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/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
RunWriteFile(Scope * scope,const FunctionCallNode * function,const std::vector<Value> & args,Err * err)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], 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