SCons: Add production=yes option to use production defaults

This is meant for users making custom builds to match the options used on
optimized, official builds.

This enables, on the platforms which support them:
- `use_static_cpp=yes` (portable binaries for Linux and Windows)
- `use_lto=yes` (link time optimizations - note: requires a lot of RAM!)
- `debug_symbols=no` (no debug symbols, smaller binaries)

Also abort when using MSVC with `production=yes`, as:
- It cannot optimize the GDScript VM like GCC or Clang do, leading to
  significant performance drops.
- Its LTO support is unreliable, at least used to trigger crashes last
  we tried it extensively.

All options can still be overridden if specified, and the `dev=yes` option
was changed to also support overrides.

(cherry picked from commit db26871210)

SConstruct

@@ -105,13 +105,14 @@ if profile:
 opts = Variables(customs, ARGUMENTS)
 
 # Target build options
-opts.Add("arch", "Platform-dependent architecture (arm/arm64/x86/x64/mips/...)", "")
-opts.Add(EnumVariable("bits", "Target platform bits", "default", ("default", "32", "64")))
 opts.Add("p", "Platform (alias for 'platform')", "")
 opts.Add("platform", "Target platform (%s)" % ("|".join(platform_list),), "")
-opts.Add(EnumVariable("target", "Compilation target", "debug", ("debug", "release_debug", "release")))
-opts.Add(EnumVariable("optimize", "Optimization type", "speed", ("speed", "size")))
 opts.Add(BoolVariable("tools", "Build the tools (a.k.a. the Godot editor)", True))
+opts.Add(EnumVariable("target", "Compilation target", "debug", ("debug", "release_debug", "release")))
+opts.Add("arch", "Platform-dependent architecture (arm/arm64/x86/x64/mips/...)", "")
+opts.Add(EnumVariable("bits", "Target platform bits", "default", ("default", "32", "64")))
+opts.Add(EnumVariable("optimize", "Optimization type", "speed", ("speed", "size")))
+opts.Add(BoolVariable("production", "Set defaults to build Godot for use in production", False))
 opts.Add(BoolVariable("use_lto", "Use link-time optimization", False))
 
 # Components
@@ -122,11 +123,11 @@ opts.Add(BoolVariable("xaudio2", "Enable the XAudio2 audio driver", False))
 opts.Add("custom_modules", "A list of comma-separated directory paths containing custom modules to build.", "")
 
 # Advanced options
-opts.Add(BoolVariable("verbose", "Enable verbose output for the compilation", False))
+opts.Add(BoolVariable("dev", "If yes, alias for verbose=yes warnings=extra werror=yes", False))
 opts.Add(BoolVariable("progress", "Show a progress indicator during compilation", True))
+opts.Add(BoolVariable("verbose", "Enable verbose output for the compilation", False))
 opts.Add(EnumVariable("warnings", "Level of compilation warnings", "all", ("extra", "all", "moderate", "no")))
 opts.Add(BoolVariable("werror", "Treat compiler warnings as errors", False))
-opts.Add(BoolVariable("dev", "If yes, alias for verbose=yes warnings=extra werror=yes", False))
 opts.Add("extra_suffix", "Custom extra suffix added to the base filename of all generated binary files", "")
 opts.Add(BoolVariable("vsproj", "Generate a Visual Studio solution", False))
 opts.Add(
@@ -313,10 +314,32 @@ if selected_platform in platform_list:
         env.Tool("compilation_db")
         env.Alias("compiledb", env.CompilationDatabase())
 
+    # 'dev' and 'production' are aliases to set default options if they haven't been set
+    # manually by the user. We use `ARGUMENTS.get()` to check if they were manually set.
     if env["dev"]:
-        env["verbose"] = True
+        env["verbose"] = ARGUMENTS.get("verbose", True)
-        env["warnings"] = "extra"
+        env["warnings"] = ARGUMENTS.get("warnings", "extra")
-        env["werror"] = True
+        env["werror"] = ARGUMENTS.get("werror", True)
+    if env["production"]:
+        env["use_static_cpp"] = ARGUMENTS.get("use_static_cpp", True)
+        env["use_lto"] = ARGUMENTS.get("use_lto", True)
+        env["debug_symbols"] = ARGUMENTS.get("debug_symbols", False)
+        if not env["tools"] and env["target"] == "debug":
+            print(
+                "WARNING: Requested `production` build with `tools=no target=debug`, "
+                "this will give you a full debug template (use `target=release_debug` "
+                "for an optimized template with debug features)."
+            )
+        if env.msvc:
+            print(
+                "WARNING: For `production` Windows builds, you should use MinGW with GCC "
+                "or Clang instead of Visual Studio, as they can better optimize the "
+                "GDScript VM in a very significant way. MSVC LTO also doesn't work "
+                "reliably for our use case."
+                "If you want to use MSVC nevertheless for production builds, set "
+                "`debug_symbols=no use_lto=no` instead of the `production=yes` option."
+            )
+            Exit(255)
 
     env.extra_suffix = ""
 

platform/osx/detect.py

@@ -25,7 +25,7 @@ def get_opts():
         ("osxcross_sdk", "OSXCross SDK version", "darwin14"),
         ("MACOS_SDK_PATH", "Path to the macOS SDK", ""),
         EnumVariable("macports_clang", "Build using Clang from MacPorts", "no", ("no", "5.0", "devel")),
-        EnumVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", "yes", ("yes", "no")),
+        BoolVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", True),
         BoolVariable("separate_debug_symbols", "Create a separate file containing debugging symbols", False),
         BoolVariable("use_ubsan", "Use LLVM/GCC compiler undefined behavior sanitizer (UBSAN)", False),
         BoolVariable("use_asan", "Use LLVM/GCC compiler address sanitizer (ASAN))", False),

platform/server/detect.py

@@ -32,12 +32,12 @@ def get_opts():
 
     return [
         BoolVariable("use_llvm", "Use the LLVM compiler", False),
-        BoolVariable("use_static_cpp", "Link libgcc and libstdc++ statically for better portability", False),
+        BoolVariable("use_static_cpp", "Link libgcc and libstdc++ statically for better portability", True),
         BoolVariable("use_ubsan", "Use LLVM/GCC compiler undefined behavior sanitizer (UBSAN)", False),
         BoolVariable("use_asan", "Use LLVM/GCC compiler address sanitizer (ASAN))", False),
         BoolVariable("use_lsan", "Use LLVM/GCC compiler leak sanitizer (LSAN))", False),
         BoolVariable("use_tsan", "Use LLVM/GCC compiler thread sanitizer (TSAN))", False),
-        EnumVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", "yes", ("yes", "no")),
+        BoolVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", True),
         BoolVariable("separate_debug_symbols", "Create a separate file containing debugging symbols", False),
         BoolVariable("execinfo", "Use libexecinfo on systems where glibc is not available", False),
     ]

platform/windows/detect.py

@@ -64,7 +64,7 @@ def get_opts():
         # XP support dropped after EOL due to missing API for IPv6 and other issues
         # Vista support dropped after EOL due to GH-10243
         ("target_win_version", "Targeted Windows version, >= 0x0601 (Windows 7)", "0x0601"),
-        EnumVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", "yes", ("yes", "no")),
+        BoolVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", True),
         BoolVariable("separate_debug_symbols", "Create a separate file containing debugging symbols", False),
         ("msvc_version", "MSVC version to use. Ignored if VCINSTALLDIR is set in shell env.", None),
         BoolVariable("use_mingw", "Use the Mingw compiler, even if MSVC is installed.", False),

platform/x11/detect.py

@@ -72,7 +72,7 @@ def get_opts():
         BoolVariable("use_tsan", "Use LLVM/GCC compiler thread sanitizer (TSAN))", False),
         BoolVariable("pulseaudio", "Detect and use PulseAudio", True),
         BoolVariable("udev", "Use udev for gamepad connection callbacks", True),
-        EnumVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", "yes", ("yes", "no")),
+        BoolVariable("debug_symbols", "Add debugging symbols to release/release_debug builds", True),
         BoolVariable("separate_debug_symbols", "Create a separate file containing debugging symbols", False),
         BoolVariable("touch", "Enable touch events", True),
         BoolVariable("execinfo", "Use libexecinfo on systems where glibc is not available", False),