Allow private header files in the srcs attribute of objc_* rules.

This uses CppModuleMap and CppModuleMapAction to generate clang module maps for the target and its transitive dependencies. clang enforces private header usage through these maps. Right now module maps are interpreted but modules aren't enabled.

RELNOTES: Allow private header files in the srcs attribute of objc_* rules.

--
MOS_MIGRATED_REVID=95844137

1 files changed, 60 insertions, 9 deletions

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 e311bc3473..bf6acfd396 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
@@ -34,11 +34,13 @@ import static com.google.devtools.build.lib.rules.objc.ObjcProvider.INCLUDE;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.INSTRUMENTED_SOURCE;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.LIBRARY;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.LINKED_BINARY;
+import static com.google.devtools.build.lib.rules.objc.ObjcProvider.MODULE_MAP;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.SDK_DYLIB;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.SDK_FRAMEWORK;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.SOURCE;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.STORYBOARD;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.STRINGS;
+import static com.google.devtools.build.lib.rules.objc.ObjcProvider.TOP_LEVEL_MODULE_MAP;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.WEAK_SDK_FRAMEWORK;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.XCASSETS_DIR;
 import static com.google.devtools.build.lib.rules.objc.ObjcProvider.XCDATAMODEL;
@@ -60,10 +62,12 @@ import com.google.devtools.build.lib.packages.Type;
 import com.google.devtools.build.lib.rules.cpp.CcCommon;
 import com.google.devtools.build.lib.rules.cpp.CcLinkParamsProvider;
 import com.google.devtools.build.lib.rules.cpp.CppCompilationContext;
+import com.google.devtools.build.lib.rules.cpp.CppModuleMap;
 import com.google.devtools.build.lib.util.FileType;
 import com.google.devtools.build.lib.util.RegexFilter;
 import com.google.devtools.build.lib.vfs.PathFragment;
 
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -91,6 +95,10 @@ public final class ObjcCommon {
     }
 
     ImmutableList<Artifact> hdrs() {
+      // Some rules may compile but not have the "hdrs" attribute".
+      if (!ruleContext.attributes().has("hdrs", Type.LABEL_LIST)) {
+        return ImmutableList.of();
+      }
       return ImmutableList.copyOf(CcCommon.getHeaders(ruleContext));
     }
 
@@ -176,6 +184,37 @@ public final class ObjcCommon {
       }
       return optionsProvider.getCopts();
     }
+
+    /**
+     * The clang module maps of direct dependencies of this rule. These are needed to generate
+     * this rule's module map.
+     */
+    public List<CppModuleMap> directDepModuleMaps() {
+      // Make sure all dependencies that have headers are included here. If a module map is missing,
+      // its private headers will be treated as public!
+      ArrayList<CppModuleMap> moduleMaps = new ArrayList<>();
+      collectModuleMapsFromAttributeIfExists(moduleMaps, "deps");
+      collectModuleMapsFromAttributeIfExists(moduleMaps, "non_propagated_deps");
+      return moduleMaps;
+    }
+
+    /**
+     * Collects all module maps from the targets in a certain attribute and adds them into
+     * {@code moduleMaps}.
+     *
+     * @param moduleMaps an {@link ArrayList} to collect the module maps into
+     * @param attribute the name of a label list attribute to collect module maps from
+     */
+    private void collectModuleMapsFromAttributeIfExists(ArrayList<CppModuleMap> moduleMaps,
+        String attribute) {
+      if (ruleContext.attributes().has(attribute, Type.LABEL_LIST)) {
+        Iterable<ObjcProvider> providers =
+            ruleContext.getPrerequisites(attribute, Mode.TARGET, ObjcProvider.class);
+        for (ObjcProvider provider : providers) {
+          moduleMaps.addAll(provider.get(TOP_LEVEL_MODULE_MAP).toCollection());
+        }
+      }
+    }
   }
 
   /**
@@ -234,9 +273,9 @@ public final class ObjcCommon {
     private Iterable<ObjcProvider> directDepObjcProviders = ImmutableList.of();
     private Iterable<String> defines = ImmutableList.of();
     private Iterable<PathFragment> userHeaderSearchPaths = ImmutableList.of();
-    private Iterable<Artifact> headers = ImmutableList.of();
     private IntermediateArtifacts intermediateArtifacts;
     private boolean alwayslink;
+    private boolean generatesModuleMap;
     private Iterable<Artifact> extraImportLibraries = ImmutableList.of();
     private Optional<Artifact> linkedBinary = Optional.absent();
     private Optional<Artifact> breakpadFile = Optional.absent();
@@ -319,11 +358,6 @@ public final class ObjcCommon {
       return this;
     }
 
-    public Builder addHeaders(Iterable<Artifact> headers) {
-      this.headers = Iterables.concat(this.headers, headers);
-      return this;
-    }
-
     Builder setIntermediateArtifacts(IntermediateArtifacts intermediateArtifacts) {
       this.intermediateArtifacts = intermediateArtifacts;
       return this;
@@ -335,6 +369,15 @@ public final class ObjcCommon {
     }
 
     /**
+     * Specifies that this target has a clang module map. This should be called if this target
+     * compiles sources or exposes headers for other targets to use.
+     */
+    Builder setGeneratesModuleMap() {
+      this.generatesModuleMap = true;
+      return this;
+    }
+
+    /**
      * Adds additional static libraries to be linked into the final ObjC application bundle.
      */
     Builder addExtraImportLibraries(Iterable<Artifact> extraImportLibraries) {
@@ -390,7 +433,6 @@ public final class ObjcCommon {
           .addAll(FRAMEWORK_DIR, uniqueContainers(frameworkImports, FRAMEWORK_CONTAINER_TYPE))
           .addAll(INCLUDE, userHeaderSearchPaths)
           .addAll(DEFINE, defines)
-          .addAll(HEADER, headers)
           .addTransitiveAndPropagate(depObjcProviders)
           .addTransitiveWithoutPropagating(directDepObjcProviders);
 
@@ -442,8 +484,11 @@ public final class ObjcCommon {
       for (CompilationArtifacts artifacts : compilationArtifacts.asSet()) {
         Iterable<Artifact> allSources =
             Iterables.concat(artifacts.getSrcs(), artifacts.getNonArcSrcs());
-        objcProvider.addAll(LIBRARY, artifacts.getArchive().asSet());
-        objcProvider.addAll(SOURCE, allSources);
+        objcProvider
+            .addAll(HEADER, artifacts.getAdditionalHdrs())
+            .addAll(HEADER, artifacts.getPrivateHdrs())
+            .addAll(LIBRARY, artifacts.getArchive().asSet())
+            .addAll(SOURCE, allSources);
         BuildConfiguration configuration = context.getConfiguration();
         RegexFilter filter = configuration.getInstrumentationFilter();
         if (configuration.isCodeCoverageEnabled()
@@ -480,6 +525,12 @@ public final class ObjcCommon {
         }
       }
 
+      if (this.generatesModuleMap) {
+        CppModuleMap moduleMap = intermediateArtifacts.moduleMap();
+        objcProvider.addWithoutPropagating(TOP_LEVEL_MODULE_MAP, moduleMap);
+        objcProvider.add(MODULE_MAP, moduleMap.getArtifact());
+      }
+
       objcProvider.addAll(LINKED_BINARY, linkedBinary.asSet())
           .addAll(BREAKPAD_FILE, breakpadFile.asSet());