);
+
+    ImmutableList.Builder<ObjcProvider> repropagatedModuleMapsProviders =
+        new ImmutableList.Builder<>();
+
+    // In order to support strict Obj-C deps from Swift, we need to repropagate the module maps of
+    // targets that swift_libraries cannot directly depend on, like java_library. So we repropagate
+    // for any dependency *except* j2objc_library (which are detected by looking for
+    // J2ObjcEntryClassProvider). This keeps dependencies between j2objc_libraries strict (Swift
+    // can't indirectly depend on a j2objc_library through another one), but ensures that the
+    // underlying java_library/proto_library dependencies can be imported.
+    for (ConfiguredTargetAndData dep : deps) {
+      ConfiguredTarget target = dep.getConfiguredTarget();
+      if (target.getProvider(J2ObjcEntryClassProvider.class) == null) {
+        ObjcProvider objcProvider = target.get(ObjcProvider.SKYLARK_CONSTRUCTOR);
+        if (objcProvider != null) {
+          repropagatedModuleMapsProviders.add(objcProvider);
+        }
+      }
+    }
+
+    // JRE deps are objc_libraries, so always repropagate them.
+    for (ConfiguredTargetAndData dep : jreDeps) {
+      ConfiguredTarget target = dep.getConfiguredTarget();
+      ObjcProvider objcProvider = target.get(ObjcProvider.SKYLARK_CONSTRUCTOR);
+      if (objcProvider != null) {
+        repropagatedModuleMapsProviders.add(objcProvider);
+      }
+    }
+
+    // Adding the deps and jreDeps here is still required to propagate the rest of the dependencies'
+    // providers' information up the tree (whether transitively or only to direct dependencies,
+    // depending on the key in question). The repropagated module map providers merely decide which
+    // providers should *also* have their module maps re-propagated to the next direct dependency.
     return new ObjcCommon.Builder(ruleContext)
         .setCompilationAttributes(
             CompilationAttributes.Builder.fromRuleContext(ruleContext).build())
-        .addDeps(ruleContext.getPrerequisiteConfiguredTargetAndTargets("deps", Mode.TARGET))
-        .addDeps(ruleContext.getPrerequisiteConfiguredTargetAndTargets("jre_deps", Mode.TARGET))
+        .addDeps(deps)
+        .addDeps(jreDeps)
         .setIntermediateArtifacts(ObjcRuleClasses.intermediateArtifacts(ruleContext))
         .setHasModuleMap()
+        .addRepropagatedModuleMapObjcProviders(repropagatedModuleMapsProviders.build())
         .build();
   }
 
@@ -72,24 +109,12 @@ public class J2ObjcLibrary implements RuleConfiguredTargetFactory {
         .addEntryClasses(ruleContext.attributes().get("entry_classes", Type.STRING_LIST))
         .build();
 
-    Iterable<ObjcProvider> jreDeps =
-        ruleContext.getPrerequisites("jre_deps", Mode.TARGET, ObjcProvider.SKYLARK_CONSTRUCTOR);
-    ObjcProvider.Builder objcProviderBuilder =
-        new ObjcProvider.Builder(ruleContext.getAnalysisEnvironment().getSkylarkSemantics())
-            .addTransitiveAndPropagate(jreDeps)
-            .addTransitiveAndPropagate(
-                ruleContext.getPrerequisites(
-                    "deps", Mode.TARGET, ObjcProvider.SKYLARK_CONSTRUCTOR));
-    for (ObjcProvider prereq : jreDeps) {
-      objcProviderBuilder.addTransitiveAndPropagate(JRE_LIBRARY, prereq.get(LIBRARY));
-    }
-
-    ObjcProvider objcProvider = objcProviderBuilder.build();
+    ObjcCommon common = common(ruleContext);
+    ObjcProvider objcProvider = common.getObjcProvider();
 
     J2ObjcMappingFileProvider j2ObjcMappingFileProvider = J2ObjcMappingFileProvider.union(
         ruleContext.getPrerequisites("deps", Mode.TARGET, J2ObjcMappingFileProvider.class));
 
-    ObjcCommon common = common(ruleContext);
     CompilationArtifacts moduleMapCompilationArtifacts =
         new CompilationArtifacts.Builder()
             .setIntermediateArtifacts(ObjcRuleClasses.intermediateArtifacts(ruleContext))
@@ -101,7 +126,7 @@ public class J2ObjcLibrary implements RuleConfiguredTargetFactory {
         .doNotUsePch()
         .build()
         .registerFullyLinkAction(
-            common.getObjcProvider(),
+            objcProvider,
             ruleContext.getImplicitOutputArtifact(CompilationSupport.FULLY_LINKED_LIB))
         .registerGenerateModuleMapAction(moduleMapCompilationArtifacts)
         .validateAttributes();
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommon.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommon.java
index d4a26a234d..13a915f22a 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommon.java
@@ -157,6 +157,7 @@ public final class ObjcCommon {
     private Iterable<ObjcProvider> depObjcProviders = ImmutableList.of();
     private Iterable<ObjcProvider> directDepObjcProviders = ImmutableList.of();
     private Iterable<ObjcProvider> runtimeDepObjcProviders = ImmutableList.of();
+    private Iterable<ObjcProvider> repropagatedModuleMapObjcProviders = ImmutableList.of();
     private Iterable<String> defines = ImmutableList.of();
     private Iterable<PathFragment> includes = ImmutableList.of();
     private Iterable<PathFragment> directDependencyIncludes = ImmutableList.of();
@@ -363,6 +364,22 @@ public final class ObjcCommon {
     }
 
     /**
+     * Adds Objc providers whose module maps should be repropagated as if they are directly
+     * associated with the target propagating the provider being built.
+     *
+     * <p>This supports a small number of specialized use cases, like J2Objc, where the module maps
+     * associated with the {@code java_library} (via an aspect) need to be repropagated by the
+     * {@code j2objc_library} that depends on them so that Swift code can access those module maps
+     * for the purposes of strict module map propagation (without propagating the module maps
+     * _fully_ transitively).
+     */
+    Builder addRepropagatedModuleMapObjcProviders(Iterable<ObjcProvider> objcProviders) {
+      this.repropagatedModuleMapObjcProviders =
+          Iterables.concat(this.repropagatedModuleMapObjcProviders, objcProviders);
+      return this;
+    }
+
+    /**
      * Adds additional static libraries to be linked into the final ObjC application bundle.
      */
     Builder addExtraImportLibraries(Iterable<Artifact> extraImportLibraries) {
@@ -544,13 +561,21 @@ public final class ObjcCommon {
         }
       }
 
+      if (useStrictObjcModuleMaps(context)) {
+        for (ObjcProvider provider : repropagatedModuleMapObjcProviders) {
+          objcProvider.addAllForDirectDependents(MODULE_MAP, provider.get(ObjcProvider.MODULE_MAP));
+          objcProvider.addAllForDirectDependents(
+              TOP_LEVEL_MODULE_MAP, provider.get(ObjcProvider.TOP_LEVEL_MODULE_MAP));
+        }
+      }
+
       if (hasModuleMap) {
         CppModuleMap moduleMap = intermediateArtifacts.moduleMap();
         Optional<Artifact> umbrellaHeader = moduleMap.getUmbrellaHeader();
         if (umbrellaHeader.isPresent()) {
           objcProvider.add(UMBRELLA_HEADER, umbrellaHeader.get());
         }
-        if (context.getFragment(ObjcConfiguration.class).useStrictObjcModuleMaps()) {
+        if (useStrictObjcModuleMaps(context)) {
           objcProvider.addForDirectDependents(MODULE_MAP, moduleMap.getArtifact());
           objcProvider.addForDirectDependents(TOP_LEVEL_MODULE_MAP, moduleMap);
         } else {
@@ -572,6 +597,13 @@ public final class ObjcCommon {
       return new ObjcCommon(objcProvider.build(), compilationArtifacts);
     }
 
+    private static boolean useStrictObjcModuleMaps(RuleContext context) {
+      // We need to check isLegalFragment first because some non-compilation rules, like
+      // objc_bundle_library, don't declare this fragment.
+      return context.isLegalFragment(ObjcConfiguration.class)
+          && context.getFragment(ObjcConfiguration.class).useStrictObjcModuleMaps();
+    }
+
     private static boolean isCcLibrary(ConfiguredTargetAndData info) {
       try {
         String targetName = info.getTarget().getTargetKind();