1 files changed, 15 insertions, 9 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/apple/XcodeConfig.java b/src/main/java/com/google/devtools/build/lib/rules/apple/XcodeConfig.java
index d2b5859ef9..fed295e6fc 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/apple/XcodeConfig.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/apple/XcodeConfig.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.rules.apple;
 
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
 import com.google.devtools.build.lib.analysis.ConfiguredTarget;
@@ -171,7 +172,7 @@ public class XcodeConfig implements RuleConfiguredTargetFactory {
    */
   static XcodeVersionProperties resolveXcodeVersion(
       boolean requireDefinedVersions,
-      DottedVersion xcodeVersionOverrideFlag,
+      String xcodeVersionOverrideFlag,
       Iterable<XcodeVersionRuleData> xcodeVersions,
       @Nullable XcodeVersionRuleData defaultVersion)
       throws XcodeConfigException {
@@ -180,11 +181,16 @@ public class XcodeConfig implements RuleConfiguredTargetFactory {
 
     if (xcodeVersion != null) {
       return xcodeVersion.getXcodeVersionProperties();
-    } else if (xcodeVersionOverrideFlag != null) {
-      return new XcodeVersionProperties(xcodeVersionOverrideFlag);
-    } else {
-      return XcodeVersionProperties.unknownXcodeVersionProperties();
     }
+    // TODO(b/64576392): Remove this fallback logic. An xcode_version target should be explicitly
+    // matched in all cases where --xcode_version is specified.
+    try {
+      DottedVersion dottedVersion = DottedVersion.fromString(xcodeVersionOverrideFlag);
+      return new XcodeVersionProperties(dottedVersion);
+    } catch (IllegalArgumentException e) {
+      // The --xcode_version flag is not a valid DottedVersion, so there is nothing to go on.
+    }
+    return XcodeVersionProperties.unknownXcodeVersionProperties();
   }
 
   /**
@@ -200,16 +206,16 @@ public class XcodeConfig implements RuleConfiguredTargetFactory {
       boolean requireDefinedVersions,
       Iterable<XcodeVersionRuleData> xcodeVersionRules,
       @Nullable XcodeVersionRuleData defaultVersion,
-      DottedVersion versionOverrideFlag)
+      String versionOverrideFlag)
       throws XcodeConfigException {
 
     Map<String, XcodeVersionRuleData> aliasesToVersionMap = aliasesToVersionMap(xcodeVersionRules);
 
-    if (versionOverrideFlag != null) {
+    if (!Strings.isNullOrEmpty(versionOverrideFlag)) {
       // The version override flag is not necessarily an actual version - it may be a version
       // alias.
       XcodeVersionRuleData explicitVersion =
-          aliasesToVersionMap.get(versionOverrideFlag.toString());
+          aliasesToVersionMap.get(versionOverrideFlag);
       if (explicitVersion != null) {
         return explicitVersion;
       }
@@ -217,7 +223,7 @@ public class XcodeConfig implements RuleConfiguredTargetFactory {
       // No override specified. Use default.
       return defaultVersion;
     }
-    
+
     if (requireDefinedVersions) {
       throw new XcodeConfigException(
           "xcode version config required an explicitly defined version, but none was available");