Add support for generating the QtCreator projects from GN.

tools/gn/qt_creator_writer.cc

Index: tools/gn/qt_creator_writer.cc
diff --git a/tools/gn/qt_creator_writer.cc b/tools/gn/qt_creator_writer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..96f247f5719a0a580fa874b37ce39bb6351b1e02
--- /dev/null
+++ b/tools/gn/qt_creator_writer.cc
@@ -0,0 +1,174 @@
+// Copyright (c) 2016 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 "tools/gn/qt_creator_writer.h"
+
+#include <set>
+#include <sstream>
+#include <string>
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/strings/utf_string_conversions.h"
+
+#include "tools/gn/builder.h"
+#include "tools/gn/config_values_extractors.h"
+#include "tools/gn/deps_iterator.h"
+#include "tools/gn/filesystem_utils.h"
+#include "tools/gn/label.h"
+#include "tools/gn/loader.h"
+
+namespace {
+base::FilePath::CharType kProjectDirName[] =
+    FILE_PATH_LITERAL("qtcreator_project");
+base::FilePath::CharType kProjectName[] = FILE_PATH_LITERAL("all");
+base::FilePath::CharType kMainProjectFileSuffix[] =
+    FILE_PATH_LITERAL(".creator");
+base::FilePath::CharType kSourcesFileSuffix[] = FILE_PATH_LITERAL(".files");
+base::FilePath::CharType kIncludesFileSuffix[] = FILE_PATH_LITERAL(".includes");
+base::FilePath::CharType kDefinesFileSuffix[] = FILE_PATH_LITERAL(".config");
+}
+
+// static
+bool QtCreatorWriter::RunAndWriteFile(const BuildSettings* build_settings,
+                                      const Builder* builder,
+                                      Err* err,
+                                      const std::string& root_target) {
+  base::FilePath project_dir =
+      build_settings->GetFullPath(build_settings->build_dir())
+          .Append(kProjectDirName);
+  if (!base::DirectoryExists(project_dir)) {
+    base::File::Error error;
+    if (!base::CreateDirectoryAndGetError(project_dir, &error)) {
+      *err =
+          Err(Location(), "Could not create the QtCreator project directory '" +
+                              FilePathToUTF8(project_dir) + "': " +
+                              base::File::ErrorToString(error));
+      return false;
+    }
+  }
+
+  base::FilePath project_prefix = project_dir.Append(kProjectName);
+  QtCreatorWriter gen(build_settings, builder, project_prefix, root_target);
+  gen.Run();
+  if (gen.err_.has_error()) {
+    *err = gen.err_;
+    return false;
+  }
+  return true;
+}
+
+QtCreatorWriter::QtCreatorWriter(const BuildSettings* build_settings,
+                                 const Builder* builder,
+                                 const base::FilePath& project_prefix,
+                                 const std::string& root_target_name)
+    : build_settings_(build_settings),
+      builder_(builder),
+      project_prefix_(project_prefix),
+      root_target_name_(root_target_name) {}
+
+QtCreatorWriter::~QtCreatorWriter() {}
+
+void QtCreatorWriter::CollectDeps(const Target* target) {
+  for (const auto& dep : target->GetDeps(Target::DEPS_ALL)) {
+    const Target* dep_target = dep.ptr;
+    if (targets_.count(dep_target))
+      continue;
+    targets_.insert(dep_target);
+    CollectDeps(dep_target);
+  }
+}
+
+bool QtCreatorWriter::DiscoverTargets() {
+  auto all_targets = builder_->GetAllResolvedTargets();
+
+  if (root_target_name_.empty()) {
+    targets_ = std::set<const Target*>(all_targets.begin(), all_targets.end());
+    return true;
+  }
+
+  const Target* root_target = nullptr;
+  for (const Target* target : all_targets) {
+    if (target->label().name() == root_target_name_) {
+      root_target = target;
+      break;
+    }
+  }
+
+  if (!root_target) {
+    err_ = Err(Location(), "Target '" + root_target_name_ + "' not found.");
+    return false;
+  }
+
+  targets_.insert(root_target);
+  CollectDeps(root_target);
+  return true;
+}
+
+void QtCreatorWriter::AddToSources(const Target::FileList& files) {
+  for (const SourceFile& file : files) {
+    const std::string& file_path =
+        FilePathToUTF8(build_settings_->GetFullPath(file));
+    sources_.insert(file_path);
+  }
+}
+
+void QtCreatorWriter::HandleTarget(const Target* target) {
+  SourceFile build_file = Loader::BuildFileForLabel(target->label());
+  sources_.insert(FilePathToUTF8(build_settings_->GetFullPath(build_file)));
+  AddToSources(target->settings()->import_manager().GetImportedFiles());
+
+  AddToSources(target->sources());
+  AddToSources(target->public_headers());
+  AddToSources(target->inputs());
+
+  for (ConfigValuesIterator it(target); !it.done(); it.Next()) {
+    SourceFile precompiled_source = it.cur().precompiled_source();
+    if (!precompiled_source.is_null()) {
+      sources_.insert(
+          FilePathToUTF8(build_settings_->GetFullPath(precompiled_source)));
+    }
+
+    for (const SourceDir& include_dir : it.cur().include_dirs()) {
+      includes_.insert(
+          FilePathToUTF8(build_settings_->GetFullPath(include_dir)));
+    }
+
+    for (std::string define : it.cur().defines()) {
+      size_t equal_pos = define.find('=');
+      if (equal_pos != std::string::npos)
+        define[equal_pos] = ' ';
+      define.insert(0, "#define ");
+      defines_.insert(define);
+    }
+  }
+}
+
+void QtCreatorWriter::GenerateFile(const base::FilePath::CharType* suffix,
+                                   const std::set<std::string>& items) {
+  const base::FilePath file_path = project_prefix_.AddExtension(suffix);
+  std::ostringstream output;
+  for (const std::string& item : items)
+    output << item << std::endl;
+  WriteFileIfChanged(file_path, output.str(), &err_);
+}
+
+void QtCreatorWriter::Run() {
+  if (!DiscoverTargets())
+    return;
+
+  for (const Target* target : targets_) {
+    if (target->toolchain()->label() !=
+        builder_->loader()->GetDefaultToolchain())
+      continue;
+    HandleTarget(target);
+  }
+
+  std::set<std::string> empty_list;
+
+  GenerateFile(kMainProjectFileSuffix, empty_list);
+  GenerateFile(kSourcesFileSuffix, sources_);
+  GenerateFile(kIncludesFileSuffix, includes_);
+  GenerateFile(kDefinesFileSuffix, defines_);
+}