Reduce binary size by removing unused functions even when not using LTO (~200-900kb reduction)

cmake/android.cmake

@@ -45,5 +45,7 @@ endfunction()
 function(android_generate)
     target_compile_definitions(godot-cpp PUBLIC ANDROID_ENABLED UNIX_ENABLED)
 
+    target_link_options(godot-cpp PUBLIC -Wl,--gc-sections)
+
     common_compiler_flags()
 endfunction()

cmake/common_compiler_flags.cmake

@@ -81,6 +81,8 @@ function(common_compiler_flags)
 
             $<${HOT_RELOAD}:$<${IS_GNU}:-fno-gnu-unique>>
 
+            $<${NOT_MSVC}:$<$<NOT:$<PLATFORM_ID:Windows>>:-ffunction-sections -fdata-sections>>
+
             # MSVC only
             $<${IS_MSVC}:
                 # /MP isn't valid for clang-cl with msvc frontend
@@ -185,7 +187,7 @@ function(common_compiler_flags)
             $<$<NOT:${DEBUG_SYMBOLS}>:
                 $<${IS_GNU}:-s>
                 $<${IS_CLANG}:-s>
-                $<${IS_APPLECLANG}:-Wl,-S -Wl,-x -Wl,-dead_strip>
+                $<${IS_APPLECLANG}:-Wl,-S -Wl,-x>
             >
         PRIVATE
             $<${IS_MSVC}:

cmake/ios.cmake

@@ -32,5 +32,7 @@ endfunction()
 function(ios_generate)
     target_compile_definitions(godot-cpp PUBLIC IOS_ENABLED UNIX_ENABLED)
 
+    target_link_options(godot-cpp PUBLIC -Wl,-dead_strip)
+
     common_compiler_flags()
 endfunction()

cmake/linux.cmake

@@ -28,6 +28,7 @@ function(linux_generate)
     target_link_options(
         godot-cpp
         PUBLIC
+            -Wl,--gc-sections
             $<${STATIC_CPP}:
                 -static-libgcc
                 -static-libstdc++

cmake/macos.cmake

@@ -37,5 +37,7 @@ endfunction()
 function(macos_generate)
     target_compile_definitions(godot-cpp PUBLIC MACOS_ENABLED UNIX_ENABLED)
 
+    target_link_options(godot-cpp PUBLIC -Wl,-dead_strip)
+
     common_compiler_flags()
 endfunction()

cmake/windows.cmake

@@ -103,6 +103,7 @@ function(windows_generate)
         PUBLIC
             $<${NOT_MSVC}:
                 -Wl,--no-undefined
+                -Wl,--gc-sections
                 $<${STATIC_CPP}:
                     -static
                     -static-libgcc

tools/android.py

@@ -118,6 +118,8 @@ def generate(env):
     env.Append(CCFLAGS=arch_info["ccflags"])
     env.Append(LINKFLAGS=["--target=" + arch_info["target"] + env["android_api_level"], "-march=" + arch_info["march"]])
 
+    env.Append(LINKFLAGS=["-Wl,--gc-sections"])
+
     env.Append(CPPDEFINES=["ANDROID_ENABLED", "UNIX_ENABLED"])
 
     # Refer to https://github.com/godotengine/godot/blob/master/platform/android/detect.py

tools/common_compiler_flags.py

@@ -49,6 +49,9 @@ def generate(env):
         env.Append(CXXFLAGS=["/EHsc"])
 
     if not env.get("is_msvc", False):
+        if not env["use_mingw"]:
+            env.Append(CCFLAGS=["-ffunction-sections", "-fdata-sections"])
+
         if env["symbols_visibility"] == "visible":
             env.Append(CCFLAGS=["-fvisibility=default"])
             env.Append(LINKFLAGS=["-fvisibility=default"])
@@ -108,7 +111,7 @@ def generate(env):
         else:
             if using_clang(env) and not is_vanilla_clang(env) and not env["use_mingw"]:
                 # Apple Clang, its linker doesn't like -s.
-                env.Append(LINKFLAGS=["-Wl,-S", "-Wl,-x", "-Wl,-dead_strip"])
+                env.Append(LINKFLAGS=["-Wl,-S", "-Wl,-x"])
             else:
                 env.Append(LINKFLAGS=["-s"])
 

tools/ios.py

@@ -97,6 +97,8 @@ def generate(env):
     env.Append(CCFLAGS=["-isysroot", env["IOS_SDK_PATH"]])
     env.Append(LINKFLAGS=["-isysroot", env["IOS_SDK_PATH"], "-F" + env["IOS_SDK_PATH"]])
 
+    env.Append(LINKFLAGS=["-Wl,-dead_strip"])
+
     env.Append(CPPDEFINES=["IOS_ENABLED", "UNIX_ENABLED"])
 
     # Refer to https://github.com/godotengine/godot/blob/master/platform/ios/detect.py:

tools/linux.py

@@ -42,6 +42,8 @@ def generate(env):
         env.Append(CCFLAGS=["-march=rv64gc"])
         env.Append(LINKFLAGS=["-march=rv64gc"])
 
+    env.Append(LINKFLAGS=["-Wl,--gc-sections"])
+
     # Link statically for portability
     if env["use_static_cpp"]:
         env.Append(LINKFLAGS=["-static-libgcc", "-static-libstdc++"])

tools/macos.py

@@ -63,6 +63,8 @@ def generate(env):
         env.Append(CCFLAGS=["-isysroot", env["macos_sdk_path"]])
         env.Append(LINKFLAGS=["-isysroot", env["macos_sdk_path"]])
 
+    env.Append(LINKFLAGS=["-Wl,-dead_strip"])
+
     env.Append(CPPDEFINES=["MACOS_ENABLED", "UNIX_ENABLED"])
 
     # Refer to https://github.com/godotengine/godot/blob/master/platform/macos/detect.py

tools/windows.py

@@ -140,7 +140,7 @@ def generate(env):
         env["SHLIBSUFFIX"] = ".dll"
 
         env.Append(CCFLAGS=["-Wwrite-strings"])
-        env.Append(LINKFLAGS=["-Wl,--no-undefined"])
+        env.Append(LINKFLAGS=["-Wl,--no-undefined", "-Wl,--gc-sections"])
         if env["use_static_cpp"]:
             env.Append(
                 LINKFLAGS=[
@@ -186,7 +186,7 @@ def generate(env):
         env["SHLIBSUFFIX"] = ".dll"
 
         env.Append(CCFLAGS=["-Wwrite-strings"])
-        env.Append(LINKFLAGS=["-Wl,--no-undefined"])
+        env.Append(LINKFLAGS=["-Wl,--no-undefined", "-Wl,--gc-sections"])
         if env["use_static_cpp"]:
             env.Append(
                 LINKFLAGS=[