Add an output_dir override to GN.

tools/gn/binary_target_generator.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/binary_target_generator.h"
 
 #include "tools/gn/config_values_generator.h"
 #include "tools/gn/deps_iterator.h"
 #include "tools/gn/err.h"
+#include "tools/gn/filesystem_utils.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/scope.h"
+#include "tools/gn/settings.h"
 #include "tools/gn/value_extractors.h"
 #include "tools/gn/variables.h"
 
 BinaryTargetGenerator::BinaryTargetGenerator(
     Target* target,
     Scope* scope,
     const FunctionCallNode* function_call,
     Target::OutputType type,
     Err* err)
     : TargetGenerator(target, scope, function_call, err),
       output_type_(type) {
 }
 
 BinaryTargetGenerator::~BinaryTargetGenerator() {
 }
 
 void BinaryTargetGenerator::DoRun() {
   target_->set_output_type(output_type_);
 
   if (!FillOutputName())
     return;
 
   if (!FillOutputPrefixOverride())
     return;
 
+  if (!FillOutputDir())
+    return;
+
   if (!FillOutputExtension())
     return;
 
   if (!FillSources())
     return;
 
   if (!FillPublic())
     return;
 
   if (!FillCheckIncludes())
@@ skipping 44 matching lines @@
 bool BinaryTargetGenerator::FillOutputPrefixOverride() {
   const Value* value = scope_->GetValue(variables::kOutputPrefixOverride, true);
   if (!value)
     return true;
   if (!value->VerifyTypeIs(Value::BOOLEAN, err_))
     return false;
   target_->set_output_prefix_override(value->boolean_value());
   return true;
 }
 
+bool BinaryTargetGenerator::FillOutputDir() {
+  const Value* value = scope_->GetValue(variables::kOutputDir, true);
+  if (!value)
+    return true;
+  if (!value->VerifyTypeIs(Value::STRING, err_))
+    return false;
+
+  if (value->string_value().empty())
+    return true;  // Treat empty string as the default and do nothing.
+
+  const BuildSettings* build_settings = scope_->settings()->build_settings();
+  SourceDir dir = scope_->GetSourceDir().ResolveRelativeDir(
+      *value, err_, build_settings->root_path_utf8());
+  if (err_->has_error())
+    return false;
+
+  if (!EnsureStringIsInOutputDir(build_settings->build_dir(),
+                                 dir.value(), value->origin(), err_))
+    return false;
+  target_->set_output_dir(dir);
+  return true;
+}
+
 bool BinaryTargetGenerator::FillOutputExtension() {
   const Value* value = scope_->GetValue(variables::kOutputExtension, true);
   if (!value)
     return true;
   if (!value->VerifyTypeIs(Value::STRING, err_))
     return false;
   target_->set_output_extension(value->string_value());
   return true;
 }
 
@@ skipping 26 matching lines @@
           "deps.");
       return false;
     }
   }
 
   // Add to the set.
   for (const auto& cur : circular)
     target_->allow_circular_includes_from().insert(cur);
   return true;
 }