[GN] Add support for generating Xcode projects.

tools/gn/commands.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/commands.h"
 
 #include "base/command_line.h"
+#include "base/strings/string_split.h"
 #include "tools/gn/builder.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/item.h"
 #include "tools/gn/label.h"
 #include "tools/gn/label_pattern.h"
 #include "tools/gn/setup.h"
 #include "tools/gn/standard_out.h"
 #include "tools/gn/target.h"
 
 namespace commands {
@@ skipping 443 matching lines @@
   for (const auto& target : input) {
     for (const auto& pattern : filter) {
       if (pattern.Matches(target->label())) {
         output->push_back(target);
         break;
       }
     }
   }
 }
 
+bool FilterPatternsFromString(const BuildSettings* build_settings,
+                              const std::string& label_list_string,
+                              std::vector<LabelPattern>* filters,
+                              Err* err) {
+  std::vector<std::string> tokens = base::SplitString(
+      label_list_string, ";", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+  SourceDir root_dir =
+      SourceDirForCurrentDirectory(build_settings->root_path());
+
+  filters->reserve(tokens.size());
+  for (const std::string& token : tokens) {
+    LabelPattern pattern =
+        LabelPattern::GetPattern(root_dir, Value(nullptr, token), err);
+    if (err->has_error())
+      return false;
+    filters->push_back(pattern);
+  }
+
+  return true;
+}
+
 void FilterAndPrintTargets(bool indent, std::vector<const Target*>* targets) {
   if (targets->empty())
     return;
 
   if (!ApplyTestonlyFilter(targets))
     return;
   if (!ApplyTypeFilter(targets))
     return;
 
   TargetPrintingMode printing_mode = TARGET_PRINT_LABEL;
@@ skipping 12 matching lines @@
   }
 }
 
 void FilterAndPrintTargetSet(bool indent,
                              const std::set<const Target*>& targets) {
   std::vector<const Target*> target_vector(targets.begin(), targets.end());
   FilterAndPrintTargets(indent, &target_vector);
 }
 
 }  // namespace commands