Add the LABEL_KEYED_STRING_DICT type for attributes.

This enables both native and Skylark rules to declare attributes which
have labels/Targets as keys, and have string values.

--
PiperOrigin-RevId: 148365033
MOS_MIGRATED_REVID=148365033

1 files changed, 3 insertions, 2 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/syntax/TypeTest.java b/src/test/java/com/google/devtools/build/lib/syntax/TypeTest.java
index a0e36fc7bd..a4e42c7a32 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/TypeTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/TypeTest.java
@@ -493,7 +493,8 @@ public class TypeTest {
       Type.STRING_DICT.convert("some string", null);
       fail();
     } catch (ConversionException e) {
-      assertThat(e).hasMessage("Expected a map for dictionary but got a java.lang.String");
+      assertThat(e).hasMessage(
+          "expected value of type 'dict(string, string)', but got \"some string\" (string)");
     }
   }
 
@@ -509,4 +510,4 @@ public class TypeTest {
     }, value);
     return result.build();
   }
-}
\ No newline at end of file
+}