Support more configurability in GN toolchains

tools/gn/escape.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/escape.h"
 
 #include "base/containers/stack_container.h"
 #include "base/logging.h"
 
 namespace {
@@ skipping 30 matching lines @@
 
 template<typename DestString>
 void EscapeStringToString_Ninja(const base::StringPiece& str,
                                 const EscapeOptions& options,
                                 DestString* dest,
                                 bool* needed_quoting) {
   for (size_t i = 0; i < str.size(); i++)
     NinjaEscapeChar(str[i], dest);
 }
 
+template<typename DestString>
+void EscapeStringToString_NinjaPreformatted(const base::StringPiece& str,
+                                            DestString* dest) {
+  // Only Ninja-escape $.
+  for (size_t i = 0; i < str.size(); i++) {
+    if (str[i] == '$')
+      dest->push_back('$');
+    dest->push_back(str[i]);
+  }
+}
+
 // Escape for CommandLineToArgvW and additionally escape Ninja characters.
 //
 // The basic algorithm is if the string doesn't contain any parse-affecting
 // characters, don't do anything (other than the Ninja processing). If it does,
 // quote the string, and backslash-escape all quotes and backslashes.
 // See:
 //   http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx
 //   http://blogs.msdn.com/b/oldnewthing/archive/2010/09/17/10063629.aspx
 template<typename DestString>
 void EscapeStringToString_WindowsNinjaFork(const base::StringPiece& str,
@@ skipping 98 matching lines @@
                                                 needed_quoting);
           break;
         case ESCAPE_PLATFORM_POSIX:
           EscapeStringToString_PosixNinjaFork(str, options, dest,
                                               needed_quoting);
           break;
         default:
           NOTREACHED();
       }
       break;
+    case ESCAPE_NINJA_PREFORMATTED_COMMAND:
+      EscapeStringToString_NinjaPreformatted(str, dest);
+      break;
     default:
       NOTREACHED();
   }
 }
 
 }  // namespace
 
 std::string EscapeString(const base::StringPiece& str,
                          const EscapeOptions& options,
                          bool* needed_quoting) {
   std::string result;
   result.reserve(str.size() + 4);  // Guess we'll add a couple of extra chars.
   EscapeStringToString(str, options, &result, needed_quoting);
   return result;
 }
 
 void EscapeStringToStream(std::ostream& out,
                           const base::StringPiece& str,
                           const EscapeOptions& options) {
   base::StackString<256> escaped;
   EscapeStringToString(str, options, &escaped.container(), NULL);
   if (!escaped->empty())
     out.write(escaped->data(), escaped->size());
 }