Support private values in GN.

tools/gn/scope_unittest.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/input_file.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/scope.h"
 #include "tools/gn/test_with_scope.h"
 
@@ skipping 18 matching lines @@
   // Make a pretend parse node with proper tracking that we can blame for the
   // given value.
   InputFile input_file(SourceFile("//foo"));
   Token assignment_token(Location(&input_file, 1, 1), Token::STRING,
       "\"hello\"");
   LiteralNode assignment;
   assignment.set_value(assignment_token);
 
   Value old_value(&assignment, "hello");
   setup.scope()->SetValue("v", old_value, &assignment);
+  base::StringPiece private_var_name("_private");
+  setup.scope()->SetValue(private_var_name, old_value, &assignment);
 
   // Detect collisions of values' values.
   {
     Scope new_scope(setup.settings());
     Value new_value(&assignment, "goodbye");
     new_scope.SetValue("v", new_value, &assignment);
 
     Err err;
     EXPECT_FALSE(setup.scope()->NonRecursiveMergeTo(
-        &new_scope, false, &assignment, "error", &err));
+        &new_scope, Scope::MergeOptions(),
+        &assignment, "error", &err));
     EXPECT_TRUE(err.has_error());
   }
 
   // The clobber flag should just overwrite colliding values.
   {
     Scope new_scope(setup.settings());
     Value new_value(&assignment, "goodbye");
     new_scope.SetValue("v", new_value, &assignment);
 
     Err err;
+    Scope::MergeOptions options;
+    options.clobber_existing = true;
     EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
-        &new_scope, true, &assignment, "error", &err));
+        &new_scope, options, &assignment, "error", &err));
     EXPECT_FALSE(err.has_error());
 
     const Value* found_value = new_scope.GetValue("v");
     ASSERT_TRUE(found_value);
     EXPECT_TRUE(old_value == *found_value);
   }
 
   // Don't flag values that technically collide but have the same value.
   {
     Scope new_scope(setup.settings());
     Value new_value(&assignment, "hello");
     new_scope.SetValue("v", new_value, &assignment);
 
     Err err;
+    Scope::MergeOptions options;
+    options.clobber_existing = true;
     EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
-        &new_scope, false, &assignment, "error", &err));
+        &new_scope, options, &assignment, "error", &err));
     EXPECT_FALSE(err.has_error());
   }
+
+  // Copy private values.
+  {
+    Scope new_scope(setup.settings());
+
+    Err err;
+    EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
+        &new_scope, Scope::MergeOptions(), &assignment, "error", &err));
+    EXPECT_FALSE(err.has_error());
+    EXPECT_TRUE(new_scope.GetValue(private_var_name));
+  }
+
+  // Skip private values.
+  {
+    Scope new_scope(setup.settings());
+
+    Err err;
+    Scope::MergeOptions options;
+    options.copy_private_vars = false;
+    EXPECT_TRUE(setup.scope()->NonRecursiveMergeTo(
+        &new_scope, options, &assignment, "error", &err));
+    EXPECT_FALSE(err.has_error());
+    EXPECT_FALSE(new_scope.GetValue(private_var_name));
+  }
 }
 
 TEST(Scope, MakeClosure) {
   // Create 3 nested scopes [const root from setup] <- nested1 <- nested2.
   TestWithScope setup;
 
   // Make a pretend parse node with proper tracking that we can blame for the
   // given value.
   InputFile input_file(SourceFile("//foo"));
   Token assignment_token(Location(&input_file, 1, 1), Token::STRING,
@@ skipping 71 matching lines @@
   mutable1_result = mutable_scope2.GetMutableValue(kOnMutable1, true);
   EXPECT_TRUE(mutable1_result);
   err = Err();
   EXPECT_TRUE(mutable_scope1.CheckForUnusedVars(&err));
 
   // Test reading a value from scope 2.
   Value* mutable2_result = mutable_scope2.GetMutableValue(kOnMutable2, true);
   ASSERT_TRUE(mutable2_result);
   EXPECT_TRUE(*mutable2_result == value);
 }