Distinguish between user-supplied ios_cpu and the default, and don't propagate the default to the XCode project control.

--
MOS_MIGRATED_REVID=101644957

3 files changed, 47 insertions, 5 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommandLineOptions.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommandLineOptions.java
index 047fd3c7d9..550aaea0a5 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommandLineOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcCommandLineOptions.java
@@ -15,6 +15,8 @@
 package com.google.devtools.build.lib.rules.objc;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Multimap;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration.LabelConverter;
@@ -58,10 +60,11 @@ public class ObjcCommandLineOptions extends FragmentOptions {
           + "on the machine the simulator will be run on.")
   public String iosSimulatorDevice;
 
+  // TODO(bazel-team): Consider using optional for values like these.
   @Option(name = "ios_cpu",
-      defaultValue = DEFAULT_IOS_CPU,
+      defaultValue = "",
       category = "build",
-      help = "Specifies to target CPU of iOS compilation.")
+      help = "The target CPU for iOS compilation.")
   public String iosCpu;
 
   @Option(name = "xcode_options",
@@ -179,13 +182,33 @@ public class ObjcCommandLineOptions extends FragmentOptions {
     }
   }
 
+  /**
+   * Returns the value of the ios_cpu flag, or a default value if none was specified.
+   */
+  public String getIosCpu() {
+    if ("".equals(iosCpu)) {
+      return DEFAULT_IOS_CPU;
+    } else {
+      return iosCpu;
+    }
+  }
+
+  /**
+   * Returns the value of the ios_cpu flag, if it was specified.
+   * This is to distinguish between the default cpu used by the build tools and the cpu explicitly
+   * requested by user configuration.
+   */
+  public Optional<String> getConfiguredIosCpu() {
+    return Strings.isNullOrEmpty(iosCpu) ? Optional.<String>absent() : Optional.of(iosCpu);
+  }
+
   private Platform getPlatform() {
     for (String architecture : iosMultiCpus) {
       if (Platform.forArch(architecture) == Platform.DEVICE) {
         return Platform.DEVICE;
       }
     }
-    return Platform.forArch(iosCpu);
+    return Platform.forArch(getIosCpu());
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
index 8741f6784a..7f450114e1 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcConfiguration.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.rules.objc;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
+import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
@@ -53,6 +54,7 @@ public class ObjcConfiguration extends BuildConfiguration.Fragment {
   private final String iosSimulatorVersion;
   private final String iosSimulatorDevice;
   private final String iosCpu;
+  private final Optional<String> configuredIosCpu;
   private final String xcodeOptions;
   private final boolean generateDebugSymbols;
   private final boolean runMemleaks;
@@ -84,7 +86,9 @@ public class ObjcConfiguration extends BuildConfiguration.Fragment {
         Preconditions.checkNotNull(objcOptions.iosSimulatorDevice, "iosSimulatorDevice");
     this.iosSimulatorVersion =
         Preconditions.checkNotNull(objcOptions.iosSimulatorVersion, "iosSimulatorVersion");
-    this.iosCpu = Preconditions.checkNotNull(objcOptions.iosCpu, "iosCpu");
+    this.iosCpu = Preconditions.checkNotNull(objcOptions.getIosCpu(), "iosCpu");
+    this.configuredIosCpu =
+        Preconditions.checkNotNull(objcOptions.getConfiguredIosCpu(), "configuredIosCpu");
     this.xcodeOptions = Preconditions.checkNotNull(objcOptions.xcodeOptions, "xcodeOptions");
     this.generateDebugSymbols = objcOptions.generateDebugSymbols;
     this.runMemleaks = objcOptions.runMemleaks;
@@ -126,11 +130,22 @@ public class ObjcConfiguration extends BuildConfiguration.Fragment {
     return iosSimulatorVersion;
   }
 
+  /**
+   * Returns the ios_cpu value to use.
+   */
   public String getIosCpu() {
     return iosCpu;
   }
 
   /**
+   * Returns the ios_cpu value set by the configuration (that is, by a command-line flag
+   * or by an ios_multi_cpu split configuration), if it is present.
+   */
+  public Optional<String> getConfiguredIosCpu() {
+    return configuredIosCpu;
+  }
+
+  /**
    * Returns the platform of the configuration for the current bundle, based on configured
    * architectures (for example, {@code i386} maps to {@link Platform#SIMULATOR}).
    *
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/XcodeSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/XcodeSupport.java
index 45f9726009..d0015fcd70 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/XcodeSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/XcodeSupport.java
@@ -234,7 +234,11 @@ public final class XcodeSupport {
 
         List<String> multiCpus = objcConfiguration.getIosMultiCpus();
         if (multiCpus.isEmpty()) {
-          builder.addCpuArchitecture(objcConfiguration.getIosCpu());
+          // Only add a CPU architecture if one was explicitly configured.
+          // Otherwise, the XCode generation tools will supply a default for XCode.
+          if (objcConfiguration.getConfiguredIosCpu().isPresent()) {
+            builder.addCpuArchitecture(objcConfiguration.getConfiguredIosCpu().get());
+          }
         } else {
           builder.addAllCpuArchitecture(multiCpus);
         }