Ladybird+LibWebView: Add -P/--enable-callgrind-profiling option

This adds a -P option to run Ladybird under callgrind. It starts with
instrumentation disabled. To start capturing a profile (once Ladybird
has launched) run `callgrind_control -i on` and to stop it again run
`callgrind_control -i off`.

P.s. This is pretty much stolen from Andreas (and is based on the patch
everyone [that wants a profile] have been manually applying).

12 files changed, 52 insertions, 26 deletions

diff --git a/Ladybird/BrowserWindow.cpp b/Ladybird/BrowserWindow.cpp
index aea82e4d41..dc45a367c3 100644
--- a/Ladybird/BrowserWindow.cpp
+++ b/Ladybird/BrowserWindow.cpp
@@ -27,9 +27,11 @@
 extern DeprecatedString s_serenity_resource_root;
 extern Browser::Settings* s_settings;
 
-BrowserWindow::BrowserWindow(Browser::CookieJar& cookie_jar, StringView webdriver_content_ipc_path)
+BrowserWindow::BrowserWindow(Browser::CookieJar& cookie_jar, StringView webdriver_content_ipc_path, WebView::EnableCallgrindProfiling enable_callgrind_profiling)
     : m_cookie_jar(cookie_jar)
     , m_webdriver_content_ipc_path(webdriver_content_ipc_path)
+    , m_enable_callgrind_profiling(enable_callgrind_profiling)
+
 {
     m_tabs_container = new QTabWidget(this);
     m_tabs_container->installEventFilter(this);
@@ -348,7 +350,7 @@ void BrowserWindow::debug_request(DeprecatedString const& request, DeprecatedStr
 
 Tab& BrowserWindow::new_tab(QString const& url, Web::HTML::ActivateTab activate_tab)
 {
-    auto tab = make<Tab>(this, m_webdriver_content_ipc_path);
+    auto tab = make<Tab>(this, m_webdriver_content_ipc_path, m_enable_callgrind_profiling);
     auto tab_ptr = tab.ptr();
     m_tabs.append(std::move(tab));
 
diff --git a/Ladybird/BrowserWindow.h b/Ladybird/BrowserWindow.h
index ff51ebe79f..fe3274e8ae 100644
--- a/Ladybird/BrowserWindow.h
+++ b/Ladybird/BrowserWindow.h
@@ -26,7 +26,7 @@ class CookieJar;
 class BrowserWindow : public QMainWindow {
     Q_OBJECT
 public:
-    explicit BrowserWindow(Browser::CookieJar&, StringView webdriver_content_ipc_path);
+    explicit BrowserWindow(Browser::CookieJar&, StringView webdriver_content_ipc_path, WebView::EnableCallgrindProfiling);
 
     WebContentView& view() const { return m_current_tab->view(); }
 
@@ -70,4 +70,5 @@ private:
     Browser::CookieJar& m_cookie_jar;
 
     StringView m_webdriver_content_ipc_path;
+    WebView::EnableCallgrindProfiling m_enable_callgrind_profiling;
 };
diff --git a/Ladybird/Tab.cpp b/Ladybird/Tab.cpp
index 9fc60a5752..aff795dee7 100644
--- a/Ladybird/Tab.cpp
+++ b/Ladybird/Tab.cpp
@@ -20,7 +20,7 @@
 extern DeprecatedString s_serenity_resource_root;
 extern Browser::Settings* s_settings;
 
-Tab::Tab(BrowserWindow* window, StringView webdriver_content_ipc_path)
+Tab::Tab(BrowserWindow* window, StringView webdriver_content_ipc_path, WebView::EnableCallgrindProfiling enable_callgrind_profiling)
     : QWidget(window)
     , m_window(window)
 {
@@ -28,7 +28,7 @@ Tab::Tab(BrowserWindow* window, StringView webdriver_content_ipc_path)
     m_layout->setSpacing(0);
     m_layout->setContentsMargins(0, 0, 0, 0);
 
-    m_view = new WebContentView(webdriver_content_ipc_path);
+    m_view = new WebContentView(webdriver_content_ipc_path, enable_callgrind_profiling);
     m_toolbar = new QToolBar(this);
     m_location_edit = new LocationEdit(this);
     m_reset_zoom_button = new QToolButton(m_toolbar);
diff --git a/Ladybird/Tab.h b/Ladybird/Tab.h
index 3c89cd6ae9..2ab47470ea 100644
--- a/Ladybird/Tab.h
+++ b/Ladybird/Tab.h
@@ -24,7 +24,7 @@ class BrowserWindow;
 class Tab final : public QWidget {
     Q_OBJECT
 public:
-    Tab(BrowserWindow* window, StringView webdriver_content_ipc_path);
+    Tab(BrowserWindow* window, StringView webdriver_content_ipc_path, WebView::EnableCallgrindProfiling);
 
     WebContentView& view() { return *m_view; }
 
diff --git a/Ladybird/WebContentView.cpp b/Ladybird/WebContentView.cpp
index 7210a15e07..3a02f536f7 100644
--- a/Ladybird/WebContentView.cpp
+++ b/Ladybird/WebContentView.cpp
@@ -55,7 +55,7 @@
 #include <QTimer>
 #include <QToolTip>
 
-WebContentView::WebContentView(StringView webdriver_content_ipc_path)
+WebContentView::WebContentView(StringView webdriver_content_ipc_path, WebView::EnableCallgrindProfiling enable_callgrind_profiling)
     : m_webdriver_content_ipc_path(webdriver_content_ipc_path)
 {
     setMouseTracking(true);
@@ -76,7 +76,7 @@ WebContentView::WebContentView(StringView webdriver_content_ipc_path)
         update_viewport_rect();
     });
 
-    create_client();
+    create_client(enable_callgrind_profiling);
 }
 
 WebContentView::~WebContentView()
@@ -599,12 +599,12 @@ void WebContentView::update_palette()
     client().async_update_system_theme(make_system_theme_from_qt_palette(*this));
 }
 
-void WebContentView::create_client()
+void WebContentView::create_client(WebView::EnableCallgrindProfiling enable_callgrind_profiling)
 {
     m_client_state = {};
 
     auto candidate_web_content_paths = get_paths_for_helper_process("WebContent"sv).release_value_but_fixme_should_propagate_errors();
-    auto new_client = launch_web_content_process(candidate_web_content_paths).release_value_but_fixme_should_propagate_errors();
+    auto new_client = launch_web_content_process(candidate_web_content_paths, enable_callgrind_profiling).release_value_but_fixme_should_propagate_errors();
 
     m_web_content_notifier.setSocket(new_client->socket().fd().value());
     m_web_content_notifier.setEnabled(true);
diff --git a/Ladybird/WebContentView.h b/Ladybird/WebContentView.h
index b6855c1435..3ec8c44878 100644
--- a/Ladybird/WebContentView.h
+++ b/Ladybird/WebContentView.h
@@ -47,7 +47,7 @@ class WebContentView final
     , public WebView::ViewImplementation {
     Q_OBJECT
 public:
-    explicit WebContentView(StringView webdriver_content_ipc_path);
+    explicit WebContentView(StringView webdriver_content_ipc_path, WebView::EnableCallgrindProfiling);
     virtual ~WebContentView() override;
 
     Function<String(Web::HTML::ActivateTab)> on_new_tab;
@@ -185,7 +185,7 @@ signals:
 
 private:
     // ^WebView::ViewImplementation
-    virtual void create_client() override;
+    virtual void create_client(WebView::EnableCallgrindProfiling = WebView::EnableCallgrindProfiling::No) override;
     virtual void update_zoom() override;
 
     void request_repaint();
diff --git a/Ladybird/main.cpp b/Ladybird/main.cpp
index 9ef3e088b3..2eb14608a7 100644
--- a/Ladybird/main.cpp
+++ b/Ladybird/main.cpp
@@ -67,11 +67,13 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     StringView raw_url;
     StringView webdriver_content_ipc_path;
+    bool enable_callgrind_profiling = false;
 
     Core::ArgsParser args_parser;
     args_parser.set_general_help("The Ladybird web browser :^)");
     args_parser.add_positional_argument(raw_url, "URL to open", "url", Core::ArgsParser::Required::No);
     args_parser.add_option(webdriver_content_ipc_path, "Path to WebDriver IPC for WebContent", "webdriver-content-path", 0, "path");
+    args_parser.add_option(enable_callgrind_profiling, "Enable Callgrind profiling", "enable-callgrind-profiling", 'P');
     args_parser.parse(arguments);
 
     auto get_formatted_url = [&](StringView const& raw_url) -> ErrorOr<URL> {
@@ -90,7 +92,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     auto cookie_jar = TRY(Browser::CookieJar::create(*database));
 
     s_settings = adopt_own_if_nonnull(new Browser::Settings());
-    BrowserWindow window(cookie_jar, webdriver_content_ipc_path);
+    BrowserWindow window(cookie_jar, webdriver_content_ipc_path, enable_callgrind_profiling ? WebView::EnableCallgrindProfiling::Yes : WebView::EnableCallgrindProfiling::No);
     window.setWindowTitle("Ladybird");
     window.resize(800, 600);
     window.show();
diff --git a/Userland/Libraries/LibWebView/OutOfProcessWebView.cpp b/Userland/Libraries/LibWebView/OutOfProcessWebView.cpp
index cee2b51ba1..52a1185550 100644
--- a/Userland/Libraries/LibWebView/OutOfProcessWebView.cpp
+++ b/Userland/Libraries/LibWebView/OutOfProcessWebView.cpp
@@ -59,7 +59,7 @@ void OutOfProcessWebView::handle_web_content_process_crash()
     load_html(builder.to_deprecated_string(), m_url);
 }
 
-void OutOfProcessWebView::create_client()
+void OutOfProcessWebView::create_client(EnableCallgrindProfiling)
 {
     m_client_state = {};
 
diff --git a/Userland/Libraries/LibWebView/OutOfProcessWebView.h b/Userland/Libraries/LibWebView/OutOfProcessWebView.h
index e521b29751..1e66ecd62c 100644
--- a/Userland/Libraries/LibWebView/OutOfProcessWebView.h
+++ b/Userland/Libraries/LibWebView/OutOfProcessWebView.h
@@ -121,7 +121,7 @@ private:
     virtual void did_scroll() override;
 
     // ^WebView::ViewImplementation
-    virtual void create_client() override;
+    virtual void create_client(EnableCallgrindProfiling = EnableCallgrindProfiling::No) override;
     virtual void update_zoom() override;
     virtual void notify_server_did_layout(Badge<WebContentClient>, Gfx::IntSize content_size) override;
     virtual void notify_server_did_paint(Badge<WebContentClient>, i32 bitmap_id) override;
diff --git a/Userland/Libraries/LibWebView/ViewImplementation.cpp b/Userland/Libraries/LibWebView/ViewImplementation.cpp
index c77b8c27f9..0686544921 100644
--- a/Userland/Libraries/LibWebView/ViewImplementation.cpp
+++ b/Userland/Libraries/LibWebView/ViewImplementation.cpp
@@ -126,7 +126,7 @@ void ViewImplementation::run_javascript(StringView js_source)
 
 #if !defined(AK_OS_SERENITY)
 
-ErrorOr<NonnullRefPtr<WebView::WebContentClient>> ViewImplementation::launch_web_content_process(ReadonlySpan<String> candidate_web_content_paths)
+ErrorOr<NonnullRefPtr<WebView::WebContentClient>> ViewImplementation::launch_web_content_process(ReadonlySpan<String> candidate_web_content_paths, EnableCallgrindProfiling enable_callgrind_profiling)
 {
     int socket_fds[2] {};
     TRY(Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, socket_fds));
@@ -149,15 +149,22 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> ViewImplementation::launch_web
 
         auto webcontent_fd_passing_socket_string = TRY(String::number(wc_fd_passing_fd));
 
-        auto arguments = Array {
-            "WebContent"sv,
-            "--webcontent-fd-passing-socket"sv,
-            webcontent_fd_passing_socket_string
-        };
-
         ErrorOr<void> result;
         for (auto const& path : candidate_web_content_paths) {
-            result = Core::System::exec(path, arguments, Core::System::SearchInPath::Yes);
+            constexpr auto callgrind_prefix_length = 3;
+            auto arguments_with_callgrind_prefix = Array {
+                "valgrind"sv,
+                "--tool=callgrind"sv,
+                "--instr-atstart=no"sv,
+                path.bytes_as_string_view(),
+                "--webcontent-fd-passing-socket"sv,
+                webcontent_fd_passing_socket_string
+            };
+            auto arguments = arguments_with_callgrind_prefix.span();
+            if (enable_callgrind_profiling == EnableCallgrindProfiling::No)
+                arguments = arguments.slice(callgrind_prefix_length);
+
+            result = Core::System::exec(arguments[0], arguments, Core::System::SearchInPath::Yes);
             if (!result.is_error())
                 break;
         }
@@ -176,6 +183,13 @@ ErrorOr<NonnullRefPtr<WebView::WebContentClient>> ViewImplementation::launch_web
     auto new_client = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) WebView::WebContentClient(move(socket), *this)));
     new_client->set_fd_passing_socket(TRY(Core::LocalSocket::adopt_fd(ui_fd_passing_fd)));
 
+    if (enable_callgrind_profiling == EnableCallgrindProfiling::Yes) {
+        dbgln();
+        dbgln("\033[1;45mLaunched WebContent process under callgrind!\033[0m");
+        dbgln("\033[100mRun `\033[4mcallgrind_control -i on\033[24m` to start instrumentation and `\033[4mcallgrind_control -i off\033[24m` stop it again.\033[0m");
+        dbgln();
+    }
+
     return new_client;
 }
 
diff --git a/Userland/Libraries/LibWebView/ViewImplementation.h b/Userland/Libraries/LibWebView/ViewImplementation.h
index 0aa276da80..a7342a3cb8 100644
--- a/Userland/Libraries/LibWebView/ViewImplementation.h
+++ b/Userland/Libraries/LibWebView/ViewImplementation.h
@@ -18,6 +18,12 @@
 
 namespace WebView {
 
+// Note: This only exists inside Serenity to avoid #ifdefs in all implementors of ViewImplementation.
+enum class EnableCallgrindProfiling {
+    No,
+    Yes
+};
+
 class ViewImplementation {
 public:
     virtual ~ViewImplementation() { }
@@ -120,11 +126,12 @@ protected:
 
     WebContentClient& client();
     WebContentClient const& client() const;
-    virtual void create_client() = 0;
     virtual void update_zoom() = 0;
 
+    virtual void create_client(EnableCallgrindProfiling = EnableCallgrindProfiling::No) {};
+
 #if !defined(AK_OS_SERENITY)
-    ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(ReadonlySpan<String> candidate_web_content_paths);
+    ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_process(ReadonlySpan<String> candidate_web_content_paths, EnableCallgrindProfiling = EnableCallgrindProfiling::No);
 #endif
 
     struct SharedBitmap {
diff --git a/Userland/Utilities/headless-browser.cpp b/Userland/Utilities/headless-browser.cpp
index 2dfca6f1ee..8c6420aca6 100644
--- a/Userland/Utilities/headless-browser.cpp
+++ b/Userland/Utilities/headless-browser.cpp
@@ -157,7 +157,7 @@ private:
 
     void notify_server_did_finish_handling_input_event(bool) override { }
     void update_zoom() override { }
-    void create_client() override { }
+    void create_client(WebView::EnableCallgrindProfiling) override { }
 };
 
 static ErrorOr<NonnullRefPtr<Core::Timer>> load_page_for_screenshot_and_exit(Core::EventLoop& event_loop, HeadlessWebContentView& view, int screenshot_timeout)