Template invocation fixes in GN

tools/gn/scope_per_file_provider.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 "tools/gn/scope_per_file_provider.h"
 
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/source_file.h"
 #include "tools/gn/value.h"
 #include "tools/gn/variables.h"
 
-ScopePerFileProvider::ScopePerFileProvider(Scope* scope)
-    : ProgrammaticProvider(scope) {
+ScopePerFileProvider::ScopePerFileProvider(Scope* scope,
+                                           bool allow_target_vars)
+    : ProgrammaticProvider(scope),
+      allow_target_vars_(allow_target_vars) {
 }
 
 ScopePerFileProvider::~ScopePerFileProvider() {
 }
 
 const Value* ScopePerFileProvider::GetProgrammaticValue(
     const base::StringPiece& ident) {
   if (ident == variables::kCurrentToolchain)
     return GetCurrentToolchain();
   if (ident == variables::kDefaultToolchain)
     return GetDefaultToolchain();
   if (ident == variables::kPythonPath)
     return GetPythonPath();
 
   if (ident == variables::kRootBuildDir)
     return GetRootBuildDir();
   if (ident == variables::kRootGenDir)
     return GetRootGenDir();
   if (ident == variables::kRootOutDir)
     return GetRootOutDir();
-  if (ident == variables::kTargetGenDir)
-    return GetTargetGenDir();
-  if (ident == variables::kTargetOutDir)
-    return GetTargetOutDir();
+
+  if (allow_target_vars_) {
+    if (ident == variables::kTargetGenDir)
+      return GetTargetGenDir();
+    if (ident == variables::kTargetOutDir)
+      return GetTargetOutDir();
+  }
   return NULL;
 }
 
 const Value* ScopePerFileProvider::GetCurrentToolchain() {
   if (!current_toolchain_) {
     current_toolchain_.reset(new Value(NULL,
         scope_->settings()->toolchain_label().GetUserVisibleName(false)));
   }
   return current_toolchain_.get();
 }
@@ skipping 47 matching lines @@
   return target_gen_dir_.get();
 }
 
 const Value* ScopePerFileProvider::GetTargetOutDir() {
   if (!target_out_dir_) {
     target_out_dir_.reset(new Value(NULL,
         DirectoryWithNoLastSlash(GetCurrentOutputDir(scope_))));
   }
   return target_out_dir_.get();
 }