SCons: Disable C++ exception handling by default

Counterpart to godotengine/godot#80612.

Author: akien-mga

CMakeLists.txt

@@ -72,21 +72,22 @@ endif()
 # Input from user for GDExtension interface header and the API JSON file
 set(GODOT_GDEXTENSION_DIR "gdextension" CACHE STRING "")
 set(GODOT_CUSTOM_API_FILE "" CACHE STRING "")
-set(FLOAT_PRECISION "single" CACHE STRING "")
-if ("${FLOAT_PRECISION}" STREQUAL "double")
-	add_definitions(-DREAL_T_IS_DOUBLE)
-endif()
 
 set(GODOT_GDEXTENSION_API_FILE "${GODOT_GDEXTENSION_DIR}/extension_api.json")
 if (NOT "${GODOT_CUSTOM_API_FILE}" STREQUAL "")  # User-defined override.
 	set(GODOT_GDEXTENSION_API_FILE "${GODOT_CUSTOM_API_FILE}")
 endif()
 
+set(FLOAT_PRECISION "single" CACHE STRING "")
+if ("${FLOAT_PRECISION}" STREQUAL "double")
+	add_definitions(-DREAL_T_IS_DOUBLE)
+endif()
+
 set(GODOT_COMPILE_FLAGS )
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 	# using Visual Studio C++
-	set(GODOT_COMPILE_FLAGS "/EHsc /utf-8") # /GF /MP
+	set(GODOT_COMPILE_FLAGS "/utf-8") # /GF /MP
 
 	if(CMAKE_BUILD_TYPE MATCHES Debug)
 		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /MDd") # /Od /RTC1 /Zi
@@ -107,6 +108,21 @@ else()  # GCC/Clang
 	endif(CMAKE_BUILD_TYPE MATCHES Debug)
 endif()
 
+# Disable exception handling. Godot doesn't use exceptions anywhere, and this
+# saves around 20% of binary size and very significant build time (GH-80513).
+option(GODOT_DISABLE_EXCEPTIONS ON "Force disabling exception handling code")
+if (GODOT_DISABLE_EXCEPTIONS)
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -D_HAS_EXCEPTIONS=0")
+	else()
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -fno-exceptions")
+	endif()
+else()
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /EHsc")
+	endif()
+endif()
+
 # Generate source from the bindings file
 find_package(Python3 3.4 REQUIRED) # pathlib should be present
 if(GENERATE_TEMPLATE_GET_NODE)

SConstruct

@@ -145,7 +145,6 @@ opts.Add(
         default=env.get("generate_template_get_node", True),
     )
 )
-
 opts.Add(BoolVariable(key="build_library", help="Build the godot-cpp library.", default=env.get("build_library", True)))
 opts.Add(
     EnumVariable(
@@ -155,6 +154,7 @@ opts.Add(
         allowed_values=("single", "double"),
     )
 )
+opts.Add(BoolVariable("disable_exceptions", "Force disabling exception handling code", True))
 
 # compiledb
 opts.Add(
@@ -264,6 +264,16 @@ else:
 if env["precision"] == "double":
     env.Append(CPPDEFINES=["REAL_T_IS_DOUBLE"])
 
+# 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.get("is_msvc", False):
+        env.Append(CPPDEFINES=[("_HAS_EXCEPTIONS", 0)])
+    else:
+        env.Append(CCFLAGS=["-fno-exceptions"])
+elif env.get("is_msvc", False):
+    env.Append(CCFLAGS=["/EHsc"])
+
 # compile_commands.json
 if env.get("compiledb", False):
     env.Tool("compilation_db")

test/CMakeLists.txt

@@ -36,7 +36,7 @@ set(GODOT_LINKER_FLAGS )
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 	# using Visual Studio C++
-	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /EHsc /WX") # /GF /MP
+	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /WX") # /GF /MP
 	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /DTYPED_METHOD_BIND")
 
 	if(CMAKE_BUILD_TYPE MATCHES Debug)
@@ -92,6 +92,21 @@ else()
 	endif(CMAKE_BUILD_TYPE MATCHES Debug)
 endif()
 
+# Disable exception handling. Godot doesn't use exceptions anywhere, and this
+# saves around 20% of binary size and very significant build time (GH-80513).
+option(GODOT_DISABLE_EXCEPTIONS ON "Force disabling exception handling code")
+if (GODOT_DISABLE_EXCEPTIONS)
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -D_HAS_EXCEPTIONS=0")
+	else()
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -fno-exceptions")
+	endif()
+else()
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /EHsc")
+	endif()
+endif()
+
 # Get Sources
 file(GLOB_RECURSE SOURCES src/*.c**)
 file(GLOB_RECURSE HEADERS include/*.h**)

tools/windows.py

@@ -31,7 +31,7 @@ def generate(env):
         env.Tool("mslink")
 
         env.Append(CPPDEFINES=["TYPED_METHOD_BIND", "NOMINMAX"])
-        env.Append(CCFLAGS=["/EHsc", "/utf-8"])
+        env.Append(CCFLAGS=["/utf-8"])
         env.Append(LINKFLAGS=["/WX"])
 
         if env["use_clang_cl"]: