feat: Remove unused data and function for AppleClang

zchrissirhcz · Nov 24, 2024 · 2e2d919 · 2e2d919
1 parent 9cccc2e
commit 2e2d919
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Showing 4 changed files with 74 additions and 4 deletions.
diff --git a/rocbuild.cmake b/rocbuild.cmake
@@ -283,5 +283,21 @@ function(rocbuild_link_as_needed TARGET)
 endfunction()
 
 
+function(rocbuild_remove_unused_data_and_function TARGET)
+  if(CMAKE_BUILD_TYPE STREQUAL "Release" OR "$<CONFIG:Release>")
+    if((CMAKE_C_COMPILER_ID MATCHES "^(GNU|Clang)$") OR
+       (CMAKE_CXX_COMPILER_ID MATCHES "^(GNU|Clang)$"))
+       target_compile_options(${TARGET} PRIVATE "-fdata-sections" "-ffunction-sections")
+       target_link_options(${TARGET} PRIVATE "LINKER:--gc-sections")
+    elseif((CMAKE_C_COMPILER_ID STREQUAL "AppleClang") OR
+           (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang"))
+       target_compile_options(${TARGET} PRIVATE "-fdata-sections" "-ffunction-sections")
+       target_link_options(${TARGET} PRIVATE "LINKER:-dead_strip")
+       #target_link_options(${TARGET} PRIVATE "LINKER:-s,-S")
+    endif()
+  endif()
+endfunction()
+
+
 rocbuild_set_artifacts_path()
 rocbuild_enable_ninja_colorful_output()
diff --git a/test.py b/test.py
@@ -228,7 +228,6 @@ def test_link_as_needed(self):
             self.check_build('link_as_needed')
             cmd = 'ldd build/link_as_needed/libfoo_math.so'
             ret, out = check_output(cmd)
-            print(out)
             self.assertEqual(0, ret, out)
             self.assertIn('libfoo.so =>', out)
             shutil.rmtree('build/link_as_needed')
@@ -237,7 +236,6 @@ def test_link_as_needed(self):
             self.check_build('link_as_needed')
             cmd = 'ldd build/link_as_needed/libfoo_math.so'
             ret, out = check_output(cmd)
-            print(out)
             self.assertEqual(0, ret, out)
             self.assertTrue('libfoo.so =>' not in out)
             shutil.rmtree('build/link_as_needed')
@@ -246,7 +244,6 @@ def test_link_as_needed(self):
             self.check_build('link_as_needed')
             cmd = 'otool -L build/link_as_needed/libfoo_math.dylib'
             ret, out = check_output(cmd)
-            print(out)
             self.assertEqual(0, ret, out)
             self.assertIn('@rpath/libfoo.dylib', out)
             shutil.rmtree('build/link_as_needed')
@@ -255,10 +252,35 @@ def test_link_as_needed(self):
             self.check_build('link_as_needed')
             cmd = 'otool -L build/link_as_needed/libfoo_math.dylib'
             ret, out = check_output(cmd)
-            print(out)
             self.assertEqual(0, ret, out)
             self.assertTrue('@rpath/libfoo.dylib' not in out)
             shutil.rmtree('build/link_as_needed')
 
+    def test_unused_data_and_function(self):
+        if os_name == 'mac':
+            self.check_generate('unused_data_and_function', args='-DCMAKE_BUILD_TYPE=Release REMOVE_UNUSED_DATA_AND_FUNCTION=0')
+            self.check_build('unused_data_and_function')
+            cmd = 'objdump -t build/unused_data_and_function/test'
+            ret, out = check_output(cmd)
+            self.assertEqual(0, ret, out)
+            out = out.replace('\r\n', '\n')
+            lines = out.strip().split('\n')
+            self.assertEqual(len(lines), 11, lines)
+            self.assertTrue(lines[5].endswith('g     F __TEXT,__text _unused_function'))
+            self.assertTrue(lines[6].endswith('g     O __DATA,__data _unused_global_variable'))
+            shutil.rmtree('build/unused_data_and_function')
+
+            self.check_generate('unused_data_and_function', args='-DCMAKE_BUILD_TYPE=Release -DREMOVE_UNUSED_DATA_AND_FUNCTION=1')
+            self.check_build('unused_data_and_function')
+            cmd = 'objdump -t build/unused_data_and_function/test'
+            ret, out = check_output(cmd)
+            self.assertEqual(0, ret, out)
+            out = out.replace('\r\n', '\n')
+            lines = out.strip().split('\n')
+            self.assertEqual(len(lines), 9, lines)
+            for line in lines:
+                self.assertTrue(not line.endswith('unused_function'))
+            shutil.rmtree('build/unused_data_and_function')
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/tests/unused_data_and_function/CMakeLists.txt b/tests/unused_data_and_function/CMakeLists.txt
@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.10)
+project(test_artifacts_path)
+include(../../rocbuild.cmake)
+
+add_executable(test test.c)
+if(REMOVE_UNUSED_DATA_AND_FUNCTION)
+  rocbuild_remove_unused_data_and_function(test)
+endif()
diff --git a/tests/unused_data_and_function/test.c b/tests/unused_data_and_function/test.c
@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+// Unused function (should be removed)
+void unused_function() {
+    printf("This function is not used.\n");
+}
+
+// Used function (should be kept)
+void used_function() {
+    printf("This function is used.\n");
+}
+
+// Unused global variable (should be removed)
+int unused_global_variable = 42;
+
+// Used global variable (should be kept)
+int used_global_variable = 100;
+
+int main() {
+    void (*volatile func_ptr)() = used_function;
+    func_ptr();
+    printf("Used global variable: %d\n", used_global_variable);
+    return 0;
+}