Import chromium-63.0.3239.132

tools/gn/function_write_file.cc

@@ -0,0 +1,103 @@
+// 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 <iostream>
+#include <sstream>
+
+#include "base/files/file_util.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
+#include "tools/gn/err.h"
+#include "tools/gn/filesystem_utils.h"
+#include "tools/gn/functions.h"
+#include "tools/gn/input_file.h"
+#include "tools/gn/parse_tree.h"
+#include "tools/gn/scheduler.h"
+
+namespace functions {
+
+const char kWriteFile[] = "write_file";
+const char kWriteFile_HelpShort[] =
+    "write_file: Write a file to disk.";
+const char kWriteFile_Help[] =
+    R"(write_file: Write a file to disk.
+
+  write_file(filename, data)
+
+  If data is a list, the list will be written one-item-per-line with no quoting
+  or brackets.
+
+  If the file exists and the contents are identical to that being written, the
+  file will not be updated. This will prevent unnecessary rebuilds of targets
+  that depend on this file.
+
+  One use for write_file is to write a list of inputs to an script that might
+  be too long for the command line. However, it is preferrable to use response
+  files for this purpose. See "gn help response_file_contents".
+
+  TODO(brettw) we probably need an optional third argument to control list
+  formatting.
+
+Arguments
+
+  filename
+      Filename to write. This must be within the output directory.
+
+  data
+      The list or string to write.
+)";
+
+Value RunWriteFile(Scope* scope,
+                   const FunctionCallNode* function,
+                   const std::vector<Value>& args,
+                   Err* err) {
+  if (args.size() != 2) {
+    *err = Err(function->function(), "Wrong number of arguments to write_file",
+               "I expected two arguments.");
+    return Value();
+  }
+
+  // Compute the file name and make sure it's in the output dir.
+  const SourceDir& cur_dir = scope->GetSourceDir();
+  SourceFile source_file = cur_dir.ResolveRelativeFile(args[0], err,
+      scope->settings()->build_settings()->root_path_utf8());
+  if (err->has_error())
+    return Value();
+  if (!EnsureStringIsInOutputDir(
+          scope->settings()->build_settings()->build_dir(),
+          source_file.value(), args[0].origin(), err))
+    return Value();
+  g_scheduler->AddWrittenFile(source_file);  // Track that we wrote this file.
+
+  // Track how to recreate this file, since we write it a gen time.
+  // Note this is a hack since the correct output is not a dependency proper,
+  // but an addition of this file to the output of the gn rule that writes it.
+  // This dependency will, however, cause the gen step to be re-run and the
+  // build restarted if the file is missing.
+  g_scheduler->AddGenDependency(
+      scope->settings()->build_settings()->GetFullPath(source_file));
+
+  // Compute output.
+  std::ostringstream contents;
+  if (args[1].type() == Value::LIST) {
+    const std::vector<Value>& list = args[1].list_value();
+    for (const auto& cur : list)
+      contents << cur.ToString(false) << std::endl;
+  } else {
+    contents << args[1].ToString(false);
+  }
+
+  base::FilePath file_path =
+      scope->settings()->build_settings()->GetFullPath(source_file);
+
+  // Make sure we're not replacing the same contents.
+  if (!WriteFileIfChanged(file_path, contents.str(), err))
+    *err = Err(function->function(), err->message(), err->help_text());
+
+  return Value();
+}
+
+}  // namespace functions