Add an assert_no_deps variable to GN.

tools/gn/value_extractors.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/value_extractors.h"
 
 #include <stddef.h>
 
 #include "tools/gn/build_settings.h"
 #include "tools/gn/err.h"
@@ skipping 126 matching lines @@
     if (!v.VerifyTypeIs(Value::STRING, err))
       return false;
     out->label = Label::Resolve(current_dir, current_toolchain, v, err);
     out->origin = v.origin();
     return !err->has_error();
   }
   const SourceDir& current_dir;
   const Label& current_toolchain;
 };
 
+struct LabelPatternResolver {
+  LabelPatternResolver(const SourceDir& current_dir_in)
+      : current_dir(current_dir_in) {
+  }
+  bool operator()(const Value& v, LabelPattern* out, Err* err) const {
+    *out = LabelPattern::GetPattern(current_dir, v, err);
+    return !err->has_error();
+  }
+  const SourceDir& current_dir;
+};
+
 }  // namespace
 
 bool ExtractListOfStringValues(const Value& value,
                                std::vector<std::string>* dest,
                                Err* err) {
   if (!value.VerifyTypeIs(Value::LIST, err))
     return false;
   const std::vector<Value>& input_list = value.list_value();
   dest->reserve(input_list.size());
   for (const auto& item : input_list) {
@@ skipping 72 matching lines @@
 }
 
 bool ExtractRelativeFile(const BuildSettings* build_settings,
                          const Value& value,
                          const SourceDir& current_dir,
                          SourceFile* file,
                          Err* err) {
   RelativeFileConverter converter(build_settings, current_dir);
   return converter(value, file, err);
 }
+
+bool ExtractListOfLabelPatterns(const Value& value,
+                                const SourceDir& current_dir,
+                                std::vector<LabelPattern>* patterns,
+                                Err* err) {
+  return ListValueExtractor(value, patterns, err,
+                            LabelPatternResolver(current_dir));
+}