[GN] Add support for generating Xcode projects.

tools/gn/xcode_writer.cc

Index: tools/gn/xcode_writer.cc
diff --git a/tools/gn/xcode_writer.cc b/tools/gn/xcode_writer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4168f7f068d5171746ecbe6b06d88a352f175868
--- /dev/null
+++ b/tools/gn/xcode_writer.cc
@@ -0,0 +1,432 @@
+// Copyright 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/xcode_writer.h"
+
+#include <iomanip>
+#include <map>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <utility>
+
+#include "base/environment.h"
+#include "base/logging.h"
+#include "base/sha1.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "tools/gn/args.h"
+#include "tools/gn/build_settings.h"
+#include "tools/gn/builder.h"
+#include "tools/gn/commands.h"
+#include "tools/gn/deps_iterator.h"
+#include "tools/gn/filesystem_utils.h"
+#include "tools/gn/settings.h"
+#include "tools/gn/source_file.h"
+#include "tools/gn/target.h"
+#include "tools/gn/value.h"
+#include "tools/gn/variables.h"
+#include "tools/gn/xcode_object.h"
+
+namespace {
+
+XcodeWriter::TargetOsType GetTargetOs(const Args& args) {
+  const Value* target_os_value = args.GetArgOverride(variables::kTargetOs);
+  if (target_os_value) {
+    if (target_os_value->type() == Value::STRING) {
+      if (target_os_value->string_value() == "ios")
+        return XcodeWriter::WRITER_TARGET_OS_IOS;
+    }
+  }
+  return XcodeWriter::WRITER_TARGET_OS_MACOS;
+}
+
+std::string GetArchs(const Args& args) {
+  const Value* target_cpu_value = args.GetArgOverride(variables::kTargetCpu);
+  if (target_cpu_value) {
+    if (target_cpu_value->type() == Value::STRING) {
+      if (target_cpu_value->string_value() == "x86")
+        return "i386";
+      if (target_cpu_value->string_value() == "x64")
+        return "x86_64";
+      if (target_cpu_value->string_value() == "arm")
+        return "armv7";
+      if (target_cpu_value->string_value() == "armv7")
+        return "armv7";
+      if (target_cpu_value->string_value() == "arm64")
+        return "armv64";
+    }
+  }
+  return "x86_64";
+}
+
+std::string GetBuildScript(const std::string& target_name,
+                           const std::string& build_path,
+                           const std::string& ninja_extra_args) {
+  std::stringstream script;
+  script << "echo note: \"Compile and copy " << target_name << " via ninja\"\n"
+         << "exec ";
+  if (!build_path.empty())
+    script << "env PATH=\"" << build_path << "\" ";
+  script << "ninja -C .";
+  if (!ninja_extra_args.empty())
+    script << " " << ninja_extra_args;
+  if (!target_name.empty())
+    script << " " << target_name;
+  script << "\nexit 1\n";
+  return script.str();
+}
+
+class CollectPBXObjectsPerClassHelper : public PBXObjectVisitor {
+ public:
+  CollectPBXObjectsPerClassHelper() {}
+
+  void Visit(PBXObject* object) override {
+    DCHECK(object);
+    objects_per_class_[object->Class()].push_back(object);
+  }
+
+  const std::map<PBXObjectClass, std::vector<const PBXObject*>>&
+  objects_per_class() const {
+    return objects_per_class_;
+  }
+
+ private:
+  std::map<PBXObjectClass, std::vector<const PBXObject*>> objects_per_class_;
+
+  DISALLOW_COPY_AND_ASSIGN(CollectPBXObjectsPerClassHelper);
+};
+
+std::map<PBXObjectClass, std::vector<const PBXObject*>>
+CollectPBXObjectsPerClass(PBXProject* project) {
+  CollectPBXObjectsPerClassHelper visitor;
+  project->Visit(visitor);
+  return visitor.objects_per_class();
+}
+
+class RecursivelyAssignIdsHelper : public PBXObjectVisitor {
+ public:
+  RecursivelyAssignIdsHelper(const std::string& seed)
+      : seed_(seed), counter_(0) {}
+
+  void Visit(PBXObject* object) override {
+    std::stringstream buffer;
+    buffer << seed_ << " " << object->Name() << " " << counter_;
+    std::string hash = base::SHA1HashString(buffer.str());
+    DCHECK_EQ(hash.size() % 4, 0u);
+
+    uint32_t id[3] = {0, 0, 0};
+    const uint32_t* ptr = reinterpret_cast<const uint32_t*>(hash.data());
+    for (size_t i = 0; i < hash.size() / 4; i++)
+      id[i % 3] ^= ptr[i];
+
+    object->SetId(base::HexEncode(id, sizeof(id)));
+    ++counter_;
+  }
+
+ private:
+  std::string seed_;
+  int64_t counter_;
+
+  DISALLOW_COPY_AND_ASSIGN(RecursivelyAssignIdsHelper);
+};
+
+void RecursivelyAssignIds(PBXProject* project) {
+  RecursivelyAssignIdsHelper visitor(project->Name());
+  project->Visit(visitor);
+}
+
+}  // namespace
+
+// static
+bool XcodeWriter::RunAndWriteFiles(const std::string& workspace_name,
+                                   const std::string& root_target_name,
+                                   const std::string& ninja_extra_args,
+                                   const std::string& dir_filters_string,
+                                   const BuildSettings* build_settings,
+                                   Builder* builder,
+                                   Err* err) {
+  const XcodeWriter::TargetOsType target_os =
+      GetTargetOs(build_settings->build_args());
+
+  PBXAttributes attributes;
+  switch (target_os) {
+    case XcodeWriter::WRITER_TARGET_OS_IOS:
+      attributes["SDKROOT"] = "iphoneos";
+      attributes["TARGETED_DEVICE_FAMILY"] = "1,2";
+      break;
+    case XcodeWriter::WRITER_TARGET_OS_MACOS:
+      attributes["ARCHS"] = GetArchs(build_settings->build_args());
+      attributes["SDKROOT"] = "macosx10.11";
+      break;
+  }
+
+  const std::string source_path =
+      base::FilePath::FromUTF8Unsafe(
+          RebasePath("//", build_settings->build_dir()))
+          .StripTrailingSeparators()
+          .AsUTF8Unsafe();
+
+  std::string config_name = build_settings->build_dir()
+                                .Resolve(base::FilePath())
+                                .StripTrailingSeparators()
+                                .BaseName()
+                                .AsUTF8Unsafe();
+  DCHECK(!config_name.empty());
+
+  std::string::size_type separator = config_name.find('-');
+  if (separator != std::string::npos)
+    config_name = config_name.substr(0, separator);
+
+  std::vector<const Target*> targets;
+  std::vector<const Target*> all_targets = builder->GetAllResolvedTargets();
+  if (!XcodeWriter::FilterTargets(build_settings, all_targets,
+                                  dir_filters_string, &targets, err)) {
+    return false;
+  }
+
+  XcodeWriter workspace(workspace_name);
+  workspace.CreateProductsProject(targets, attributes, source_path, config_name,
+                                  root_target_name, ninja_extra_args,
+                                  target_os);
+
+  workspace.CreateSourcesProject(all_targets, build_settings->build_dir(),
+                                 attributes, source_path, config_name,
+                                 target_os);
+
+  return workspace.WriteFiles(build_settings, err);
+}
+
+XcodeWriter::XcodeWriter(const std::string& name) : name_(name) {
+  if (name_.empty())
+    name_.assign("all");
+}
+
+XcodeWriter::~XcodeWriter() {}
+
+// static
+bool XcodeWriter::FilterTargets(const BuildSettings* build_settings,
+                                const std::vector<const Target*>& all_targets,
+                                const std::string& dir_filters_string,
+                                std::vector<const Target*>* targets,
+                                Err* err) {
+  // Filter targets according to the semicolon-delimited list of label patterns,
+  // if defined, first.
+  targets->reserve(all_targets.size());
+  if (dir_filters_string.empty()) {
+    *targets = all_targets;
+  } else {
+    std::vector<LabelPattern> filters;
+    if (!commands::FilterPatternsFromString(build_settings, dir_filters_string,
+                                            &filters, err)) {
+      return false;
+    }
+
+    commands::FilterTargetsByPatterns(all_targets, filters, targets);
+  }
+
+  // Filter out all target of type EXECUTABLE that are direct dependency of
+  // a BUNDLE_DATA target (under the assumption that they will be part of a
+  // CREATE_BUNDLE target generating an application bundle). Sort the list
+  // of targets per pointer to use binary search for the removal.
+  std::sort(targets->begin(), targets->end());
+
+  for (const Target* target : all_targets) {
+    if (!target->settings()->is_default())
+      continue;
+
+    if (target->output_type() != Target::BUNDLE_DATA)
+      continue;
+
+    for (const auto& pair : target->GetDeps(Target::DEPS_LINKED)) {
+      if (pair.ptr->output_type() != Target::EXECUTABLE)
+        continue;
+
+      auto iter = std::lower_bound(targets->begin(), targets->end(), pair.ptr);
+      if (iter != targets->end() && *iter == pair.ptr)
+        targets->erase(iter);
+    }
+  }
+
+  // Sort the list of targets per-label to get a consistent ordering of them
+  // in the generated Xcode project (and thus stability of the file generated).
+  std::sort(targets->begin(), targets->end(),
+            [](const Target* a, const Target* b) {
+              return a->label().name() < b->label().name();
+            });
+
+  return true;
+}
+
+void XcodeWriter::CreateProductsProject(
+    const std::vector<const Target*>& targets,
+    const PBXAttributes& attributes,
+    const std::string& source_path,
+    const std::string& config_name,
+    const std::string& root_target,
+    const std::string& ninja_extra_args,
+    TargetOsType target_os) {
+  std::unique_ptr<PBXProject> main_project(
+      new PBXProject("products", config_name, source_path, attributes));
+
+  std::string build_path;
+  std::unique_ptr<base::Environment> env(base::Environment::Create());
+  env->GetVar("PATH", &build_path);
+
+  main_project->AddAggregateTarget(
+      "All", GetBuildScript(root_target, build_path, ninja_extra_args));
+
+  for (const Target* target : targets) {
+    switch (target->output_type()) {
+      case Target::EXECUTABLE:
+        if (target_os == XcodeWriter::WRITER_TARGET_OS_IOS)
+          continue;
+
+        main_project->AddNativeTarget(
+            target->label().name(), "compiled.mach-o.executable",
+            target->output_name().empty() ? target->label().name()
+                                          : target->output_name(),
+            "com.apple.product-type.tool",
+            GetBuildScript(target->label().name(), build_path,
+                           ninja_extra_args));
+        break;
+
+      case Target::CREATE_BUNDLE:
+        if (target->bundle_data().product_type().empty())
+          continue;
+
+        main_project->AddNativeTarget(
+            target->label().name(), std::string(),
+            target->bundle_data()
+                .GetBundleRootDirOutput(target->settings())
+                .Resolve(base::FilePath())
+                .AsUTF8Unsafe(),
+            target->bundle_data().product_type(),
+            GetBuildScript(target->label().name(), build_path,
+                           ninja_extra_args));
+        break;
+
+      default:
+        break;
+    }
+  }
+
+  projects_.push_back(std::move(main_project));
+}
+
+void XcodeWriter::CreateSourcesProject(
+    const std::vector<const Target*>& targets,
+    const SourceDir& root_build_dir,
+    const PBXAttributes& attributes,
+    const std::string& source_path,
+    const std::string& config_name,
+    TargetOsType target_os) {
+  std::vector<SourceFile> sources;
+  for (const Target* target : targets) {
+    if (!target->settings()->is_default())
+      continue;
+
+    for (const SourceFile& source : target->sources()) {
+      if (source.is_system_absolute())
+        continue;
+
+      if (IsStringInOutputDir(root_build_dir, source.value()))
+        continue;
+
+      sources.push_back(source);
+    }
+  }
+
+  std::unique_ptr<PBXProject> sources_for_indexing(
+      new PBXProject("sources", config_name, source_path, attributes));
+
+  // Sort sources to ensure determinisn of the project file generation and
+  // remove duplicate reference to the source files (can happen due to the
+  // bundle_data targets).
+  std::sort(sources.begin(), sources.end());
+  sources.erase(std::unique(sources.begin(), sources.end()), sources.end());
+
+  for (const SourceFile& source : sources) {
+    base::FilePath source_path = source.Resolve(base::FilePath());
+    sources_for_indexing->AddSourceFile(source_path.AsUTF8Unsafe());
+  }
+
+  projects_.push_back(std::move(sources_for_indexing));
+}
+
+bool XcodeWriter::WriteFiles(const BuildSettings* build_settings, Err* err) {
+  for (const auto& project : projects_) {
+    if (!WriteProjectFile(build_settings, project.get(), err))
+      return false;
+  }
+
+  SourceFile xcworkspacedata_file =
+      build_settings->build_dir().ResolveRelativeFile(
+          Value(nullptr, name_ + ".xcworkspace/contents.xcworkspacedata"), err);
+  if (xcworkspacedata_file.is_null())
+    return false;
+
+  std::stringstream xcworkspacedata_string_out;
+  WriteWorkspaceContent(xcworkspacedata_string_out);
+
+  return WriteFileIfChanged(build_settings->GetFullPath(xcworkspacedata_file),
+                            xcworkspacedata_string_out.str(), err);
+}
+
+bool XcodeWriter::WriteProjectFile(const BuildSettings* build_settings,
+                                   PBXProject* project,
+                                   Err* err) {
+  SourceFile pbxproj_file = build_settings->build_dir().ResolveRelativeFile(
+      Value(nullptr, project->Name() + ".xcodeproj/project.pbxproj"), err);
+  if (pbxproj_file.is_null())
+    return false;
+
+  std::stringstream pbxproj_string_out;
+  WriteProjectContent(pbxproj_string_out, project);
+
+  if (!WriteFileIfChanged(build_settings->GetFullPath(pbxproj_file),
+                          pbxproj_string_out.str(), err))
+    return false;
+
+  return true;
+}
+
+void XcodeWriter::WriteWorkspaceContent(std::ostream& out) {
+  out << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+      << "<Workspace version = \"1.0\">\n";
+  for (const auto& project : projects_) {
+    out << "  <FileRef location = \"group:" << project->Name()
+        << ".xcodeproj\"></FileRef>\n";
+  }
+  out << "</Workspace>\n";
+}
+
+void XcodeWriter::WriteProjectContent(std::ostream& out, PBXProject* project) {
+  RecursivelyAssignIds(project);
+
+  out << "// !$*UTF8*$!\n"
+      << "{\n"
+      << "\tarchiveVersion = 1;\n"
+      << "\tclasses = {\n"
+      << "\t};\n"
+      << "\tobjectVersion = 46;\n"
+      << "\tobjects = {\n";
+
+  for (auto& pair : CollectPBXObjectsPerClass(project)) {
+    out << "\n"
+        << "/* Begin " << ToString(pair.first) << " section */\n";
+    std::sort(pair.second.begin(), pair.second.end(),
+              [](const PBXObject* a, const PBXObject* b) {
+                return a->id() < b->id();
+              });
+    for (const auto& object : pair.second) {
+      object->Print(out, 2);
+    }
+    out << "/* End " << ToString(pair.first) << " section */\n";
+  }
+
+  out << "\t};\n"
+      << "\trootObject = " << project->Reference() << ";\n"
+      << "}\n";
+}