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
18namespace functions {
19
20const char kWriteFile[] = "write_file";
21const char kWriteFile_HelpShort[] =
22    "write_file: Write a file to disk.";
23const 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
46Value 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