Merge pull request #80612 from akien-mga/scons-disable-exception-handling

SCons: Disable C++ exception handling

SConstruct

@@ -193,6 +193,7 @@ opts.Add(BoolVariable("vulkan", "Enable the vulkan rendering driver", True))
 opts.Add(BoolVariable("opengl3", "Enable the OpenGL/GLES3 rendering driver", True))
 opts.Add(BoolVariable("openxr", "Enable the OpenXR driver", True))
 opts.Add(BoolVariable("use_volk", "Use the volk library to load the Vulkan loader dynamically", True))
+opts.Add(BoolVariable("disable_exceptions", "Force disabling exception handling code", True))
 opts.Add("custom_modules", "A list of comma-separated directory paths containing custom modules to build.", "")
 opts.Add(BoolVariable("custom_modules_recursive", "Detect custom modules recursively for each specified path.", True))
 
@@ -710,6 +711,16 @@ if selected_platform in platform_list:
             )
             Exit(255)
 
+    # Disable exception handling. Godot doesn't use exceptions anywhere, and this
+    # saves around 20% of binary size and very significant build time (GH-80513).
+    if env["disable_exceptions"]:
+        if env.msvc:
+            env.Append(CPPDEFINES=[("_HAS_EXCEPTIONS", 0)])
+        else:
+            env.Append(CCFLAGS=["-fno-exceptions"])
+    elif env.msvc:
+        env.Append(CCFLAGS=["/EHsc"])
+
     # Configure compiler warnings
     if env.msvc:  # MSVC
         if env["warnings"] == "no":
@@ -739,9 +750,6 @@ if selected_platform in platform_list:
                 ]
             )
 
-        # Set exception handling model to avoid warnings caused by Windows system headers.
-        env.Append(CCFLAGS=["/EHsc"])
-
         if env["werror"]:
             env.Append(CCFLAGS=["/WX"])
     else:  # GCC, Clang

modules/denoise/SCsub

@@ -109,6 +109,15 @@ env_oidn.AppendUnique(CPPDEFINES=["NDEBUG"])  # No assert() even in debug builds
 
 env_thirdparty = env_oidn.Clone()
 env_thirdparty.disable_warnings()
+
+if env["disable_exceptions"]:
+    # OIDN hard-requires exceptions, so we re-enable them here.
+    if env.msvc and ("_HAS_EXCEPTIONS", 0) in env_thirdparty["CPPDEFINES"]:
+        env_thirdparty["CPPDEFINES"].remove(("_HAS_EXCEPTIONS", 0))
+        env_thirdparty.AppendUnique(CCFLAGS=["/EHsc"])
+    elif not env.msvc and "-fno-exceptions" in env_thirdparty["CCFLAGS"]:
+        env_thirdparty["CCFLAGS"].remove("-fno-exceptions")
+
 env_thirdparty.add_source_files(thirdparty_obj, thirdparty_sources)
 env.modules_sources += thirdparty_obj
 

modules/openxr/SCsub

@@ -52,10 +52,11 @@ if env["builtin_openxr"]:
 
     env_thirdparty = env_openxr.Clone()
     env_thirdparty.disable_warnings()
+
     env_thirdparty.AppendUnique(CPPDEFINES=["DISABLE_STD_FILESYSTEM"])
+    if env["disable_exceptions"]:
+        env_thirdparty.AppendUnique(CPPDEFINES=["XRLOADER_DISABLE_EXCEPTION_HANDLING", ("JSON_USE_EXCEPTION", 0)])
 
-    if "-fno-exceptions" in env_thirdparty["CXXFLAGS"]:
-        env_thirdparty["CXXFLAGS"].remove("-fno-exceptions")
     env_thirdparty.Append(CPPPATH=[thirdparty_dir + "/src/loader"])
 
     # add in external jsoncpp dependency

platform/android/detect.py

@@ -170,10 +170,6 @@ def configure(env: "Environment"):
     env["RANLIB"] = compiler_path + "/llvm-ranlib"
     env["AS"] = compiler_path + "/clang"
 
-    # Disable exceptions on template builds
-    if not env.editor_build:
-        env.Append(CXXFLAGS=["-fno-exceptions"])
-
     env.Append(
         CCFLAGS=(
             "-fpic -ffunction-sections -funwind-tables -fstack-protector-strong -fvisibility=hidden -fno-strict-aliasing".split()

platform/ios/detect.py

@@ -30,7 +30,6 @@ def get_opts():
         ),
         ("IOS_SDK_PATH", "Path to the iOS SDK", ""),
         BoolVariable("ios_simulator", "Build for iOS Simulator", False),
-        BoolVariable("ios_exceptions", "Enable exceptions", False),
         ("ios_triple", "Triple for ios toolchain", ""),
     ]
 
@@ -138,11 +137,6 @@ def configure(env: "Environment"):
         env.Append(ASFLAGS=["-arch", "arm64"])
         env.Append(CPPDEFINES=["NEED_LONG_INT"])
 
-    if env["ios_exceptions"]:
-        env.Append(CCFLAGS=["-fexceptions"])
-    else:
-        env.Append(CCFLAGS=["-fno-exceptions"])
-
     # Temp fix for ABS/MAX/MIN macros in iOS SDK blocking compilation
     env.Append(CCFLAGS=["-Wno-ambiguous-macro"])
 

platform/web/detect.py

@@ -97,12 +97,9 @@ def configure(env: "Environment"):
     if env["use_assertions"]:
         env.Append(LINKFLAGS=["-s", "ASSERTIONS=1"])
 
-    if env.editor_build:
-        if env["initial_memory"] < 64:
-            print('Note: Forcing "initial_memory=64" as it is required for the web editor.')
-            env["initial_memory"] = 64
-    else:
-        env.Append(CPPFLAGS=["-fno-exceptions"])
+    if env.editor_build and env["initial_memory"] < 64:
+        print('Note: Forcing "initial_memory=64" as it is required for the web editor.')
+        env["initial_memory"] = 64
 
     env.Append(LINKFLAGS=["-s", "INITIAL_MEMORY=%sMB" % env["initial_memory"]])
 

tests/SCsub

@@ -13,10 +13,8 @@ env_tests = env.Clone()
 if env_tests["platform"] == "windows":
     env_tests.Append(CPPDEFINES=[("DOCTEST_THREAD_LOCAL", "")])
 
-# Increase number of addressable sections in object files
-# due to doctest's heavy use of templates and macros.
-if env_tests.msvc:
-    env_tests.Append(CCFLAGS=["/bigobj"])
+if env["disable_exceptions"]:
+    env_tests.Append(CPPDEFINES=["DOCTEST_CONFIG_NO_EXCEPTIONS_BUT_WITH_ALL_ASSERTS"])
 
 env_tests.add_source_files(env.tests_sources, "*.cpp")
 

tests/core/io/test_image.h

@@ -262,9 +262,7 @@ TEST_CASE("[Image] Modifying pixels of an image") {
 
 		for (const Rect2i &rect : rects) {
 			Ref<Image> img = memnew(Image(img_width, img_height, false, Image::FORMAT_RGBA8));
-			CHECK_NOTHROW_MESSAGE(
-					img->fill_rect(rect, Color(1, 1, 1, 1)),
-					"fill_rect() shouldn't throw for any rect.");
+			img->fill_rect(rect, Color(1, 1, 1, 1));
 			for (int y = 0; y < img->get_height(); y++) {
 				for (int x = 0; x < img->get_width(); x++) {
 					if (rect.abs().has_point(Point2(x, y))) {
@@ -317,7 +315,7 @@ TEST_CASE("[Image] Modifying pixels of an image") {
 	// Pre-multiply Alpha then Convert from RGBA to L8, checking alpha
 	{
 		Ref<Image> gray_image = memnew(Image(3, 3, false, Image::FORMAT_RGBA8));
-		CHECK_NOTHROW_MESSAGE(gray_image->fill_rect(Rect2i(0, 0, 3, 3), Color(1, 1, 1, 0)), "fill_rect() shouldn't throw for any rect.");
+		gray_image->fill_rect(Rect2i(0, 0, 3, 3), Color(1, 1, 1, 0));
 		gray_image->set_pixel(1, 1, Color(1, 1, 1, 1));
 		gray_image->set_pixel(1, 2, Color(0.5, 0.5, 0.5, 0.5));
 		gray_image->set_pixel(2, 1, Color(0.25, 0.05, 0.5, 1.0));

tests/scene/test_viewport.h

@@ -226,7 +226,7 @@ TEST_CASE("[SceneTree][Viewport] Controls and InputEvent handling") {
 
 	SUBCASE("[Viewport][GuiInputEvent] nullptr as argument doesn't lead to a crash.") {
 		ERR_PRINT_OFF;
-		CHECK_NOTHROW(root->push_input(nullptr));
+		root->push_input(nullptr);
 		ERR_PRINT_ON;
 	}