Add module_map attribute to objc_library

This allows users to specify a custom module map.

PiperOrigin-RevId: 161827651

6 files changed, 49 insertions, 11 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcLibraryHelper.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcLibraryHelper.java
index 7b7230c27b..e940d57823 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcLibraryHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcLibraryHelper.java
@@ -303,6 +303,7 @@ public final class CcLibraryHelper {
   private final FdoSupportProvider fdoSupport;
   private String linkedArtifactNameSuffix = "";
   private boolean useDeps = true;
+  private boolean generateModuleMap = true;
 
   /**
    * Creates a CcLibraryHelper.
@@ -1388,13 +1389,17 @@ public final class CcLibraryHelper {
           featureConfiguration.isEnabled(CppRuleClasses.HEADER_MODULES)
               || featureConfiguration.isEnabled(CppRuleClasses.COMPILE_ALL_MODULES);
       Iterable<CppModuleMap> dependentModuleMaps = collectModuleMaps();
-      Optional<Artifact> umbrellaHeader = cppModuleMap.getUmbrellaHeader();
-      if (umbrellaHeader.isPresent()) {
+
+      if (generateModuleMap) {
+        Optional<Artifact> umbrellaHeader = cppModuleMap.getUmbrellaHeader();
+        if (umbrellaHeader.isPresent()) {
+          ruleContext.registerAction(
+              createUmbrellaHeaderAction(umbrellaHeader.get(), publicHeaders));
+        }
+
         ruleContext.registerAction(
-            createUmbrellaHeaderAction(umbrellaHeader.get(), publicHeaders));
+            createModuleMapAction(cppModuleMap, publicHeaders, dependentModuleMaps, compiled));
       }
-      ruleContext.registerAction(
-          createModuleMapAction(cppModuleMap, publicHeaders, dependentModuleMaps, compiled));
       if (model.getGeneratesPicHeaderModule()) {
         contextBuilder.setPicHeaderModule(model.getPicHeaderModule(cppModuleMap.getArtifact()));
       }
@@ -1594,4 +1599,12 @@ public final class CcLibraryHelper {
   public void registerAdditionalModuleMap(CppModuleMap cppModuleMap) {
     this.additionalCppModuleMaps.add(Preconditions.checkNotNull(cppModuleMap));
   }
+
+  /**
+   * Don't generate a module map for this target if a custom module map is provided.
+   */
+  public CcLibraryHelper doNotGenerateModuleMap() {
+    generateModuleMap = false;
+    return this;
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
index 5945dbc413..39ed3e564c 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
@@ -875,7 +875,7 @@ public abstract class CompilationSupport {
       }
     }
 
-    if (attributes.enableModules()) {
+    if (attributes.enableModules() && !getCustomModuleMap(ruleContext).isPresent()) {
       copts.add("-fmodules");
     }
     if (copts.contains("-fmodules")) {
@@ -1484,4 +1484,11 @@ public abstract class CompilationSupport {
       return null;
     }
   }
+
+  public static Optional<Artifact> getCustomModuleMap(RuleContext ruleContext) {
+    if (ruleContext.attributes().has("module_map", BuildType.LABEL)) {
+      return Optional.fromNullable(ruleContext.getPrerequisiteArtifact("module_map", Mode.TARGET));
+    }
+    return Optional.absent();
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java
index ad0fed4039..ff1d068a54 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java
@@ -464,6 +464,9 @@ public class CrosstoolCompilationSupport extends CompilationSupport {
     if (!useDeps) {
       result.doNotUseDeps();
     }
+    if (getCustomModuleMap(ruleContext).isPresent()) {
+      result.doNotGenerateModuleMap();
+    }
     return result;
   }
 
@@ -490,7 +493,8 @@ public class CrosstoolCompilationSupport extends CompilationSupport {
             .add(isHost ? "host" : "nonhost")
             .add(configuration.getCompilationMode().toString());
 
-    if (configuration.getFragment(ObjcConfiguration.class).moduleMapsEnabled()) {
+    if (configuration.getFragment(ObjcConfiguration.class).moduleMapsEnabled()
+        && !getCustomModuleMap(ruleContext).isPresent()) {
       activatedCrosstoolSelectables.add(OBJC_MODULE_FEATURE_NAME);
     }
     if (!CompilationAttributes.Builder.fromRuleContext(ruleContext).build().enableModules()) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java b/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java
index f6d037b4cb..668790132b 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/IntermediateArtifacts.java
@@ -14,6 +14,7 @@
 
 package com.google.devtools.build.lib.rules.objc;
 
+import com.google.common.base.Optional;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.Root;
 import com.google.devtools.build.lib.analysis.RuleContext;
@@ -440,9 +441,13 @@ public final class IntermediateArtifacts {
             .replace("@", "")
             .replace("/", "_")
             .replace(":", "_");
-    // To get Swift to pick up module maps, we need to name them "module.modulemap" and have their
-    // parent directory in the module map search paths.
-    if (umbrellaHeaderStrategy == UmbrellaHeaderStrategy.GENERATE) {
+ 
+    Optional<Artifact> customModuleMap = CompilationSupport.getCustomModuleMap(ruleContext);
+    if (customModuleMap.isPresent()) {
+      return new CppModuleMap(customModuleMap.get(), moduleName);
+    } else if (umbrellaHeaderStrategy == UmbrellaHeaderStrategy.GENERATE) {
+      // To get Swift to pick up module maps, we need to name them "module.modulemap" and have their
+      // parent directory in the module map search paths.
       return new CppModuleMap(
           appendExtensionInGenfiles(".modulemaps/module.modulemap"),
           appendExtensionInGenfiles(".modulemaps/umbrella.h"),
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/LegacyCompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/LegacyCompilationSupport.java
index 7a703fe818..82de6228ac 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/LegacyCompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/LegacyCompilationSupport.java
@@ -335,7 +335,7 @@ public class LegacyCompilationSupport extends CompilationSupport {
     }
 
     // Add module map arguments.
-    if (moduleMap.isPresent()) {
+    if (moduleMap.isPresent() && !getCustomModuleMap(ruleContext).isPresent()) {
       // If modules are enabled for the rule, -fmodules is added to the copts already. (This implies
       // module map usage). Otherwise, we need to pass -fmodule-maps.
       if (!attributes.enableModules()) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java
index 453776db23..411a7957f7 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcRuleClasses.java
@@ -716,6 +716,15 @@ public class ObjcRuleClasses {
           @import path_to_package_target;
           <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
           .add(attr("enable_modules", BOOLEAN))
+          /* <!-- #BLAZE_RULE($objc_compiling_rule).ATTRIBUTE(module_map) -->
+          A custom Clang module map for this target. Use of a custom module map is discouraged. Most
+          users should use module maps generated by Bazel.
+          If specified, Bazel will not generate a module map for this target, but will pass the
+          provided module map to the compiler.
+          <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
+          .add(
+              attr("module_map", LABEL)
+                  .allowedFileTypes(FileType.of(".modulemap")))
           /* Provides the label for header_scanner tool that is used to scan inclusions for ObjC
           sources and provide a list of required headers via a .header_list file.