Remove the flag `incompatible_no_kwargs_in_build_files`.

 https://github.com/bazelbuild/bazel/issues/8021

RELNOTES: None.
PiperOrigin-RevId: 253049309
diff --git a/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java b/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java
index 46c45e8..939711f 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/StarlarkSemanticsOptions.java
@@ -491,20 +491,6 @@
   public boolean incompatibleNoTransitiveLoads;
 
   @Option(
-      name = "incompatible_no_kwargs_in_build_files",
-      defaultValue = "true",
-      documentationCategory = OptionDocumentationCategory.STARLARK_SEMANTICS,
-      effectTags = {OptionEffectTag.BUILD_FILE_SEMANTICS},
-      metadataTags = {
-        OptionMetadataTag.INCOMPATIBLE_CHANGE,
-        OptionMetadataTag.TRIGGERED_BY_ALL_INCOMPATIBLE_CHANGES
-      },
-      help =
-          "If set to true, *args and **kwargs are not allowed in BUILD files. See "
-              + "https://github.com/bazelbuild/bazel/issues/8021")
-  public boolean incompatibleNoKwargsInBuildFiles;
-
-  @Option(
       name = "incompatible_remap_main_repo",
       defaultValue = "false",
       documentationCategory = OptionDocumentationCategory.STARLARK_SEMANTICS,
@@ -645,7 +631,6 @@
         .incompatibleExpandDirectories(incompatibleExpandDirectories)
         .incompatibleNewActionsApi(incompatibleNewActionsApi)
         .incompatibleNoAttrLicense(incompatibleNoAttrLicense)
-        .incompatibleNoKwargsInBuildFiles(incompatibleNoKwargsInBuildFiles)
         .incompatibleNoOutputAttrDefault(incompatibleNoOutputAttrDefault)
         .incompatibleNoRuleOutputsParam(incompatibleNoRuleOutputsParam)
         .incompatibleNoSupportToolsInActionInputs(incompatibleNoSupportToolsInActionInputs)
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java b/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java
index 9c955dd..cd4f402 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/StarlarkSemantics.java
@@ -175,8 +175,6 @@
 
   public abstract boolean incompatibleNoAttrLicense();
 
-  public abstract boolean incompatibleNoKwargsInBuildFiles();
-
   public abstract boolean incompatibleNoOutputAttrDefault();
 
   public abstract boolean incompatibleNoRuleOutputsParam();
@@ -261,7 +259,6 @@
           .incompatibleExpandDirectories(true)
           .incompatibleNewActionsApi(true)
           .incompatibleNoAttrLicense(true)
-          .incompatibleNoKwargsInBuildFiles(true)
           .incompatibleNoOutputAttrDefault(true)
           .incompatibleNoRuleOutputsParam(false)
           .incompatibleNoSupportToolsInActionInputs(true)
@@ -336,8 +333,6 @@
 
     public abstract Builder incompatibleNewActionsApi(boolean value);
 
-    public abstract Builder incompatibleNoKwargsInBuildFiles(boolean value);
-
     public abstract Builder incompatibleNoAttrLicense(boolean value);
 
     public abstract Builder incompatibleNoOutputAttrDefault(boolean value);
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java b/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
index 6233bfd..ada8a87 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
@@ -460,9 +460,7 @@
                         + "explicitly.");
               }
             }
-            if (env.getSemantics().incompatibleNoKwargsInBuildFiles()) {
-              super.visit(node);
-            }
+            super.visit(node);
           }
         };
     checker.visitAll(statements);
diff --git a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
index 86f9ccc..a7d4a66 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
@@ -153,7 +153,6 @@
         "--incompatible_expand_directories=" + rand.nextBoolean(),
         "--incompatible_new_actions_api=" + rand.nextBoolean(),
         "--incompatible_no_attr_license=" + rand.nextBoolean(),
-        "--incompatible_no_kwargs_in_build_files=" + rand.nextBoolean(),
         "--incompatible_no_output_attr_default=" + rand.nextBoolean(),
         "--incompatible_no_rule_outputs_param=" + rand.nextBoolean(),
         "--incompatible_no_support_tools_in_action_inputs=" + rand.nextBoolean(),
@@ -206,7 +205,6 @@
         .incompatibleExpandDirectories(rand.nextBoolean())
         .incompatibleNewActionsApi(rand.nextBoolean())
         .incompatibleNoAttrLicense(rand.nextBoolean())
-        .incompatibleNoKwargsInBuildFiles(rand.nextBoolean())
         .incompatibleNoOutputAttrDefault(rand.nextBoolean())
         .incompatibleNoRuleOutputsParam(rand.nextBoolean())
         .incompatibleNoSupportToolsInActionInputs(rand.nextBoolean())
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
index b06623c..d199a91 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
@@ -705,6 +705,10 @@
   public void testKwargsForbiddenInBuild() throws Exception {
     new BuildTest()
         .testIfErrorContains("**kwargs arguments are not allowed in BUILD files", "print(**dict)");
+
+    new BuildTest()
+        .testIfErrorContains(
+            "**kwargs arguments are not allowed in BUILD files", "len(dict(**{'a': 1}))");
   }
 
   @Test
@@ -712,17 +716,4 @@
     new BuildTest()
         .testIfErrorContains("*args arguments are not allowed in BUILD files", "print(*['a'])");
   }
-
-  @Test
-  public void testIncompatibleKwargsInBuildFiles() throws Exception {
-    new BuildTest("--incompatible_no_kwargs_in_build_files=true")
-        .testIfErrorContains(
-            "kwargs arguments are not allowed in BUILD files", "len(dict(**{'a': 1}))");
-
-    new BuildTest("--incompatible_no_kwargs_in_build_files=false")
-        .testStatement("len(dict(**{'a': 1}))", 1);
-
-    new SkylarkTest("--incompatible_no_kwargs_in_build_files")
-        .testStatement("len(dict(**{'a': 1}))", 1);
-  }
 }