tools/gn/function_process_file_template.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "tools/gn/functions.h"
   6 #include "tools/gn/parse_tree.h"
   7 #include "tools/gn/scope.h"
   8 #include "tools/gn/settings.h"
   9 #include "tools/gn/substitution_list.h"
  10 #include "tools/gn/substitution_writer.h"
  11 #include "tools/gn/target.h"
  12 #include "tools/gn/value_extractors.h"
  13
  14 namespace functions {
  15
  16 const char kProcessFileTemplate[] = "process_file_template";
  17 const char kProcessFileTemplate_HelpShort[] =
  18     "process_file_template: Do template expansion over a list of files.";
  19 const char kProcessFileTemplate_Help[] =
  20     "process_file_template: Do template expansion over a list of files.\n"
  21     "\n"
  22     "  process_file_template(source_list, template)\n"
  23     "\n"
  24     "  process_file_template applies a template list to a source file list,\n"
  25     "  returning the result of applying each template to each source. This is\n"
  26     "  typically used for computing output file names from input files.\n"
  27     "\n"
  28     "  In most cases, get_target_outputs() will give the same result with\n"
  29     "  shorter, more maintainable code. This function should only be used\n"
  30     "  when that function can't be used (like there's no target or the target\n"
  31     "  is defined in another build file).\n"
  32     "\n"
  33     "Arguments:\n"
  34     "\n"
  35     "  The source_list is a list of file names.\n"
  36     "\n"
  37     "  The template can be a string or a list. If it is a list, multiple\n"
  38     "  output strings are generated for each input.\n"
  39     "\n"
  40     "  The template should contain source expansions to which each name in\n"
  41     "  the source list is applied. See \"gn help source_expansion\".\n"
  42     "\n"
  43     "Example:\n"
  44     "\n"
  45     "  sources = [\n"
  46     "    \"foo.idl\",\n"
  47     "    \"bar.idl\",\n"
  48     "  ]\n"
  49     "  myoutputs = process_file_template(\n"
  50     "      sources,\n"
  51     "      [ \"$target_gen_dir/{{source_name_part}}.cc\",\n"
  52     "        \"$target_gen_dir/{{source_name_part}}.h\" ])\n"
  53     "\n"
  54     " The result in this case will be:\n"
  55     "    [ \"//out/Debug/foo.cc\"\n"
  56     "      \"//out/Debug/foo.h\"\n"
  57     "      \"//out/Debug/bar.cc\"\n"
  58     "      \"//out/Debug/bar.h\" ]\n";
  59
  60 Value RunProcessFileTemplate(Scope* scope,
  61                              const FunctionCallNode* function,
  62                              const std::vector<Value>& args,
  63                              Err* err) {
  64   if (args.size() != 2) {
  65     *err = Err(function->function(), "Expected two arguments");
  66     return Value();
  67   }
  68
  69   // Source list.
  70   Target::FileList input_files;
  71   if (!ExtractListOfRelativeFiles(scope->settings()->build_settings(), args[0],
  72                                   scope->GetSourceDir(), &input_files, err))
  73     return Value();
  74
  75   std::vector<std::string> result_files;
  76   SubstitutionList subst;
  77
  78   // Template.
  79   const Value& template_arg = args[1];
  80   if (template_arg.type() == Value::STRING) {
  81     // Convert the string to a SubstitutionList with one pattern in it to
  82     // simplify the code below.
  83     std::vector<std::string> list;
  84     list.push_back(template_arg.string_value());
  85     if (!subst.Parse(list, template_arg.origin(), err))
  86       return Value();
  87   } else if (template_arg.type() == Value::LIST) {
  88     if (!subst.Parse(template_arg, err))
  89       return Value();
  90   } else {
  91     *err = Err(template_arg, "Not a string or a list.");
  92     return Value();
  93   }
  94
  95   SubstitutionWriter::ApplyListToSourcesAsString(
  96       scope->settings(), subst, input_files, &result_files);
  97
  98   // Convert the list of strings to the return Value.
  99   Value ret(function, Value::LIST);
 100   ret.list_value().reserve(result_files.size());
 101   for (const auto& file : result_files)
 102     ret.list_value().push_back(Value(function, file));
 103
 104   return ret;
 105 }
 106
 107 }  // namespace functions