Userland: Change static const variables to static constexpr

`static const` variables can be computed and initialized at run-time
during initialization or the first time a function is called. Change
them to `static constexpr` to ensure they are computed at
compile-time.

This allows some removal of `strlen` because the length of the
`StringView` can be used which is pre-computed at compile-time.

Userland/Demos/Fire/Fire.cpp

@@ -23,6 +23,7 @@
  * [ ] handle fire bitmap edges better
  */
 
+#include <AK/Array.h>
 #include <LibCore/ElapsedTimer.h>
 #include <LibCore/System.h>
 #include <LibGUI/Action.h>
@@ -45,7 +46,7 @@
 #define FIRE_HEIGHT 200
 #define FIRE_MAX 29
 
-static const Color s_palette[] = {
+static constexpr Array<Color, 30> 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),

Userland/Demos/VirGLDemo/CommandBufferBuilder.cpp

@@ -1,9 +1,11 @@
 /*
  * Copyright (c) 2022, Sahan Fernando <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/StringView.h>
 #include <Kernel/API/VirGL.h>
 #include <sys/ioctl_numbers.h>
 
@@ -235,9 +237,9 @@ void CommandBufferBuilder::append_set_constant_buffer(Vector<float> const& const
  }
 }
 
-void CommandBufferBuilder::append_create_shader(ObjectHandle handle, Gallium::ShaderType shader_type, const char* shader_data)
+void CommandBufferBuilder::append_create_shader(ObjectHandle handle, Gallium::ShaderType shader_type, StringView shader_data)
 {
- size_t shader_len = strlen(shader_data) + 1; // Need to remember to copy null terminator as well if needed
+ size_t shader_len = shader_data.length() + 1; // Need to remember to copy null terminator as well if needed
  CommandBuilder builder(m_buffer, Protocol::VirGLCommand::CREATE_OBJECT, to_underlying(Protocol::ObjectType::SHADER));
  builder.appendu32(handle.value()); // VIRGL_OBJ_CREATE_HANDLE
  builder.appendu32(to_underlying(shader_type));

Userland/Demos/VirGLDemo/CommandBufferBuilder.h

@@ -1,11 +1,13 @@
 /*
  * Copyright (c) 2022, Sahan Fernando <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #pragma once
 
+#include <AK/StringView.h>
 #include <AK/Vector.h>
 #include <sys/ioctl_numbers.h>
 
@@ -28,7 +30,7 @@ class CommandBufferBuilder {
  void append_gl_viewport();
  void append_set_framebuffer_state_no_attach();
  void append_set_constant_buffer(Vector<float> const& constant_buffer);
- void append_create_shader(ObjectHandle handle, Gallium::ShaderType shader_type, const char* shader_data);
+ void append_create_shader(ObjectHandle handle, Gallium::ShaderType shader_type, StringView shader_data);
  void append_bind_shader(ObjectHandle handle, Gallium::ShaderType shader_type);
  void append_create_rasterizer(ObjectHandle handle);
  void append_bind_rasterizer(ObjectHandle handle);

Userland/Demos/VirGLDemo/VirGLDemo.cpp

@@ -1,10 +1,13 @@
 /*
  * Copyright (c) 2022, Sahan Fernando <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Array.h>
 #include <AK/String.h>
+#include <AK/StringView.h>
 #include <AK/Vector.h>
 #include <Kernel/API/VirGL.h>
 #include <LibGUI/Application.h>
@@ -23,26 +26,26 @@
 #include "VirGLProtocol.h"
 #include "Widget.h"
 
-static const char* frag_shader = "FRAG\n"
- "PROPERTY FS_COLOR0_WRITES_ALL_CBUFS 1\n"
- "DCL IN[0], COLOR, COLOR\n"
- "DCL OUT[0], COLOR\n"
- " 0: MOV OUT[0], IN[0]\n"
- " 1: END\n";
+static constexpr StringView frag_shader = "FRAG\n"
+  "PROPERTY FS_COLOR0_WRITES_ALL_CBUFS 1\n"
+  "DCL IN[0], COLOR, COLOR\n"
+  "DCL OUT[0], COLOR\n"
+  " 0: MOV OUT[0], IN[0]\n"
+  " 1: END\n";
 
-static const char* vert_shader = "VERT\n"
- "DCL IN[0]\n"
- "DCL IN[1]\n"
- "DCL OUT[0], POSITION\n"
- "DCL OUT[1], COLOR\n"
- "DCL CONST[0..3]\n"
- "DCL TEMP[0..1]\n"
- " 0: MUL TEMP[0], IN[0].xxxx, CONST[0]\n"
- " 1: MAD TEMP[1], IN[0].yyyy, CONST[1], TEMP[0]\n"
- " 2: MAD TEMP[0], IN[0].zzzz, CONST[2], TEMP[1]\n"
- " 3: MAD OUT[0], IN[0].wwww, CONST[3], TEMP[0]\n"
- " 4: MOV_SAT OUT[1], IN[1]\n"
- " 5: END\n";
+static constexpr StringView vert_shader = "VERT\n"
+  "DCL IN[0]\n"
+  "DCL IN[1]\n"
+  "DCL OUT[0], POSITION\n"
+  "DCL OUT[1], COLOR\n"
+  "DCL CONST[0..3]\n"
+  "DCL TEMP[0..1]\n"
+  " 0: MUL TEMP[0], IN[0].xxxx, CONST[0]\n"
+  " 1: MAD TEMP[1], IN[0].yyyy, CONST[1], TEMP[0]\n"
+  " 2: MAD TEMP[0], IN[0].zzzz, CONST[2], TEMP[1]\n"
+  " 3: MAD OUT[0], IN[0].wwww, CONST[3], TEMP[0]\n"
+  " 4: MOV_SAT OUT[1], IN[1]\n"
+  " 5: END\n";
 
 struct VertexData {
  float r;
@@ -92,7 +95,7 @@ static ResourceID create_virgl_resource(VirGL3DResourceSpec& spec)
 static Vector<VertexData> gen_vertex_data()
 {
  Vector<VertexData> data;
- static const VertexData vertices[8] = {
+ static constexpr Array<VertexData, 8> vertices = {
  VertexData { .r = 0, .g = 0, .b = 0, .x = -0.5, .y = -0.5, .z = -0.5 },
  VertexData { .r = 0, .g = 0, .b = 0, .x = 0.5, .y = -0.5, .z = -0.5 },
  VertexData { .r = 0, .g = 0, .b = 0, .x = -0.5, .y = 0.5, .z = -0.5 },
@@ -102,7 +105,7 @@ static Vector<VertexData> gen_vertex_data()
  VertexData { .r = 0, .g = 0, .b = 0, .x = -0.5, .y = 0.5, .z = 0.5 },
  VertexData { .r = 0, .g = 0, .b = 0, .x = 0.5, .y = 0.5, .z = 0.5 },
  };
- size_t tris[36] = {
+ static constexpr Array<size_t, 36> tris = {
  0, 1, 2, 1, 3, 2, // Top
  4, 0, 6, 0, 2, 6, // Left
  4, 5, 0, 5, 1, 0, // Up

Userland/Games/Breakout/Game.h

@@ -16,8 +16,8 @@ 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 = default;
 

Userland/Games/FlappyBug/Game.h

@@ -22,8 +22,8 @@ class Game final : public GUI::Frame {
  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;
 
  Function<u32(u32)> on_game_end;
 

Userland/Games/Pong/Game.h

@@ -23,8 +23,8 @@ 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 = default;
 

Userland/Libraries/LibAudio/Loader.h

@@ -20,8 +20,7 @@
 
 namespace Audio {
 
-static const String empty_string = "";
-static String no_plugin_error = "No loader plugin available";
+static constexpr StringView no_plugin_error = "No loader plugin available";
 
 using LoaderSamples = Result<NonnullRefPtr<Buffer>, LoaderError>;
 using MaybeLoaderError = Result<void, LoaderError>;

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<StringView, 7> 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<StringView, 7> short_day_names = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
+static constexpr Array<StringView, 7> mini_day_names = { "Su", "Mo", "Tu", "We", "Th", "Fr", "Sa" };
+static constexpr Array<StringView, 7> micro_day_names = { "S", "M", "T", "W", "T", "F", "S" };
 
-static const char* long_month_names[] = {
+static constexpr Array<StringView, 12> long_month_names = {
  "January", "February", "March", "April", "May", "June",
  "July", "August", "September", "October", "November", "December"
 };
 
-static const char* short_month_names[] = {
+static constexpr Array<StringView, 12> short_month_names = {
  "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 };

Userland/Libraries/LibGUI/CheckBox.cpp

@@ -16,9 +16,9 @@ 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))

Userland/Libraries/LibGUI/FileIconProvider.cpp

@@ -1,9 +1,11 @@
 /*
  * Copyright (c) 2020-2021, Andreas Kling <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Array.h>
 #include <AK/LexicalPath.h>
 #include <AK/String.h>
 #include <LibCore/ConfigFile.h>
@@ -178,7 +180,10 @@ 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 } };
+ static constexpr Array<IconSection, 2> 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) {

Userland/Libraries/LibGUI/LinkLabel.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Alex McGrath <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -48,7 +49,7 @@ void LinkLabel::set_hovered(bool hover)
 
 void LinkLabel::mousemove_event(MouseEvent& event)
 {
- static const int extra_target_width = 3;
+ constexpr int extra_target_width = 3;
  set_hovered(event.position().x() <= font().width(text()) + extra_target_width);
 }
 

Userland/Libraries/LibGfx/GIFLoader.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2021, Andreas Kling <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -16,8 +17,8 @@
 namespace Gfx {
 
 // Row strides and offsets for each interlace pass.
-static const int INTERLACE_ROW_STRIDES[] = { 8, 8, 4, 2 };
-static const int INTERLACE_ROW_OFFSETS[] = { 0, 4, 2, 1 };
+static constexpr Array<int, 4> INTERLACE_ROW_STRIDES = { 8, 8, 4, 2 };
+static constexpr Array<int, 4> INTERLACE_ROW_OFFSETS = { 0, 4, 2, 1 };
 
 struct GIFImageDescriptor {
  u16 x { 0 };

Userland/Libraries/LibGfx/PNGLoader.cpp

@@ -1,9 +1,11 @@
 /*
  * Copyright (c) 2018-2020, Andreas Kling <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Array.h>
 #include <AK/Debug.h>
 #include <AK/Endian.h>
 #include <AK/Vector.h>
@@ -17,7 +19,7 @@
 
 namespace Gfx {
 
-static const u8 png_header[8] = { 0x89, 'P', 'N', 'G', 13, 10, 26, 10 };
+static constexpr Array<u8, 8> png_header = { 0x89, 'P', 'N', 'G', 13, 10, 26, 10 };
 
 struct PNG_IHDR {
  NetworkOrdered<u32> width;
@@ -516,7 +518,7 @@ static bool decode_png_header(PNGLoadingContext& context)
  return false;
  }
 
- if (memcmp(context.data, png_header, sizeof(png_header)) != 0) {
+ if (memcmp(context.data, png_header.span().data(), sizeof(png_header)) != 0) {
  dbgln_if(PNG_DEBUG, "Invalid PNG header");
  context.state = PNGLoadingContext::State::Error;
  return false;

Userland/Libraries/LibJS/Runtime/NumberPrototype.cpp

@@ -1,10 +1,12 @@
 /*
  * Copyright (c) 2020, Andreas Kling <[email protected]>
  * Copyright (c) 2021, Linus Groh <[email protected]>
+ * Copyright (c) 2022, the SerenityOS developers.
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Array.h>
 #include <AK/Function.h>
 #include <AK/TypeCasts.h>
 #include <LibJS/Runtime/AbstractOperations.h>
@@ -19,7 +21,7 @@
 
 namespace JS {
 
-static const u8 max_precision_for_radix[37] = {
+static constexpr AK::Array<u8, 37> max_precision_for_radix = {
  // clang-format off
  0, 0, 52, 32, 26, 22, 20, 18, 17, 16,
  15, 15, 14, 14, 13, 13, 13, 12, 12, 12,
@@ -28,7 +30,11 @@ static const u8 max_precision_for_radix[37] = {
  // clang-format on
 };
 
-static char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
+static constexpr AK::Array<char, 36> digits = {
+ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+ 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+ 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
+};
 
 static String decimal_digits_to_string(double number)
 {