Home | History | Annotate | Download | only in gn 
      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 <iostream>
      6 #include <sstream>
      7 
      8 #include "base/files/file_util.h"
      9 #include "base/strings/string_split.h"
     10 #include "base/strings/string_util.h"
     11 #include "tools/gn/err.h"
     12 #include "tools/gn/filesystem_utils.h"
     13 #include "tools/gn/functions.h"
     14 #include "tools/gn/input_file.h"
     15 #include "tools/gn/parse_tree.h"
     16 #include "tools/gn/scheduler.h"
     17 
     18 namespace functions {
     19 
     20 const char kWriteFile[] = "write_file";
     21 const char kWriteFile_HelpShort[] =
     22     "write_file: Write a file to disk.";
     23 const char kWriteFile_Help[] =
     24     "write_file: Write a file to disk.\n"
     25     "\n"
     26     "  write_file(filename, data)\n"
     27     "\n"
     28     "  If data is a list, the list will be written one-item-per-line with no\n"
     29     "  quoting or brackets.\n"
     30     "\n"
     31     "  If the file exists and the contents are identical to that being\n"
     32     "  written, the file will not be updated. This will prevent unnecessary\n"
     33     "  rebuilds of targets that depend on this file.\n"
     34     "\n"
     35     "  TODO(brettw) we probably need an optional third argument to control\n"
     36     "  list formatting.\n"
     37     "\n"
     38     "Arguments:\n"
     39     "\n"
     40     "  filename\n"
     41     "      Filename to write. This must be within the output directory.\n"
     42     "\n"
     43     "  data:\n"
     44     "      The list or string to write.\n";
     45 
     46 Value RunWriteFile(Scope* scope,
     47                    const FunctionCallNode* function,
     48                    const std::vector<Value>& args,
     49                    Err* err) {
     50   if (args.size() != 2) {
     51     *err = Err(function->function(), "Wrong number of arguments to write_file",
     52                "I expected two arguments.");
     53     return Value();
     54   }
     55 
     56   // Compute the file name and make sure it's in the output dir.
     57   if (!args[0].VerifyTypeIs(Value::STRING, err))
     58     return Value();
     59   const SourceDir& cur_dir = scope->GetSourceDir();
     60   SourceFile source_file = cur_dir.ResolveRelativeFile(args[0].string_value());
     61   if (!EnsureStringIsInOutputDir(
     62           scope->settings()->build_settings()->build_dir(),
     63           source_file.value(), args[0].origin(), err))
     64     return Value();
     65 
     66   // Compute output.
     67   std::ostringstream contents;
     68   if (args[1].type() == Value::LIST) {
     69     const std::vector<Value>& list = args[1].list_value();
     70     for (size_t i = 0; i < list.size(); i++)
     71       contents << list[i].ToString(false) << std::endl;
     72   } else {
     73     contents << args[1].ToString(false);
     74   }
     75   const std::string& new_contents = contents.str();
     76   base::FilePath file_path =
     77       scope->settings()->build_settings()->GetFullPath(source_file);
     78 
     79   // Make sure we're not replacing the same contents.
     80   std::string existing_contents;
     81   if (base::ReadFileToString(file_path, &existing_contents) &&
     82       existing_contents == new_contents)
     83     return Value();  // Nothing to do.
     84 
     85   // Write file, creating the directory if necessary.
     86   if (!base::CreateDirectory(file_path.DirName())) {
     87     *err = Err(function->function(), "Unable to create directory.",
     88                "I was using \"" + FilePathToUTF8(file_path.DirName()) + "\".");
     89     return Value();
     90   }
     91 
     92   int int_size = static_cast<int>(new_contents.size());
     93   if (base::WriteFile(file_path, new_contents.c_str(), int_size)
     94       != int_size) {
     95     *err = Err(function->function(), "Unable to write file.",
     96                "I was writing \"" + FilePathToUTF8(file_path) + "\".");
     97     return Value();
     98   }
     99   return Value();
    100 }
    101 
    102 }  // namespace functions
    103