From e56ae86f0b1012e528d8d3ca6d8c96fc2a79298d Mon Sep 17 00:00:00 2001
From: sdk2 <469656392@qq.com>
Date: Wed, 15 Sep 2021 11:57:27 +0800
Subject: [PATCH 1/2] fix clang flag use-ctor-homing

---
 CMakeLists.txt          | 9 +++++----
 cmake/check_flags.cmake | 1 +
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 897111e66bf..3625db4a2d7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,6 +28,9 @@ endforeach()
 
 project(ClickHouse)
 
+# Check if needed compiler flags are supported
+include (cmake/check_flags.cmake)
+
 # If turned off: e.g. when ENABLE_FOO is ON, but FOO tool was not found, the CMake will continue.
 option(FAIL_ON_UNSUPPORTED_OPTIONS_COMBINATION
    "Stop/Fail CMake configuration if some ENABLE_XXX option is defined (either ON or OFF)
@@ -166,7 +169,8 @@ if (COMPILER_CLANG)
         set(COMPILER_FLAGS "${COMPILER_FLAGS} -gdwarf-aranges")
     endif ()
 
-    if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0.0)
+    message(STATUS "HAS_USE_CTOR_HOMING: ${HAS_USE_CTOR_HOMING}")
+    if (HAS_USE_CTOR_HOMING AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0.0)
 		if (CMAKE_BUILD_TYPE_UC STREQUAL "DEBUG" OR CMAKE_BUILD_TYPE_UC STREQUAL "RELWITHDEBINFO")
             set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Xclang -fuse-ctor-homing")
             set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Xclang -fuse-ctor-homing")
@@ -629,9 +633,6 @@ include_directories(${ConfigIncludePath})
 # Add as many warnings as possible for our own code.
 include (cmake/warnings.cmake)
 
-# Check if needed compiler flags are supported
-include (cmake/check_flags.cmake)
-
 add_subdirectory (base)
 add_subdirectory (src)
 add_subdirectory (programs)
diff --git a/cmake/check_flags.cmake b/cmake/check_flags.cmake
index 5a4ff472868..58605543dff 100644
--- a/cmake/check_flags.cmake
+++ b/cmake/check_flags.cmake
@@ -4,3 +4,4 @@ include (CheckCCompilerFlag)
 check_cxx_compiler_flag("-Wsuggest-destructor-override" HAS_SUGGEST_DESTRUCTOR_OVERRIDE)
 check_cxx_compiler_flag("-Wshadow" HAS_SHADOW)
 check_cxx_compiler_flag("-Wsuggest-override" HAS_SUGGEST_OVERRIDE)
+check_cxx_compiler_flag("-Xclang -fuse-ctor-homing" HAS_USE_CTOR_HOMING)

From 9117c88a924712b0c83ea7e1e8a0d34622b05555 Mon Sep 17 00:00:00 2001
From: sdk2 <469656392@qq.com>
Date: Wed, 15 Sep 2021 12:26:27 +0800
Subject: [PATCH 2/2] better flag check

---
 CMakeLists.txt | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3625db4a2d7..9c8903d853c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,9 +28,6 @@ endforeach()
 
 project(ClickHouse)
 
-# Check if needed compiler flags are supported
-include (cmake/check_flags.cmake)
-
 # If turned off: e.g. when ENABLE_FOO is ON, but FOO tool was not found, the CMake will continue.
 option(FAIL_ON_UNSUPPORTED_OPTIONS_COMBINATION
    "Stop/Fail CMake configuration if some ENABLE_XXX option is defined (either ON or OFF)
@@ -155,6 +152,7 @@ if (CMAKE_GENERATOR STREQUAL "Ninja" AND NOT DISABLE_COLORED_BUILD)
     set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdiagnostics-color=always")
 endif ()
 
+include (cmake/check_flags.cmake)
 include (cmake/add_warning.cmake)
 
 if (NOT MSVC)
@@ -169,8 +167,8 @@ if (COMPILER_CLANG)
         set(COMPILER_FLAGS "${COMPILER_FLAGS} -gdwarf-aranges")
     endif ()
 
-    message(STATUS "HAS_USE_CTOR_HOMING: ${HAS_USE_CTOR_HOMING}")
-    if (HAS_USE_CTOR_HOMING AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 12.0.0)
+    if (HAS_USE_CTOR_HOMING)
+        # For more info see https://blog.llvm.org/posts/2021-04-05-constructor-homing-for-debug-info/
 		if (CMAKE_BUILD_TYPE_UC STREQUAL "DEBUG" OR CMAKE_BUILD_TYPE_UC STREQUAL "RELWITHDEBINFO")
             set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Xclang -fuse-ctor-homing")
             set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Xclang -fuse-ctor-homing")