Userland: static vs non-static constexpr variables

Problem: - `static` variables consume memory and sometimes are less optimizable. - `static const` variables can be `constexpr`, usually. - `static` function-local variables require an initialization check every time the function is run. Solution: - If a global `static` variable is only used in a single function then move it into the function and make it non-`static` and `constexpr`. - Make all global `static` variables `constexpr` instead of `const`. - Change function-local `static const[expr]` variables to be just `constexpr`.
fleximus · May 21, 2021 · 800ea8e · 800ea8e
1 parent 17ff895
commit 800ea8e
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Showing 38 changed files with 191 additions and 183 deletions.
diff --git a/Userland/Applications/Browser/CookieJar.cpp b/Userland/Applications/Browser/CookieJar.cpp
@@ -7,6 +7,7 @@
 #include "CookieJar.h"
 #include <AK/IPv4Address.h>
 #include <AK/StringBuilder.h>
+#include <AK/StringView.h>
 #include <AK/URL.h>
 #include <AK/Vector.h>
 #include <LibWeb/Cookie/ParsedCookie.h>
@@ -48,9 +49,9 @@ void CookieJar::set_cookie(const URL& url, const Web::Cookie::ParsedCookie& pars
 
 void CookieJar::dump_cookies() const
 {
- static const char* key_color = "\033[34;1m";
- static const char* attribute_color = "\033[33m";
- static const char* no_color = "\033[0m";
+ constexpr StringView key_color = "\033[34;1m";
+ constexpr StringView attribute_color = "\033[33m";
+ constexpr StringView no_color = "\033[0m";
 
  StringBuilder builder;
  builder.appendff("{} cookies stored\n", m_cookies.size());

diff --git a/Userland/Applications/Calendar/AddEventDialog.cpp b/Userland/Applications/Calendar/AddEventDialog.cpp
@@ -5,6 +5,7 @@
  */
 
 #include "AddEventDialog.h"
+#include <AK/StringView.h>
 #include <LibCore/DateTime.h>
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/Button.h>
@@ -20,11 +21,6 @@
 #include <LibGfx/Font.h>
 #include <LibGfx/FontDatabase.h>
 
-static const char* short_month_names[] = {
- "Jan", "Feb", "Mar", "Apr", "May", "Jun",
- "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
-};
-
 AddEventDialog::AddEventDialog(Core::DateTime date_time, Window* parent_window)
  : Dialog(parent_window)
  , m_date_time(date_time)
@@ -121,6 +117,11 @@ String AddEventDialog::MonthListModel::column_name(int column) const
 
 GUI::Variant AddEventDialog::MonthListModel::data(const GUI::ModelIndex& index, GUI::ModelRole role) const
 {
+ constexpr StringView short_month_names[] = {
+ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+ };
+
  auto& month = short_month_names[index.row()];
  if (role == GUI::ModelRole::Display) {
  switch (index.column()) {

diff --git a/Userland/Applications/FontEditor/FontEditor.cpp b/Userland/Applications/FontEditor/FontEditor.cpp
@@ -9,6 +9,7 @@
 #include "GlyphMapWidget.h"
 #include "NewFontDialog.h"
 #include <AK/StringBuilder.h>
+#include <AK/StringView.h>
 #include <AK/UnicodeUtils.h>
 #include <Applications/FontEditor/FontEditorWindowGML.h>
 #include <LibDesktop/Launcher.h>
@@ -37,19 +38,19 @@
 #include <LibGfx/TextDirection.h>
 #include <stdlib.h>
 
-static constexpr int s_pangram_count = 7;
-static const char* pangrams[s_pangram_count] = {
- "quick fox jumps nightly above wizard",
- "five quacking zephyrs jolt my wax bed",
- "pack my box with five dozen liquor jugs",
- "quick brown fox jumps over the lazy dog",
- "waxy and quivering jocks fumble the pizza",
- "~#:[@_1%]*{$2.3}/4^(5'6\")-&|7+8!=<9,0\\>?;",
- "byxfjärmat föl gick på duvshowen"
-};
-
 static RefPtr<GUI::Window> create_font_preview_window(FontEditorWidget& editor)
 {
+ constexpr int pangram_count = 7;
+ constexpr StringView pangrams[pangram_count] = {
+ "quick fox jumps nightly above wizard",
+ "five quacking zephyrs jolt my wax bed",
+ "pack my box with five dozen liquor jugs",
+ "quick brown fox jumps over the lazy dog",
+ "waxy and quivering jocks fumble the pizza",
+ "~#:[@_1%]*{$2.3}/4^(5'6\")-&|7+8!=<9,0\\>?;",
+ "byxfjärmat föl gick på duvshowen"
+ };
+
  auto window = GUI::Window::construct();
  window->set_window_type(GUI::WindowType::ToolWindow);
  window->set_title("Font preview");
@@ -94,7 +95,7 @@ static RefPtr<GUI::Window> create_font_preview_window(FontEditorWidget& editor)
  reload_button.set_fixed_width(22);
  reload_button.on_click = [&] {
  static int i = 1;
- if (i >= s_pangram_count)
+ if (i >= pangram_count)
  i = 0;
  preview_textbox.set_text(pangrams[i]);
  i++;

diff --git a/Userland/Applications/HexEditor/FindDialog.cpp b/Userland/Applications/HexEditor/FindDialog.cpp
@@ -5,9 +5,9 @@
  */
 
 #include "FindDialog.h"
+#include <AK/Array.h>
 #include <AK/Hex.h>
 #include <AK/String.h>
-#include <AK/Vector.h>
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/Button.h>
 #include <LibGUI/Label.h>
@@ -19,17 +19,12 @@
 #include <LibGfx/FontDatabase.h>
 
 struct Option {
- String title;
+ StringView title;
  OptionId opt;
  bool enabled;
  bool default_action;
 };
 
-static const Vector<Option> options = {
- { "ACII String", OPTION_ASCII_STRING, true, true },
- { "Hex value", OPTION_HEX_VALUE, true, false },
-};
-
 int FindDialog::show(GUI::Window* parent_window, String& out_text, ByteBuffer& out_buffer)
 {
  auto dialog = FindDialog::construct();
@@ -88,6 +83,11 @@ Result<ByteBuffer, String> FindDialog::process_input(String text_value, OptionId
 FindDialog::FindDialog()
  : Dialog(nullptr)
 {
+ constexpr Array options = {
+ Option { "ACII String", OPTION_ASCII_STRING, true, true },
+ Option { "Hex value", OPTION_HEX_VALUE, true, false },
+ };
+
  resize(280, 180 + ((static_cast<int>(options.size()) - 3) * 16));
  center_on_screen();
  set_resizable(false);
@@ -113,7 +113,7 @@ FindDialog::FindDialog()
  radio.set_enabled(action.enabled);
  radio.set_text(action.title);
 
- radio.on_checked = [this, i](auto) {
+ radio.on_checked = [&](auto) {
  m_selected_option = options[i].opt;
  };
 

diff --git a/Userland/Applications/SpaceAnalyzer/TreeMapWidget.cpp b/Userland/Applications/SpaceAnalyzer/TreeMapWidget.cpp
@@ -5,6 +5,7 @@
  */
 
 #include "TreeMapWidget.h"
+#include <AK/Array.h>
 #include <AK/NumberFormat.h>
 #include <LibGUI/Painter.h>
 #include <LibGUI/WindowServerConnection.h>
@@ -24,7 +25,7 @@ TreeMapWidget::~TreeMapWidget()
 {
 }
 
-static const Color colors[] = {
+static constexpr Array colors = {
  Color(253, 231, 37),
  Color(148, 216, 64),
  Color(60, 188, 117),

diff --git a/Userland/Applications/SpaceAnalyzer/main.cpp b/Userland/Applications/SpaceAnalyzer/main.cpp
@@ -9,6 +9,7 @@
 #include <AK/Queue.h>
 #include <AK/QuickSort.h>
 #include <AK/RefCounted.h>
+#include <AK/StringView.h>
 #include <AK/URL.h>
 #include <Applications/SpaceAnalyzer/SpaceAnalyzerGML.h>
 #include <LibCore/DirIterator.h>
@@ -27,8 +28,6 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-static const char* APP_NAME = "Space Analyzer";
-
 struct TreeNode : public SpaceAnalyzer::TreeMapNode {
  TreeNode(String name)
  : m_name(move(name)) {};
@@ -253,6 +252,8 @@ static String get_absolute_path_to_selected_node(const SpaceAnalyzer::TreeMapWid
 
 int main(int argc, char* argv[])
 {
+ constexpr StringView APP_NAME = "Space Analyzer";
+
  auto app = GUI::Application::construct(argc, argv);
 
  RefPtr<Tree> tree = adopt_ref(*new Tree(""));

diff --git a/Userland/Demos/Fire/Fire.cpp b/Userland/Demos/Fire/Fire.cpp
@@ -22,6 +22,7 @@
  * [ ] handle fire bitmap edges better
 */
 
+#include <AK/Array.h>
 #include <LibCore/ElapsedTimer.h>
 #include <LibGUI/Action.h>
 #include <LibGUI/Application.h>
@@ -38,22 +39,9 @@
 #include <time.h>
 #include <unistd.h>
 
-#define FIRE_WIDTH 320
-#define FIRE_HEIGHT 168
-#define FIRE_MAX 29
-
-static const Color s_palette[] = {
- Color(0x07, 0x07, 0x07), Color(0x1F, 0x07, 0x07), Color(0x2F, 0x0F, 0x07),
- Color(0x47, 0x0F, 0x07), Color(0x57, 0x17, 0x07), Color(0x67, 0x1F, 0x07),
- Color(0x77, 0x1F, 0x07), Color(0x9F, 0x2F, 0x07), Color(0xAF, 0x3F, 0x07),
- Color(0xBF, 0x47, 0x07), Color(0xC7, 0x47, 0x07), Color(0xDF, 0x4F, 0x07),
- Color(0xDF, 0x57, 0x07), Color(0xD7, 0x5F, 0x07), Color(0xD7, 0x5F, 0x07),
- Color(0xD7, 0x67, 0x0F), Color(0xCF, 0x6F, 0x0F), Color(0xCF, 0x7F, 0x0F),
- Color(0xCF, 0x87, 0x17), Color(0xC7, 0x87, 0x17), Color(0xC7, 0x8F, 0x17),
- Color(0xC7, 0x97, 0x1F), Color(0xBF, 0x9F, 0x1F), Color(0xBF, 0xA7, 0x27),
- Color(0xBF, 0xAF, 0x2F), Color(0xB7, 0xAF, 0x2F), Color(0xB7, 0xB7, 0x37),
- Color(0xCF, 0xCF, 0x6F), Color(0xEF, 0xEF, 0xC7), Color(0xFF, 0xFF, 0xFF)
-};
+static constexpr auto FIRE_WIDTH = 320;
+static constexpr auto FIRE_HEIGHT = 168;
+static constexpr auto FIRE_MAX = 29;
 
 class Fire : public GUI::Widget {
  C_OBJECT(Fire)
@@ -80,11 +68,24 @@ class Fire : public GUI::Widget {
 
 Fire::Fire()
 {
+ constexpr Array palette = {
+ Color(0x07, 0x07, 0x07), Color(0x1F, 0x07, 0x07), Color(0x2F, 0x0F, 0x07),
+ Color(0x47, 0x0F, 0x07), Color(0x57, 0x17, 0x07), Color(0x67, 0x1F, 0x07),
+ Color(0x77, 0x1F, 0x07), Color(0x9F, 0x2F, 0x07), Color(0xAF, 0x3F, 0x07),
+ Color(0xBF, 0x47, 0x07), Color(0xC7, 0x47, 0x07), Color(0xDF, 0x4F, 0x07),
+ Color(0xDF, 0x57, 0x07), Color(0xD7, 0x5F, 0x07), Color(0xD7, 0x5F, 0x07),
+ Color(0xD7, 0x67, 0x0F), Color(0xCF, 0x6F, 0x0F), Color(0xCF, 0x7F, 0x0F),
+ Color(0xCF, 0x87, 0x17), Color(0xC7, 0x87, 0x17), Color(0xC7, 0x8F, 0x17),
+ Color(0xC7, 0x97, 0x1F), Color(0xBF, 0x9F, 0x1F), Color(0xBF, 0xA7, 0x27),
+ Color(0xBF, 0xAF, 0x2F), Color(0xB7, 0xAF, 0x2F), Color(0xB7, 0xB7, 0x37),
+ Color(0xCF, 0xCF, 0x6F), Color(0xEF, 0xEF, 0xC7), Color(0xFF, 0xFF, 0xFF)
+ };
+
  bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::Indexed8, { 320, 200 });
 
  /* Initialize fire palette */
  for (int i = 0; i < 30; i++)
- bitmap->set_palette_color(i, s_palette[i]);
+ bitmap->set_palette_color(i, palette[i]);
 
  /* Set remaining entries to white */
  for (int i = 30; i < 256; i++)

diff --git a/Userland/Games/Breakout/Game.h b/Userland/Games/Breakout/Game.h
@@ -14,8 +14,8 @@ class Game final : public GUI::Widget {
  C_OBJECT(Game);
 
 public:
- static const int game_width = 480;
- static const int game_height = 500;
+ static constexpr int game_width = 480;
+ static constexpr int game_height = 500;
 
  virtual ~Game() override;
 

diff --git a/Userland/Games/Pong/Game.h b/Userland/Games/Pong/Game.h
@@ -22,8 +22,8 @@ class Game final : public GUI::Widget {
  C_OBJECT(Game);
 
 public:
- static const int game_width = 560;
- static const int game_height = 480;
+ static constexpr int game_width = 560;
+ static constexpr int game_height = 480;
 
  virtual ~Game() override;
 

diff --git a/Userland/Libraries/LibC/netdb.cpp b/Userland/Libraries/LibC/netdb.cpp
@@ -36,7 +36,7 @@ static constexpr i32 lookup_server_endpoint_magic = 9001;
 
 // Get service entry buffers and file information for the getservent() family of functions.
 static FILE* services_file = nullptr;
-static const char* services_path = "/etc/services";
+static constexpr char services_path[] = "/etc/services";
 
 static bool fill_getserv_buffers(const char* line, ssize_t read);
 static servent __getserv_buffer;
@@ -50,7 +50,7 @@ static ssize_t service_file_offset = 0;
 
 // Get protocol entry buffers and file information for the getprotent() family of functions.
 static FILE* protocols_file = nullptr;
-static const char* protocols_path = "/etc/protocols";
+static constexpr char protocols_path[] = "/etc/protocols";
 
 static bool fill_getproto_buffers(const char* line, ssize_t read);
 static protoent __getproto_buffer;

diff --git a/Userland/Libraries/LibC/time.cpp b/Userland/Libraries/LibC/time.cpp
@@ -70,10 +70,9 @@ char* ctime_r(const time_t* t, char* buf)
  return asctime_r(localtime_r(t, &tm_buf), buf);
 }
 
-static const int __seconds_per_day = 60 * 60 * 24;
-
 static void time_to_tm(struct tm* tm, time_t t)
 {
+ constexpr int __seconds_per_day = 60 * 60 * 24;
  int year = 1970;
  for (; t >= days_in_year(year) * __seconds_per_day; ++year)
  t -= days_in_year(year) * __seconds_per_day;

diff --git a/Userland/Libraries/LibGUI/Calendar.cpp b/Userland/Libraries/LibGUI/Calendar.cpp
@@ -5,6 +5,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Array.h>
 #include <LibCore/DateTime.h>
 #include <LibGUI/Calendar.h>
 #include <LibGUI/Painter.h>
@@ -16,21 +17,21 @@ REGISTER_WIDGET(GUI, Calendar);
 
 namespace GUI {
 
-static const char* long_day_names[] = {
+static constexpr Array long_day_names = {
  "Sunday", "Monday", "Tuesday", "Wednesday",
  "Thursday", "Friday", "Saturday"
 };
 
-static const char* short_day_names[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
-static const char* mini_day_names[] = { "Su", "Mo", "Tu", "We", "Th", "Fr", "Sa" };
-static const char* micro_day_names[] = { "S", "M", "T", "W", "T", "F", "S" };
+static constexpr Array short_day_names = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
+static constexpr Array mini_day_names = { "Su", "Mo", "Tu", "We", "Th", "Fr", "Sa" };
+static constexpr Array micro_day_names = { "S", "M", "T", "W", "T", "F", "S" };
 
-static const char* long_month_names[] = {
+static constexpr Array long_month_names = {
  "January", "February", "March", "April", "May", "June",
  "July", "August", "September", "October", "November", "December"
 };
 
-static const char* short_month_names[] = {
+static constexpr Array short_month_names = {
  "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 };

diff --git a/Userland/Libraries/LibGUI/CheckBox.cpp b/Userland/Libraries/LibGUI/CheckBox.cpp
@@ -15,9 +15,9 @@ REGISTER_WIDGET(GUI, CheckBox)
 
 namespace GUI {
 
-static const int s_box_width = 13;
-static const int s_box_height = 13;
-static const int s_horizontal_padding = 6;
+static constexpr int s_box_width = 13;
+static constexpr int s_box_height = 13;
+static constexpr int s_horizontal_padding = 6;
 
 CheckBox::CheckBox(String text)
  : AbstractButton(move(text))

diff --git a/Userland/Libraries/LibGUI/ColumnsView.cpp b/Userland/Libraries/LibGUI/ColumnsView.cpp
@@ -13,7 +13,7 @@
 
 namespace GUI {
 
-static const char* s_arrow_bitmap_data = {
+static constexpr char s_arrow_bitmap_data[] = {
  " "
  " # "
  " ## "
@@ -24,8 +24,8 @@ static const char* s_arrow_bitmap_data = {
  " # "
  " "
 };
-static const int s_arrow_bitmap_width = 9;
-static const int s_arrow_bitmap_height = 9;
+static constexpr int s_arrow_bitmap_width = 9;
+static constexpr int s_arrow_bitmap_height = 9;
 
 ColumnsView::ColumnsView()
 {

diff --git a/Userland/Libraries/LibGUI/FileIconProvider.cpp b/Userland/Libraries/LibGUI/FileIconProvider.cpp
@@ -169,7 +169,10 @@ Icon FileIconProvider::icon_for_executable(const String& path)
  int image_size;
  };
 
- static const IconSection icon_sections[] = { { .section_name = "serenity_icon_s", .image_size = 16 }, { .section_name = "serenity_icon_m", .image_size = 32 } };
+ constexpr Array icon_sections = {
+ IconSection { .section_name = "serenity_icon_s", .image_size = 16 },
+ IconSection { .section_name = "serenity_icon_m", .image_size = 32 }
+ };
 
  bool had_error = false;
  for (const auto& icon_section : icon_sections) {