Add "bundle_data" target as first step for adding bundle support to gn.

tools/gn/bundle_data_target_generator.cc

+// Copyright 2016 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/bundle_data_target_generator.h"
+
+#include "tools/gn/parse_tree.h"
+#include "tools/gn/scope.h"
+#include "tools/gn/substitution_type.h"
+#include "tools/gn/target.h"
+#include "tools/gn/value.h"
+#include "tools/gn/variables.h"
+
+BundleDataTargetGenerator::BundleDataTargetGenerator(
+    Target* target,
+    Scope* scope,
+    const FunctionCallNode* function_call,
+    Err* err) : TargetGenerator(target, scope, function_call, err) {}
+
+BundleDataTargetGenerator::~BundleDataTargetGenerator() {}
+
+void BundleDataTargetGenerator::DoRun() {
+  target_->set_output_type(Target::BUNDLE_DATA);
+
+  if (!FillSources())
+    return;
+  if (!FillOutputs())
+    return;
+
+  if (target_->sources().empty()) {
+    *err_ = Err(function_call_, "Empty sources for bundle_data target."
+        "You have to specify at least one file in the \"sources\".");
+    return;
+  }
+  if (target_->action_values().outputs().list().size() != 1) {
+    *err_ = Err(function_call_,
+        "Target bundle_data must have exactly one ouput.",
+        "You must specify exactly one value in the \"output\" array for the"
+        "destination\ninto the generated bundle (see \"gn help bundle_data\"). "
+        "If there are multiple\nsources to copy, use source expansion (see "
+        "\"gn help source_expansion\").");
+    return;
+  }
+}
+
+bool BundleDataTargetGenerator::FillOutputs() {
+  const Value* value = scope_->GetValue(variables::kOutputs, true);
+  if (!value)
+    return true;
+
+  SubstitutionList& outputs = target_->action_values().outputs();
+  if (!outputs.Parse(*value, err_))
+    return false;
+
+  // Check the substitutions used are valid for this purpose.
+  for (SubstitutionType type : outputs.required_types()) {
+    if (!IsValidBundleDataSubstitution(type)) {
+      *err_ = Err(value->origin(), "Invalid substitution type.",
+          "The substitution " + std::string(kSubstitutionNames[type]) +
+          " isn't valid for something\n"
+          "operating on a bundle_data file such as this.");
+      return false;
+    }
+  }
+
+  // Validate that outputs are in the bundle.
+  CHECK(outputs.list().size() == value->list_value().size());
+  for (size_t i = 0; i < outputs.list().size(); i++) {
+    if (!EnsureSubstitutionIsInBundleDir(outputs.list()[i],
+                                         value->list_value()[i]))
+      return false;
+  }
+
+  return true;
+}
+
+bool BundleDataTargetGenerator::EnsureSubstitutionIsInBundleDir(
+    const SubstitutionPattern& pattern,
+    const Value& original_value) {
+  if (pattern.ranges().empty()) {
+    // Pattern is empty, error out (this prevents weirdness below).
+    *err_ = Err(original_value, "This has an empty value in it.");
+    return false;
+  }
+
+  if (SubstitutionIsInBundleDir(pattern.ranges()[0].type))
+    return true;
+
+  *err_ = Err(original_value,
+      "File is not inside bundle directory.",
+      "The given file should be in the output directory. Normally you\n"
+      "would specify {{bundle_resources_dir}} or such substitution.");
+  return false;
+}