Allow a config_setting() to match against the default grte_top.

--
MOS_MIGRATED_REVID=124792198

2 files changed, 14 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java
index dd1b3da2a7..0d60a44401 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppOptions.java
@@ -107,6 +107,13 @@ public class CppOptions extends FragmentOptions {
   public static class LibcTopConverter implements Converter<LibcTop> {
     @Override
     public LibcTop convert(String input) throws OptionsParsingException {
+      if (input.equals("default")) {
+        // This is needed for defining config_setting() values, the syntactic form
+        // of which must be a String, to match absence of a --grte_top option.
+        // "--grte_top=default" works on the command-line too,
+        // but that's an inconsequential side-effect, not the intended purpose.
+        return null;
+      }
       if (!input.startsWith("//")) {
         throw new OptionsParsingException("Not a label");
       }
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/config/ConfigSettingTest.java b/src/test/java/com/google/devtools/build/lib/analysis/config/ConfigSettingTest.java
index f5e9543acd..3005c077be 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/config/ConfigSettingTest.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/config/ConfigSettingTest.java
@@ -245,6 +245,13 @@ public class ConfigSettingTest extends BuildViewTestCase {
   }
 
   @Test
+  public void testSelectForDefaultGrteTop() throws Exception {
+    scratchConfiguredTarget("a", "a",
+        "config_setting(name='cs', values={'grte_top': 'default'})",
+        "sh_library(name='a', srcs=['a.sh'], deps=select({':cs': []}))");
+  }
+
+  @Test
   public void testRequiredConfigFragmentMatcher() throws Exception {
     scratch.file("test/BUILD",
         "config_setting(",